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Jeanphilippe Pignol - One of the best experts on this subject based on the ideXlab platform.

  • permanent breast Seed Implant for partial breast radiotherapy after partial mastectomy for favorable breast cancer technique results and applications to various seroma presentations
    Brachytherapy, 2019
    Co-Authors: Juanita Crook, Michelle Hilts, Deidre Batchelar, Mariepierre Milette, Martin Kozeniowski, Laurie Pilote, Jeanphilippe Pignol
    Abstract:

    Abstract Purpose Adjuvant partial breast radiotherapy is the standard of care for early-stage favorable breast cancer. We report dosimetry, acute and late tolerance for 67 permanent breast Seed Implants. Materials and Methods From July 2012 to October 2018, 67 postmenopausal women with unifocal pT1pN0 invasive ductal or ductal carcinoma in situ received partial breast radiotherapy using stranded Pd-103 Seeds after breast-conserving surgery, delivering 90 Gy to the seroma + margin (1.25–1.5 cm), planned with computed tomography simulation and performed as an ultrasound-guided outpatient procedure. The planning and postImplant computed tomography images were fused for seroma delineation for postImplant dosimetry. Evaluations were performed at 1, 2, 6, and 12 months and then annually. Results Although patient acceptance is high, only 40% met technical requirements of seroma volume, location, and visibility. For 67 patients, the median seroma volume was 6.6 cc, PTV 61 cc, and number of needles 18. In day 0 dosimetry, median seroma D90 dose was 132 Gy; seroma + 5 mm, 106 Gy; and seroma + 10 mm, 80 Gy. Peak reaction at 6 weeks is limited to the Implant site: 51% grade 1 erythema and 12% focal desquamation. Late reactions (>2 years) are generally minimal: 35% no sequelae, 43% localized fibrosis, 20% mild telangiectasia (6% moderate but asymptomatic), 22% contour change. At minimum 6-month follow-up, 94% were “very or totally satisfied.” Recurrences (median follow-up: 3.3 years) were one in breast (different quadrant) and 2 contralateral. Three patients have had biopsies of fibrosis, all negative for malignancy. Conclusions Our experience with permanent breast Seed Implant is favorable with a high patient acceptance and satisfaction, excellent early efficacy, and very satisfactory cosmesis.

  • clinical significance of accounting for tissue heterogeneity in permanent breast Seed Implant brachytherapy planning
    International Journal of Radiation Oncology Biology Physics, 2016
    Co-Authors: Shahram Mashouf, Jeanphilippe Pignol, C Mccann, Emmanuelle Fleury, Priscilla Lai, Tomas Merino, Eli Lechtman, Alex Kiss
    Abstract:

    Purpose The inhomogeneity correction factor (ICF) method provides heterogeneity correction for the fast calculation TG43 formalism in Seed brachytherapy. This study compared ICF-corrected plans to their standard TG43 counterparts, looking at their capacity to assess inadequate coverage and/or risk of any skin toxicities for patients who received permanent breast Seed Implant (PBSI). Methods and Materials Two-month postImplant computed tomography scans and plans of 140 PBSI patients were used to calculate dose distributions by using the TG43 and the ICF methods. Multiple dose-volume histogram (DVH) parameters of clinical target volume (CTV) and skin were extracted and compared for both ICF and TG43 dose distributions. Short-term (desquamation and erythema) and long-term (telangiectasia) skin toxicity data were available on 125 and 110 of the patients, respectively, at the time of the study. The predictive value of each DVH parameter of skin was evaluated using the area under the receiver operating characteristic (ROC) curve for each toxicity endpoint. Results Dose-volume histogram parameters of CTV, calculated using the ICF method, showed an overall decrease compared to TG43, whereas those of skin showed an increase, confirming previously reported findings of the impact of heterogeneity with low-energy sources. The ICF methodology enabled us to distinguish patients for whom the CTV V100 and V90 are up to 19% lower compared to TG43, which could present a risk of recurrence not detected when heterogeneity are not accounted for. The ICF method also led to an increase in the prediction of desquamation, erythema, and telangiectasia for 91% of skin DVH parameters studied. Conclusions The ICF methodology has the advantage of distinguishing any inadequate dose coverage of CTV due to breast heterogeneity, which can be missed by TG43. Use of ICF correction also led to an increase in prediction accuracy of skin toxicities in most cases.

  • report on the clinical outcomes of permanent breast Seed Implant for early stage breast cancers
    International Journal of Radiation Oncology Biology Physics, 2015
    Co-Authors: Juanita Crook, Jeanphilippe Pignol, Jeanmichel Caudrelier, C Mccann, Pauline T Truong, Helena A Verkooijen
    Abstract:

    Purpose Permanent breast Seed Implant is an accelerated partial breast irradiation technique realizing the insertion of 103 Pd Seeds in the seroma after lumpectomy. We report the 5-year efficacy and tolerance for a cohort, pooling patients from 3 clinical trials. Methods and Materials The trials accrued postmenopausal patients with infiltrating ductal carcinoma or ductal carcinoma in situ ≤3 cm and clear surgical margins, who were node negative, and had a planning target volume 3 . The outcomes included overall and disease-free survival and local and contralateral recurrence at 5 years. The true local recurrence rate was compared using 2-tailed paired t tests for estimates calculated using the Tufts University ipsilateral breast tumor recurrence and Memorial Sloan Kettering ductal carcinoma in situ nomograms. Results The cohort included 134 patients, and the observed local recurrence rate at a median follow-up period of 63 months was 1.2% ± 1.2%, similar to the estimate for whole breast irradiation ( P =.23), significantly better than for surgery alone (relative risk 0.27; P P Conclusions The 5-year data suggest that permanent breast Seed Implantation is a safe accelerated partial breast irradiation option after lumpectomy for early-stage breast cancer with a tolerance profile similar to that of whole breast irradiation.

  • permanent breast Seed Implant for early stage breast cancer impact of primary tumour location on the overall cosmetic outcome
    Journal of Medical Imaging and Radiation Sciences, 2015
    Co-Authors: Jee Hae Rebekah Shin, Jeanphilippe Pignol, B Keller, Merrylee Mcguffin, Laura Dalimonte
    Abstract:

    Abstract Introduction Permanent breast Seed Implants (PBSIs) have been introduced as an alternative to whole breast irradiation with equivalent rates of tumour control but fewer associated morbidities. However, there is some suggestion that tumour location has an effect on cosmesis in patients having PBSI. Therefore, the aim of the present study was to determine whether tumour location can predict long-term cosmesis. Methods A retrospective chart review was conducted from May 2004 to November 2009. Tumour location was categorized according to breast quadrant. Late cosmesis was scored as the presence or absence of induration, telangiectasia, and pigmentation change at 3 years after Implant. Acute toxicities were also recorded as the presence or absence of induration, dryness, and radiation dermatitis at 8 weeks after Implant. Additionally, the tumour size, depth of the seroma, depth of 100% isodose, and tissue thickness were collected. Descriptive statistics and Fisher exact tests were used to analyze the relationship between tumour location and both acute and late morbidities. Individual t tests were used to determine whether tumour size, depth, and tissue thickness were predictive of acute and long-term side effects. Results Of the 70 patients included in the study, 17 (24%) had tumours located in the upper inner quadrant (UIQ), 37 (53%) had tumours located in the upper outer quadrant, and 8 (11%) had tumours located in each of the remaining two quadrants. In general, 35% (6/17) of patients with tumours in the UIQ experienced long-term side effects compared with 34% (18/53) of patients with tumours in any other quadrant ( P = .7617). Also, 82% (14/17) of patients with tumours in the UIQ experienced acute side effects compared with only 51% (27/53) of patients with tumours in any other quadrant ( P = .0259). There was a significant effect of both primary tumour size ( P = .004) and the depth of the 100% isodose ( P = .028) on overall long-term cosmesis, but there was no significant relationship between physical factors and overall acute side effects. Conclusions Patients with tumours in the UIQ experience acute side effects more frequently than patients with tumours in any other quadrant. However, this trend is not as obvious for long-term cosmesis. Instead, tumour size and depth may be more useful when considering late effects.

  • su e t 566 optimization of permanent Seed Implant dosimetry incorporating tissue heterogeneity
    Medical Physics, 2013
    Co-Authors: Shahram Mashouf, Ananth Ravi, Brian M Keller, Eli Lechtman, Jeanphilippe Pignol
    Abstract:

    Purpose: Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. In this technique low dose rate (LDR) radioactive Seeds are permanently Implanted across the treatment volume to deliver a prescribed amount of dose. The current standard for calculation of dose surrounding the brachytherapy Seeds is based on American Association of Physicist in Medicine Task Group No. 43 (TG43 formalism) which generates the dose in homogeneous water medium. For low energy sources and especially in breast, the absorbed dose is highly influenced by heterogeneities. Our work focuses on the development of a dose calculation algorithm similar to TG43 applicable in heterogeneous media. Methods: An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of source structure. The absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG43 formalism times ICF. We used Monte Carlo simulations in a heterogeneous model of breast to benchmark the improvements achieved in the calculation of dose using the ICF methodology. Results: The dose distributions obtained through applying ICF to TG43 protocol agreed very well with those of Monte Carlo simulations. Over all and across the whole calculation domain, the mean relative error was reduced from 40.8% to 12.7% when ICF correction factor is applied to the TG43 protocol. Conclusion: We have developed a new analytical dose calculation method which enables personalized dose calculations in heterogeneous media. The methodology offers several advantages including the use of standard TG43 formalism, fast calculation time and extraction of the ICF parameters directly from Hounsfield Units. Funding: NSERC

Juanita Crook - One of the best experts on this subject based on the ideXlab platform.

  • characterization and registration of 3d ultrasound for use in permanent breast Seed Implant brachytherapy treatment planning
    Brachytherapy, 2020
    Co-Authors: Claire Zhang, Michelle Hilts, Deidre Batchelar, Nathan Orlando, Lori Gardi, Aaron Fenster, Juanita Crook
    Abstract:

    Abstract Purpose Permanent breast Seed Implant (PBSI) brachytherapy is a novel technique for early-stage breast cancer. Computed tomography (CT) images are used for treatment planning and freehand 2D ultrasound for Implant guidance. The multimodality imaging approach leads to discrepancies in target identification. To address this, a prototype 3D ultrasound (3DUS) system was recently developed for PBSI. In this study, we characterize the 3DUS system performance, establish QA baselines, and develop and test a method to register 3DUS images to CT images for PBSI planning. Methods and Materials 3DUS system performance was characterized by testing distance and volume measurement accuracy, and needle template alignment accuracy. 3DUS-CT registration was achieved through point-based registration using a 3D-printed model designed and constructed to provide visible landmarks on both images and tested on an in-house made gel breast phantom. Results The 3DUS system mean distance measurement accuracy was within 1% in axial, lateral, and elevational directions. A volumetric error of 3% was observed. The mean needle template alignment error was 1.0° ± 0.3 ° and 1.3 ± 0.5 mm. The mean 3DUS-CT registration error was within 3 mm when imaging at the breast centre or across all breast quadrants. Conclusions This study provided baseline data to characterize the performance of a prototype 3DUS system for PBSI planning and developed and tested a method to obtain accurate 3DUS-CT image registration for PBSI planning. Future work will focus on system validation and characterization in a clinical context as well as the assessment of impact on treatment plans.

  • a reliable skin toxicity predictor in permanent breast Seed Implant brachytherapy
    Brachytherapy, 2020
    Co-Authors: Zahra Anjomani, Michelle Hilts, Deidre Batchelar, Juanita Crook
    Abstract:

    Abstract Purpose To establish skin dose–outcome relationships using a reliable metric in permanent breast Seed Implant (PBSI). Methods Sixty-seven consecutive patients who underwent PBSI at our institution were included. Skin doses were calculated using two skin dose indices: maximum point dose to the skin surface, Dmax, and D0.2cc for a 2-mm internal skin rind (a surrogate to the dose to 1 cm2 area of skin) from CT-based postoperative treatment plans. Toxicity data were extracted from patients’ charts and photographs. The associations between skin dose and skin toxicity were investigated using the analysis of variance, and the predictive performance of skin dose measures was evaluated using receiver operating characteristic curves. Results For acute reactions, 49.3% of patients had Grade 1, 4.5% Grade 2, and 1.5% Grade 3 toxicity. For telangiectasia at 3 years, very minor and minimally apparent telangiectasia was observed in 25% of patients. Moderate but asymptomatic telangiectasia was observed in 9.1% of cases. Both metrics were significantly associated with the occurrence of acute toxicity and telangiectasia at 3 years (p Conclusion D0.2cc, as an alternate skin dose measure to Dmax, is a robust metric for measuring skin dose that is simple to calculate, yet is clinically relevant and not prone to inaccuracies inherent to point dose measurement.

  • Peer-based credentialing for brachytherapy: Application in permanent Seed Implant
    Brachytherapy, 2020
    Co-Authors: Tyler Meyer, Michelle Hilts, Deidre Batchelar, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Stephen F Kry
    Abstract:

    Abstract Purpose The purpose of the study was to establish a quantitative method for Implant quality evaluation in permanent Seed Implant brachytherapy for credentialing. Delivery-based credentialing will promote consistency in brachytherapy Seed delivery and improve patient outcomes. Methods A workflow for delivery-based credentialing was outlined and applied to permanent breast Seed Implant brachytherapy. Delivery simulations were performed on Implantable anthropomorphic breast phantoms. Two institutions experienced in permanent Seed Implant brachytherapy demonstrated the peer credentialing process. Each delivery was evaluated for Seed placement accuracy as the measure of Implant quality, both for Implant accuracy and across five simulations to assess Implant variation. Initial credentialing criteria are set based on two factors; the mean Seed placement accuracy (Implant accuracy) and the mean standard deviation (Seed variation) with the threshold for each set with the addition of two standard deviations. Results Across two institutions, Seed placement accuracy (±standard deviation) was calculated for all five delivery simulations to yield 6.1 (±2.6) mm. To set credentialing criteria, the Implant accuracy (6.1 mm) plus two standard deviations (2.0 mm) and the Seed variation (2.6 mm) plus two standard deviations (0.8) mm yield a threshold of 8.1 ± 3.4 mm. It is expected that 95% of experienced institutions would perform the phantom simulation within this threshold. Conclusion Brachytherapy programs should validate delivery accuracy by formal credentialing, which is standard in external beam programs. This quantitative Implant evaluation should be combined with current credentialing standards for permanent Seed brachytherapy to form a comprehensive validation of institutional brachytherapy program quality.

  • establishing a simulation based education program for radiation oncology learners in permanent Seed Implant brachytherapy building validation evidence
    Brachytherapy, 2020
    Co-Authors: Michael Roumeliotis, Michelle Hilts, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Kevin Martell, Deidre Batchelar
    Abstract:

    Abstract Purpose The purpose of this study was to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy. The first step in formalizing any education program is a validation process that builds evidence-based verification that the learning environment is appropriate. Methods and Materials The primary education task allowed practitioners to use an anthropomorphic breast phantom to simulate a permanent Seed Implant brachytherapy delivery. Validation evidence is built by generating data to assess learner and expert cohorts according to their proficiency. Each practitioner's performance during the simulation was evaluated by Seed placement accuracy, procedural time-to-complete, and two qualitative evaluation tools—a global rating scale and procedural checklist. Results The average Seed placement accuracy (±SD) was 8.1 ± 3.5 mm compared to 6.1 ± 2.6 mm for the learner and expert cohort, respectively. The median (range) procedural time-to-complete was 64 (60–77) minutes and 43 (41–50) minutes for the learner and expert cohort, respectively. Seed placement accuracy (student t-test, p  Conclusions This validation evidence supports the utilization of this simulation environment toward appropriately capturing the delivery experience of practitioners. The results demonstrate that, in all areas of evaluation, expert cohort proficiency was superior to learner cohort proficiency. This methodology will be used to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy.

  • permanent breast Seed Implant for partial breast radiotherapy after partial mastectomy for favorable breast cancer technique results and applications to various seroma presentations
    Brachytherapy, 2019
    Co-Authors: Juanita Crook, Michelle Hilts, Deidre Batchelar, Mariepierre Milette, Martin Kozeniowski, Laurie Pilote, Jeanphilippe Pignol
    Abstract:

    Abstract Purpose Adjuvant partial breast radiotherapy is the standard of care for early-stage favorable breast cancer. We report dosimetry, acute and late tolerance for 67 permanent breast Seed Implants. Materials and Methods From July 2012 to October 2018, 67 postmenopausal women with unifocal pT1pN0 invasive ductal or ductal carcinoma in situ received partial breast radiotherapy using stranded Pd-103 Seeds after breast-conserving surgery, delivering 90 Gy to the seroma + margin (1.25–1.5 cm), planned with computed tomography simulation and performed as an ultrasound-guided outpatient procedure. The planning and postImplant computed tomography images were fused for seroma delineation for postImplant dosimetry. Evaluations were performed at 1, 2, 6, and 12 months and then annually. Results Although patient acceptance is high, only 40% met technical requirements of seroma volume, location, and visibility. For 67 patients, the median seroma volume was 6.6 cc, PTV 61 cc, and number of needles 18. In day 0 dosimetry, median seroma D90 dose was 132 Gy; seroma + 5 mm, 106 Gy; and seroma + 10 mm, 80 Gy. Peak reaction at 6 weeks is limited to the Implant site: 51% grade 1 erythema and 12% focal desquamation. Late reactions (>2 years) are generally minimal: 35% no sequelae, 43% localized fibrosis, 20% mild telangiectasia (6% moderate but asymptomatic), 22% contour change. At minimum 6-month follow-up, 94% were “very or totally satisfied.” Recurrences (median follow-up: 3.3 years) were one in breast (different quadrant) and 2 contralateral. Three patients have had biopsies of fibrosis, all negative for malignancy. Conclusions Our experience with permanent breast Seed Implant is favorable with a high patient acceptance and satisfaction, excellent early efficacy, and very satisfactory cosmesis.

Michelle Hilts - One of the best experts on this subject based on the ideXlab platform.

  • characterization and registration of 3d ultrasound for use in permanent breast Seed Implant brachytherapy treatment planning
    Brachytherapy, 2020
    Co-Authors: Claire Zhang, Michelle Hilts, Deidre Batchelar, Nathan Orlando, Lori Gardi, Aaron Fenster, Juanita Crook
    Abstract:

    Abstract Purpose Permanent breast Seed Implant (PBSI) brachytherapy is a novel technique for early-stage breast cancer. Computed tomography (CT) images are used for treatment planning and freehand 2D ultrasound for Implant guidance. The multimodality imaging approach leads to discrepancies in target identification. To address this, a prototype 3D ultrasound (3DUS) system was recently developed for PBSI. In this study, we characterize the 3DUS system performance, establish QA baselines, and develop and test a method to register 3DUS images to CT images for PBSI planning. Methods and Materials 3DUS system performance was characterized by testing distance and volume measurement accuracy, and needle template alignment accuracy. 3DUS-CT registration was achieved through point-based registration using a 3D-printed model designed and constructed to provide visible landmarks on both images and tested on an in-house made gel breast phantom. Results The 3DUS system mean distance measurement accuracy was within 1% in axial, lateral, and elevational directions. A volumetric error of 3% was observed. The mean needle template alignment error was 1.0° ± 0.3 ° and 1.3 ± 0.5 mm. The mean 3DUS-CT registration error was within 3 mm when imaging at the breast centre or across all breast quadrants. Conclusions This study provided baseline data to characterize the performance of a prototype 3DUS system for PBSI planning and developed and tested a method to obtain accurate 3DUS-CT image registration for PBSI planning. Future work will focus on system validation and characterization in a clinical context as well as the assessment of impact on treatment plans.

  • a reliable skin toxicity predictor in permanent breast Seed Implant brachytherapy
    Brachytherapy, 2020
    Co-Authors: Zahra Anjomani, Michelle Hilts, Deidre Batchelar, Juanita Crook
    Abstract:

    Abstract Purpose To establish skin dose–outcome relationships using a reliable metric in permanent breast Seed Implant (PBSI). Methods Sixty-seven consecutive patients who underwent PBSI at our institution were included. Skin doses were calculated using two skin dose indices: maximum point dose to the skin surface, Dmax, and D0.2cc for a 2-mm internal skin rind (a surrogate to the dose to 1 cm2 area of skin) from CT-based postoperative treatment plans. Toxicity data were extracted from patients’ charts and photographs. The associations between skin dose and skin toxicity were investigated using the analysis of variance, and the predictive performance of skin dose measures was evaluated using receiver operating characteristic curves. Results For acute reactions, 49.3% of patients had Grade 1, 4.5% Grade 2, and 1.5% Grade 3 toxicity. For telangiectasia at 3 years, very minor and minimally apparent telangiectasia was observed in 25% of patients. Moderate but asymptomatic telangiectasia was observed in 9.1% of cases. Both metrics were significantly associated with the occurrence of acute toxicity and telangiectasia at 3 years (p Conclusion D0.2cc, as an alternate skin dose measure to Dmax, is a robust metric for measuring skin dose that is simple to calculate, yet is clinically relevant and not prone to inaccuracies inherent to point dose measurement.

  • Peer-based credentialing for brachytherapy: Application in permanent Seed Implant
    Brachytherapy, 2020
    Co-Authors: Tyler Meyer, Michelle Hilts, Deidre Batchelar, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Stephen F Kry
    Abstract:

    Abstract Purpose The purpose of the study was to establish a quantitative method for Implant quality evaluation in permanent Seed Implant brachytherapy for credentialing. Delivery-based credentialing will promote consistency in brachytherapy Seed delivery and improve patient outcomes. Methods A workflow for delivery-based credentialing was outlined and applied to permanent breast Seed Implant brachytherapy. Delivery simulations were performed on Implantable anthropomorphic breast phantoms. Two institutions experienced in permanent Seed Implant brachytherapy demonstrated the peer credentialing process. Each delivery was evaluated for Seed placement accuracy as the measure of Implant quality, both for Implant accuracy and across five simulations to assess Implant variation. Initial credentialing criteria are set based on two factors; the mean Seed placement accuracy (Implant accuracy) and the mean standard deviation (Seed variation) with the threshold for each set with the addition of two standard deviations. Results Across two institutions, Seed placement accuracy (±standard deviation) was calculated for all five delivery simulations to yield 6.1 (±2.6) mm. To set credentialing criteria, the Implant accuracy (6.1 mm) plus two standard deviations (2.0 mm) and the Seed variation (2.6 mm) plus two standard deviations (0.8) mm yield a threshold of 8.1 ± 3.4 mm. It is expected that 95% of experienced institutions would perform the phantom simulation within this threshold. Conclusion Brachytherapy programs should validate delivery accuracy by formal credentialing, which is standard in external beam programs. This quantitative Implant evaluation should be combined with current credentialing standards for permanent Seed brachytherapy to form a comprehensive validation of institutional brachytherapy program quality.

  • establishing a simulation based education program for radiation oncology learners in permanent Seed Implant brachytherapy building validation evidence
    Brachytherapy, 2020
    Co-Authors: Michael Roumeliotis, Michelle Hilts, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Kevin Martell, Deidre Batchelar
    Abstract:

    Abstract Purpose The purpose of this study was to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy. The first step in formalizing any education program is a validation process that builds evidence-based verification that the learning environment is appropriate. Methods and Materials The primary education task allowed practitioners to use an anthropomorphic breast phantom to simulate a permanent Seed Implant brachytherapy delivery. Validation evidence is built by generating data to assess learner and expert cohorts according to their proficiency. Each practitioner's performance during the simulation was evaluated by Seed placement accuracy, procedural time-to-complete, and two qualitative evaluation tools—a global rating scale and procedural checklist. Results The average Seed placement accuracy (±SD) was 8.1 ± 3.5 mm compared to 6.1 ± 2.6 mm for the learner and expert cohort, respectively. The median (range) procedural time-to-complete was 64 (60–77) minutes and 43 (41–50) minutes for the learner and expert cohort, respectively. Seed placement accuracy (student t-test, p  Conclusions This validation evidence supports the utilization of this simulation environment toward appropriately capturing the delivery experience of practitioners. The results demonstrate that, in all areas of evaluation, expert cohort proficiency was superior to learner cohort proficiency. This methodology will be used to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy.

  • permanent breast Seed Implant for partial breast radiotherapy after partial mastectomy for favorable breast cancer technique results and applications to various seroma presentations
    Brachytherapy, 2019
    Co-Authors: Juanita Crook, Michelle Hilts, Deidre Batchelar, Mariepierre Milette, Martin Kozeniowski, Laurie Pilote, Jeanphilippe Pignol
    Abstract:

    Abstract Purpose Adjuvant partial breast radiotherapy is the standard of care for early-stage favorable breast cancer. We report dosimetry, acute and late tolerance for 67 permanent breast Seed Implants. Materials and Methods From July 2012 to October 2018, 67 postmenopausal women with unifocal pT1pN0 invasive ductal or ductal carcinoma in situ received partial breast radiotherapy using stranded Pd-103 Seeds after breast-conserving surgery, delivering 90 Gy to the seroma + margin (1.25–1.5 cm), planned with computed tomography simulation and performed as an ultrasound-guided outpatient procedure. The planning and postImplant computed tomography images were fused for seroma delineation for postImplant dosimetry. Evaluations were performed at 1, 2, 6, and 12 months and then annually. Results Although patient acceptance is high, only 40% met technical requirements of seroma volume, location, and visibility. For 67 patients, the median seroma volume was 6.6 cc, PTV 61 cc, and number of needles 18. In day 0 dosimetry, median seroma D90 dose was 132 Gy; seroma + 5 mm, 106 Gy; and seroma + 10 mm, 80 Gy. Peak reaction at 6 weeks is limited to the Implant site: 51% grade 1 erythema and 12% focal desquamation. Late reactions (>2 years) are generally minimal: 35% no sequelae, 43% localized fibrosis, 20% mild telangiectasia (6% moderate but asymptomatic), 22% contour change. At minimum 6-month follow-up, 94% were “very or totally satisfied.” Recurrences (median follow-up: 3.3 years) were one in breast (different quadrant) and 2 contralateral. Three patients have had biopsies of fibrosis, all negative for malignancy. Conclusions Our experience with permanent breast Seed Implant is favorable with a high patient acceptance and satisfaction, excellent early efficacy, and very satisfactory cosmesis.

Deidre Batchelar - One of the best experts on this subject based on the ideXlab platform.

  • characterization and registration of 3d ultrasound for use in permanent breast Seed Implant brachytherapy treatment planning
    Brachytherapy, 2020
    Co-Authors: Claire Zhang, Michelle Hilts, Deidre Batchelar, Nathan Orlando, Lori Gardi, Aaron Fenster, Juanita Crook
    Abstract:

    Abstract Purpose Permanent breast Seed Implant (PBSI) brachytherapy is a novel technique for early-stage breast cancer. Computed tomography (CT) images are used for treatment planning and freehand 2D ultrasound for Implant guidance. The multimodality imaging approach leads to discrepancies in target identification. To address this, a prototype 3D ultrasound (3DUS) system was recently developed for PBSI. In this study, we characterize the 3DUS system performance, establish QA baselines, and develop and test a method to register 3DUS images to CT images for PBSI planning. Methods and Materials 3DUS system performance was characterized by testing distance and volume measurement accuracy, and needle template alignment accuracy. 3DUS-CT registration was achieved through point-based registration using a 3D-printed model designed and constructed to provide visible landmarks on both images and tested on an in-house made gel breast phantom. Results The 3DUS system mean distance measurement accuracy was within 1% in axial, lateral, and elevational directions. A volumetric error of 3% was observed. The mean needle template alignment error was 1.0° ± 0.3 ° and 1.3 ± 0.5 mm. The mean 3DUS-CT registration error was within 3 mm when imaging at the breast centre or across all breast quadrants. Conclusions This study provided baseline data to characterize the performance of a prototype 3DUS system for PBSI planning and developed and tested a method to obtain accurate 3DUS-CT image registration for PBSI planning. Future work will focus on system validation and characterization in a clinical context as well as the assessment of impact on treatment plans.

  • a reliable skin toxicity predictor in permanent breast Seed Implant brachytherapy
    Brachytherapy, 2020
    Co-Authors: Zahra Anjomani, Michelle Hilts, Deidre Batchelar, Juanita Crook
    Abstract:

    Abstract Purpose To establish skin dose–outcome relationships using a reliable metric in permanent breast Seed Implant (PBSI). Methods Sixty-seven consecutive patients who underwent PBSI at our institution were included. Skin doses were calculated using two skin dose indices: maximum point dose to the skin surface, Dmax, and D0.2cc for a 2-mm internal skin rind (a surrogate to the dose to 1 cm2 area of skin) from CT-based postoperative treatment plans. Toxicity data were extracted from patients’ charts and photographs. The associations between skin dose and skin toxicity were investigated using the analysis of variance, and the predictive performance of skin dose measures was evaluated using receiver operating characteristic curves. Results For acute reactions, 49.3% of patients had Grade 1, 4.5% Grade 2, and 1.5% Grade 3 toxicity. For telangiectasia at 3 years, very minor and minimally apparent telangiectasia was observed in 25% of patients. Moderate but asymptomatic telangiectasia was observed in 9.1% of cases. Both metrics were significantly associated with the occurrence of acute toxicity and telangiectasia at 3 years (p Conclusion D0.2cc, as an alternate skin dose measure to Dmax, is a robust metric for measuring skin dose that is simple to calculate, yet is clinically relevant and not prone to inaccuracies inherent to point dose measurement.

  • Peer-based credentialing for brachytherapy: Application in permanent Seed Implant
    Brachytherapy, 2020
    Co-Authors: Tyler Meyer, Michelle Hilts, Deidre Batchelar, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Stephen F Kry
    Abstract:

    Abstract Purpose The purpose of the study was to establish a quantitative method for Implant quality evaluation in permanent Seed Implant brachytherapy for credentialing. Delivery-based credentialing will promote consistency in brachytherapy Seed delivery and improve patient outcomes. Methods A workflow for delivery-based credentialing was outlined and applied to permanent breast Seed Implant brachytherapy. Delivery simulations were performed on Implantable anthropomorphic breast phantoms. Two institutions experienced in permanent Seed Implant brachytherapy demonstrated the peer credentialing process. Each delivery was evaluated for Seed placement accuracy as the measure of Implant quality, both for Implant accuracy and across five simulations to assess Implant variation. Initial credentialing criteria are set based on two factors; the mean Seed placement accuracy (Implant accuracy) and the mean standard deviation (Seed variation) with the threshold for each set with the addition of two standard deviations. Results Across two institutions, Seed placement accuracy (±standard deviation) was calculated for all five delivery simulations to yield 6.1 (±2.6) mm. To set credentialing criteria, the Implant accuracy (6.1 mm) plus two standard deviations (2.0 mm) and the Seed variation (2.6 mm) plus two standard deviations (0.8) mm yield a threshold of 8.1 ± 3.4 mm. It is expected that 95% of experienced institutions would perform the phantom simulation within this threshold. Conclusion Brachytherapy programs should validate delivery accuracy by formal credentialing, which is standard in external beam programs. This quantitative Implant evaluation should be combined with current credentialing standards for permanent Seed brachytherapy to form a comprehensive validation of institutional brachytherapy program quality.

  • establishing a simulation based education program for radiation oncology learners in permanent Seed Implant brachytherapy building validation evidence
    Brachytherapy, 2020
    Co-Authors: Michael Roumeliotis, Michelle Hilts, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Kevin Martell, Deidre Batchelar
    Abstract:

    Abstract Purpose The purpose of this study was to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy. The first step in formalizing any education program is a validation process that builds evidence-based verification that the learning environment is appropriate. Methods and Materials The primary education task allowed practitioners to use an anthropomorphic breast phantom to simulate a permanent Seed Implant brachytherapy delivery. Validation evidence is built by generating data to assess learner and expert cohorts according to their proficiency. Each practitioner's performance during the simulation was evaluated by Seed placement accuracy, procedural time-to-complete, and two qualitative evaluation tools—a global rating scale and procedural checklist. Results The average Seed placement accuracy (±SD) was 8.1 ± 3.5 mm compared to 6.1 ± 2.6 mm for the learner and expert cohort, respectively. The median (range) procedural time-to-complete was 64 (60–77) minutes and 43 (41–50) minutes for the learner and expert cohort, respectively. Seed placement accuracy (student t-test, p  Conclusions This validation evidence supports the utilization of this simulation environment toward appropriately capturing the delivery experience of practitioners. The results demonstrate that, in all areas of evaluation, expert cohort proficiency was superior to learner cohort proficiency. This methodology will be used to establish a simulation-based education program for radiation oncology learners in permanent Seed Implant brachytherapy.

  • permanent breast Seed Implant for partial breast radiotherapy after partial mastectomy for favorable breast cancer technique results and applications to various seroma presentations
    Brachytherapy, 2019
    Co-Authors: Juanita Crook, Michelle Hilts, Deidre Batchelar, Mariepierre Milette, Martin Kozeniowski, Laurie Pilote, Jeanphilippe Pignol
    Abstract:

    Abstract Purpose Adjuvant partial breast radiotherapy is the standard of care for early-stage favorable breast cancer. We report dosimetry, acute and late tolerance for 67 permanent breast Seed Implants. Materials and Methods From July 2012 to October 2018, 67 postmenopausal women with unifocal pT1pN0 invasive ductal or ductal carcinoma in situ received partial breast radiotherapy using stranded Pd-103 Seeds after breast-conserving surgery, delivering 90 Gy to the seroma + margin (1.25–1.5 cm), planned with computed tomography simulation and performed as an ultrasound-guided outpatient procedure. The planning and postImplant computed tomography images were fused for seroma delineation for postImplant dosimetry. Evaluations were performed at 1, 2, 6, and 12 months and then annually. Results Although patient acceptance is high, only 40% met technical requirements of seroma volume, location, and visibility. For 67 patients, the median seroma volume was 6.6 cc, PTV 61 cc, and number of needles 18. In day 0 dosimetry, median seroma D90 dose was 132 Gy; seroma + 5 mm, 106 Gy; and seroma + 10 mm, 80 Gy. Peak reaction at 6 weeks is limited to the Implant site: 51% grade 1 erythema and 12% focal desquamation. Late reactions (>2 years) are generally minimal: 35% no sequelae, 43% localized fibrosis, 20% mild telangiectasia (6% moderate but asymptomatic), 22% contour change. At minimum 6-month follow-up, 94% were “very or totally satisfied.” Recurrences (median follow-up: 3.3 years) were one in breast (different quadrant) and 2 contralateral. Three patients have had biopsies of fibrosis, all negative for malignancy. Conclusions Our experience with permanent breast Seed Implant is favorable with a high patient acceptance and satisfaction, excellent early efficacy, and very satisfactory cosmesis.

Tyler Meyer - One of the best experts on this subject based on the ideXlab platform.

  • Peer-based credentialing for brachytherapy: Application in permanent Seed Implant
    Brachytherapy, 2020
    Co-Authors: Tyler Meyer, Michelle Hilts, Deidre Batchelar, Juanita Crook, Sarah Quirk, Siraj Husain, Elizabeth Watt, Alexandra Guebert, Amy Frederick, Stephen F Kry
    Abstract:

    Abstract Purpose The purpose of the study was to establish a quantitative method for Implant quality evaluation in permanent Seed Implant brachytherapy for credentialing. Delivery-based credentialing will promote consistency in brachytherapy Seed delivery and improve patient outcomes. Methods A workflow for delivery-based credentialing was outlined and applied to permanent breast Seed Implant brachytherapy. Delivery simulations were performed on Implantable anthropomorphic breast phantoms. Two institutions experienced in permanent Seed Implant brachytherapy demonstrated the peer credentialing process. Each delivery was evaluated for Seed placement accuracy as the measure of Implant quality, both for Implant accuracy and across five simulations to assess Implant variation. Initial credentialing criteria are set based on two factors; the mean Seed placement accuracy (Implant accuracy) and the mean standard deviation (Seed variation) with the threshold for each set with the addition of two standard deviations. Results Across two institutions, Seed placement accuracy (±standard deviation) was calculated for all five delivery simulations to yield 6.1 (±2.6) mm. To set credentialing criteria, the Implant accuracy (6.1 mm) plus two standard deviations (2.0 mm) and the Seed variation (2.6 mm) plus two standard deviations (0.8) mm yield a threshold of 8.1 ± 3.4 mm. It is expected that 95% of experienced institutions would perform the phantom simulation within this threshold. Conclusion Brachytherapy programs should validate delivery accuracy by formal credentialing, which is standard in external beam programs. This quantitative Implant evaluation should be combined with current credentialing standards for permanent Seed brachytherapy to form a comprehensive validation of institutional brachytherapy program quality.

  • post Implant analysis in permanent breast Seed Implant automated plan reconstruction using simulated annealing
    Journal of Contemporary Brachytherapy, 2019
    Co-Authors: Elizabeth Watt, Siraj Husain, Michael Roumeliotis, Matthew Skarsgard, Tyler Meyer
    Abstract:

    Purpose Post-Implant analysis in permanent breast Seed Implant (PBSI) brachytherapy is an important component of the quality assurance process that indicates dosimetric quality relevant to patient outcome, indicating salvage therapy if inadequate, as well as providing feedback to the brachytherapy team to improve future treatments. To measure geometric indices on Implant quality, plan reconstruction must be performed to correlate each planned and post-Implant Seed location. In this work, a simulated-annealing-based algorithm is developed to perform this plan reconstruction automatically. Material and methods The plan reconstruction algorithm was developed in MATLAB, taking the patient pre-treatment and post-Implant (Day 0) plan and associated contours as inputs. For 19 treated patients, a reconstruction was obtained that defined the correspondence between each planned and post-Implant Seed. The simulated-annealing algorithm was used to reconstruct each patient 10 times to assess the variability in convergence. Manual reconstructions performed by at least two independent observers to obtain consensus were defined as the ground truth; these were compared to the automatic reconstructions obtained by the algorithm. Metrics on Seed placement accuracy and needle strand angulation were calculated for the patients. Results The algorithm performed reconstructions on 19 patients (1235 Seeds) with ground-truth reconstructions, obtaining 97 ± 8% correct matches. This strong performance indicates the ability to incorporate this algorithm into the clinical quality assurance workflow. Conclusions The plan reconstruction algorithm developed herein performed very well in a 19-patient cohort. This algorithm can be incorporated into the clinical process to assist in the assessment of center-specific Seed placement accuracy and can be used to gather Implant metrics in an automated, standardized fashion for future PBSI trials.

  • demonstration of simulated annealing optimization for permanent breast Seed Implant treatment planning
    Brachytherapy, 2018
    Co-Authors: Michael Roumeliotis, Amy Frederick, Elizabeth Watt, Brock Yates, Tyler Meyer
    Abstract:

    Abstract Purpose Permanent breast Seed Implant (PBSI) is a developing brachytherapy technique for the treatment of early-stage breast cancer. In current practice, PBSI uses manual planning strategies to generate clinical treatment plans. In this work, a simulated annealing-based algorithm is developed to demonstrate the first application of inverse optimization for PBSI. Methods and Materials Target, skin, and chest wall muscle contours, exported from a treatment planning system in digital imaging and communications in medicine format, are used as inputs. To optimize, the user defines the dose–volume histogram objectives for the target and specifies a relative weighting for target and skin constraints. A 10-patient cohort of previously treated patients was planned by using the inverse optimization algorithm. Plan quality was compared to the clinically treated manually generated plans using the V 90% , V 100% , V 150% , and V 200% for the planning target volume (PTV), V 90% and D 0.2 cc for skin dose, and PTV conformity indices. Results For each of the 10 patients, patient-wise paired differences between inverse and manual plans were analyzed and presented in box plots. Comparing inverse and manual planning techniques, a statistical difference was not observed ( p  > 0.05) in PTV coverage criteria ( V 90% , V 100% ) and dose to skin 2mm . A statistical difference was observed in the inverse plans as a reduction of the V 150% (mean of 6.2%) and increase in conformity index of the 20%, 50%, 90%, and 100% isodose lines. Conclusions This work presents the first application of inverse optimization used to generate PBSI treatment plans. A 10-patient cohort previously treated with PBSI was retrospectively planned for comparison with the clinically treated manually generated plans.

  • development and characterization of an anthropomorphic breast phantom for permanent breast Seed Implant brachytherapy credentialing
    Brachytherapy, 2017
    Co-Authors: Sarah Quirk, Elizabeth Watt, Michael Roumeliotis, Matthew Skarsgard, Tiana Trumpour, Tyler Meyer
    Abstract:

    Abstract Purpose To develop an anthropomorphic breast phantom for use in credentialing of permanent breast Seed Implant brachytherapy. Methods and Materials A representative external contour and target volume was used as the basis of mold manufacturing for anthropomorphic breast phantom development. Both target and normal tissue were composed of gel-like materials that provide suitable computed tomography and ultrasound contrast for brachytherapy delivery. The phantoms were evaluated for consistency in construction (target location) and Hounsfield unit (computed tomography contrast). For both target and normal tissue, the speed of sound was measured and compared to the image reconstruction algorithm's expectation value. Five phantoms were imaged preImplant and postImplant to assess interphantom similarity as well as to evaluate the uncertainty in quantifying Seed position. Results The average Hounsfield units of the target and normal tissue gels is −146 ± 5 and 23 ± 1, respectively. The average speed of sound of the target and normal tissue gels is 1485 ± 7 m/s and 1558 ± 9 m/s, respectively, resulting in an estimated 0.4 mm uncertainty in image guidance. The registration/deformation uncertainty was determined to be 0.8 mm. The standard combined uncertainty in assessing Seed position spatial accuracy, also including a 0.9 mm estimate based on literature for Seed localization, is estimated to be 1.3 mm. Conclusions The development of the anthropomorphic breast phantom and evaluation of both the consistency as well as overall Seed position uncertainty illustrates the suitability of this phantom for use in brachytherapy end-to-end delivery and Implant accuracy evaluation. When evaluating a user's Implant accuracy, we estimate a standard combined uncertainty of 1.3 mm.

  • treatment planning considerations for permanent breast Seed Implant
    Brachytherapy, 2017
    Co-Authors: Tyler Meyer, Amy Frederick, Michael Roumeliotis
    Abstract:

    Abstract Purpose To determine an optimal planning strategy for permanent breast Seed Implant that minimizes dose heterogeneity without degrading coverage and conformity. Methods and Materials A simple model was developed to investigate planning strategies incorporating a range of 103Pd Seed activities, needle and Seed spacings, and Implants in which Seed positions are either restricted to or permitted outside of spherical planning target volumes (PTVs). To address more realistic target geometries, model parameters were used to retrospectively replan a 10-patient cohort in MIM Symphony. Results We confirm that the current clinical modified uniform Implantation pattern provides the most favorable dose distributions, given the resolution of the template grid and spacer length. We show that needle and Seed counts for replans with Seed placement permitted 0.3 cm outside of the PTV are most comparable to clinical preplans, but offer a 13 ± 11% average reduction in the VPTV150%. Replans produced with Seed placement 0.5 cm outside of the PTV provide the largest improvement in dose homogeneity, at the cost of a slight increase in irradiated volume and an increase in the number of needles and Seeds. Conclusions Implanting Seeds beyond the PTV within a 0.3–0.5 cm margin, and optimizing Seed activity on a per patient basis, allows for improvement in dose homogeneity. However, these plans require higher needle and Seed counts and result in a small increase in irradiated volume. Before planning recommendations can be made, the implications of these changes must be investigated in the context of clinical outcome for permanent breast Seed Implant.