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Pehr Lind - One of the best experts on this subject based on the ideXlab platform.
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radiation induced pulmonary toxicity a dose volume Histogram analysis in 201 patients with lung cancer
International Journal of Radiation Oncology Biology Physics, 2001Co-Authors: Maria L Hernando, Lawrence B Marks, Gunilla C Bentel, Su Min Zhou, Donna Hollis, Michael T Munley, Timothy D Shafman, Mitchell S Anscher, Pehr LindAbstract:Abstract Purpose: To relate lung Dose-Volume Histogram-based factors to symptomatic radiation pneumonitis (RP) in patients with lung cancer undergoing 3-dimensional (3D) radiotherapy planning. Methods and Materials: Between 1991 and 1999, 318 patients with lung cancer received external beam radiotherapy (RT) with 3D planning tools at Duke University Medical Center. One hundred seventeen patients were not evaluated for RP because of Results: Thirty-nine patients (19%) developed RP. In the univariate analysis, all dosimetric factors (i.e., mean lung dose, volume of lung receiving ≥30 Gy, and normal tissue complication probability) were associated with RP ( p range 0.006–0.003). Of the clinical factors, ongoing tobacco use at the time of referral for RT was associated with fewer cases of RP ( p = 0.05). These factors were also independently associated with RP according to the multivariate analysis ( p = 0.001). Models predictive for RP based on dosimetric factors only, or on a combination with the influence of tobacco use, had a concordance of 64% and 68%, respectively. Conclusions: Dosimetric factors were the best predictors of symptomatic RP after external beam RT for lung cancer. Multivariate models that also include clinical variables were slightly more predictive.
Richard Potter - One of the best experts on this subject based on the ideXlab platform.
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dose volume Histogram parameters and late side effects in magnetic resonance image guided adaptive cervical cancer brachytherapy
International Journal of Radiation Oncology Biology Physics, 2011Co-Authors: Petra Georg, Johannes Dimopoulos, Stefan Lang, Christian Kirisits, Daniel Berger, Wolfgang Dorr, A Sturdza, Dietmar Georg, Richard PotterAbstract:Purpose To evaluate the predictive value of dose–volume Histogram (DVH) parameters for late side effects of the rectum, sigmoid colon, and bladder in image-guided brachytherapy for cervix cancer patients. Methods and Materials A total of 141 patients received external-beam radiotherapy and image-guided brachytherapy with or without chemotherapy. The DVH parameters for the most exposed 2, 1, and 0.1 cm 3 (D 2cc , D 1cc , and D 0.1cc ) of the rectum, sigmoid, and bladder, as well as International Commission on Radiation Units and Measurements point doses (D ICRU ) were computed. Total doses were converted to equivalent doses in 2 Gy by applying the linear-quadratic model (α/β = 3 Gy). Late side effects were prospectively assessed using the Late Effects in Normal Tissues–Subjective, Objective, Management and Analytic score. The following patient groups were defined: Group 1: no side effects (Grade 0); Group 2: side effects (Grade 1–4); Group 3: minor side effects (Grade 0–1); and Group 4: major side effects (Grade 2–4). Results The median follow-up was 51 months. The overall 5-year actuarial side effect rates were 12% for rectum, 3% for sigmoid, and 23% for bladder. The mean total D 2cc were 65 ± 12 Gy for rectum, 62 ± 12 Gy for sigmoid, and 95 ± 22 Gy for bladder. For rectum, statistically significant differences were observed between Groups 1 and 2 in all DVH parameters and D ICRU . Between Groups 3 and 4, no difference was observed for D 0.1cc. For sigmoid, significant differences were observed for D 2cc and D 1cc , but not for D 0.1cc in all groups. For bladder, significant differences were observed for all DVH parameters only comparing Groups 3 and 4. No differences were observed for D ICRU . Conclusions The parameters D 2cc and D 1cc have a good predictive value for rectal toxicity. For sigmoid, no prediction could be postulated because of limited data. In bladder, DVH parameters were predictive only for major toxicity.
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dose volume Histogram parameters and local tumor control in magnetic resonance image guided cervical cancer brachytherapy
International Journal of Radiation Oncology Biology Physics, 2009Co-Authors: Johannes Dimopoulos, Stefan Lang, Christian Kirisits, Elena Fidarova, Daniel Berger, Petra Georg, Wolfgang Dorr, Richard PotterAbstract:Purpose To investigate the value of dose–volume Histogram (DVH) parameters for predicting local control in magnetic resonance (MR) image-guided brachytherapy (IGBT) for patients with cervical cancer. Methods and Materials Our study population consists of 141 patients with cervical cancer (Stages IB–IVA) treated with 45–50 Gy external beam radiotherapy plus four times 7 Gy IGBT with or without cisplatin. Gross tumor volume (GTV), high-risk clinical target volume (HRCTV), and intermediate-risk clinical target volume (IRCTV) were contoured, and DVH parameters (minimum dose delivered to 90% of the volume of interest [D90] and D100) were assessed. Doses were converted to the equivalent dose in 2 Gy (EQD2) by applying the linear quadratic model (α/β = 10 Gy). Groups were defined for patients with or without local recurrence (LR) in the true pelvis for tumor size at diagnosis (GTV at diagnosis [GTVD] of 2–5 cm (Group 1) or greater than 5 cm (Group 2) and for tumor size response at IGBT (HRCTV) of 2–5 cm (Group 2a) or greater than 5 cm (Group 2b). Results Eighteen LRs were observed. The most important DVH parameters correlated with LR were the D90 and D100 for HRCTV. Mean D90 and D100 values for HRCTV were 86 ± 16 and 65 ± 10 Gy, respectively. The D90 for HRCTV greater than 87 Gy resulted in an LR incidence of 4% (3 of 68) compared with 20% (15 of 73) for D90 less than 87 Gy. The effect was most pronounced in the tumor group (Group 2b). Conclusions We showed an increase in local control in IGBT in patients with cervical cancer with the dose delivered, which can be expressed by the D90 and D100 for HRCTV. Local control rates greater than 95% can be achieved if the D90 (EQD2) for HRCTV is 87 Gy or greater.
Joost J. M. E. Nuyttens - One of the best experts on this subject based on the ideXlab platform.
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predicting high grade esophagus toxicity after treating central lung tumors with stereotactic radiation therapy using a normal tissue complication probability model
International Journal of Radiation Oncology Biology Physics, 2020Co-Authors: Marloes Duijm, Noelle C Van Der Voort Van Zyp, Esther Oomende Hoop, Mirjam E Mast, Paul Van De Vaart, Mischa S Hoogeman, Joost J. M. E. NuyttensAbstract:PURPOSE: The treatment of central lung tumors with stereotactic body radiation therapy (SBRT) is challenged by the risk of excessive esophageal toxicity. To improve clinical decision making, we aimed to derive normal tissue complication probability (NTCP) models in a patient cohort with central lung tumors treated with SBRT and to evaluate the currently used esophagus dose constraints. METHODS AND MATERIALS: Patients with a central lung tumor who received SBRT (8 fractions of 7.5 Gy or 12 fractions of 5 Gy) were included. Doses were recalculated to an equivalent dose of 2 Gy with an alpha/beta-ratio of 10 Gy for acute and 3 Gy for late toxicity (the cut-off was 3 months). The esophagus was manually delineated. NTCP modeling based on logistic regression was used to relate Dose-Volume Histogram parameters (Dmax, D1cc, D2cc, D5cc) to acute and late toxicity. Parameters with a P < .05 were included in the model. Based on the NTCP models, we determined the probability of toxicity for the currently used dose constraints: D1cc toxicity occurred in 33 patients (18%). Late high-grade toxicity consisted of 2 possible treatment-related deaths (grade 5) and 2 patients with grade 3 toxicity. Acute toxicity consisted of only grade 1 (n = 19) and grade 2 toxicity (n = 10). All investigated Dose-Volume Histogram parameters were significantly correlated to acute and late toxicity. The probability of late high-grade toxicity is 1.1% for 8 fractions and 1.4% for 12 fractions when applying the current dose constraints. CONCLUSIONS: High-grade esophageal toxicity occurred in 2.1% of the patients, including 2 possible treatment-related deaths. The currently used dose constraints correspond to a low risk of high-grade toxicity.
A Mans - One of the best experts on this subject based on the ideXlab platform.
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in vivo portal dosimetry for head and neck vmat and lung imrt linking γ analysis with differences in dose volume Histograms of the ptv
Radiotherapy and Oncology, 2014Co-Authors: R Rozendaal, Ben J Mijnheer, Marcel Van Herk, A MansAbstract:Abstract Purpose To relate the results of γ-analysis and dose–volume Histogram (DVH) analysis of the PTV for detecting dose deviations with in vivo dosimetry for two treatment sites. Methods and materials In vivo 3D dose distributions were reconstructed for 722 fractions of 200 head-and-neck (HN for H&N VMAT treatments, DVH-analysis is preferable. As a result of this study, a smooth transition to using DVH-analysis clinically for detecting in vivo dose deviations in the PTV is within reach.
Marloes Duijm - One of the best experts on this subject based on the ideXlab platform.
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predicting high grade esophagus toxicity after treating central lung tumors with stereotactic radiation therapy using a normal tissue complication probability model
International Journal of Radiation Oncology Biology Physics, 2020Co-Authors: Marloes Duijm, Noelle C Van Der Voort Van Zyp, Esther Oomende Hoop, Mirjam E Mast, Paul Van De Vaart, Mischa S Hoogeman, Joost J. M. E. NuyttensAbstract:PURPOSE: The treatment of central lung tumors with stereotactic body radiation therapy (SBRT) is challenged by the risk of excessive esophageal toxicity. To improve clinical decision making, we aimed to derive normal tissue complication probability (NTCP) models in a patient cohort with central lung tumors treated with SBRT and to evaluate the currently used esophagus dose constraints. METHODS AND MATERIALS: Patients with a central lung tumor who received SBRT (8 fractions of 7.5 Gy or 12 fractions of 5 Gy) were included. Doses were recalculated to an equivalent dose of 2 Gy with an alpha/beta-ratio of 10 Gy for acute and 3 Gy for late toxicity (the cut-off was 3 months). The esophagus was manually delineated. NTCP modeling based on logistic regression was used to relate Dose-Volume Histogram parameters (Dmax, D1cc, D2cc, D5cc) to acute and late toxicity. Parameters with a P < .05 were included in the model. Based on the NTCP models, we determined the probability of toxicity for the currently used dose constraints: D1cc toxicity occurred in 33 patients (18%). Late high-grade toxicity consisted of 2 possible treatment-related deaths (grade 5) and 2 patients with grade 3 toxicity. Acute toxicity consisted of only grade 1 (n = 19) and grade 2 toxicity (n = 10). All investigated Dose-Volume Histogram parameters were significantly correlated to acute and late toxicity. The probability of late high-grade toxicity is 1.1% for 8 fractions and 1.4% for 12 fractions when applying the current dose constraints. CONCLUSIONS: High-grade esophageal toxicity occurred in 2.1% of the patients, including 2 possible treatment-related deaths. The currently used dose constraints correspond to a low risk of high-grade toxicity.