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Chris H.j. Terhaard - One of the best experts on this subject based on the ideXlab platform.
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New insights in the vascular supply of the human Parotid Gland - consequences for Parotid Gland-sparing irradiation.
Head & neck, 2010Co-Authors: Marjolein J. Van Holten, Judith M. Roesink, Chris H.j. Terhaard, Pètra M. BraamAbstract:Background. Xerostomia is caused by irradiation for head and neck cancer, depending on the dose to the pa- rotid Gland. To investigate which part of the Parotid Gland has to be spared with radiotherapy, detailed information about the vascular supply of the Parotid Gland is necessary. Methods. Arterial vessels of the head of a human cadaver were colored. A 3-dimensional reconstruction of the Parotid Gland and the arterial vessels was made and analyzed. Results. Five arterial vessels were responsible for the vas- cular supply of the Parotid Gland: the posterior auricular artery, 2 branches so far unnamed, the superficial temporal artery, and the transverse facial artery. All arteries were branches off the external carotid artery, and supplied different parts of the Parotid Gland. Conclusions. This study describes the detailed vascular supply of the human Parotid Gland. These results may contrib- ute to improve Parotid sparing radiotherapy, thus reducing complications such as xerostomia in the future. V V C 2009 Wiley Periodicals, Inc. Head Neck 32: 837-843, 2010
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Parotid Gland function after radiotherapy.
The Lancet. Oncology, 2010Co-Authors: Cornelis P.j. Raaijmakers, Judith M. Roesink, Tim Dijkema, Antonetta C. Houweling, Chris H.j. TerhaardAbstract:Radiotherapy is a common treatment for head and neck cancer patients. Unfortunately, it produces serious acute and long-term side effects to the oral cavity. One severe complication is the loss of salivary Gland function, which can persists for many years. Saliva has multiple functions relating to speech, taste perception, mastication, and swallowing and bolus formation. Cleansing and dental and mucosal protection are also important functions. In this thesis, a detailed report is given on the effects of radiotherapy on changes in the Parotid Gland function. Different methods of measuring Gland function are described. Moreover, a preventive measure to limit the Gland toxicity was investigated in rodents. The radiation field and, in particular, the volume of the Parotid Gland tissue exposed to radiation is of notable importance with regard to the development of Gland damage and hypofunction. Therefore, it is important to achieve detailed information about the size and position of the Parotid Gland. Great differences in size and position of the Parotid Glands between the patients were seen. In order to exactly define the localisation of the Glands, it is essential to use CT-based simulation of radiation fields. The radiation tolerance of the Parotid Glands as a function of dose and volume irradiated was accurately described. The best parameter for evaluation of the Parotid Gland function appeared to be the flow measurement using the Lashley cups. However, if direct flow measurements are not feasible, 99mTc-pertechnetate scintigraphy might be a good alternative. Flow reduction depended on the mean Parotid Gland dose. For a post treatment Parotid flow ratio a 25%, the TD50 (the dose to the whole organ leading to a complication probability of 50%) was found to be 31, 35 and 39 Gy at 6 weeks, 6 months and 1 year after radiotherapy respectively. The consequences of Parotid Gland injury are still difficult to manage. Prophylactic treatment with sialogogues like the muscarinic receptor agonist pilocarpine has been shown to have radioprotective potential. The effects of preirradiation treatment of pilocarpine on rat Parotid Gland function were investigated in relation to radiation dose. Pilocarpine induced compensation, which at least underlies the radioprotective effect of the drug. This effect seemed to be dependent on the amount of damage induced. Therefore, the type of fractionation scheme and the volume of the Gland that lies within the radiation portal will be crucial for the effectiveness of a prophylactic pilocarpine treatment. With the more detailed knowledge on the dose/volume effects of radiation on Parotid function, we can try to focus on sparing the Parotid Gland function. The prevention of radiation-induced loss of Parotid Gland function will depend on both optimal sparing radiation therapy techniques and on pharmacological agents, which can selectively interfere with the radiation-induced effects. These preventing strategies will need a joint effort of radiation-oncologists, clinical physicists and radiobiologists.
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a comparison of mean Parotid Gland dose with measures of Parotid Gland function after radiotherapy for head and neck cancer implications for future trials
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Judith M. Roesink, Cornelis P.j. Raaijmakers, Maria Schipper, Wim B Busschers, Chris H.j. TerhaardAbstract:Purpose: To determine the most adequate parameter to measure the consequences of reducing the Parotid Gland dose. Methods and Materials: One hundred eight patients treated with radiotherapy for various malignancies of the head and neck were prospectively evaluated using three methods. Parotid Gland function was objectively determined by measuring stimulated Parotid flow using Lashley cups and scintigraphy. To assess xerostomia-related quality of life, the head-and-neck cancer module European Organization for Research and Treatment of Cancer QLQ (Quality of Life Questionnaire) H&N35 was used. Measurements took place before radiotherapy and 6 weeks and 12 months after the completion of radiotherapy. Complication was defined for each method using cutoff values. The correlation between these complications and the mean Parotid Gland dose was investigated to find the best measure for Parotid Gland function. Results: For both flow and scintigraphy data, the best definition for objective Parotid Gland toxicity seemed to be reduction of stimulated Parotid flow to ≤25% of the preradiotherapy flow. Of all the subjective variables, only the single item dry mouth 6 weeks after radiotherapy was found to be significant. The best correlation with the mean Parotid Gland dose was found for the stimulated flow measurements. The predictive ability was the highest for the time point 1 year after radiotherapy. Subjective findings did not correlate with the mean Parotid dose. Conclusions: Stimulated flow measurements using Lashley cups, with a complication defined as flow ≤25% of the preradiotherapy output, correlated best with the mean Parotid Gland dose. When reduction of the mean dose to the Parotid Gland is intended, the stimulated flow measurement is the best method for evaluating Parotid Gland function.
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CT-based Parotid Gland location: implications for preservation of Parotid function
Radiotherapy and Oncology, 2000Co-Authors: Judith M. Roesink, Chris H.j. Terhaard, Marinus A. Moerland, Frans Van Iersel, Jan J. BattermannAbstract:Abstract Purpose : The position of the Parotid Gland in relation to surrounding structures was investigated. Materials and methods : Sixty-five patients with head and neck tumours were prospectively evaluated. Parotid position was determined using beam's eye views of CT images projected on simulator films. Distances between the different borders of the Parotid Gland and surrounding bony marks were quantitatively assessed. Results : The Parotid Gland volume ranged from 12.9 to 46.4 cm 3 . The distance between the cranial border of the Parotid Gland and the tuberculum anterior of the atlas ranged between 0.7 and 4.8 cm. The position of the Parotid Gland was unaffected by the angle of the mandible. Conclusions : The size and position of the Parotid Gland varies largely among patients. As the extent of radiation-induced salivary dysfunction depends on the volume of the Gland tissue exposed, CT-based simulation of radiation fields is necessary.
Judith M. Roesink - One of the best experts on this subject based on the ideXlab platform.
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New insights in the vascular supply of the human Parotid Gland - consequences for Parotid Gland-sparing irradiation.
Head & neck, 2010Co-Authors: Marjolein J. Van Holten, Judith M. Roesink, Chris H.j. Terhaard, Pètra M. BraamAbstract:Background. Xerostomia is caused by irradiation for head and neck cancer, depending on the dose to the pa- rotid Gland. To investigate which part of the Parotid Gland has to be spared with radiotherapy, detailed information about the vascular supply of the Parotid Gland is necessary. Methods. Arterial vessels of the head of a human cadaver were colored. A 3-dimensional reconstruction of the Parotid Gland and the arterial vessels was made and analyzed. Results. Five arterial vessels were responsible for the vas- cular supply of the Parotid Gland: the posterior auricular artery, 2 branches so far unnamed, the superficial temporal artery, and the transverse facial artery. All arteries were branches off the external carotid artery, and supplied different parts of the Parotid Gland. Conclusions. This study describes the detailed vascular supply of the human Parotid Gland. These results may contrib- ute to improve Parotid sparing radiotherapy, thus reducing complications such as xerostomia in the future. V V C 2009 Wiley Periodicals, Inc. Head Neck 32: 837-843, 2010
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Parotid Gland function after radiotherapy.
The Lancet. Oncology, 2010Co-Authors: Cornelis P.j. Raaijmakers, Judith M. Roesink, Tim Dijkema, Antonetta C. Houweling, Chris H.j. TerhaardAbstract:Radiotherapy is a common treatment for head and neck cancer patients. Unfortunately, it produces serious acute and long-term side effects to the oral cavity. One severe complication is the loss of salivary Gland function, which can persists for many years. Saliva has multiple functions relating to speech, taste perception, mastication, and swallowing and bolus formation. Cleansing and dental and mucosal protection are also important functions. In this thesis, a detailed report is given on the effects of radiotherapy on changes in the Parotid Gland function. Different methods of measuring Gland function are described. Moreover, a preventive measure to limit the Gland toxicity was investigated in rodents. The radiation field and, in particular, the volume of the Parotid Gland tissue exposed to radiation is of notable importance with regard to the development of Gland damage and hypofunction. Therefore, it is important to achieve detailed information about the size and position of the Parotid Gland. Great differences in size and position of the Parotid Glands between the patients were seen. In order to exactly define the localisation of the Glands, it is essential to use CT-based simulation of radiation fields. The radiation tolerance of the Parotid Glands as a function of dose and volume irradiated was accurately described. The best parameter for evaluation of the Parotid Gland function appeared to be the flow measurement using the Lashley cups. However, if direct flow measurements are not feasible, 99mTc-pertechnetate scintigraphy might be a good alternative. Flow reduction depended on the mean Parotid Gland dose. For a post treatment Parotid flow ratio a 25%, the TD50 (the dose to the whole organ leading to a complication probability of 50%) was found to be 31, 35 and 39 Gy at 6 weeks, 6 months and 1 year after radiotherapy respectively. The consequences of Parotid Gland injury are still difficult to manage. Prophylactic treatment with sialogogues like the muscarinic receptor agonist pilocarpine has been shown to have radioprotective potential. The effects of preirradiation treatment of pilocarpine on rat Parotid Gland function were investigated in relation to radiation dose. Pilocarpine induced compensation, which at least underlies the radioprotective effect of the drug. This effect seemed to be dependent on the amount of damage induced. Therefore, the type of fractionation scheme and the volume of the Gland that lies within the radiation portal will be crucial for the effectiveness of a prophylactic pilocarpine treatment. With the more detailed knowledge on the dose/volume effects of radiation on Parotid function, we can try to focus on sparing the Parotid Gland function. The prevention of radiation-induced loss of Parotid Gland function will depend on both optimal sparing radiation therapy techniques and on pharmacological agents, which can selectively interfere with the radiation-induced effects. These preventing strategies will need a joint effort of radiation-oncologists, clinical physicists and radiobiologists.
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a comparison of mean Parotid Gland dose with measures of Parotid Gland function after radiotherapy for head and neck cancer implications for future trials
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Judith M. Roesink, Cornelis P.j. Raaijmakers, Maria Schipper, Wim B Busschers, Chris H.j. TerhaardAbstract:Purpose: To determine the most adequate parameter to measure the consequences of reducing the Parotid Gland dose. Methods and Materials: One hundred eight patients treated with radiotherapy for various malignancies of the head and neck were prospectively evaluated using three methods. Parotid Gland function was objectively determined by measuring stimulated Parotid flow using Lashley cups and scintigraphy. To assess xerostomia-related quality of life, the head-and-neck cancer module European Organization for Research and Treatment of Cancer QLQ (Quality of Life Questionnaire) H&N35 was used. Measurements took place before radiotherapy and 6 weeks and 12 months after the completion of radiotherapy. Complication was defined for each method using cutoff values. The correlation between these complications and the mean Parotid Gland dose was investigated to find the best measure for Parotid Gland function. Results: For both flow and scintigraphy data, the best definition for objective Parotid Gland toxicity seemed to be reduction of stimulated Parotid flow to ≤25% of the preradiotherapy flow. Of all the subjective variables, only the single item dry mouth 6 weeks after radiotherapy was found to be significant. The best correlation with the mean Parotid Gland dose was found for the stimulated flow measurements. The predictive ability was the highest for the time point 1 year after radiotherapy. Subjective findings did not correlate with the mean Parotid dose. Conclusions: Stimulated flow measurements using Lashley cups, with a complication defined as flow ≤25% of the preradiotherapy output, correlated best with the mean Parotid Gland dose. When reduction of the mean dose to the Parotid Gland is intended, the stimulated flow measurement is the best method for evaluating Parotid Gland function.
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CT-based Parotid Gland location: implications for preservation of Parotid function
Radiotherapy and Oncology, 2000Co-Authors: Judith M. Roesink, Chris H.j. Terhaard, Marinus A. Moerland, Frans Van Iersel, Jan J. BattermannAbstract:Abstract Purpose : The position of the Parotid Gland in relation to surrounding structures was investigated. Materials and methods : Sixty-five patients with head and neck tumours were prospectively evaluated. Parotid position was determined using beam's eye views of CT images projected on simulator films. Distances between the different borders of the Parotid Gland and surrounding bony marks were quantitatively assessed. Results : The Parotid Gland volume ranged from 12.9 to 46.4 cm 3 . The distance between the cranial border of the Parotid Gland and the tuberculum anterior of the atlas ranged between 0.7 and 4.8 cm. The position of the Parotid Gland was unaffected by the angle of the mandible. Conclusions : The size and position of the Parotid Gland varies largely among patients. As the extent of radiation-induced salivary dysfunction depends on the volume of the Gland tissue exposed, CT-based simulation of radiation fields is necessary.
Eugene N Myers - One of the best experts on this subject based on the ideXlab platform.
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squamous cell carcinoma of the Parotid Gland
Head and Neck-journal for The Sciences and Specialties of The Head and Neck, 2006Co-Authors: Yulan Mary Ying, Jonas T Johnson, Eugene N MyersAbstract:Background. Our objective was to evaluate the outcome of patients treated for squamous cell carcinoma (SCC) of the Parotid Gland. Methods. We conducted a retrospective chart review of the tumor registry from 1982 through 2003 at a tertiary referral medical center. Patients with SCC of the Parotid Gland were identified and followed for a minimum of 2 years after therapy. Results. SCC involving the Parotid was identified in 66 patients. The tumor was a metastasis from a known primary site in 41 patients (62%). In 16 patients (24%), no other primary site was identified, and the tumor may have originated in the Parotid Gland. Nine patients (14%) were undetermined. Therapy frequently included surgery. The integrity of the facial nerve was preserved in 92% of surgical patients. Only eight patients initially had clinical evidence of cervical metastasis; however, cervical metastasis was identified in 25 patients (44%), changing the course of therapy. Conclusion. SCC of the Parotid Gland was metastatic from a known primary tumor in more than half of the patients. The most common site of the primary tumor was a cutaneous malignancy of the head and neck. The high incidence of cervical lymph node involvement underscores the diagnostic and therapeutic importance of neck dissection with Parotidectomy. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
Cornelis P.j. Raaijmakers - One of the best experts on this subject based on the ideXlab platform.
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Parotid Gland function after radiotherapy.
The Lancet. Oncology, 2010Co-Authors: Cornelis P.j. Raaijmakers, Judith M. Roesink, Tim Dijkema, Antonetta C. Houweling, Chris H.j. TerhaardAbstract:Radiotherapy is a common treatment for head and neck cancer patients. Unfortunately, it produces serious acute and long-term side effects to the oral cavity. One severe complication is the loss of salivary Gland function, which can persists for many years. Saliva has multiple functions relating to speech, taste perception, mastication, and swallowing and bolus formation. Cleansing and dental and mucosal protection are also important functions. In this thesis, a detailed report is given on the effects of radiotherapy on changes in the Parotid Gland function. Different methods of measuring Gland function are described. Moreover, a preventive measure to limit the Gland toxicity was investigated in rodents. The radiation field and, in particular, the volume of the Parotid Gland tissue exposed to radiation is of notable importance with regard to the development of Gland damage and hypofunction. Therefore, it is important to achieve detailed information about the size and position of the Parotid Gland. Great differences in size and position of the Parotid Glands between the patients were seen. In order to exactly define the localisation of the Glands, it is essential to use CT-based simulation of radiation fields. The radiation tolerance of the Parotid Glands as a function of dose and volume irradiated was accurately described. The best parameter for evaluation of the Parotid Gland function appeared to be the flow measurement using the Lashley cups. However, if direct flow measurements are not feasible, 99mTc-pertechnetate scintigraphy might be a good alternative. Flow reduction depended on the mean Parotid Gland dose. For a post treatment Parotid flow ratio a 25%, the TD50 (the dose to the whole organ leading to a complication probability of 50%) was found to be 31, 35 and 39 Gy at 6 weeks, 6 months and 1 year after radiotherapy respectively. The consequences of Parotid Gland injury are still difficult to manage. Prophylactic treatment with sialogogues like the muscarinic receptor agonist pilocarpine has been shown to have radioprotective potential. The effects of preirradiation treatment of pilocarpine on rat Parotid Gland function were investigated in relation to radiation dose. Pilocarpine induced compensation, which at least underlies the radioprotective effect of the drug. This effect seemed to be dependent on the amount of damage induced. Therefore, the type of fractionation scheme and the volume of the Gland that lies within the radiation portal will be crucial for the effectiveness of a prophylactic pilocarpine treatment. With the more detailed knowledge on the dose/volume effects of radiation on Parotid function, we can try to focus on sparing the Parotid Gland function. The prevention of radiation-induced loss of Parotid Gland function will depend on both optimal sparing radiation therapy techniques and on pharmacological agents, which can selectively interfere with the radiation-induced effects. These preventing strategies will need a joint effort of radiation-oncologists, clinical physicists and radiobiologists.
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a comparison of mean Parotid Gland dose with measures of Parotid Gland function after radiotherapy for head and neck cancer implications for future trials
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Judith M. Roesink, Cornelis P.j. Raaijmakers, Maria Schipper, Wim B Busschers, Chris H.j. TerhaardAbstract:Purpose: To determine the most adequate parameter to measure the consequences of reducing the Parotid Gland dose. Methods and Materials: One hundred eight patients treated with radiotherapy for various malignancies of the head and neck were prospectively evaluated using three methods. Parotid Gland function was objectively determined by measuring stimulated Parotid flow using Lashley cups and scintigraphy. To assess xerostomia-related quality of life, the head-and-neck cancer module European Organization for Research and Treatment of Cancer QLQ (Quality of Life Questionnaire) H&N35 was used. Measurements took place before radiotherapy and 6 weeks and 12 months after the completion of radiotherapy. Complication was defined for each method using cutoff values. The correlation between these complications and the mean Parotid Gland dose was investigated to find the best measure for Parotid Gland function. Results: For both flow and scintigraphy data, the best definition for objective Parotid Gland toxicity seemed to be reduction of stimulated Parotid flow to ≤25% of the preradiotherapy flow. Of all the subjective variables, only the single item dry mouth 6 weeks after radiotherapy was found to be significant. The best correlation with the mean Parotid Gland dose was found for the stimulated flow measurements. The predictive ability was the highest for the time point 1 year after radiotherapy. Subjective findings did not correlate with the mean Parotid dose. Conclusions: Stimulated flow measurements using Lashley cups, with a complication defined as flow ≤25% of the preradiotherapy output, correlated best with the mean Parotid Gland dose. When reduction of the mean dose to the Parotid Gland is intended, the stimulated flow measurement is the best method for evaluating Parotid Gland function.
Yulan Mary Ying - One of the best experts on this subject based on the ideXlab platform.
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squamous cell carcinoma of the Parotid Gland
Head and Neck-journal for The Sciences and Specialties of The Head and Neck, 2006Co-Authors: Yulan Mary Ying, Jonas T Johnson, Eugene N MyersAbstract:Background. Our objective was to evaluate the outcome of patients treated for squamous cell carcinoma (SCC) of the Parotid Gland. Methods. We conducted a retrospective chart review of the tumor registry from 1982 through 2003 at a tertiary referral medical center. Patients with SCC of the Parotid Gland were identified and followed for a minimum of 2 years after therapy. Results. SCC involving the Parotid was identified in 66 patients. The tumor was a metastasis from a known primary site in 41 patients (62%). In 16 patients (24%), no other primary site was identified, and the tumor may have originated in the Parotid Gland. Nine patients (14%) were undetermined. Therapy frequently included surgery. The integrity of the facial nerve was preserved in 92% of surgical patients. Only eight patients initially had clinical evidence of cervical metastasis; however, cervical metastasis was identified in 25 patients (44%), changing the course of therapy. Conclusion. SCC of the Parotid Gland was metastatic from a known primary tumor in more than half of the patients. The most common site of the primary tumor was a cutaneous malignancy of the head and neck. The high incidence of cervical lymph node involvement underscores the diagnostic and therapeutic importance of neck dissection with Parotidectomy. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
