A CORRELATION BETWEEN RADIOTHERAPY DOSE ON THE MEDIASTINAL LYMPHOMA AND CARDIOVASCULAR DOSE WITH USING RESPIRATORY CONTROL SYSTEM
Rubrics: RADIATION THERAPY
Authors:
1.
Russian Federation
2.
Russian Federation
3.
Russian Federation
4.
Russian Federation
Type:
Article
Pages:
from 40
to 46
Status:
Published
Received:
27.10.2017
Accepted:
27.10.2017
Published:
27.10.2017
Subject area:
UDK 61 Медицина. Охрана здоровья
GRNTI 29.15 Ядерная физика
GRNTI 29.15 Ядерная физика
Language:
Russian, English
Keywords:
mediastinal lymphoma, radiation therapy, respiratory control system, cardiotoxicity, cardiovascular system, heart, ascending aorta
Abstract (English):
Purpose: To find a correlation between prescribed dose on the irradiation area and dose on heart and ascending aorta, using the "breath holding" method in classical radiotherapy course for patients with Hodgkin and non-Hodgkin mediastinal lymphomas. Material and methods: For patients of reproductive age with diagnose Hodgkin, non-Hodgkin mediastinal lymphomas we conducted radiotherapy with contouring of tumor, and critical structures, include heart and ascending aorta. Radiotherapy was conducted on breath holding (ABC) for shielding radiation dose from heart, ascending aorta and lungs. We did calculations of length and diameter of the contoured aorta and dose that it and heart took. Also, we did correlation calculation of relationship between prescribed dose on the tumor and doses cover to the heart and aorta on 6 and 10 MV nominal energies. Results: According to the protocol RTOG 1005 for the heart zone, exceeding the threshold level for V20 < 5 % occurred in 11 cases out 21, and 8 cases from them are for 10 MV energy. For V10 < 30 % it happened in nine cases from 21, and seven cases from them are for 10 MV energy too. The correlation coefficient between the prescribed dose and the received dose for protocol RTOG 1005 V10 < 30 % was 0.71 and it showed the highest value. This index is lower on 13 % for protocol RTOG 0623 (V67) – 0..58, and it has the weakest coefficient correlation (V33) – 0.45. The value of the correlation coefficient for the aorta decreased with an increase in the volume to which the prescribed dose of the irradiation area falls and, consequently a 10 and 20 % of the aorta volume is getting a maximum value from the prescribed dose. Conclusion: Our research showed what contouring of ascending aorta is obligatorily procedure, because the average dose on it was 10.73 Gy for 10 MV and 6.50 Gy for 6 MV energies. It is obvious that using 6 MV energy is more organ-preserving method of thea radiotherapy treatment when using a such techniques as ABC. It is a very important to study the issue of the permissible dose per volume of ascending aorta without critical consequences for cardiovascular system. In addition, it particularly important if we take into account that all patients had a chemotherapy course before radiation therapy which also caused cardiotoxicity.
Purpose: To find a correlation between prescribed dose on the irradiation area and dose on heart and ascending aorta, using the "breath holding" method in classical radiotherapy course for patients with Hodgkin and non-Hodgkin mediastinal lymphomas. Material and methods: For patients of reproductive age with diagnose Hodgkin, non-Hodgkin mediastinal lymphomas we conducted radiotherapy with contouring of tumor, and critical structures, include heart and ascending aorta. Radiotherapy was conducted on breath holding (ABC) for shielding radiation dose from heart, ascending aorta and lungs. We did calculations of length and diameter of the contoured aorta and dose that it and heart took. Also, we did correlation calculation of relationship between prescribed dose on the tumor and doses cover to the heart and aorta on 6 and 10 MV nominal energies. Results: According to the protocol RTOG 1005 for the heart zone, exceeding the threshold level for V20 < 5 % occurred in 11 cases out 21, and 8 cases from them are for 10 MV energy. For V10 < 30 % it happened in nine cases from 21, and seven cases from them are for 10 MV energy too. The correlation coefficient between the prescribed dose and the received dose for protocol RTOG 1005 V10 < 30 % was 0.71 and it showed the highest value. This index is lower on 13 % for protocol RTOG 0623 (V67) – 0..58, and it has the weakest coefficient correlation (V33) – 0.45. The value of the correlation coefficient for the aorta decreased with an increase in the volume to which the prescribed dose of the irradiation area falls and, consequently a 10 and 20 % of the aorta volume is getting a maximum value from the prescribed dose. Conclusion: Our research showed what contouring of ascending aorta is obligatorily procedure, because the average dose on it was 10.73 Gy for 10 MV and 6.50 Gy for 6 MV energies. It is obvious that using 6 MV energy is more organ-preserving method of thea radiotherapy treatment when using a such techniques as ABC. It is a very important to study the issue of the permissible dose per volume of ascending aorta without critical consequences for cardiovascular system. In addition, it particularly important if we take into account that all patients had a chemotherapy course before radiation therapy which also caused cardiotoxicity.
Keywords:
mediastinal lymphoma, radiation therapy, respiratory control system, cardiotoxicity, cardiovascular system, heart, ascending aorta
mediastinal lymphoma, radiation therapy, respiratory control system, cardiotoxicity, cardiovascular system, heart, ascending aorta
Опухоли средостения составляют менее 1 % всех опухолей человека, но большую часть из них представляют лимфопролиферативные заболевания, поддающиеся системному лечению. Заболеваемость классической лимфомой Ходжкина (ЛХ) составляет 2–4 случая на 100 тыс. человек в год. Согласно данным источника World Cancer Research Fund International, за 2012 г. зарегистрировано около 66 тыс. новых случаев с диагнозом ЛХ.
