Substantial Volume Changes and Plan Adaptations During Preoperative Radiation Therapy in Extremity Soft Tissue Sarcoma Patients
| Autor: | A.N. Scholten, Peter Remeijer, Fenna Heres Diddens, F. Koetsveld, Shaheen Ali, Rick L. Haas, C. Schneider, Suzanne van Beek, Anja Betgen |
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| Rok vydání: | 2019 |
| Předmět: |
Adult
Male Organs at Risk medicine.medical_specialty Cone beam computed tomography Soft Tissue Neoplasms 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Preoperative radiation Humans Medicine Radiology Nuclear Medicine and imaging Aged Neoplasm Staging Retrospective Studies Aged 80 and over medicine.diagnostic_test business.industry Radiotherapy Planning Computer-Assisted Soft tissue sarcoma Soft tissue Extremities Sarcoma Magnetic resonance imaging Retrospective cohort study Cone-Beam Computed Tomography Middle Aged medicine.disease Magnetic Resonance Imaging Neoadjuvant Therapy Tumor Burden Regimen Oncology 030220 oncology & carcinogenesis Female Radiology business Volume (compression) |
| Zdroj: | Practical Radiation Oncology. 9:115-122 |
| ISSN: | 1879-8500 |
| DOI: | 10.1016/j.prro.2018.11.001 |
| Popis: | Purpose Many authors suggest that extremity soft tissue sarcomas (ESTS) do not change significantly in size during preoperative radiation therapy (RT). This cone beam computed tomography study investigates the justification to deliver the entire course with 1 initial RT plan by observing anatomic changes during RT. Methods and Materials Between 2015 and 2017, 99 patients with ESTS were treated with either curative (n = 80) or palliative intent (n = 19) with a regimen of at least 6 fractions. The clinical target volume to planning target volume margin was 1 cm. Action levels were assigned by radiation technicians. An extremity contour change of >1 cm and/or tumor size change >0.5 cm required a physician's action before the next fraction. Results A total of 982 cone beam computed tomography logfiles were studied. In 41 of 99 patients, the dose coverage of the initial treatment plan was fully satisfactory throughout the RT course. However, action levels were observed in 58 patients (59%). In 41 of these 58 patients, a contour increase of 5 to 23 mm was noted (29 tumor size increase only, 3 extremity contour increase, and 9 both). In 21 of 58 patients, a decrease of 5 to 33 mm was observed (20 tumor size decrease only and 1 tumor size decrease and extremity contour decrease). In 4 cases, contours initially increased and subsequently decreased. In 33 of 41 patients with increasing contours, the dose distribution adequately covered gross tumor volume because of the 1 cm planning target volume margin applied. For the remaining 8 patients (8%), the plan needed to be adapted. Conclusions ESTS volumes may change substantially during RT in 59% of all patients, leading to plan adaptations resulting from increased volumes in 8%. Daily critical observation of these patients is mandatory to avoid geographic misses because of increases in size and overdosing of normal tissues when masses shrink. |
| Databáze: | OpenAIRE |
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