1. Clinical Outcomes of Stereotactic MR-Guided Adaptive Radiation Therapy for High-Risk Lung Tumors
- Author
-
Tobias Finazzi, Suresh Senan, Frank J. Lagerwaard, Berend J. Slotman, Marjan A. Admiraal, Miguel A. Palacios, C.J.A. Haasbeek, A. Bruynzeel, Femke O.B. Spoelstra, Radiation Oncology, and CCA - Cancer Treatment and quality of life
- Subjects
Adult ,Male ,Risk ,Cancer Research ,medicine.medical_specialty ,Lung Neoplasms ,SABR volatility model ,Radiosurgery ,Disease-Free Survival ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Lung cancer ,Aged ,Retrospective Studies ,Aged, 80 and over ,Radiation ,Lung ,medicine.diagnostic_test ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Interstitial lung disease ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Comorbidity ,Magnetic Resonance Imaging ,Confidence interval ,medicine.anatomical_structure ,Treatment Outcome ,Oncology ,030220 oncology & carcinogenesis ,Cohort ,Female ,Radiology ,Dose Fractionation, Radiation ,business ,Follow-Up Studies ,Radiotherapy, Image-Guided - Abstract
Purpose Magnetic resonance (MR)-guided SABR was performed for patients with lung tumors in whom treatment delivery was challenging owing to tumor location, motion, or pulmonary comorbidity. Because stereotactic MR-guided adaptive radiation therapy (SMART) is a novel approach, we studied clinical outcomes in these high-risk lung tumors. Methods and Materials Fifty consecutive patients (54 lung tumors) underwent SMART between 2016 and 2018 for either a primary lung cancer (29 patients) or for lung metastases (21 patients). Eligible patients had risk factors that could predispose them to toxicity, including a central tumor location (n = 30), previous thoracic radiation therapy (n = 17), and interstitial lung disease (n = 7). A daily 17-second breath-hold MR scan was acquired in treatment position, and on-table plan adaptation was performed using the anatomy of the day. Gated SABR was delivered during repeated breath-holds under continuous MR guidance. Results All but 1 patient completed the planned SMART schedule. With daily plan adaptation, a biologically effective dose ≥100 Gy to 95% of the planning target volume was delivered in 50 tumors (93%). Median follow-up was 21.7 months (95% confidence interval, 19.9-28.1). Local control and overall and disease-free survival rates at 12 months were 95.6%, 88.0%, and 63.6%, respectively. Local failures developed in 4 patients: in 2 after reirradiation for a recurrent lung cancer and in 2 patients with a colorectal metastasis. Overall rates of any grade ≥2 and ≥3 toxicity were 30% and 8%, respectively. Commonest toxicities were grade ≥2 radiation pneumonitis (12%) and chest wall pain (8%). No grade 4 or 5 toxicities were observed. Conclusions Use of MR-guided SABR resulted in low rates of high-grade toxicity and encouraging early local control in a cohort of high-risk lung tumors. Additional studies are needed to identify patients who are most likely to benefit from the SMART approach.
- Published
- 2019