Stereotactic body radiation therapy as palliative management for incurable thoracic malignancies.

Abstract

e24097 Background: Radiation therapy plays an important role in symptom palliation for patients with incurable cancer. Currently limited data exists regarding the role of SBRT vs conformal radiation for the palliation of symptoms due to malignancy. We report the symptom management and local control of palliative SBRT for incurable thoracic malignancies at a single institution. Methods: We retrospectively identified patients who underwent palliative SBRT between Jan 1st, 2009 and March 26th, 2019. Patients all had thoracic tumors that were not candidates for curative radiation due to age, stage, comorbidity, and/or prior treatment. We identified courses with total doses between 25-50 Gy (median 40) and total fractions between 3-10 (median 5). Symptoms such as cough, chest pain, hemoptysis, and shortness of breath were assessed at time of consult and first follow-up between 1-6 months post treatment. We also reviewed follow-up CT imaging to evaluate for local control using RECIST criteria. Descriptive statistics were used to evaluate patients’ clinicopathologic data and symptom palliation. Local control was analyzed via Kaplan-Meier method. Results: Of the 76 patients who completed palliative SBRT to 92 total lung lesions, 45 patients reported symptoms at consult and completed 50 courses of radiation to 55 lesions. Within this symptomatic cohort, average age was 71 (range, 42-93), 32 were female (58%), and most were stage IV (n = 42, 76%). Most lesions treated were non-small cell lung cancer (n = 34, 62%) while the most common primary site of metastatic lesions was colorectal (n = 6, 11%). Additional primary sites included breast, renal, sarcoma, and others (n = 15, 27%). Of the 53 lesions treated with follow-up within 6 months, 21 (40%) showed relief of at least 1 symptom and 31 (58%) showed stable symptoms. Only 1 patient (2%) showed symptom progression. All patients with hemoptysis at presentation achieved hemostasis following SBRT. Among 48 treated lesions with follow-up CT imaging, 1 (2%) showed complete response, 28 (58%) showed partial response (PR), 15 (31%) showed stable disease (SD), and 4 (8%) showed progressive disease. With further follow-up (median 23 months), 30 of the 53 lesions with initial PR or SD demonstrated local control until death. Conclusions: There is conflicting literature regarding the ideal palliative radiation dose for thoracic tumors. SBRT has the advantage of allowing a higher biologic dose without protracted treatment courses in the setting of palliation of symptoms. Our symptomatic cohort showed good symptom palliation and long-term local control of treated lesions. Prospective studies are required to further confirm the role of palliative SBRT for symptomatic thoracic tumors.