2740 - Real-World Efficiency and Pain Outcomes of VMAT for Palliative Radiotherapy of Bone Metastases
Presenter(s)
A. Gonzalez1,2, J. I. Linares-Vasquez3, Y. V. Sierra1, V. Ávila-Rodríguez2, L. Gutiérrez-Babativa4, J. Leon5, D. M. Cuevas1, A. P. Rodríguez1, and I. Bobadilla1,2; 1Radiotherapy Functional Unit, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center–CTIC, Bogota, Colombia, 2GIGA/TERA Research Group (CTIC/Universidad El Bosque), Bogota, Colombia, 3Radiation Oncology Resident, Department of Radiation Oncology, Hospital Universitario San Ignacio, Pontificia Universidad Javeriana, Bogota, Colombia, 4Institute for Research, Science and Education, GIGA research group, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center (CTIC), Bogotá, Colombia, 5Internal Medicine, Luis Carlos Sarmiento Angulo Cancer Treatment and Research Center – CTIC, Bogota, Colombia
Purpose/Objective(s):
In resource-constrained radiotherapy environments, palliative treatments must be efficient and safe for patients who often live months and continue systemic therapy. We evaluated real-world delivery efficiency and symptom outcomes of volumetric modulated arc therapy (VMAT) for palliative radiotherapy (RT) of bone metastases.Materials/Methods:
Retrospective cohort of consecutive VMAT courses for bone metastases treated in 2022-2025. Outcomes: pain control after RT and at 12 weeks (per chart), patient-reported percent pain reduction, grade >=3 toxicity, treatment completion, re-irradiation to the same site, and vital status at 90 days (as recorded). Efficiency metrics: recorded treatment delivery time and number of fields/arcs. Data are summarized using descriptive statistics; continuous variables are reported as median (IQR), and categorical variables are reported as frequencies.Results:
Fifty-four RT courses in 41 patients were included (median age 64.5 years; 56% female). Primary cancers were breast (54%), prostate (44%), and lung (2%). Treated sites were spine (57%), pelvis (22%), extremities (9%), rib cage (9%), and skull (2%); spinal cord compression was present in 12/54 (22%). Prescriptions were 20 Gy/5 (76%), 30 Gy/10 (13%), 25 Gy/5 (7%), and other (4%). Treatment completion was 52/54 (96%) and grade >=3 toxicity was recorded in 1/54 (2%). Pain was controlled after RT in 46/51 evaluable courses (90%); median reported pain reduction was 70% (IQR 50-90; n=53). At 12 weeks, pain control was achieved in 27/38 (71%) among evaluable courses. Subsequent chemotherapy after RT occurred in 41/54 (76%). Ninety-day vital status was alive in 36/52 (69%). Median recorded treatment time was 225 seconds (IQR 166-311; 70% <=300 seconds) and 43/54 (80%) plans used 2 fields/arcs (median 2). Results were similar in sensitivity analyses limited to first RT course per patient.Conclusion:
In real-world practice from an upper-middle-income Latin American setting, VMAT palliation for bone metastases achieved high rates of pain control with efficient delivery and rare recorded severe toxicity. Given meaningful 90-day survival and frequent subsequent chemotherapy, protocolized VMAT use may improve supportive-care value by minimizing treatment burden while maintaining symptom benefit.