ESTRO 2023 - Abstract Book

S342

Sunday 14 May 2023

ESTRO 2023

Results Thirty two patients enrolled on the trial of which 4, 12, 8 and 8 were in the 10 Gy, 12 Gy, 14 Gy and 16 Gy cord Dmax cohorts, respectively. The most common histology was renal cell carcinoma (n=12). The most common GTV prescription dose was 18 Gy (n=17) followed by 24 Gy (n=15). The median age was 62.7 yrs (range 35-81 yrs). At baseline, there were 10 sites with MESCC Grade 1B, 10 sites with Grade 1C, 9 sites with Grade 2, 2 sites with Grade 1A, and 1 site with Grade 3 disease. Of the 32 patients treated with SSRS, 4 were lost to follow-up without post-SSRS evaluation. Of the remaining 28 patients, the median overall survival was 32.3 months (range 5.8-122.6 mo). The 1-year and 5-year LC was 84.5% and 79.5%, respectively, while the median LC was not met The 2-year LC did not statistically differ between the 14-16 Gy cord Dmax combined cohorts and the 10-12 Gy cord Dmax combined cohorts (92.9% vs. 62.9%, p=0.15)(Figure 2). With a median clinical follow-up of 22.7 months (range 3-122.3 mo), there were no cases of RM including in the 13 patients who survived at least 3 years. In the cohort receiving a cord Dmax of 16 Gy, there were no cases of RM with a median follow-up of 18.6 mo (range 9.0-97.1 mo).

Conclusion With long-term follow-up, these data demonstrate that SSRS is a safe and effective tool in patients with MESCC. Cord constraint relaxation may be considered in inoperable patients with MESCC. OC-0441 Pre-operative stereotactic radiosurgery for brain metastases: a prospective observational study R. Chelvarajah 1 , M. Pinkham 1 , M. Foote 1 , M. Shanker 1 , B. Hall 2 , S. Olson 2 , T. Watkins 3 , A. Bernard 4 , M. Huo 1 1 Princess Alexandra Hospital, Radiation Oncology, Brisbane, Australia; 2 Princess Alexandra Hospital, Neurosurgery, Brisbane, Australia; 3 Princess Alexandra Hospital, Radiology, Brisbane, Australia; 4 Queensland Cyber Infrastructure Foundation Ltd, QCIF Facility for Advanced Bioinformatics, Brisbane, Australia

Purpose or Objective