LINAC-based Stereotactic Radiotherapy for Acromegaly: A Single-center Retrospective Cohort.

BACKGROUND

Most results for stereotactic radiotherapy (SRT) for acromegaly patients come from Gamma-Knife series. We aim to describe outcomes for LINAC-based SRT, as well as compare results for single-dose (SRS) and fractionated (SFRT) treatments.

METHODS

Single-center retrospective cohort in a tertiary, academic hospital assessed between 2008 and 2024.

RESULTS

A total of 48 patients were assessed for outcomes of acromegaly after SRT. Most of them female (62.5%). Mean age was 42.5 years (range 12-73). Median lesion size was 2.1 cm (range 0.2 to 7.2 cm). Among previous deficits, previous hormonal deficits (31.3%) and visual deficits (45.8%) were common. Most patients were diagnosed with pure somatotrophic lesions (87.5%). SRS was done in 16 (33.3%) patients and 32 (66.7%) underwent SFRT. Concurrent octreotide long-acting release (Oct-LAR) (29/60.4%) and cabergoline (20/41.7%) were also common. Median follow-up was 85.3 months (8.2-187.9 months). Tumor control was achieved in 47 (97.9%). Mean progression-free survival (PFS) was 85.3 months (92.4 months for SRS and 81.7 months for SFRT, p  = 0.42). Univariate analysis showed no variable impacted overall survival (OS), PFS, new visual, or new hormonal disorders. Hormonal remission was achieved in 22 (45.8%) patients. Median time to hormonal disease control (THC) was 73.1 months for the entire cohort, and 45.8 months for SRS patients and 74.7 months for SFRT patients, with no difference between groups ([HR], 0.30; 95% CI, -1.14 to 0.53; p  = 0.47).

CONCLUSION

We described acromegaly patients treated with LINAC SRS and with the current criteria for hormonal cure. THC was longer for SFRT patients, with no statistical differences. Concurrent treatment did not impact outcomes.