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OBJECTIVE: As novel therapies improve survival for men with prostate cancer, intracranial metastatic disease has become more common. The purpose of this multicenter study was to evaluate the safety and efficacy of stereotactic radiosurgery (SRS) in the management of intracranial prostate cancer metastases. METHODS: Demographic data, primary tumor characteristics, SRS treatment parameters, and clinical and imaging follow-up data of patients from nine institutions treated with SRS from July 2005 to June 2020 for cerebral metastases from prostate carcinoma were collected and analyzed. RESULTS: Forty-six patients were treated in 51 SRS procedures for 120 prostate cancer intracranial metastases. At SRS, the mean patient age was 68.04 ± 9.05 years, the mean time interval from prostate cancer diagnosis to SRS was 4.82 ± 4.89 years, and extracranial dissemination was noted in 34 (73.9%) patients. The median patient Karnofsky Performance Scale (KPS) score at SRS was 80, and neurological symptoms attributed to intracranial involvement were present prior to 39 (76%) SRS procedures. Single-fraction SRS was used in 49 procedures. Stereotactic radiotherapy using 6 Gy in five sessions was utilized in 2 procedures. The median margin dose was 18 (range 6-28) Gy, and the median tumor volume was 2.45 (range 0.04-45) ml. At a median radiological follow-up of 6 (range 0-156) months, local progression was seen with 14 lesions. The median survival following SRS was 15.18 months, and the 1-year overall intracranial progression-free survival was 44%. The KPS score at SRS was noted to be associated with improved overall (p = 0.02) and progression-free survival (p = 0.03). Age ≥ 65 years at SRS was associated with decreased overall survival (p = 0.04). There were no serious grade 3-5 toxicities noted. CONCLUSIONS: SRS appears to be a safe, well-tolerated, and effective management option for patients with prostate cancer intracranial metastases.
RESUMO
Background: Brain metastases (BM) from differentiated thyroid cancer are rare. Stereotactic radiosurgery (SRS) is commonly used for the treatment of BMs; however, the experience with SRS for thyroid cancer BMs remains limited. The goal of this international, multi-centered study was to evaluate the efficacy and safety of SRS for thyroid cancer BMs. Methods: From 10 institutions participating in the International Radiosurgery Research Foundation, we pooled patients with established papillary or follicular thyroid cancer diagnosis who underwent SRS for histologically confirmed or radiologically suspected BMs. We investigated patient overall survival (OS), local tumor control, and adverse radiation events (AREs). Results: We studied 42 (52% men) patients who underwent SRS for 122 papillary (83%) or follicular (17%) thyroid cancer BMs. The mean age at SRS was 59.86 ± 12.69 years. The mean latency from thyroid cancer diagnosis to SRS for BMs was 89.05 ± 105.49 months. The median number of BMs per patient was 2 (range: 1-10 BMs). The median SRS treatment volume was 0.79 cm3 (range: 0.003-38.18 cm3), and the median SRS prescription dose was 20 Gy (range: 8-24 Gy). The median survival after SRS for BMs was 14 months (range: 3-58 months). The OS was significantly shorter in patients harboring ≥2 BMs, when compared with patients with one BM (Log-rank = 5.452, p = 0.02). Two or more BMs (odds ratio [OR] = 3.688; confidence interval [CI]: 1.143-11.904; p = 0.03) and lower Karnofsky performance score at the time of SRS (OR = 0.807; CI: 0.689-0.945; p = 0.008) were associated with shorter OS. During post-SRS imaging follow-up of 25.21 ± 30.49 months, local failure (progression and/or radiation necrosis) of BMs treated with SRS was documented in five (4%) BMs at 7.2 ± 7.3 months after the SRS. At the last imaging follow-up, the majority of patients with available imaging data had stable intracranial disease (33%) or achieved complete (26%) or partial (24%) response. There were no clinical AREs. Post-SRS peritumoral T2/fluid attenuated inversion recovery signal hyperintensity was noted in 7% BMs. Conclusion: The SRS allows durable local control of papillary and follicular thyroid cancer BMs in the vast majority of patients. Higher number of BMs and worse functional status at the time of SRS are associated with shorter OS in patients with thyroid cancer BMs. The SRS is safe and is associated with a low risk of AREs.
