Intraoperative radiotherapy for brain metastases: first-stage results of a single-arm, open-label, phase 2 trial.

OBJECTIVE: Focal stereotactic radiosurgery to the surgical cavity lowers local recurrence after resection of brain metastases (BM). To evaluate local control (LC) and brain disease control (BDC) after intraoperative radiotherapy (IORT) for resected BM. METHODS: Adult patients with completely resected single supratentorial BM were recruited and underwent IORT to the cavity with a prescribed dose of 18 Gy to 1 mm-depth. Primary endpoints were actuarial LC and BDC. Local failure (LF) and distant brain failure (DBF), with death as a competing risk, were estimated. Secondary endpoints were overall survival (OS) and incidence of radiation necrosis (RN). Simon's two-stage design was used and estimated an accrual of 10 patients for the first-stage analysis and a LC higher than 63% to proceed to second stage. We report the final analysis of the first stage. RESULTS: Between June 2019 to November 2020, 10 patients were accrued. Median clinical and imaging FU was 11.2 and 9.7 months, respectively. Median LC was not reached and median BDC was 5 months. The 6-month and 12-month LC was 87.5%. The 6-month and 12-month BDC was 39% and 13%, respectively. Incidence of LF at 6 and 12 months was 10% and of DBF at 6 and 12 months was 50% and 70%, respectively. Median OS was not reached. The 6-month and 12-month OS was 80%. One patient had asymptomatic RN. CONCLUSION: IORT for completely resected BM is associated with a potential high local control and low risk of RN, reaching the pre-specified criteria to proceed to second stage and warranting further studies.

Prognostic impact of platinum sensitivity in ovarian carcinoma patients with brain metastasis.

BACKGROUND: Brain metastasis (BM) is a rare event in ovarian cancer patients. The current prognostic scores that have been used for other tumors do not account for specific characteristics of ovarian cancer, such as platinum sensitivity. METHODS: This retrospective cohort study examined patients with ovarian carcinoma and BM who were treated at a single institution from January 2007 to December 2017. Clinical data on the diagnosis of BM and follow-up were collected. Cox regression was used to evaluate prognostic factors for overall survival (OS). RESULTS: Of 560 patients, 26 presented with BM. Eight patients were treated with surgery, 15 with whole-brain radiotherapy (RT), and 5 with stereotactic RT, and 4 patients received systemic treatment at the diagnosis of BM. The median OS was 10.8 months. The following factors were associated with OS: platinum-sensitive recurrence (HR 0.34, 95% CI 0.12-0.99; p = 0.049), higher number of previous treatment lines (HR 1.57, 95% CI 1.12-2.19; p = 0.008), ECOG performance status (HR 2.52, 95% CI 1.24-5.09; p = 0.010), and longer interval from initial diagnosis to BM (p = 0.025). Notably, the number of brain metastasis, the largest tumor size, and progression outside of the CNS were not related to survival. Platinum sensitivity was not associated with any of the classic prognostic factors in brain metastasis patients such as number or size of brain metastasis or disease progression outside the CNS strengthening the hypothesis of the importance of platinum sensitivity to the prognosis of ovarian cancer patients with BM. CONCLUSIONS: The factors related to the biological behavior of the ovarian cancer such as platinum sensitivity at the time of BM diagnosis, fewer number of previous treatment lines and interval from initial diagnosis were associated with survival in ovarian cancer patients with BM, while factors that are usually related to survival in BM in other cancers were not associated with survival in this cohort of ovarian cancer patients. The small number of patients did not allow us to exclude the prognostic role of these former factors that were not associated with survival in the present cohort.

Local control after radiosurgery for brain metastases: predictive factors and implications for clinical decision.

BACKGROUND: To evaluate the local control of brain metastases (BM) in patients treated with stereotactic radiosurgery (SRS), correlate the outcome with treatment parameters and lesion characteristics, and define its implications for clinical decisions. METHODS: Between 2007 and 2012, 305 BM in 141 consecutive patients were treated with SRS. After exclusions, 216 BM in 100 patients were analyzed. Doses were grouped as follows: ≤15 Gy, 16-20 Gy, and ≥21 Gy. Sizes were classified as ≤10 mm and >10 mm. Local control (LC) and overall survival (OS) were estimated using the Kaplan-Meier method. Log-rank statistics were used to identify the prognostic factors affecting LC and OS. For multivariate analyses, a Cox proportional model was applied including all potentially significant variables reached on univariate analyses. RESULTS: Median age was 54 years (18-80). Median radiological follow-up of the lesions was 7 months (1-66). Median LC and the LC at 1 year were 22.3 months and 69.7%, respectively. On univariate analysis, tumor size, SRS dose, and previous whole brain irradiation (WBRT) were significant factors for LC. Patients with lesions >10 and ≤10 mm had an LC at 1 year of 58.6% and 79.1%, respectively (p = 0.008). In lesions receiving ≤15 Gy, 16-20 Gy, and ≥21 Gy, the 1-year LC rates were 39.6%, 71.7%, and 92.3%, respectively (p < 0.001). When WBRT was done previously, LC at 1 year was 57.9% compared with 78.4% for those who did not undergo WBRT (p = 0.004). On multivariate analysis, dose remained the single most powerful prognostic factor for LC. Median OS for all patients was 17 months, with no difference among the groups. CONCLUSIONS: Dose is the most important predictive factor for LC of BM. Doses below 16 Gy correlated with poor LC. The SRS dose as salvage treatment after previous WBRT should not be reduced unless there is a pressing reason to do so.