Radiosurgery consultation to treatment interval, additional brain metastases during the interim and outcomes after therapy

Background: Expediting the process of diagnosis and treatment should theoretically improve outcome. Delays in beginning therapy can cause anxiety to the patients and physicians who may be concerned about tumor progression before treatment is initiated. Treatment delays can be characterized as patient-generated or logistical medical infrastructure prolongations. Objective: The goal of the present study was to determine the impact of stereotactic radiosurgery (RS) consultation to treatment interval (CTI) and the development of additional brain metastases (BRM) during the interim on outcomes after RS. Methods: Between October 2014 and April 2018, 15 individuals developed more contrast-enhancing BRMs during the CTI. These patients were treated with gamma knife RS (including the six patients who underwent gross resection of metastatic intracranial neoplasm). The median duration of CTI was 19 days (range 5-61 days). A comparison of the ≤19 days CTI (eight patients) to the >19 days CTI (seven patients) was performed to assess the effects of the extent of delay to RS. The total number of BRM for RS was 68. The median target volume was 0.48 cm3, and the median margin dose was 24 Gy. Results: Most (67%) of the subjects exhibited good performance status. The overall crude survival rate at two years was 27%; acute or late toxicity after RS was not observed. Comparison of the CTI groups revealed: i) A longer CTI was not associated with a poorer prognosis; ii) BRM recurrence after RS was less common in this patient subgroup; iii) Quality of life (QOL) was satisfactory even though the CTI was prolonged. Conclusion: Acceptable longevity with minimal morbidity satisfying the QOL consideration was found in this audit of cases about CTI and the occurrence of more BRMs during the interim. Decreasing CTI in patients with BRM remains an important goal of quality improvement. Citation Format: Federico Ampil, Gloria Caldito, Troy Richards. Radiosurgery consultation to treatment interval, additional brain metastases during the interim and outcomes after therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4867.