Treatment of brain metastases in lung cancer: strategies to avoid/reduce late complications of whole brain radiation therapy.

OPINION STATEMENT: Brain metastases occur in 20-40 % of lung cancer patients. The use of whole brain radiation therapy (WBRT) has been shown to ameliorate many neurological symptoms, facilitate corticosteroid reduction, enhance quality of life (QOL), and prolong survival. The acute and early delayed side effects of WBRT are generally mild and inconsequential, whereas late complications often are progressive, irreversible, and may have a profound effect on neurocognitive function and QOL. Nevertheless, WBRT remains the cornerstone for treatment of multiple brain metastases due to its efficacy and the paucity of other treatment options. In avoidance of WBRT and its potential toxicity, patients of good performance status and ≤3 metastases may be treated reasonably with focal therapy alone (surgery or radiosurgery) without a compromise in survival. In patients with multiple brain metastases and those undergoing prophylactic cranial irradiation (PCI), established methods to mitigate the late complications of WBRT include total dose observation, dose per fraction restrictions, and avoidance of concomitant chemotherapy. Current areas of active research that hold great potential for benefit include hippocampal-sparing radiotherapy and the use of neuroprotective agents.

Stereotactic Radiotherapy and Short-course Pembrolizumab for Oligometastatic Renal Cell Carcinoma-The RAPPORT Trial.

BACKGROUND: Stereotactic ablative body radiotherapy (SABR) is an option for oligometastatic clear cell renal cell carcinoma (ccRCC) but is limited by a lack of prospective clinical trial data. OBJECTIVE: The RAPPORT trial evaluated the safety and efficacy of total metastatic irradiation followed by short-course anti-programmed death receptor-1 immunotherapy in patients with oligometastatic ccRCC. DESIGN SETTING, AND PARTICIPANTS: RAPPORT was a single-arm multi-institutional phase I/II trial (NCT02855203). Patients with two or fewer lines of prior systemic therapy and one to five oligometastases from ccRCC were eligible. INTERVENTION: A single fraction of 20 Gy SABR (or if not feasible, ten fractions of 3 Gy) was given to all metastatic sites, followed by pembrolizumab 200 mg administered Q3W for eight cycles. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The endpoints were adverse events (AEs), disease control rate (DCR) for at least 6 mo, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The Kaplan-Meier method was used for time-to-event endpoints. Freedom from local progression (FFLP) was assessed per lesion adding patient as a cluster effect. RESULTS AND LIMITATIONS: Thirty evaluable patients, with a median age of 62 yr, were enrolled. The median follow-up was 28 mo. There were 44% of patients with intermediate-risk and 56% with favorable-risk disease. Eighty-three oligometastases were irradiated (median three per patient): eight adrenal, 11 bone, 43 lung, 12 lymph node, and nine soft tissue. Four patients (13%) had grade 3 treatment-related AEs: pneumonitis (n = 2), dyspnea (n = 1), and elevated alkaline phosphatase/alanine transaminase (n = 1). There were no grade 4 or 5 AEs. FFLP at 2 yr was 92%. ORR was 63% and DCR was 83%. Estimated 1- and 2-yr OS was 90% and 74%, respectively, and PFS was 60% and 45%, respectively. Limitations include a single-arm design and selected patient population. CONCLUSIONS: SABR and short-course pembrolizumab in oligometastatic ccRCC is well tolerated, with excellent local control. Durable responses and encouraging PFS were observed, warranting further investigation. PATIENT SUMMARY: The RAPPORT trial investigated the combination of high-dose precision radiotherapy and a short course of immunotherapy in patients with low-volume metastatic kidney cancer. We found that this treatment regimen was well tolerated, with excellent cancer control in sites of known disease. A proportion of patients were free from cancer relapse in the longer term, and these encouraging findings warrant further investigation.