Life-threatening hemoptysis in patients with metastatic kidney cancer.

Hemoptysis is a complication of intrathoracic tumors, both primary and metastatic, and the risk may be increased by procedural interventions as well as Stereotactic Ablative Radiation (SAbR). The risk of hemoptysis with SAbR for lung cancer is well characterized, but there is a paucity of data about intrathoracic metastases. Here, we sought to evaluate the incidence of life-threatening/fatal hemoptysis (LTH) in patients with renal cell carcinoma (RCC) chest metastases with a focus on SAbR. We systematically evaluated patients with RCC at UT Southwestern Medical Center (UTSW) Kidney Cancer Program (KCP) from July 2005 to March 2020. We queried Kidney Cancer Explorer (KCE), a data portal with clinical, pathological, and experimental genomic data. Patients were included in the study based on mention of "hemoptysis" in clinical documentation, if they had a previous bronchoscopy, or had undergone SAbR to any site within the chest. Two hundred and thirty four patients met query criteria and their records were individually reviewed. We identified 10 patients who developed LTH. Of these, 4 had LTH as an immediate procedural complication whilst the remaining 6 had prior SAbR to ultra-central (UC; abutting the central bronchial tree) metastases. These 6 patients had a total of 10 lung lesions irradiated (UC, 8; central 1, peripheral 1), with a median total cumulative SAbR dose of 38 Gray (Gy/ lesion) (range: 25-50 Gy). Other risk factors included intrathoracic disease progression (n = 4, 67%), concurrent anticoagulant therapy (n = 1, 17%) and concurrent systemic therapy (n = 4, 67%). Median time to LTH from first SAbR was 26 months (range: 8-61 months). Considering that 130 patients received SAbR to a chest lesion during the study period, the overall incidence of LTH following SAbR was 4.6% (6/130). The patient population that received SAbR (n = 130) was at particularly high risk for complications, with 67 (52%) having two or more chest metastaes treated, and 29 (22%) receiving SAbR to three or more lesions. Overall, the risk of LTH following SAbR to a central or UC lesion was 10.5% (6/57). In conclusion, SAbR of RCC metastases located near the central bronchial tree may increase the risk of LTH.