The purpose of this retrospective monocentric review was to evaluate the different techniques of stereotactic radiosurgery in the management of brain tumors from renal cell carcinoma (RCC).
From 2005 to 2015, 120 patients, with a total of 398 brain metastasis of RCC, were treated at least by stereotactic radiosurgery. Median age was 58 years (31–82). Median Karnofski performance status was 90 (50-100). One hundred ten tumors (92%) were clear cell carcinoma. Ninety-nine patients (82.5%) have undergone nephrectomy. The median time between the diagnosis of RCC and the first brain metastasis was 24 months (0-252).
The median number of tumors per patient was 2 (1-46). The median diameter of the tumors was 13 mm (1-60). For the 120 patients, 222 procedures of treatment were recorded and 187 stereotactic irradiations were reviewed. Sixty-one patients (226 metastasis) were treated by Gamma Knife Surgery (GKS) and received a median dose on the 50% prescription isodose of 18 Gy (14-22). The minimal and maximal median dose was respectively 18.4 Gy (12.5-40.1) and 36 Gy (23.3-51.2). Sixty-three patients (136 metastasis) were treated by linear accelerator (photon 10 MV). The minimal (isodose 70%) and maximal (isocentre) median dose were respectively 16 Gy (9.8-25.8) and 20.3 Gy (15.3-33.74). The median disease-free survival time is 5.5 months (0-252). The median survival time between the first brain metastasis diagnosis and death is 13.5 months (0.5-147). The tumor growth control rates at 3, 6, 12 months are respectively 86%, 62%, 36%. Following the 187 stereotactic irradiations, 95 (51%) cerebral disease progressions are recorded, after a median time of 5 months (1-81); 81 progressions (85%) are due to new lesions and 25 (26%) due to local failures. Analyses of prognostic factors related to survival are still in progress.
Stereotactic radiosurgery is associated with a high local control of brain metastasis from RCC without whole brain radiotherapy. The two described modalities present different characteristics whose advantages will be further discussed with the assessment of prognostic and predictive factors of local control.
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Assistance Publique des Hôpitaux de Paris (APHP)
All authors have declared no conflicts of interest.