Patient selection for whole brain radiotherapy (WBRT) in a large lung cancer cohort: Impact of a new Dutch guideline on brain metastases

Background. Median survival after diagnosis of brain metastases is, depending on the Recursive Partitioning Analysis (RPA) classes, 7.1 (class I) to 2.3 months (class III). In 2011 the Dutch guideline on brain metastases was revised, advising to withhold whole brain radiotherapy (WBRT) in RPA class III. In this large retrospective study, we evaluated the guideline's use in daily practice. Material and methods. Data of 428 lung cancer patients undergoing WBRT for brain metastases (2004-2012) referred from three Dutch hospitals were retrospectively analyzed. Details on Karnofsky performance score (KPS), age, control of primary tumor, extracranial metastases, histology, and survival after diagnosis of brain metastases were collected. RPA class was determined using the first four items. Results. In total 327 patients had non-small cell lung cancer (NSCLC) and 101 small cell lung cancer (SCLC). For NSCLC, 6.1%, 71.9%, and 16.2% were classified as RPA I, II, and III, respectively, and 5.8% could not be classified. For SCLC this was 8.9%, 66.3%, 14.9%, and 9.9%, respectively. Before the revised guideline was implemented, 11.3-21.3% of WBRT patients were annually classified as RPA III. In the year thereafter, this was 13.0% (p = 0.646). Median survival (95% CI) for NSCLC RPA class I, II, and III was 11.4 (9.9-12.9), 4.0 (3.4-4.7), and 1.7 (1.3-2.0) months, respectively. For SCLC this was 7.9 (4.1-11.7), 4.7 (3.3-6.1), and 1.7 (1.5-1.8) months. Conclusions. Although it is advised to withhold WBRT in RPA class III patients, in daily practice 11.3-21.3% of WBRT-treated patients were classified as RPA III. The new guideline did not result in a decrease. Reasons for referral of RPA III patients despite a low KPS were not found. Despite WBRT, survival of RPA III patients remains poor and this poor outcome should be stressed in practice guidelines. Therefore, better awareness amongst physicians would prevent some patients from being treated unnecessarily.