Self-Reported Cognitive Function and Quality of Life in Patients With SCLC in the Hippocampal Avoidance Prophylactic Cranial Irradiation Versus Prophylactic Cranial Irradiation Randomized Phase 3 Trial (NCT01780675)

Introduction: In the randomized controlled trial in patients with SCLC comparing standard prophylactic cranial irradiation (PCI) with hippocampal avoidance PCI (HA-PCI), we did not observe beneficial effects of HA-PCI on tested cognition. Here, we report findings on self-reported cognitive functioning (SRCF) and quality of life (QoL). Methods: Patients with SCLC were randomized to receive PCI with or without HA (NCT01780675) and assessed at baseline (82 HA-PCI and 79 PCI patients) and at 4, 8, 12, 18, and 24 months of follow-up, using the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and EORTC QLQ- brain cancer module (BN20). SRCF was assessed with the cognitive functioning scale of the EORTC QLQ-C30 and the Medical Outcomes Study questionnaire. A change of 10 points was used for minimal clinically important differ-ences. Percentages of patients classified with having improved, stable, or deteriorated SRCF were compared between groups using chi-square tests. Changes in mean scores were analyzed using linear mixed models.Results: There was no significant difference in the percentage of patients with deteriorated, stable, or improved SRCF between the treatment arms. Depending on the evaluated time point, 31% to 46% and 29% to 43% of patients in the HA-PCI and PCI arm, respectively, reported a deteriorated SRCF on the basis of the EORTC QLQ-C30 and Medical Outcomes Study. QoL outcomes were not significantly different between the study arms, except for physical functioning at 12 months (p = 0.019) and motor dysfunction at 24 months (p = 0.020).Conclusions: Our trial did not find beneficial effects of HA-PCI over PCI on SRCF and QoL. The cognitive benefit of sparing the hippocampus in the context of PCI is still a subject of debate.(c) 2023 The Authors. Published by Elsevier Inc. on behalf of the International Association for the Study of Lung Cancer. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).