Nationwide shift in patterns of prophylactic cranial irradiation utilization for extensive-stage small cell lung cancer patients.

e20099 Background: A recent phase III trial (Takahashi et al., 2017) showed no overall survival (OS) benefit in patients with extensive-stage small cell lung cancer (ES-SCLC) treated with prophylactic cranial irradiation (PCI), casting doubt on the practice of PCI as established in a prior phase III trial (Slotman et al., 2007). We undertook a nationwide survey of radiation oncologists to ascertain the impact of the Takahashi trial on the utilization of PCI for ES-SCLC patients. Methods: A total of 3,646 ASTRO-registered radiation oncologists in the United States were invited to answer an anonymous survey on their use of PCI in ES-SCLC, and the impact of the recent Takahashi et al. trial on their practice. The survey consisted of 35 questions created using a branching logic system via RedCAP. Results: A total of 438 (12%) radiation oncologists completed the survey. Responders were well-distributed across geographic regions, practice environment, age, gender, practice size and lung cancer volume. Most respondents (92%) were aware of the Takahashi trial. While 71% routinely offered PCI to ES-SCLC patients prior to the publication of this trial, only 43% continue to do so after its publication (p < 0.001). Most respondents (66%) had altered their practice in response to the study. There was no difference in post-publication practice patterns between academic and private practice radiation oncologists (43% vs. 44%, p = 0.81). While 43% of participants who were aware of the Takahashi trial still offered PCI after its publication, 82% of those unaware of the trial still continued to offer PCI (p < 0.001). Additionally, 25% of participants noted that they have experienced a decrease in medical oncology referrals for PCI for ES-SCLC patients. Twenty-two percent of participants stated that the Takahashi trial impacted their practice with regards to limited-stage SCLC patients as well. Looking toward the future, 47% of respondents reported that they would be willing to enroll both LS- and ES-SCLC patients on a randomized trial comparing active MRI-surveillance to PCI; 15% stated that they would enroll only LS-SCLC patients on such a trial, and 20% would enroll only ES-SCLC patients. Conclusions: The phase III data from Takahashi et al. (2017) has markedly impacted the current practice patterns in the US by reducing PCI utilization for ES-SCLC patients across all practice settings and measured demographic variables. Most respondents expressed openness to a randomized trial comparing active MRI surveillance to PCI for SCLC patients.