Hippocampal avoidance prophylactic cranial irradiation in small cell lung carcinoma

Abstract

Purpose/Objective(s) Prophylactic Cranial Irradiation (PCI) is the standard of care for patients with limited-stage small cell lung carcinoma (LS-SCLC) or for those patients with extensive-stage small cell lung carcinoma (ES-SCLC), who have experienced complete response in extrathoracic sites. PCI may be associated with neurocognitive decline in up to 40 % of patients, which could be mitigated by the use of hippocampal avoidance PCI (HA-PCI). Hippocampal avoidance is currently being investigated as a means of neurocognitive function preservation, following investigation in patients with non–small cell lung carcinoma, in RTOG 0933. We outline our clinical experience with HA-PCI in a patient with LS-SCLC. Materials/Methods A 55-year-old female was diagnosed with a left hilar mass; LS-SCLC was diagnosed on EBUS of a hilar node. The patient underwent treatment with concurrent chemoradiation (Cisplatin, Etoposide q 3 weekly) with concurrent thoracic irradiation using a volumetric arc technique (VMAT) to a total dose of 50 Gy / 25 fractions / 5 weeks. The patient had a complete radiological response and was planned for prophylactic cranial irradiation to a dose of 25 Gy / 10 fractions. The patient was unwilling to undergo conventional PCI due to concerns about the potential impact of neurocognitive decline on her quality of life. Following an informed consent discussion, the patient was offered HA-PCI using VMAT to a total dose of 25 Gy / 10 fractions. Results The patient underwent HA-PCI prescribed to 25 Gy /10 fractions with maximum doses to the left and right hippocampus of 10.05 Gy and 9.98 Gy, respectively. The patient has not experienced any neurocognitive decline as measured by and has had no evidence of in-brain relapse at 9 months post-completion of treatment. Conclusion HA-PCI is safe and feasible using a VMAT technique and in our case, has resulted in durable in-brain control and an absence of neurocognitive decline. This approach may be of benefit for all patients with SCLC undergoing PCI in the future.