PROPHYLACTIC CRANIAL IRRADIATION IN LIMITED-STAGE SMALL-CELL LUNG-CANCER

Background. The role of prophylactic cranial irradiation (PCI) for pat ients with limited-stage small cell lung cancer (LSSCLC) remains a con troversial issue. This study evaluated PCI in patients with LSSCLC who achieved a complete response to initial chemotherapy. Methods. A retr ospective case study of all nonprotocol patients with LSSCLC examined at our institution from 1982 to 1990 was performed. Of the 67 nonproto col patients who were treated with combination chemotherapy (cyclophos phamide-based) and thoracic radiotherapy during those years, 43 achiev ed a complete response. Twenty-four patients received prophylactic cra nial irradiation (PCI+) (25-36 Gy in 10-16 fractions), and 19 did not (PCI-) at the physician's or patient's discretion. Results. The distri bution of prognostic factors between the PCI+ and PCI- groups was well balanced. Of the PCI- patients, the 2-year actuarial freedom from rel apse in the central nervous system was 93% versus 47% for the PCI- pat ients (log rank analysis, P = 0.001). An initial central nervous syste m relapse developed in 2 of the 24 PCI+ patients as the only site of f ailure versus 7 of 19 PCI- patients (P = 0.003). The 2-year actuarial overall survival was 50% for the PCI+ patients versus 21% for the PCI- patients (P = 0.01). The addition of prophylactic cranial irradiation was the only significant factor contributing to an improvement in tim e to central nervous system relapse and survival for the PCI+ patients . There were five patients alive at the time of this report, and all r eceived prophylactic cranial irradiation. None had cognitive or neurol ogic impairment. Conclusions. Prophylactic cranial irradiation may con tribute to improved survival in patients with LSSCLC who achieve a com plete response after chemotherapy and thoracic radiation therapy.