Prophylactic cranial irradiation in patients with small cell lung cancer. A retrospective study of recurrence, survival and morbidity.

BACKGROUND

Prophylactic cerebral irradiation (PCI) is a standard treatment for all small cell lung cancer (SCLC) patients with response to chemotherapy. The aims of this study were: to evaluate patients undergoing PCI with regard to cerebral recurrence rate, site of recurrence, and overall survival (OS) and to investigate the influence of steroid dose on acute toxicity.

MATERIALS AND METHODS

From 2007 to 2010 a total of 118 consecutive patients underwent PCI (25 Gray in 10 fractions). In total, 114/118 received full PCI dose, all 118 were included in the study. Data were analyzed retrospectively with regard to disease stage, treatment, date of PCI, steroid dose during PCI, toxicity, time to recurrence, site of recurrence and time of death. The median follow up time was 16.6 months (range 3-54 months).

RESULTS

Of the 118 patients undergoing PCI, 74 had limited disease (LD-SCLC) and 44 had extensive disease (ED-SCLC). The median age was 65 years (range 46-80 years). The median overall survival of all patients from the time of diagnosis was 16.0 months (CI 95% 13.0-19.0), in LD-SCLC it was 24.0 months (CI 95% 19.6-28.3), and in ED-SCLC it was 12.0 months (CI 95% 9.6-14.4). Twenty-one patients (17.8%) were diagnosed with cerebral recurrence. Five of these presented with metastatic disease within the limbic system. Of these five patients, four had miliary cerebral disease and one had non-oligometastatic disease. The time from PCI to cerebral recurrence ranged from 4 to 27 months. Prednisolone administration varied from 0 to 100 mg/day. Forty-eight patients were not treated with steroids, 64.6% of these patients reported acute toxicity. Of the 36 patients receiving 50 mg prednisolone, only 22.2% had side effects. The most common symptoms during PCI were nausea and headache.

CONCLUSIONS

Twenty-one patients out of 118 developed brain metastases after PCI: five of the twenty-one had metastases located in the limbic system. The study showed that prophylactic steroid use might reduce acute toxicity to PCI. Survival data and recurrence rates are comparable to other clinical studies.