Ultrarapid high-dose course of prophylactic cranial irradiation in small cell lung cancer.

Despite the reduction in the incidence of brain metastases following prophylactic cranial irradiation (PCI) in patients with small-cell lung cancer (SCLC), the use of this modality is still controversial due to the lack of improvement in survival and the appearance of neurotoxicity in long-term survivors. Moreover, the optimum dose, fraction size, and timing are not known. From 1980 to 1988, 70 patients with limited stage SCLC underwent PCI after or during multimodality treatment of their primary tumor. Most of these patients (75.7%) received an unconventional ultrarapid high-dose course of 17 Gy in two fractions over 3 days. Long-term (range 60-138 months) survivors (n = 16) were invited to have a complete neurological evaluation including computed cranial tomography (CCT), 99mTc-HMPAO single photon emission computerized tomography (SPECT) scan, electroencephalography (EEG), magnetic resonance imaging (MRI), and neuropsychometry. Delayed neurologic complications or psychometric impairment was observed in 46% of patients. One or more abnormalities were detected by CCT in all patients, and the presence of neurologic complications seemed to correlate with periventricular and subcortical white matter changes. A strong correlation was found between CCT and SPECT periventricular white matter changes. Although the incidence of late neurologic toxicity following this rapid course of irradiation was high, clinical findings were less severe than expected, and all the patients were capable of self-care.