Neurocognitive function in patients with small cell lung cancer : effect of prophylactic cranial irradiation.
BACKGROUND
The use of prophylactic cranial irradiation (PCI) in patients with small cell lung cancer (SCLC) has been tempered by fears of detrimental effects on cognitive function. Neuropsychologic testing was prospectively conducted before and after PCI to evaluate its effects on cognitive function in patients with SCLC.


METHODS
Ninety-six patients who completely or partially responded to initial therapy underwent formal neurocognitive testing before PCI. Three patients who had central nervous system metastasis were excluded. Of the remaining patients, 69 received PCI (mean dose, 25 grays [Gy] in 10 fractions). Repeat testing was performed on 37 patients (median follow-up, 23 months; range, 6-120 months).


RESULTS
Baseline impairment was defined as > or =1.5 standard deviations below the normative mean. Before undergoing PCI, 47% of patients had evidence of impaired cognitive function. After PCI, univariate analysis revealed significant transient declines in executive function (pre-PCI mean, 15.6 +/- 11.5; post-PCI, 27.1 +/- 17.6 [P = .008]) and language (pre-PCI mean, 33.8 +/- 9.9; post-PCI, 31.0 +/- 9.0 [P = .049]) at early timepoints. Controlling for noncentral nervous system disease progression the deficit in executive function was no longer significant. Moreover, these deficits were not sustained, and significant improvements in language and motor coordination were recorded. On multivariate analysis, no significant differences before and after PCI were found.


CONCLUSIONS
Neurocognitive testing demonstrated that a substantial portion of patients with SCLC had impaired brain functioning at baseline. Persistent declines in cognitive function were not observed after cranial irradiation. These data do not favor the omission of PCI on the basis of fears of neurotoxic effects.
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D018288:Carcinoma, Small Cell / Q000188:drug therapy / Q000523:psychology* / Q000532:radiotherapy; D002945:Cisplatin / Q000627:therapeutic use; D003071:Cognition / Q000528:radiation effects*; D003072:Cognition Disorders / Q000209:etiology; D003131:Combined Modality Therapy; D016371:Cranial Irradiation / Q000009:adverse effects / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D005047:Etoposide / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007069:Ifosfamide / Q000627:therapeutic use; D008175:Lung Neoplasms / Q000188:drug therapy / Q000523:psychology* / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D011597:Psychomotor Performance / Q000528:radiation effects; D013060:Speech / Q000528:radiation effects
D005047:Etoposide; D002945:Cisplatin; D007069:Ifosfamide