[The study of 201Tl, 123I-IMP-SPECT before and after radiation therapy of brain tumor].

201Tl, 123I-IMP-SPECT were performed in 17 patients with brain tumors before and after radiation therapy, compared with X-CT. 15 of 17 patients showed enhanced areas on X-CT and higher accumulations on 201Tl-SPECT in the same lesions before radiation therapy. There was significant correlation between enhanced lesions on X-CT and lesions of higher accumulation on 201Tl-SPECT before and after radiation therapy. But, the patients with residual enhanced lesions on X-CT did not always show higher accumulation on 201Tl-SPECT after radiation therapy. And, 2 patients with radiation injury after radiation therapy for brain tumor did not show higher accumulation on 201Tl-SPECT, though one patient showed enhanced lesion on X-CT. 201Tl-SPECT was expected to evaluate viability of brain tumor. 123I-IMP-SPECT was useful to recognize the site of higher 201Tl accumulation and evaluate blood flow around brain tumor. It is concluded that 201Tl, 123I-IMP-SPECT is useful for the evaluation of treatment effect of brain tumor and for the differentiation of cerebral radiation injury from recurrent tumor.