Role of 99mTc-pentavalent dimercaptosuccinic acid brain single-photon emission computed tomography/computed tomography in evaluating treated adult glioma in the era of isocitrate dehydrogenase mutation status

PURPOSE: To evaluate the utility of 99m Tc-pentavalent dimercaptosuccinic acid (DMSA-V) brain single-photon emission computed tomography/computed tomography (SPECT/CT) in treated adult glioma with respect to isocitrate dehydrogenase (IDH) mutation status. METHODS: This prospective study included pathologically proven glioma patients. Early and delayed SPECT/CT images were obtained following intravenous administration of 797.90 ± 61.77 MBq 99m Tc DMSA-V. Both qualitative and quantitative analyses were carried out. The reference standard was established by follow-up MRI, histopathology, and clinical evaluation to verify SPECT/CT findings. The predictive value of IDH mutation status was assessed. RESULTS: Our study recruited 39 patients (24 males and 15 females; mean age: 40.41 ± 14.48 years). Residual/recurrent disease was confirmed in 23 cases, whereas 16 cases were disease free. 99m Tc DMSA-V SPECT/CT revealed a specificity of 100% and a sensitivity of 73.9% in identifying residual/recurrent gliomas. IDH was mutant in 22 (56.4%) and wild in 17 (43.6%) patients. Early, delayed lesion/non-lesion ratios, and retention index were significant predictors of the true disease status in the patients with mutated IDH; the area under the curves were 0.793 [95% confidence interval (CI): 0.566-1], 0.826 (95% CI: 0.648-1), and 0.826 (95% CI: 0.648-1), respectively. Eleven patients died after a mean follow-up of 10.82 months; eight patients with positive scan and wild-type IDH vs. three with negative scan and mutant IDH ( P = 0.033). The median survival was 14 months for the first group and was not reached for the second. CONCLUSION: 99m Tc DMSA-V brain SPECT/CT is a reliable, noninvasive, and specific modality for posttherapy evaluation of glioma. It has significant diagnostic and prognostic values in the mutant IDH glioma.