Diagnostic value of posttherapy brain single photon emission computed tomography/computed tomography with pentavalent 99mTc dimercaptosuccinic acid in patients with glioblastoma multiform: preliminary report

Aim To evaluate the feasibility of performing 99mTc dimercaptosuccinic acid (DMSA) (V) brain single photon emission computed tomography/computed tomography (SPECT/CT) in patients with glioblastoma multiform after their definitive therapy. Patients and methods Patients with documented grade IV glioma were prospectively recruited for this study. 99mTc‑DMSA (V) brain SPECT/CT imaging was acquired after a mean interval of 76 ± 46 days from therapy, 2–3 h. After intravenous injection of 555–740 mBq of the tracer. Scans were interpreted visually as positive or negative by three nuclear medicine physicians. Agreement between two or more physicians was considered a consensus decision. The consensus results of DMSA (V) SPECT/CT were compared against the reference standard which was based on subsequent clinical/neuroimaging follow up or pathology whenever resurgery is performed. Lesion quantitation was performed by one nuclear medicine physician by drawing a region of interest on the lesion site (L) and a mirror region of interest on the contralateral normal brain tissue (NL) then L/NL ratio was calculated. Results A total of 20 patients were enrolled in this study. According to the reference standard, recurrence was detected in 10 patients while 10 were disease free. Interreader kappa agreement ranged from 0.65 to 0.90. Consensus reading of DMSA (V) SPECT/CT correctly detected recurrence in 8/10 (sensitivity 80%) and correctly ruled out disease in 9/10 (specificity 90%). L/NL ratio for positive and negative cases were 6.6 ± 8 and 1.3 ± 1.1, respectively (P 0.001). Conclusion 99mTc‑DMSA (V) brain SPECT/CT is feasible and may be a specific noninvasive diagnostic tool for the follow‑up of patients with glioblastoma multiform after chemoradiotherapy.