title: Glioma residual or recurrence versus radiation necrosis: accuracy of pentavalent technetium-99m-dimercaptosuccinic acid [Tc-99m (V) DMSA] brain SPECT compared to proton magnetic resonance spectroscopy (1H-MRS): initial results.
abstract: We compared pentavalent technetium-99m dimercaptosuccinic acid (Tc-99m (V) DMSA) brain single photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy ((1)H-MRS) for the detection of residual or recurrent gliomas after surgery and radiotherapy. A total of 24 glioma patients, previously operated upon and treated with radiotherapy, were studied. SPECT was acquired 2-3 h post-administration of 555-740 MBq of Tc-99m (V) DMSA. Lesion to normal (L/N) delayed uptake ratio was calculated as: mean counts of tumor ROI (L)/mean counts of normal mirror symmetric ROI (N). (1)H-MRS was performed using a 1.5-T scanner equipped with a spectroscopy package. SPECT and (1)H-MRS results were compared with pathology or follow-up neuroimaging studies. SPECT and (1)H-MRS showed concordant residue or recurrence in 9/24 (37.5%) patients. Both were true negative in 6/24 (25%) patients. SPECT and (1)H-MRS disagreed in 9 recurrences [7/9 (77.8%) and 2/9 (22.2%) were true positive by SPECT and (1)H-MRS, respectively]. Sensitivity of SPECT and (1)H-MRS in detecting recurrence was 88.8 and 61.1% with accuracies of 91.6 and 70.8%, respectively. A positive association between the delayed L/N ratio and tumor grade was found; the higher the grade, the higher is the L/N ratio (r = 0.62, P = 0.001). Tc-99m (V) DMSA brain SPECT is more accurate compared to (1)H-MRS for the detection of tumor residual tissues or recurrence in glioma patients with previous radiotherapy. It allows early and non-invasive differentiation of residual tumor or recurrence from irradiation necrosis.
authors.affiliation: Nuclear Medicine Department, Faculty of Medicine, Cairo University, Cairo, Egypt. amramin67@gmail.com
authors.forename: Amr
authors.initials: A
authors.lastname: Amin
authors.forename: Hosna
authors.initials: H
authors.lastname: Moustafa
authors.forename: Ebaa
authors.initials: E
authors.lastname: Ahmed
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Toukhy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011522:Protons; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D055815:Young Adult
chemical_list: D011522:Protons; D001224:Aspartic Acid; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline