Usefulness of Thallium-201 Single Photon Emission Computed Tomography to Quantify the Malignancy Grade of Brain Tumors

• Published in: Neurologia medico-chirurgica Vol. 36; no. 7; pp. 434 - 439
• Main Authors: IGASE, Keiji, OKA, Yoshihisa, OHTA, Shinsuke, MURAKAMI, Yoshikazu, KUMON, Yoshiaki, SAKAKI, Saburo
• Format: Journal Article
• Language: English
• Published: Japan The Japan Neurosurgical Society 1996; THE JAPAN NEUROSURGICAL SOCIETY
• Subjects: Adult; Astrocytoma - diagnostic imaging; benign brain tumor; Brain - diagnostic imaging; Brain Neoplasms - diagnostic imaging; high grade astrocytoma; Humans; low grade astrocytoma; Male; metastatic brain tumor; Middle Aged; Neoplasm Metastasis - diagnostic imaging; Severity of Illness Index; single photon emission computed tomography; Thallium Radioisotopes; thallium-201; Tomography, Emission-Computed, Single-Photon
• ISSN: 0470-8105; 1349-8029
• DOI: 10.2176/nmc.36.434

Preoperative thallium-201 (201Tl) single photon emission computed tomography (SPECT) was used to evaluate the histological malignancy in 24 patients with brain tumors. A corrected L/E ratio was calculated based on the ratio of thallium uptake in the tumor on early images versus the tumor in the delayed images (L/E ratio) corrected for thallium uptake in the contralateral cerebral hemisphere. The corrected L/E ratio in benign brain tumors was 0.79 ± 0.23, significantly different to 1.32 ± 0.25 in high grade astrocytomas (p < 0.01) and 1.19 ± 0.05 in metastatic brain tumors (p < 0.01), respectively. The corrected L/E ratio in low grade astrocytomas was 0.64 ± 0.32, significantly lower than that in high grade astrocytomas (p < 0.01) and metastatic brain tumors (p < 0.05). There was one false positive result among 24 patients using a threshold of 1.0 to separate malignant and benign tumors. 201Tl SPECT using the corrected L/E ratio is effective for determining the malignant viability of tumors.