99mTc-MIBI and 201Tl SPET in the detection of recurrent brain tumours after radiation therapy

Abstract

The purpose of this study was to evaluate whether Tc-hexakis-2-methoxyisobutylisonitrile ( Tc-MIBI) or Tl single photon emission tomography (SPET) could detect recurrent tumours in patients with previous radiation therapy for brain tumours. Dual SPET with Tc-MIBI and Tl was performed in 21 patients suspected of having recurrent brain tumours. SPET images were acquired 15 min (early) and 2 h (delayed) after injection. The ratio of the average counts for the region of interest in the lesion area and its mirror image in normal brain tissue was obtained. Early and delayed ratios were calculated. On the basis of histological and/or clinical findings, the final diagnosis was considered as recurrent tumours in 15 patients and radiation necrosis in six. Both ratios using Tc-MIBI and Tl were significantly higher in recurrent tumours than in radiation necrosis. Based on a cut-off of 5.89 of the early ratio using Tc-MIBI to distinguish between recurrent tumours and radiation necrosis, the accuracy was 90%. Based on a cut-off of 6.77 of the delayed ratio using Tc-MIBI, the accuracy was 86%. The corresponding values using cut-offs of 2.40 and 1.85 with Tl were 90% and 86%, respectively. However, within recurrent tumours, both ratios for Tc-MIBI were significantly higher than those for Tl. Early Tc-MIBI SPET may be especially useful for the detection of recurrent tumours in patients who have previously undergone radiation therapy for brain tumours.

Evaluation of brain tumor recurrence by 99mTc-tetrofosmin SPECT: a prospective pilot study

“…Tc-TF SPECT and image analysis The radiopharmaceutical was prepared using a commercially available powder kit (Myoview, General Electric Healthcare, Buckinghamshire, UK) that was reconstituted with technetium-99m pertechnetate ( 99m TcO 4 + ) sterile solution in the Nuclear Medicine Department. Based on reports of no substantial difference in 99m Tc-TF brain SPECT between imaging at 20 min, 40 min, or 120 min postinjection [5], and on 99m Tc-sestamibi reports claiming that early imaging may be superior in detecting tumor recurrence [6], we performed SPECT 20-30 min after intravenous injection of 925 MBq (25 mCi) tracer activity.…”

Pseudoprogression, radionecrosis, inflammation or true tumor progression? challenges associated with glioblastoma response assessment in an evolving therapeutic landscape

“…For instance, 18 F-FET has been shown to have greater than 90% sensitivity and specificity in the diagnosis of pseudoprogression [49]; and 18 F-FDOPA has been shown to have a nearly 90% sensitivity and 72% specificity for the diagnosis of glioblastoma recurrence [50]. Similar to amino acid PET, SPECT imaging using a variety of radiolabeled 201 Tl, 99m Tc, or 123 I compounds has shown promise [51][52][53]. Proton MR spectroscopy (MRS) may also provide value in differentiating pseudoprogression from recurrent tumor by identifying specific metabolites within the tumor that are present during active tumor growth.…”

Delineation of Target Volume for Radiotherapy of High-Grade Gliomas by 99mTc-MIBI SPECT and MRI Fusion

“…In brain tumors, its accumulation is facilitated by disruption of the blood-brain barrier. The role of 99m Tc-MIBI SPECT in the diagnosis and follow-up of brain glioma was investigated during the last decade in several studies [1,5,18,19,28,34]. The results showed that 99m Tc-MIBI uptake correlates with histological grade and prognosis and can allow to distinguish tumor recurrence from posttreatment necrosis with a sensitivity of 73-88% and a specificity of 75-100% [18,20,22].…”

“…The interest in this compound is also related to the physical properties of 99 Tc, potentially better than those of other radioisotopes like 201 Tl, and to the wider availability and lower cost of SPECT compared to PET. Several studies investigated the use of 99m Tc-MIBI imaging for detecting the biological characteristics of brain tumors [1], distinguishing between tumor tissue and radiation-induced signal alteration [29,34], predicting the response to radiotherapy and chemotherapy, and the prognosis as well [5,28].…”