Differentiation between recurrent brain tumour and post-radiation necrosis: the value of 201Tl SPET versus 18F-FDG PET using a dual-headed coincidence camera--a pilot study

Nucl Med Commun. 1999 May;20(5):411-7.


The aim of this study was to determine whether it is possible to differentiate between recurrent disease and post-treatment necrosis in patients treated for a primary brain tumour. This prospective study was designed to compare the sensitivity and specificity of 201Tl single photon emission tomography (SPET) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) using a dual-headed coincidence camera. Sixteen patients suspected of having recurrent brain tumour (10 men, 6 women) (mean age 39.5 years, range 21-57 years) were studied. 201Tl SPET and 18F-FDG PET studies were performed on the same day. An increase in activity was considered indicative of tumour recurrence. The images were also quantified using a thallium index and an FDG index. The 18F-FDG PET images were also assessed visually using a 5-point scale. The diagnosis of tumour recurrence was based on clinical course and/or follow-up computed tomography or magnetic resonance imaging. The sensitivity of 201Tl SPET and 18F-FDG PET was 92% (11/12) and 62% (7/12) respectively. One patient initially assessed as having necrosis showed a recurrence 9 months after both studies. McNemar's analysis of these results showed a statistically significant difference (P = 0.023) in the ability of the two methods to separate with accuracy tumour from radiation necrosis. No correlation was found between the thallium index and the FDG index (r = 0.36). We conclude that 201Tl SPET is a sensitive modality for the detection of brain tumour recurrence. 18F-FDG imaging using a dual-headed coincidence camera gave significantly poorer results compared to 201Tl SPET. Our results do not justify continuation of this prospective comparative study.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Astrocytoma / diagnostic imaging
  • Astrocytoma / pathology
  • Astrocytoma / radiotherapy
  • Astrocytoma / surgery
  • Brain / diagnostic imaging*
  • Brain / pathology
  • Brain Neoplasms / diagnostic imaging*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / radiotherapy*
  • Brain Neoplasms / surgery
  • Diagnosis, Differential
  • Female
  • Fluorodeoxyglucose F18*
  • Glioma / diagnostic imaging
  • Glioma / pathology
  • Glioma / radiotherapy
  • Glioma / surgery
  • Humans
  • Male
  • Middle Aged
  • Necrosis
  • Oligodendroglioma / diagnostic imaging
  • Oligodendroglioma / pathology
  • Oligodendroglioma / radiotherapy
  • Oligodendroglioma / surgery
  • Pilot Projects
  • Radiation Injuries / diagnostic imaging*
  • Radiography
  • Radiopharmaceuticals
  • Radiotherapy / adverse effects*
  • Recurrence
  • Thallium Radioisotopes*
  • Tomography, Emission-Computed
  • Tomography, Emission-Computed, Single-Photon


  • Radiopharmaceuticals
  • Thallium Radioisotopes
  • Fluorodeoxyglucose F18