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Title: Comparison of dynamic thallium brain spect and MRI in the diagnosis of recurrent brain tumor from radiation necrosis

Journal Article · · Journal of Nuclear Medicine
OSTI ID:441600
; ;  [1]
  1. Univ. of Pennsylvania, Philadelphia, PA (United States); and others

Conventional anatomical imaging techniques such as CT or MRI have a limited role in the differentiation of tumor recurrence from necrosis in patients with brain tumors following therapy. Dynamic Thallium SPECT and MR studies were performed in 6 patients with brain tumor to determine their potential application in these patients. Following the IV injection of 3 mCi Tl-201, 12 dynamic SPECT frames, of 5 minutes duration each, were acquired in each patient using a triple head scanner (Prism 3000, Picker International). Delayed static SPECT images were also obtained 3 hours post-injection. Decay and attenuation corrected mean counts of the detectable lesion and contralateral normal brain were calculated from ROIs drawn on the dynamic and static SPECT studies. Standard unenhanced spin-echo and dynamic T-2 weighted spin echo images were performed during and after the administration of Sprodiamide (a new T2 nylomed MR contrast agent). Precontrast signal intensity, peak signed intensity, time to peak and transit time all represent an index of regional CBF were measured. Biopsy or clinical outcome was used to determine tumor activity. Four of the 6 patients were diagnosed as having recurrent and active tumor, whereas the other 2 showed no evidence of tumor activity. SPECT data obtained includes the slope of the fitted line joining the lesion mean counts for each of the 12 sequential 5-minute scans, tumor to normal mean count ratio at 1 and 3 hours as well as the comparison of the 3 hour to 1 hour ratios. Lesions with residual tumor show increasing activity with time by SPECT quantification whereas successfully treated lesions have decreasing Tl-201 uptake over a 1 hour series of lesions at 1 and 3 hours when compared to contralateral normal brain tissue. Less apparent differences are noted in the MRI groups comparing active tumor vs no tumor.

OSTI ID:
441600
Report Number(s):
CONF-950603-; ISSN 0161-5505; TRN: 96:002093-0025
Journal Information:
Journal of Nuclear Medicine, Vol. 36, Issue Suppl.5; Conference: 42. annual meeting of the Society of Nuclear Medicine, Minneapolis, MN (United States), 12-15 Jun 1995; Other Information: PBD: May 1995
Country of Publication:
United States
Language:
English