OBJECT: The authors assessed the diagnostic value of 201Tl Cl single-photon emission computerized tomography (SPECT), performed after gamma knife surgery (GKS) for metastatic brain tumors in differentiating tumor recurrence from radiation injury. METHODS: Of 6503 metastatic brain tumors treated with GKS, 201Tl SPECT was required in 72 to differentiate between tumor recurrence and radiation injury. When the Tl index was greater than 5, the lesion was diagnosed as a tumor recurrence. When the index was < 3.0 it was called radiation injury. In cases with a Tl index between 3 and 5, 201Tl SPECT was repeated once per month until the Tl index was greater than 5 or less than 3. If the Tl index fluctuated between 3 and 5 for 2 months, the lesion was diagnosed as radiation injury. The final diagnosis was based on histological examination or clinical course. The sensitivity of the method was 91%; thus 201Tl SPECT is effective for differentiating between tumor recurrence and radiation injury in metastatic brain tumors treated with GKS. Caution is necessary, however, for the following reasons: 1) simple interinstitutional comparisons of Tl indices are not possible because measurement methods are institute specific; 2) steroid administration decreases the Tl index to a variable degree; and 3) a severe radiation injury lesion, as is often seen after repeated GKS or very high dose GKS, may have a Tl index greater than 5. CONCLUSIONS: Used with critical insight 201Tl Cl SPECT can be useful in distinguishing between tumor regrowth and radiation necrosis in patients with cerebral metastases.
OBJECT: The authors assessed the diagnostic value of 201Tl Cl single-photon emission computerized tomography (SPECT), performed after gamma knife surgery (GKS) for metastatic brain tumors in differentiating tumor recurrence from radiation injury. METHODS: Of 6503 metastatic brain tumors treated with GKS, 201Tl SPECT was required in 72 to differentiate between tumor recurrence and radiation injury. When the Tl index was greater than 5, the lesion was diagnosed as a tumor recurrence. When the index was < 3.0 it was called radiation injury. In cases with a Tl index between 3 and 5, 201Tl SPECT was repeated once per month until the Tl index was greater than 5 or less than 3. If the Tl index fluctuated between 3 and 5 for 2 months, the lesion was diagnosed as radiation injury. The final diagnosis was based on histological examination or clinical course. The sensitivity of the method was 91%; thus 201Tl SPECT is effective for differentiating between tumor recurrence and radiation injury in metastatic brain tumors treated with GKS. Caution is necessary, however, for the following reasons: 1) simple interinstitutional comparisons of Tl indices are not possible because measurement methods are institute specific; 2) steroid administration decreases the Tl index to a variable degree; and 3) a severe radiation injury lesion, as is often seen after repeated GKS or very high dose GKS, may have a Tl index greater than 5. CONCLUSIONS: Used with critical insight 201Tl Cl SPECT can be useful in distinguishing between tumor regrowth and radiation necrosis in patients with cerebral metastases.
Authors: G Lai; A Mahadevan; D Hackney; P C Warnke; F Nigim; E Kasper; E T Wong; B S Carter; C C Chen Journal: AJNR Am J Neuroradiol Date: 2015-10-01 Impact factor: 3.825
Authors: Abigail L Stockham; Manmeet Ahluwalia; Chandana A Reddy; John H Suh; Aryavarta Kumar; Michael A Vogelbaum; Gene H Barnett; Erin S Murphy; Samuel T Chao Journal: J Neurooncol Date: 2013-09-18 Impact factor: 4.130
Authors: Friso W A Hoefnagels; Frank J Lagerwaard; Esther Sanchez; Cornelis J A Haasbeek; Dirk L Knol; Ben J Slotman; W Peter Vandertop Journal: J Neurol Date: 2009-03-10 Impact factor: 4.849