Incremental diagnostic value of SPECT/CT with 131I scintigraphy after radioiodine therapy in patients with well-differentiated thyroid carcinoma.

PURPOSE: To retrospectively determine the incremental diagnostic value of adding single photon emission computed tomography/computed tomography (SPECT/CT) to whole-body scintigraphy with iodine 131 ((131)I) compared with scintigraphy alone after radioiodine therapy in patients with well-differentiated thyroid carcinoma. MATERIALS AND METHODS: This retrospective study was institutional review board approved; written informed consent was waived. The study included 147 patients (94 female, 53 male patients; mean age, 51 years) with well-differentiated thyroid carcinoma treated with radioiodine therapy between October 2009 and August 2010. Whole-body scintigraphy and SPECT/CT were performed on the same day in all patients receiving radioiodine therapy. Each radioactive focus at whole-body scintigraphy was classified as positive or equivocal with respect to thyroid bed, lymph node, and distant metastasis uptake. Differences between whole-body scintigraphy and SPECT/CT findings were assessed with the generalized McNemar test. RESULTS: At SPECT/CT, origin was clearly determined of all five "hot spots" in the thyroid bed (remnant thyroid tissue or metastatic lymph node) that were judged as equivocal at whole-body scintigraphy. Interpretation of 24 (22.2%) of 108 radioactive foci for lymph node metastases was changed with SPECT/CT (P < .0001). One of 85 foci that were thought to be positive findings at whole-body scintigraphy turned out to be a negative finding (false-positive finding), and 13 and seven of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after adding SPECT/CT findings. Three false-negative findings at whole-body scintigraphy were corrected with SPECT/CT. For the detection of distant metastasis, the interpretations of 21 (40%) of 52 foci were corrected with SPECT/CT (P < .0001). One of 32 foci thought to be a positive finding at whole-body scintigraphy was a negative finding, and 11 and nine of 20 equivocal foci at whole-body scintigraphy were positive and negative findings, respectively, after SPECT/CT. At a patient-based analysis, SPECT/CT findings helped change the clinical staging in nine (6.1%) of 147 patients and therapeutic planning in three (2.0%) of 147 patients. CONCLUSION: SPECT/CT improved detection and localization of (131)I accumulation in lymph node metastases and distant metastases, compared with whole-body scintigraphy.

Clinical role of 123I-IMP SPECT for the differential diagnosis of ocular malignant melanoma: a time-course analysis.

OBJECTIVE: To evaluate the efficacy of (123)I-IMP single photon emission computed tomography (SPECT) for the diagnosis of ocular malignant melanoma (MM). METHODS: Thirty-eight patients (18 males, 20 females) clinically suspected of having ocular MM were retrospectively examined in this study. The age of patients ranged from 8 to 81 years (mean 55.6 years). Twelve patients were finally diagnosed as having ocular MM. Orbital SPECT images were taken 15 min, 4 h, 24 h and 48 h after intravenous injection of 111-222 MBq (3-6 mCi) (123)I-IMP. (123)I-IMP uptake in the orbital tumor was visually evaluated as-(negative),+/-(equivocal), or+(positive). The uptake index (UI) and increase ratios (IRs) were calculated. RESULTS: For visual evaluation, the accuracy of (123)I-IMP for the diagnosis of MM was 73.7% (15 min), 81.6% (4 h), 81.6% (24 h) and 86.8% (48 h). When UI and IR were calculated on both the MM and non-MM groups, the UI and IR of the MM group were significantly higher than those of the non-MM group (P<0.001). Moreover, the highest sensitivity (100%) and accuracy (94.7%) were obtained 48 h after (123)I-IMP administration when the cut-off value of UI was defined as 1.90. CONCLUSIONS: This study shows that (123)I-IMP SPECT is useful for the diagnosis of ocular MM. The UI values 48 h after the injection were efficient for the differentiation between MM and non-MM lesions.

SPECT evaluation of cerebral blood flow during arm exercise in patients with subclavian steal.

OBJECTIVES: To explore the cerebral hemodynamics in subclavian steal syndrome, we examined the cerebral perfusion of seven patients with subclavian steal (one symptomatic and six asymptomatic) using single-photon emission computed tomography (SPECT) during resting, arm exercise, and acetazolamide-activated conditions. METHODS: The regional CBF (rCBF) was measured with SPECT under all conditions, and region of interest (ROI) analysis was performed using a three-dimensional stereotaxic ROI template (3DSRT). We evaluated the relationship between arm exercise-induced rCBF change and (1) presence of subclavian artery stenosis, (2) vertebral reverse flow severity, (3) presence of vertebro-basilar insufficiency (VBI) symptoms, and (4) cerebrovascular reactivity (CVR) to acetazolamide. RESULTS: Overall, no arm exercise-induced rCBF reduction was observed on either the affected or the unaffected side, even in patients with severe vertebral reverse flow. One patient with VBI symptoms showed an arm exercise-induced global rCBF reduction in the cerebrum and cerebellum, whereas the other asymptomatic patients did not. The %rCBF changes in segments with severely impaired CVR (-8.6%+/-10.7%, mean+/-SD) were significantly lower than those in other segments with less impaired CVR (P<0.01). CONCLUSIONS: Our results suggest that subclavian steal is a benign condition in asymptomatic patients. On the other hand, arm exercise-induced rCBF reduction can occur in the cerebrum and cerebellum in patients with VBI symptoms possibly related to low CVR.

Pre-surgical identification of epileptogenic areas in temporal lobe epilepsy by 123I-iomazenil SPECT: a comparison with IMP SPECT and FDG PET.

OBJECTIVES: The aim of this study was to evaluate the usefulness of (123)I-iomazenil (IMZ) single photon emission computed tomography (SPECT) for the pre-surgical identification of epileptogenic areas in patients with temporal lobe epilepsy and to compare the results with those of (123)I-IMP SPECT and (18)Fluorodeoxyglucose positron emission tomography (FDG PET). METHODS: We examined seven patients with medically refractory temporal lobe epilepsy (five men and two women; mean age, 28 years) with no remarkable findings on magnetic resonance imaging. Before surgery, IMZ SPECT, IMP SPECT and FDG PET were all performed in the interictal state. Then, visual assessment and region-of-interest (ROI) analysis were performed on each image. Final definitions of the epileptogenic areas were made by electrocorticography and histopathology. RESULTS: By IMZ SPECT, a decreased IMZ uptake in the ipsilateral temporal lobe was found in all patients, while a similar decrease in the contralateral temporal lobe was also found in one patient. In comparison to IMP SPECT, the extent of the abnormal area on IMZ SPECT was equal to that on IMP SPECT in one patient while it was more restricted to the epileptogenic area in five patients. In comparison to FDG PET, the extent of the abnormal area on IMZ SPECT was equal to that on FDG PET in three patients while it was more restricted in the epileptogenic area in four patients. In ROI analysis, decreases of IMZ, IMP and FDG uptake were observed in the epileptogenic area, although they were not statistically significant. CONCLUSIONS: IMZ SPECT was considered to be useful for pre-surgical determination of the epileptogenic areas in temporal lobe epilepsy with no remarkable MRI findings, and it was also found to be superior to IMP SPECT and FDG PET for this purpose.

Factors associated with effects of 90Y-ibritumomab tiuxetan in patients with relapsed or refractory low-grade B cell non-Hodgkin lymphoma: single-institution experience with 94 Japanese patients in rituximab era.

This retrospective study analyzes the results of radioimmunotherapy (RIT) with (90)Y-ibritumomab tiuxetan in 94 Japanese patients with relapsed or refractory low-grade B cell non-Hodgkin lymphoma at a single institution. All patients had previously been administered with 1-8 (median 1) regimens of rituximab alone or combined with other chemotherapeutic regimens at a mean age of 64 years. The overall response rate was 90 % and the complete response (CR) rate was 69 %. The median overall survival was not reached and progression-free survival (PFS) was 26 months, respectively, for the early phase 50 patients during a median follow-up period of 46.5 months. In this cohort, the PFS rates for the 50 early phase patients who had undergone ≤2 and ≥3 previous regimens, and for those who achieved CR compared with those who did not (partial response, PR; stable disease, SD; progressive disease, PD) were 38 and 11 months, respectively. Multivariate analysis showed that these two factors were statistically significant (p = 0.0011 and p <0.0001, respectively). The overall incidence of grade ≥3 non-hematological toxicity was 9 %. Two patients died of treatment-related deteriorating hepatitis C. A second malignancy developed in two patients at 10.5 and 3.5 months after treatment. We recommend administering (90)Y-ibritumomab tiuxetan as early in the disease course as possible, and at the latest as a third-line therapy to maximize the benefits of RIT, which should improve the quality of life for patients.