Secondary sentinel node biopsy after previous excision of the primary tumor in squamous cell carcinoma of the vulva.

BACKGROUND: To reduce morbidity of radical groin dissection, the sentinel-node (SLN) procedure was implemented for the treatment of vulvar cancer. It has been proven to be a safe alternative in early-stage disease. Feasibility and safety of the procedure after previous vulvar surgery remain unclear. METHODS: A total of 106 patients with primary vulvar cancer undergoing the SLN procedure were analyzed. Seventy-four patients received the SLN procedure concomitant to vulvar surgery [primary-sentinel group (PSG)], whereas 32 patients had vulvar surgery before secondary SLN [secondary-sentinel group (SSG)]. RESULTS: SLN detection was possible in all patients. Three (9.4 %) patients in the SSG and 30 (40.5 %) in the PSG had metastatic spread to the SLN and underwent radical groin dissection. Median interval between vulva surgery and secondary sentinel was 34 days (range, 7-98). In the SSG tumor, stages were earlier with smaller tumor size (median 19 mm in the PSG vs. 9 mm in the SSG) and lesser invasion depth (4 vs. 2 mm; p < 0.001). There were no groin recurrences in the SSG and 5.4 % in the PSG. No significant difference regarding disease-free survival (DFS) could be detected (3-year DFS of 72.5 % in the PSG compared with 92.5 % in the SSG (median DFS not reached, p = 0.114)). Adjusting for potential confounders (tumor stage, nodal status, tumor size, invasion depth) did not alter the results with regards to DFS. CONCLUSIONS: Our results suggest that a secondary SLN procedure after previous vulvar surgery is feasible and can accurately reflect the groin status of selected patients. Ideally, prospective trials should be conducted to verify accuracy and oncologic safety of the procedure.

18F-FDG PET/CT for detection and localization of residual or recurrent disease in patients with multiple myeloma after stem cell transplantation.

PURPOSE: The aim of the study was to determine the diagnostic performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for the detection and localization of residual or recurrent disease in patients with multiple myeloma (MM) after stem cell transplantation. METHODS: A total of 197 whole-body (18)F-FDG PET/CT scans were performed in 99 patients with MM at different time points in the course of disease after autologous or allogeneic stem cell transplantation. Post-transplant PET/CT scans and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were analysed and compared. RESULTS: A total of 576 focal osseous and extramedullary lesions were detected in 79 scans. Additional diffuse bone marrow involvement was detected in 17 patients. (18)F-FDG PET/CT had a sensitivity of 54.6%, a specificity of 82.1%, a positive predictive value of 82.3%, a negative predictive value of 54.2% and an overall accuracy of 65.5%. The sensitivity of (18)F-FDG PET/CT was shown to depend on the disease category according to the Uniform Response Criteria for myeloma. CONCLUSION: In patients with MM in the post-transplant setting, (18)F-FDG PET/CT may (1) contribute to the detection and localization of disease, (2) provide information about the extent of distinct myeloma manifestations and the total disease burden and (3) add information about the metabolic activity of disease, but (4) has substantially lower sensitivity for this purpose compared to the pretreatment setting.

Synchronous ileocecal neuroendocrine tumor and carotid chemodectoma: diagnosis by 111In pentetreotide SPECT/CT.

We report a case of carotid chemodectoma diagnosed by In pentetreotide SPECT/CT. A 72-year-old woman with an ileocecal neuroendocrine tumor underwent whole-body In pentetreotide scintigraphy for exclusion of distant metastases. Planar scintigraphy demonstrated marked tracer uptake in the ileocecal region and intense focal tracer accumulation within the neck. SPECT/CT demonstrated a space-occupying lesion at the carotid bifurcation. Histopathological evaluation revealed carotid chemodectoma. SPECT/CT is a valuable tool for the evaluation and precise anatomical localization of tracer uptake. In addition, other benign or malignant pathologies accumulating In pentetreotide may mimic neuroendocrine tumor metastases and should be considered particularly in unusual localizations.

Esophageal metastasis from papillary thyroid cancer: diagnosis by 131I SPECT/CT.

We report a case of esophageal metastasis from papillary thyroid cancer diagnosed by I SPECT/CT. A 70-year-old man presented with increasing thyroglobulin levels 13 years after thyroidectomy and ablation with I for thyroid cancer. The whole-body radioiodine scan demonstrated marked tracer uptake in the mediastinum, and SPECT/CT could clearly localize the activity to the esophagus. Subsequent surgical resection with histopathologic evaluation revealed an esophageal metastasis from papillary thyroid cancer. I SPECT/CT is a valuable tool for evaluation and precise anatomical localization of the foci of radionuclide activity in thyroid cancer, enabling adequate treatment.

Intraindividual comparison of 123I-mIBG SPECT/MRI, 123I-mIBG SPECT/CT, and MRI for the detection of adrenal pheochromocytoma in patients with elevated urine or plasma catecholamines.

PURPOSE: To determine the diagnostic performance of ¹²³I-metaiodobenzylguanidine (mIBG) SPECT/MRI fusion, ¹²³I-mIBG SPECT/CT and adrenal MRI for the detection of pheochromocytoma in patients with elevated urine or plasma catecholamines. PATIENTS AND METHODS: Twenty-two consecutive patients underwent both a whole-body ¹²³I-mIBG scan with SPECT/CT of the adrenal region and MRI of the adrenal glands. Fused SPECT/MRI, SPECT/CT, and MRI scans were evaluated. Imaging results were analyzed both on a per-patient and on a per-lesion basis. Histopathology and/or clinical and radiological follow-up served as the reference standard. RESULTS: Sixteen adrenal tumors were found in thirteen patients. On a per-lesion basis, SPECT/CT had a sensitivity of 87.5%, a specificity of 93.8%, and an overall accuracy of 92.5%. MRI had a sensitivity of 87.5%, a specificity of 96.9%, and an overall accuracy of 95.0%. On a per-patient basis, both SPECT/CT and MRI had a sensitivity of 85.7%, a specificity of 93.3%, and an overall accuracy of 90.9%. SPECT/CT was concordant with MRI in 81.8% of cases. SPECT/MRI fusion was superior to both SPECT/CT and MRI and had a sensitivity of 100% on both a per-lesion and a per-patient basis. CONCLUSIONS: ¹²³I-mIBG SPECT/MRI has the highest sensitivity and accuracy for the detection and localization of pheochromocytomas. SPECT/CT and MRI of the adrenal glands are equivalent diagnostic procedures. However, MRI offers the advantage of fully diagnostic assessment of adrenal lesions other than pheochromocytoma undetectable by ¹²³I-mIBG.

Correlation of inflammation assessed by 18F-FDG PET, active mineral deposition assessed by 18F-fluoride PET, and vascular calcification in atherosclerotic plaque: a dual-tracer PET/CT study.

UNLABELLED: Formation and progression of atherosclerotic plaque is a dynamic and complex process involving various pathophysiologic steps including inflammation and calcification. The purpose of this study was to compare macrophage activity as determined by (18)F-FDG PET and ongoing mineral deposition as measured by (18)F-sodium fluoride PET in atherosclerotic plaque and to correlate these findings with calcified plaque burden as assessed by CT. METHODS: Forty-five patients were examined by whole-body (18)F-FDG PET, (18)F-sodium fluoride PET, and CT. Tracer uptake in various arterial segments was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio [TBR]). The pattern of tracer uptake in atherosclerotic lesions was compared after color-coded multistudy image fusion of PET and CT studies. The Fisher exact test and the Spearman correlation coefficient r(s) were used for statistical analysis of image-based results and cardiovascular risk factors. Intra- and interrater reproducibility were evaluated using the Cohen κ. RESULTS: (18)F-sodium fluoride uptake was observed at 105 sites in 27 (60%) of the 45 study patients, and mean TBR was 2.3 ± 0.7. (18)F-FDG uptake was seen at 124 sites in 34 (75.6%) patients, and mean TBR was 1.5 ± 0.3. Calcified atherosclerotic lesions were observed at 503 sites in 34 (75.6%) patients. Eighty-one (77.1%) of the 105 lesions with marked (18)F-sodium fluoride uptake and only 18 (14.5%) of the 124 lesions with (18)F-FDG accumulation were colocalized with arterial calcification. Coincident uptake of both (18)F-sodium fluoride and (18)F-FDG was observed in only 14 (6.5%) of the 215 arterial lesions with radiotracer accumulation. CONCLUSION: PET/CT with (18)F-FDG and (18)F-sodium fluoride may allow evaluation of distinct pathophysiologic processes in atherosclerotic lesions and might provide information on the complex interactions involved in formation and progression of atherosclerotic plaque.

In vivo imaging of mineral deposition in carotid plaque using 18F-sodium fluoride PET/CT: correlation with atherogenic risk factors.

UNLABELLED: The purpose of this study was to correlate (18)F-sodium fluoride accumulation in the common carotid arteries of neurologically asymptomatic patients with cardiovascular risk factors and carotid calcified plaque burden. METHODS: Two hundred sixty-nine oncologic patients were examined by (18)F-sodium fluoride PET/CT. Tracer accumulation in the common carotid arteries was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio) and comparing it with cardiovascular risk factors and calcified plaque burden. RESULTS: (18)F-sodium fluoride uptake was observed at 141 sites in 94 (34.9%) patients. Radiotracer accumulation was colocalized with calcification in all atherosclerotic lesions. (18)F-sodium fluoride uptake was significantly associated with age (P < 0.0001), male sex (P < 0.0001), hypertension (P < 0.002), and hypercholesterolemia (P < 0.05). The presence of calcified plaque correlated significantly with these risk factors but also with diabetes (P < 0.0001), history of smoking (P = 0.03), and prior cardiovascular events (P < 0.01). There was a highly significant correlation between the presence of (18)F-sodium fluoride uptake and number of present cardiovascular risk factors (r = 0.30, P < 0.0001). CONCLUSION: Carotid (18)F-sodium fluoride uptake is a surrogate measure of calcifying carotid plaque, correlates with cardiovascular risk factors, and is more frequent in patients with a high-risk profile for atherothrombotic events but demonstrates a weaker correlation with risk factors than does calcified plaque burden. This study provides a rationale to conduct further prospective studies to determine whether (18)F-sodium fluoride uptake can predict vascular events, or if it may be used to monitor pharmacologic therapy.

Feasibility of 11C-acetate PET/CT for imaging of fatty acid synthesis in the atherosclerotic vessel wall.

UNLABELLED: Fatty acids are a common constituent of atherosclerotic plaque and may be synthesized in the plaque itself. Fatty acid synthesis requires acetyl-coenzyme-A (CoA) as a main substrate, which is produced from acetate. Currently, (11)C-acetate PET/CT is used for the evaluation of malignancies. There are no data concerning its potential for the characterization of atherosclerotic plaque. Therefore, the purpose of the present study was to examine the prevalence, distribution, and topographic relationship of arterial (11)C-acetate uptake and vascular calcification in major arteries. METHODS: Thirty-six patients were examined by whole-body (11)C-acetate PET/CT. Tracer uptake in various arterial segments was analyzed both qualitatively and semiquantitatively by measuring the blood-pool-corrected standardized uptake value (target-to-background ratio). CT images were used to measure calcified plaque burden. RESULTS: (11)C-acetate uptake was observed at 220 sites in 32 (88.8%) of the 36 study patients, and mean target-to-background ratio was 2.5 ± 1.0. Calcified atherosclerotic lesions were observed at 483 sites in 30 (83.3%) patients. Sixty-four (29.1%) of the 220 lesions with marked (11)C-acetate uptake were colocalized with arterial calcification. However, only 13.3% of all arterial calcification sites demonstrated increased radiotracer accumulation. CONCLUSION: Our data indicate the feasibility of using (11)C-acetate PET/CT for imaging of fatty acid synthesis in the atherosclerotic vessel wall. This study provides a rationale to incorporating (11)C-acetate PET into further preclinical and clinical studies to obtain new insights into fatty acid synthesis in atherosclerotic lesions and to evaluate whether it may be used to monitor pharmacologic intervention with fatty acid synthase inhibitors.