Yasemin Sanli

Diagnostic value of PET/CT is similar to that of conventional MRI and even better for detecting small peritoneal implants in patients with recurrent ovarian cancer.

ObjectiveThe aim of this study was to evaluate the diagnostic value of 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (18F-FDG) PET/CT in comparison with MRI for the detection of recurrent ovarian cancer. MethodsForty-seven patients with suspected ovarian cancer recurrence after total ablative or cytoreductive surgery, as well as neoadjuvant or adjuvant chemotherapy, who had undergone 18F-FDG PET/CT imaging were recruited for the present study. All patients also underwent MRI within a month of 18F-FDG PET/CT for the same purpose. Recurrent cancer in the abdomen and pelvis was evaluated in each of the 47 patients and classified as either distant metastasis or local pelvic recurrence involving the vaginal stump, peritoneal implants, supradiaphragmatic region, and/or abdominal and pelvic lymph nodes. Special attention was paid to peritoneal implants. These were divided into five groups according to size of the implants: less than 0.5 cm (group 1), 0.5–1 cm (group 2), 1–2 cm (group 3), 2–3 cm (group 4), and larger than 3 cm (group 5). PET/CT findings were compared with abdominopelvic MR findings. Statistical analysis was carried out using the Wilcoxon signed rank test. ResultsThirty-nine of 47 patients were found to have recurrent ovarian cancer. Both PET/CT and MRI were negative for recurrence in six patients. Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PET/CT were 97.5, 100, 100, 87.5, and 97.8%, respectively, whereas those of MRI were 95, 85.7, 97.4, 75, and 93.6%, respectively. For the peritoneal implants in groups 2 and 3, the sensitivity, negative predictive value, and diagnostic accuracy values of PET/CT were significantly better than those of MRI (P<0.05). ConclusionThe present study revealed that PET/CT is similar to conventional MRI for the detection of recurrent ovarian cancer. PET/CT has greater accuracy in the detection of small-to-medium-sized (<2 cm) peritoneal implants compared with MRI. This may affect surgical decision making.

Diagnostic spectrum of congenital hypothyroidism in Turkish children

Background:u2002 Congenital hypothyroidism (CH) is classified as transient or permanent. Transient CH can be treated with short‐term thyroxine replacement therapy or followed up without therapy, whereas lifelong thyroxine replacement is needed in permanent CH. Determination of the underlying etiology is essential for determination of follow‐up strategy. The purpose of the present study was therefore to assess the role of color Doppler ultrasonography (CDU) in etiologic diagnosis of CH together with radionuclide method and grayscale ultrasonography (GSU).

Hepatic adenomatosis may mimic metastatic lesions of liver with 18F-FDG PET/CT.

Hepatic adenomatosis is an uncommon benign neoplasm, with the presence of multiple adenomas (generally more than 4) within the liver. A 52-year-old woman presented with multiple (>10) solid liver lesions detected with abdominal ultrasonography and verified with magnetic resonance imaging (MRI). Subsequently, F-18 FDG PET/CT demonstrated increased uptake in these lesions. Histology revealed hepatic adenomatosis. F-18 FDG PET/CT cannot reliably differentiate hepatic adenomas from malignant processes on the basis of uptake.

Role of red blood cell scintigraphy for determining the localization of gastrointestinal bleeding.

BACKGROUNDnWe aimed to evaluate the role of Tc-99m labeled red blood cell (RBC) scintigraphy for determination of localization of gastrointestinal system (GIS) bleeding.nnnMETHODSnFifty-seven cases (27 females, 30 males; mean age 43.9±24; range 1 to 91 years) who referred to our clinic between 1995-2010 were evaluated for determination of localization of GIS bleeding with RBC scintigraphy. Prior to scintigraphy, gastroscopy in 51, colonoscopy in 45, and angiography in 9 patients were performed.nnnRESULTSnRBC scintigraphies were positive and negative in 31 and 26 patients, respectively. Positive scintigraphic findings were obtained within the 1st hour of dynamic imaging in 19 patients, within the 1st-4th hour static images in 7, and within the 4th-24th hour images in 5 patients. Fourteen patients underwent surgical exploration. In 13 patients, the surgery confirmed the diagnosis by RBC scintigraphy (accuracy: 92.8%). Of 43 patients without surgical exploration, 12 had anemia due to iron deficiency and their scintigraphic evaluation were negative. Four patients died and in 27 patients, GIS bleeding ceased spontaneously or with conservative measures.nnnCONCLUSIONnScintigraphy should be the primary tool for accurate diagnosis of patients with active GIS bleeding. Positive dynamic images obtained within the first hour of imaging may be more accurate for demonstrating bleeding localization and a good predictor of requirement of surgical exploration.

Prediction of outcome in pediatric Hodgkin lymphoma based on interpretation of 18 FDG-PET/CT according to ΔSUV max , Deauville 5-point scale and IHP criteria

ObjectiveMinimizing side effects by using response-adopted therapy strategies plays an important role in the management of pediatric Hodgkin lymphoma (HL); however, the criteria for the definition of adequate or inadequate response are controversial. The aim of this study is to compare different methods of interpretation of 18F-FDG-PET/CT (PET) in the prediction of disease outcome in order to determine the optimum method in this regard.MethodsBaseline, interim and post-treatment PET scans of 72 children were interpreted according to revised International Harmonization Project criteria (IHP) and Deauville criteria. Cut-off values for changes in interim and post-treatment FDG uptake (ΔSUVmax) in the prediction of progression-free survival (PFS) were measured using ROC analysis. Quantitative and visual data were compared with each other in the prediction of PFS.ResultsMean interim and post-treatment ΔSUVmax of the primary lesions were 77.4xa0±xa019.5 and 68.8xa0±xa030.4% and respective cut-off values were 82 and 73%. However, only post-treatment ΔSUVmax yielded statistically significant results in the prediction of 3-year PFS (pxa0=xa00.043). Interim ΔSUVmax was further analyzed according to the values reported in the literature (66 and 77%) yet statistically significant results were not reached (pxa0=xa00.604 and 0.431). For interim evaluation, IHP criteria was correlated to Deauville criteria (pxa0=xa00.002 and pxa0=xa00.001) and ΔSUVmax (pxa0=xa00.03), whereas for post-treatment evaluation, significant correlation with ΔSUVmax (pxa0=xa00.04) but marginally significant (pxa0=xa00.055 and pxa0=xa00.058) correlation with Deauville criteria were achieved. Overall, 1, 3 and 5-year PFS were 95.7xa0±xa00.2, 89.6xa0±xa00.4 and 80.8xa0±xa00.7%, respectively. All methods demonstrated comparable performance in the prediction of 3-year PFS; however, interim PET using Deauville criteria and post-treatment PET using IHP criteria were statistically significant. All methods demonstrated high negative-predictive value but substantially low positive-predictive value.ConclusionsDeauville criteria are superior to other methods in the prediction of pediatric HL outcome using interim PET data. On the other hand, quantitative evaluation and visual evaluation by IHP can be used reliably at the end of the treatment. In this regard, we report the optimal cut-off value of SUVmax reduction as 73%.

Metastasis of malignant melanoma to common biliary duct demonstrated with F-18 FDG PET/CT.

Malignant melanoma is well known for its propensity to spread to unpredictable sites. F-18 FDG PET can highlight metastases at unusual sites that may be missed with conventional imaging modalities. In this study, we present the case of a 57-year-old male patient who was referred to our department for PET/CT imaging because of metabolic characterization of the lesion located in distal common biliary duct and biopsied as malignant melanoma. His PET/CT images revealed a hypermetabolic lesion at the mentioned site. Interestingly, his images also showed mild FDG accumulation on right frontoparietal skin, and the biopsy of this lesion was also reported as malignant melanoma.

Neuroendocrine Tumor Diagnosis and Management: 68Ga-DOTATATE PET/CT

OBJECTIVEnThe purpose of this article is to provide a review of the use of 68Ga tetraazacyclododecanetetraacetic acid-DPhe1-Tyr3-octreotate (DOTATATE) PET/CT, a functional imaging modality for assessment of well-differentiated neuroendocrine tumors (NETs). It has become the preferred imaging modality for initial diagnosis, selection of patients for peptide receptor radionuclide therapy, and localization of unknown primary tumors. The National Comprehensive Cancer Network guideline has added 68Ga-DOTATATE PET/CT as an appropriate test in the management of NETs.nnnCONCLUSIONnIn combination with FDG PET/CT, 68Ga-DOTATATE PET/CT can noninvasively assess tumor heterogeneity, especially in G2 and G3 NETs, for personalized management of patients.

Precision Medicine and PET/Computed Tomography in Melanoma

Recent advances in genomic profiling and sequencing of melanoma have provided new insights into the development of the basis for molecular biology to more accurately subgroup patients with melanoma. The development of novel mutation-targeted and immunomodulation therapy as a major component of precision oncology has revolutionized the management and outcome of patients with metastatic melanoma. PET imaging plays an important role in noninvasively assessing the tumor biological behavior, to guide individualized treatment and assess response to therapy. This review summarizes the recent genomic discoveries in melanoma in the era of targeted therapy and their implications for functional PET imaging.

Precision Medicine and PET–Computed Tomography in Pediatric Malignancies

Fluorine-18 fluorodeoxyglucose (18F-FDG) PET-computed tomography (CT) plays a significant role in diagnosis, staging, therapy selection, and therapy assessment of multiple pediatric malignancies and facilitating precision medicine delivery in pediatric patients. In patients with Hodgkin lymphoma, interim fludeoxyglucose 18F-FDG PET/CT is highly sensitive and specific for predicting survival and multiple trials with FDG PET/CT-based adaptive therapies are currently ongoing. It is superior to iodine-131 metaiodobenzylguanidine (131I-MIBG) scintigraphy and bone scintigraphy for detecting metastases in neuroblastoma patients and sarcoma patients. It may predict histologic differentiation and neoadjuvant therapy assessment in Wilms tumor.