Importance of combined use of preoperative 18F-FDG PET/CT imaging and intraoperative 18F-FDG handheld gamma probe detection in recurrent papillary thyroid cancer.

Radio-guided surgery using an intra-operative positron emission tomography (PET) probe in recurrent thyroid cancer (RTC) can be a useful method for tumor localization, verification of complete excision and to decrease operation time. We describe a case of RTC whose serum thyroglobulin (Tg) level was 5.6ng/mL. Preoperative fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) revealed two focal abnormalities in the anterior tracheal and right upper mediastinal regions and a handheld gamma probe was used intraoperatively to identify the hot areas seen on PET scan. Postoperative 18F-FDG PET/CT imaging after tumor excision was normal. This case shows that recurrent tumor can be localized correctly using 18F-FDG PET/CT and a surgical gamma probe.

FDG PET-CT Finding in Bilateral Renal and Bone Involvement of Diffuse Large B-Cell Lymphoma.

Thirty-six year old male patient with pathological fracture of the left tibia underwent intramedullary and soft tissue curettage. The histopathological examination revealed diffuse large B cell lymphoma. The patient underwent F18-FDG PET-CT scanning for initial staging. FDG PET-CT scan revealed hypermetabolic lesions at the left tibia and in bilateral kidneys. After the systemic chemotherapy and local radiotherapy to the tibia, repeated FDG PET/CT scan showed improvement of the previous hypermetabolic lesions, suggesting good response to therapy. Bone and renal involvement is an uncommon variant of diffuse large B-cell lymphoma and FDG PET-CT is an useful whole body imaging modality in these cases.

Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism.

BACKGROUND: The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions. MATERIALS AND METHODS: In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated. RESULTS: Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results. CONCLUSION: As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images.

A rare case of solitary subcutaneous scalp metastasis from follicular thyroid carcinoma revealed with positron emission tomography/computed tomography: a case report and review.

Differentiated thyroid cancer frequently metastasizes to regional cervical lymph nodes and in advanced cases metastases can be seen in the lungs and skeleton. Metastases to the skin or subcutaneous tissue are rare. Here we present a 49-year-old female patient with solitary scalp metastasis from follicular thyroid carcinoma FTC which was revealed with positron emission tomography (PET)/computed tomography (CT) imaging. PET showed flourodeoxiglucose avid lesion in the left vertex scalp. Scalp lesion was removed totally and histopathological examination revealed well-differentiated thyroid cancer metastasis.

Detection of Hodgkin Transformation in a Case of Chronic Lymphocytic Leukemia by PET/CT.

Richter's transformation (RT) represents the development of high grade lymphoma, most commonly diffuse large B-cell lymphoma, in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL). CLL/SLL may convert also to Hodgkin's lymphoma, the so-called Hodgkin's variant of Richter transformation. Histopathological proof is needed to confirm a definitive diagnosis. Patients with RT generally have a poor prognosis, with prompt recognition optimise clinical management. Whole-body PET scan with 18F-FDG can be used for detection of RT of CLL/SLL. We describe the case of 64-year-old woman with CLL/SLL who developed Hodgkin lymphoma detected with PET/CT.

Bilateral trigeminal nerve recurrence of non-hodgkin lymphoma revealed with FDG PET/CT.

Bilateral trigeminal nerve involvement is a rare presentation of Non-Hodgkin lymphoma (NHL). The trigeminal nerve, also called the fifth cranial nerve, leaves the brainstem and exits the base of the skull to supply sensation to the face. In this case, we present a case of a 63-year-old male patient with a history of NHL and a more recent history of headache and trigeminal neuralgia. The patient underwent PET/CT demonstrating bilateral increased FDG uptake in trigeminal nerves.

Correlation of 18F-fluorodeoxyglucose uptake with histopathological prognostic factors in breast carcinoma.

OBJECTIVE: This study investigated the prognostic value of [18F]-fluorodeoxyglucose (18F-FDG) uptake in breast carcinomas by comparing 18F-FDG PET/computed tomography (CT) images with histopathological and immunohistochemical prognostic factors. METHODS: This study included 136 women and four men with positive biopsy breast carcinomas who underwent 18F-FDG PET/CT imaging for initial staging. Maximum standardized uptake values (SUVmax) and tumour-to-background SUVmax ratios were calculated and compared with histopathological and immunohistochemical tumour characteristics, patient properties and axillary lymph node involvement. Calculations of SUVmax for men were performed separately. RESULTS: For the tumours in women, the mean SUVmax was 10.06±6.91 and the median SUVmax was 9.05 (0.7-35.0). Primary tumour 18F-FDG uptake and tumour-to-background SUVmax ratios were correlated with tumour size (P<0.001), histological type (P<0.001), histological grade (P=0.004), pleomorphism (P=0.010), mitosis count (P<0.001), lymphatic invasion (P=0.009), necrosis (P=0.005), oestrogen negativity (P=0.004), high Ki-67 level (P<0.001), axillary lymph node involvement (P<0.001) and triple negativity (P=0.002). High Ki-67 level (odds ratio=16; 95% confidence interval=1.6-160; P=0.016) and tumour size (odds ratio=4; 95% confidence interval=1.5-11; P=0.007) were determining factors for high 18F-FDG uptake values. Other clinicopathological and immunohistopathological parameters including progesterone receptor (P=0.211), CerbB2 overexpression (P=0.170), perineural invasion (P=0.053), intratumoural calcification (P=0.438), desmoplasia (P=0.112), tubular formation (P=0.768) and age (P=0.675) were not significantly correlated with 18F-FDG uptake. No significant relationship was observed between the tumour/contralateral breast SUVmax ratio and mitotic count, oestrogen receptor status or triple negativity. CONCLUSION: F-FDG uptake may serve as a prognostic indicator for biological behaviour in breast tumours.

Left ventricular remodeling assessment in patients with anterior acute myocardial infarction treated with successful primary percutaneous coronary intervention: an observational study.

OBJECTIVE: We aimed to analyze the left ventricular (LV) remodeling in patients treated with coronary intervention (PCI) in the acute phase of anterior myocardial infarction (MI) and to analyze the relationship between LV functional remodeling and residual viability in the infarct zone detected by thallium-201 (Tl-201) imaging and echocardiography. METHODS: We designed an observational prospective cohort study including 30 patients (26 men, 4 women, mean age; 52±12 years old) with acute anterior MI. Echocardiography and Tl-201 imaging were performed in all patients three days and two months after PCI and left ventricular end-systolic volume (ESV), left ventricular end-diastolic volume (EDV), ejection fraction (EF) and summed redistribution score (SRS) were calculated. Paired samples t- test or Wilcoxon rank sign test for comparing continuous variables in dependent groups, Pearson correlation for testing relationship between continuous variables were used. RESULTS: Left ventricular function baseline values just after PCI and two months after PCI obtained by echocardiography and scintigraphy were statistically significant. Among patients 76.7% had an EF ≥0.50 after the event. EDV and ESV values are significantly low when compared to values two months before. There was not any marked change in SRS in five patients. Polar maps were correlated with heart rate (r=0.438; p=0.023), peak creatine kinase MB (r=0.440; p=0.015) and troponin (r=0.471; p=0.009) during acute MI. CONCLUSION: Significant recovery in EDV, ESV and SRS values, and increase in EF two months after the infarction shows us substantial part of the remodeling process is completed in two months and Tl-201 imaging is extremely effective in determining of salvaged myocardium.

Delayed imaging of the pelvis with diluted and filled bladder: a simple and efficient method in FDG PET/CT imaging of bladder carcinoma.

A 53-year-old man with recent diagnosis of urinary bladder carcinoma was referred to our PET/CT unit. There was no sign and symptom other than hematuria. Urinary ultrasound showed a mass lesion at the right wall of the urinary bladder. FDG PET/CT was performed for initial staging. One-hour whole-body PET/CT images were normal, whereas delayed pelvic images with "diluted and filled bladder" demonstrated that intense hypermetabolic lesion at the right lateral wall of the urinary bladder.

Increasing Role of FDG-PET/CT in Detecting Bone Marrow Metastasis of Solid Tumors in Adults: An Analysis of Ten Patients.

BACKGROUND: We aimed to test the hypothesis that whether FDG-PET/CT which was ordered for various purposes can predict suspected or particularly unsuspected bone marrow metastasis (BMM) from the complete blood count and therefore can change the management of these patients. METHODS: In this retrospective study, the study sample consisted of 68 subsequent patients presented to our institution's pathology department with bone marrow metastases of solid tumors. PET/CT was found to have been ordered in 10 out of 68 patients (6.8%) for various purposes. All patients gave informed consent about the PET/CT examinations and bone marrow biopsies. RESULT: FDG-PET/CT was ordered in 10 out of 68 solid tumor patients with pathologically proven BMM. Of these 10 patients, 3 were female and 7 were male; mean age was 54.7 years. While FDG PET/CT showed bone and BMM in 4 of 10 patients (40%), the rest of the patients had BMM without bone involvement. Five patients (50%) who had probable bone marrow involvement on their FDG PET/CT scans had unsuspected complete blood counts with regard to BMM. CONCLUSION: PET/CT has the ability to detect a substantial number of metabolically active tumor cells in the bone marrow in all of our patients which we proved by bone marrow biopsies. We think that this cohort of patients with solid tumors is hypothesis-generating with regard to detecting early bone marrow metastases by FDG PET/CT.

F-18 Fdg PET/CT Findings of a Patient with Takayasu Arteritis Before and After Therapy.

UNLABELLED: Vasculitis is defined as inflammation and necrosis with leukocytic infiltration of the blood vessel wall. Takayasu arteritis is a chronic inflammatory arteritis that primarily involves the aorta and its main branches. A 64-year-old female patient with a 2-month history of fever of unknown origin was presented to our clinic for F-18 FDG PET/CT imaging. Baseline PET/CT images demonstrated intense F-18 FDG uptake in the aorta, bilateral subclavian and brachiocephalic arteries consistent with Takayasu arteritis. After 2 months of immunosuppressive therapy, she was asymptomatic and follow-up FDG PET/CT scan showed almost complete disappearance of large vessels' F-18 FDG uptake. FDG PET/CT is a sensitive technique for assessing presence of large-vessel vasculitis such as Takayasu arteritis, extent of large-vessel inflammation and disease activity after therapy. CONFLICT OF INTEREST: None declared.

Cardiac hydatid cyst mimicking malignancy.

A 50-year-old man presented with chest pain symptoms for 7 years. He did not report any other complaints. The diagnostic tests including physical examination, routine laboratory tests, chest x-ray, and electrocardiography were reported as normal. Cardiac MRI, however, revealed a 64 × 66 mm mass lesion in the left myocardium. He was referred to our unit for further tests. A PET/CT was carried out which demonstrated a minimally increased fluorodeoxyglucose uptake at the peripheral margins of the mass, which deemed to be suspicious for malignancy. The patient underwent a thoracotomy and the cardiac mass was excised. Histopathologic examination reported this lesion as a hydatid cyst.

Metformin-Induced Intense Bowel Uptake Observed on Restaging FDG PET/CT Study in a Patient with Gastric Lymphoma.

UNLABELLED: A 53-year-old man with a diagnosis of gastric non-Hodgkin lymphoma (NHL) underwent PET/CT scans both prior to starting chemotherapy and immediately following completion of chemotherapy to evaluate the response to therapy. Pre-therapy PET/CT images showed intense FDG uptake in the antral region of the stomach. Biodistribution of FDG was otherwise unremarkable. The patient was started on metformin in the middle of his therapy period to provide glycemic control. Post-therapy PET/CT study performed after 6 courses of chemotherapy showed complete resolution of the disease with no evidence of residual FDG uptake. However, intense and diffuse FDG accumulation is observed in the bowel, which was interpreted as physiological and most probably due to metformin administration. It should be borne in mind that there are a number of physiological variants of FDG biodistribution seen on PET/CT imaging. Recognizing physiologic bowel activity is crucial for the accuracy of PET image interpretation. CONFLICT OF INTEREST: None declared.

Tc 99m bone scan and fluorodeoxyglucose positron emission tomography in evaluation of disseminated langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder in which pathological langerhans cells accumulate in a variety of organs. Manifestations may include lung infiltrates, lymph node involvements, bone lesions, hepatic, hematopoietic and endocrine dysfunctions. In this case report we present fluorine-18 positron emission tomography (F-18 PET/CT) and bone scintigraphy findings of a 18-year-old male patient with disseminated LCH, mimicking multiple hypermetabolic metastatic lesions. Clinicians should be aware that LCH infiltrations can be seen as intense uptake and to differentiate infiltrations from other metastatic intense uptake with fluorodeoxyglucose PET/CT and bone scintigraphy, clinical and laboratory findings should be kept in mind.