Pelin Ozcan Kara

The role of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiating between benign and malignant adrenal lesions.

ObjectivesThis retrospective study was designed to investigate the clinical role of whole-body positron emission tomography/computed tomography (PET/CT) by using 2-[18F]fluoro-2-deoxy-D-glucose (FDG), for the evaluation of adrenal lesions and to find the best index to distinguish benign from malignant lesions in various cancer patients. Materials and methodsA total of 81 patients (55 male and 26 female, age range: 31–81 years, mean: 61.5) who had confirmed primary malignancies (lung cancer in 47 patients, gastrointestinal malignancies in 13 patients, malignant melanoma in one patient, renal cell cancer in three patients, mesothelioma in two patients, breast carcinoma in nine patients, cervical cancer in one patient, ovarian cancer in two patients, pheochromocytoma in one patient, unknown primary in two patients) underwent PET/CT examinations for cancer screening, staging, restaging, and detection of suspected recurrence. Of the 81 patients, 104 adrenal lesions (34 benign and 70 malignant adrenal lesions) were shown by CT. On visual analysis of PET/CT imaging, adrenal uptake was based on a three-scale grading system. For final assessment standards of references for adrenal malignant lesions was based on biopsy (n=2), interval growth, or reduction after chemotherapy. An adrenal lesion, which remained unchanged on clinical and imaging follow-up of at least 7 months (mean follow-up time 19.31 months±6.46, range 7–30 months), was decided as a benign lesion. ResultsIn adrenal malignant lesions maximum standardized uptake value (SUVmax) (8.82±4.47) was higher than that of adrenal benign lesions (3.02±1.15, P<0.0001). In the differentiation of adrenal benign and malignant lesions, a CT threshold of 10 Hounsfield units corresponded to a sensitivity of 64.7%, specificity of 98.6%, and accuracy of 87.5%. An SUVmax cut-off value of 2.5 corresponded to a sensitivity of 100%, specificity of 38.2%, and accuracy of 80%. An SUVmax cut-off value of 4.2 corresponded to a sensitivity of 88.6%, specificity of 88.2%, and accuracy of 88.5%. The ratio of tumor SUVmax to liver SUVmean was 3.61±1.77 for adrenal malignant lesions whereas it was 1.20±0.38 for adrenal benign lesions (P<0.0001). T/L SUV ratio cut-off value of 1.8 corresponded to a sensitivity of 87%, specificity of 91%, and accuracy of 88.5%. T/L SUV ratio cut-off value of 1.68 corresponded to a sensitivity of 90%, specificity of 91.1%, and accuracy of 90.4%. Conclusion2-[18F]fluoro-2-deoxy-D-glucose-PET/CT improves the diagnostic accuracy in the differentiation of benign from malignant adrenal lesions in various cancer patients. Combined information obtained from PET/CT (SUVmax, T/L SUV ratio, visual analysis) and unenhanced CT (size, Hounsfield units measurement) is recommended for better differentiation.

Askin's Tumor in an Adult: Case Report and Findings on 18F-FDG PET/CT

Primitive neuroectodermal tumor (PNET) of the chest wall or Askins tumor is a rare neoplasm of chest wall. It most often affects children and adolescents and is a very rare tumor in adults. In this case report, we present an Askins tumor occurred in a 73-year-old male. The patient was admitted with a history of 3-month lower back pain and cough. In computed tomography, there was a lesion with dimensions of 70 × 40 × 65 mm in the superior segment of the lower lobe of the left lung. Positron emission tomography/computed tomography with 18F-flourodeoxyglucose revealed a pleural-based tumor in the left lung with a maximum standardized uptake value of 4.36. No distant or lymph node metastases were present. The patient had gone through surgery, and wedge resection of the superior segment of left lobe and partial resection of the ipsilateral ribs were performed. Pathology report with immunocytochemistry was consistent with PNET and the patient received chemotherapy after that.

Metastatic insular thyroid carcinoma: visualized on Tc-99m pertechnetate, Tc-99m MDP and iodine-131 scintigraphy; a review of the literature for other radionuclide agents.

Poorly differentiated insular thyroid carcinoma is classified as a separate entity among other tumors of the thyroid gland. Its histological pattern and clinical course are regarded as intermediate between well-differentiated and anaplastic thyroid cancer. The authors report Tc-99m pertechnetate, Tc-99m MDP and radioiodine imaging features in a 33-year-old male patient with metastatic insular carcinoma of the thyroid. The extent of involvement was almost identical in all three studies. Insular carcinoma of the thyroid was shown by biopsy, and the patient received a cumulative dose of 14,800 MBq (400 mCi) radioactive 1–131. Other radionuclide imaging agents are also reviewed.

Undescended Testis in Inguinal Canal Detected Incidentally on Fluorodeoxyglucose PET/CT Imaging

The differential diagnosis at the inguinal region is very important for hypermetabolic foci because of the possibility of metastasis at this level in cancer patients ongoing PET imaging for detection of metastases. It is important to distinguish this activity from other possible malignant and benign conditions such as lymph node activity, testicular cancer, metastatic disease activity, inflammation and urine skin contamination artefact. A 66-year-old male patient with operated colon cancer and liver metastasis was referred for PET/CT examination for re-staging because of suspicious metastases. Findings of PET/CT imaging with undescended testis detected incidentally was presented.

Prone imaging allows efficient radiopharmaceutical usage by obviating the necessity of a rest study in Tc-99m-methoxyisobutylisonitrile myocardial perfusion scintigraphy.

ObjectiveIn myocardial perfusion single-photon emission computed tomography studies, diaphragmatic attenuation of the inferior wall is a common artifact, which can be minimized by prone imaging. The aim of this retrospective study was to validate the impact of stress–prone imaging on the necessity of a rest perfusion study with a final goal of effective radiopharmaceutical usage. MethodsThe findings of 98 patients who had been examined by a combined supine and prone imaging were retrospectively evaluated. Prone acquisition was performed only when reduced perfusion was observed in the inferior wall on the stress supine images. The reconstructed images were evaluated both visually and quantitatively. Rest myocardial single-photon emission computed tomography study was omitted in patients with complete normalization of uptake in the prone images. Results obtained were also compared with the clinical data and follow-up. ResultsProne imaging obviated the necessity of a rest perfusion study in 76 of 98 patients (77.5%). Among normally reported patients (n=89), 76 (85.4%) were saved from a rest study due to the prone study results. Prone study provided improved results in quantitative analysis as well. The difference between the mean summed stress scores of supine and prone studies was statistically significant in normally reported patients (P=0.013). However, no significant difference was observed in scores of ischemic patients (P=0.341). ConclusionAdding prone imaging to a post-stress Tc-99m-methoxyisobutylisonitrile myocardial perfusion study not only minimizes the inferior wall attenuation, but also reduces the need for a rest test, particularly in low-risk or intermediate-risk patients. Thus, prone imaging seems to be both safe and effective.

Radioiodine Contamination Artifacts and Unusual Patterns of Accumulation in Whole-body I-131 Imaging: A Case Series

Introduction: Radioactive iodine has been used for more than 50 years for the treatment of thyroid diseases. Differentiated thyroid cancers have the ability to trap iodine. Therefore, radioiodine can be used both diagnostically and therapeutically. In the follow-up of patients, it is critical to interpret radioiodine scans correctly. Case Presentation: Non-physiological Iodine-131 (I-131) extra-thyroidal uptake detected on post-therapy or diagnostic I-131 scanning are not always interpreted as functioning metastatic thyroid cancer. Conclusions: This study provides detailed information and case samples of radiodine contamination artifacts and non-physiological, non-metastatic extra-thyroidal I-131 accumulation in whole-body I-131 imaging.

Detection of bone metastases in initial staging of orbital embryonal rhabdomyosarcoma by fluorodeoxyglucose positron emission tomography/computed tomography.

Rhabdomyosarcoma is the most common form of soft tissue sarcoma in young children. In soft tissue sarcomas, isolated metastases are seen in the lung, soft tissue, and bone. The optimal management of these tumors depends on the site, size, and grade of the local growth, and accurate staging of the disease when first seen. Although detection of the primary site of disease is usually accomplished well with conventional techniques, the performance of fluorodexyglucose (FDG) positron emission tomography/computed tomography (PET/CT) may be useful to determine metastases that are not clinically evident. We describe a case of early detection of distant metastases by FDG PET/CT in a young patient diagnosed with orbital embryonal rhabdomyosarcoma. Conflict of interest:None declared.

FDG-PET/CT imaging in a patient with lymphangiosarcoma.

Abstract:Lymphangiosarcoma is a well-recognized complication of chronic lymphedema. We present a rare case of lymphangiosarcoma in a 34-year-old woman who presented with a mass on her left lymphedematous leg. Her leg had become persistently swollen in the weeks during pregnancy and a clinical diagno

Radio-guided Surgery of a Patient with Secondary Hyperparathyroidism: The Clinical Impact on the Duration of Surgery in Renal Failure Patient

Secondary hyperparathyroidism is consequent to a chronic hypocalcaemic condition that can be caused primarily by renal failure. As a result of continuous stimulus to produce and secrete PTH induces parathyroid gland hyperplasia. In this case report, we present a chronic renal failure patient with high parathyroid hormon level suspected for secondary hyperparathyroidism. According to the parathyroid scan findings four glands were demonstrated concordant with parathyroid pathology and the patient was operated with intra- operative gamma probe in a very short time. Radio-guided surgery of this renal failure patient by using intra-operative gamma probe for excision of hyperplastic parathyroid glands and hereby shortening the surgery time, provided a positive impact of renal residual function of this dialysis patient. Although, radioguided surgery with minimal invasive surgery is commonly recommended for primary hyperparathyroidism with single adenoma, we recomment radioguided surgery of hyperplastic parathyroid glands especially in renal failure patients for maintaining renal residual function.

Splenic and multiple abdominal metastases of endometrial carcinoma detected with FDG-PET/CT

A 58 year old female was referred for FDG-PET/CT for restaging of endometrial adenocarcinoma. For evaluation of treatment, no metastases were detected on FDG-PET/CT which was performed 18 months later after the surgery. During follow-up, FDG-PET/CT was performed 6 months later than the previous FDG-PET/CT for restaging. A lesion with increased metabolic activity (SUV max: 10.21) was detected at spleen which was not seen on previous FDG-PET/CT scan. The lesion was consistent with metastasis of endometrial carcinoma. Splenic metastasis of endometrial carcinoma is extremely rare. There are only 13 cases of splenic metastasis from endometrial carcinoma that reported in the literature before. There is only one splenic metastasis of endometrial carcinoma case reported in the literature which is imaged with FDG-PET. To best of our knowledge this is the first report of solitary splenic metastasis of endometrial carcinoma that is imaged with FDG-PET/CT.