Journal: Clinical nuclear medicine
The differentiation of oncocytoma from renal cell carcinoma (RCC) remains a challenge with currently available cross-sectional imaging techniques. As a result, a large number of patients harboring a benign oncocytoma undergo unnecessary surgical resection. In this study, we explored the utility of Tc-MIBI SPECT/CT for the differentiation of these tumors based on the hypothesis that the large number of mitochondria in oncocytomas would lead to increased Tc-MIBI uptake.
The aim of this study was to compare the diagnostic performance of F-fluorodeoxyglucose (FDG) PET/CT and whole-body MRI for the detection of malignant peripheral nerve sheath tumors (MPNSTs) in patients with neurofibromatosis type 1, and to evaluate a panel of imaging-based criteria serving that purpose.
A 61-year-old man with severe chronic obstructive pulmonary disease presented to our hospital with recurrence of a right-sided spontaneous secondary pneumothorax. Thoracoscopic abrasion of the parietal pleura was performed, but an important air leak persisted. Presumed to originate from a bulla in the right upper lobe, bullectomy and pleural decortication were performed, but leakage remained. Lobectomy was considered, and quantitative ventilation/perfusion SPECT was performed to predict the functional outcome.Fused high-resolution CT/Tc Technegas images localized leakage not only to a bleb in the right upper lobe but also to the subcutaneous emphysema in the thoracic wall. The air leak resolved after conservative treatment.
We report a successful treatment of a patient with heavily metastasized pancreatic vasoactive intestinal polypeptide-secreting tumor, which was unresponsive to high doses of octreotide analog using peptide receptor radionuclide therapy applying a radiolabeled somatostatin analog. After the peptide receptor radionuclide therapy, there was a decrease in vasoactive intestinal polypeptide levels, a significant reduction in somatostatin receptor expression and in molecular tumor volume on Ga DOTANOC PET/CT scan, and a complete long-term resolution of symptoms of the patient.
BACKGROUND: Diffuse pigmented villonodular synovitis (DPVNS) is an uncommon proliferative disease. After only surgery, recurrence rates are high. This study presents the efficacy of combined surgical and adjuvant radiosynovectomy (RS) in the treatment of DPVNS. MATERIALS AND METHODS: Between September 2006 and September 2012, 15 knee joints of 15 patients (10 female and 5 male) with histopathological DPVNS diagnosis with mean age 27 ± 12 years underwent surgery. At mean 14.4 ± 18 weeks postoperatively, RS was applied using 5 mCi Y citrate colloid. Three-phase bone scintigraphy and contrast-enhanced MRI were used to evaluate residual and recurrent tumorous tissues in the joint. RESULTS: Mean follow-up was 48 ± 22 months. Blood flow and blood pool images showed that 2 patients had marked, 4 had moderate, 6 had mild, and 3 had no uptake. Late static images showed 5 had marked, 10 had moderate Tc-HDP uptake in the related joint. MRI examination indicated that there was no progression in any of the patients. The disease was determined to be stable in 2, regressed in 9, and totally cured in 4 cases. Bremsstrahlung imaging indicated an even distribution of radionuclide in all the knee joints. There was no evidence of leakage of radioactivity in the total body scans. There was significant improvement in Lysholm knee scores after treatment. CONCLUSION: Adjuvant yttrium-90 radiosynovectomy after surgical excision in the treatment of DPVNS is a reliable and efficient treatment method with successful clinical results. RS treatment can be considered for cases with DPVNS.
A 22-year-old man with primary mediastinal choriocarcinoma and bilateral lung metastases underwent an FDG PET/CT scan after completing chemotherapy. Serum beta-human chorionic gonadotropin had normalized. PET/CT showed increased FDG uptake in the anterior mediastinal and lung lesions, suspicious for residual disease. After resection of the mediastinal and lung lesions, histopathology revealed necrosis and fibrohistiocytic reaction with no viable tumor. There was discordance between beta-human chorionic gonadotropin (negative) and FDG PET/CT (positive) findings, with PET/CT findings being false positive. Awareness of this potential pitfall of FDG PET/CT is important, and caution should be exercised when using FDG PET/CT to assess residual masses after chemotherapy.
Lu-labeled ethylenediamine-N,N,N',N'-tetrakis methylene phosphonic acid (Lu-EDTMP), was used to palliate metastatic bone pain as a new bone-seeking radiopharmaceutical. In this phase II study, we assessed the efficacy and safety of Lu-EDTMP for bone pain palliation in patients with breast cancer and hormone refractory prostate cancer with bone metastases.
A 26-year-old man with chronic terminal renal insufficiency under dialysis was referred in our institution for a checkup before kidney transplantation to ensure the absence of malignant neoplasm. The patient had a biological secondary hyperparathyroidism with highly elevated serum parathormon, and treatment with parathyroid surgery was planned before the kidney transplant. Whole-body FDG PET/CT showed no apparent malignant neoplasm, but increased metabolism of the 4 parathyroid gland and the other pitfalls of advanced secondary hyperparathyroidism on chronic renal insufficiency: pseudotumoral calcification in soft tissues, diffuse hypermetabolic bone dystrophy, and osteolytic lesion of pelvic and peripheral skeleton corresponding to brown tumors.
Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma is a rare, recently described vascular neoplasm that occurs predominantly in the distal extremities of young to middle aged adult males. In this report, we describe a patient who presented with numerous lytic bone lesions which were intensely F-FDG avid on PET/CT and presumed to be metastatic. Pathology revealed pseudomyogenic hemangioendothelioma. Follow-up CT showed enlargement and increasing sclerosis of several lesions, believed to represent progression; however, follow-up PET/CT confirmed a spontaneous regression of the disease.
Prostate-specific membrane antigen (PSMA) is a type 2 transmembrane protein highly expressed in prostate cancer cells. We present the case of a 50-year-old man with metastatic papillary carcinoma of the thyroid, with rising thyroglobulin level and negative whole-body radioiodine scan after total thyroidectomy. Considering the limited treatment options available, it was decided to perform Ga-PSMA-HBED-CC PET/CT scan. It revealed intense radiotracer uptake in mediastinal and left supraclavicular lymph nodes, brain metastases, bilateral lung nodules, and skeletal sites. Patient also underwent F-FDG PET/CT. It demonstrated similar findings; however, the number of lesions detected in brain was less compared with Ga-PSMA PET/CT.