Role of [68Ga]DOTANOC PET/computed tomography and [131I]MIBG scintigraphy in the management of patients with pheochromocytoma and paraganglioma: a prospective study.

PURPOSE: The primary aim of study was to compare role of iodine-131 (I-131)-labeled metaiodobenzylguanidine ([I]MIBG) and gallium-68 (Ga-68)-labeled DOTA-l-Nal3-octreotide ([Ga]DOTANOC) PET/computed tomography (CT) in patients with pheochromocytoma (PCC) and paraganglioma (PGL), subsequent follow-up to see management. The secondary aim was to see association of germline mutation in histopathologically proven patients. PROCEDURES: We performed [Ga]DOTANOC PET/CT and [I]MIBG in 106 patients (61 men; age: 38.5 ± 16.2 years) of known or suspected PCC/PGL. Following scans, 16 histopathologically proven patients were screened for germline mutations. RESULTS: [I]MIBG detected 41 lesions in 34 patients and [Ga]DOTANOC PET/CT detected more than 79 lesions in 55 patients. The mean duration of follow-up was 20.6 ± 16.5 months. Management following scans: surgery in 35 patients (positive histopathology in 34 patients, negative in 1 patient); lutecium-177 (Lu-177)-labeled DOTA-0-Tyr-3 octreotate ([Lu]DOTATATE) therapy in 2 patients; chemotherapy in 1 patient; conservative therapy in 34 patients; no therapy in 17 patients; 2 patients have died and 3 were lost to follow-up. Among 12 previously operated, 2 patients showed metastatic disease and 1 showed residual disease. Out of 16 patients who underwent genotypic analysis (15 operated), 8 were positive for germline mutations. Mutations were seen in SDHB, RET, VHL, MDH2 and SDHA genes, including two germline mutations in two patients. Deletion was observed in one patient in SDHB gene and substitution in all other mutations. Four novel mutations in MDH2 (c.1005G>C, c.916G>A, c.580G>A) and SDHB (c.378_380delAAT) were observed (SRA accession: PRJNA551457). CONCLUSIONS: [Ga]DOTANOC PET/CT should be considered as a first-line investigation in PCC/PGL especially at high risk of metastasis and screening of persons with familial syndrome.

Combination of intravitreal bevacizumab and systemic therapy for choroidal metastases from lung cancer: report of two cases and a systematic review of literature.

Symptomatic choroidal metastasis (SCM) is an uncommon manifestation of lung cancer (LC). Treatment of SCM usually includes a combination of systemic therapy (chemotherapy and/or targeted therapy) for the primary tumor as well as local therapy (ocular radiation) for CM. Intravitreal bevacizumab (IV-Bev) is a newer modality being tried for local control of SCM. We describe here two patients with LC who presented with CM and were treated with IV-Bev. We performed a systematic literature review of previously reported patients with CM from LC who were treated with IV-Bev. Six reports (involving seven patients) in which IV-Bev was used as primary treatment modality for CM from LC were identified in the systematic literature review. A total of nine patients (seven previously reported and two index cases) were analyzed further. Along with individual case descriptions of index patients, pooled analysis of demographic profile, histology and outcomes with treatment (systemic and ocular) for the nine patients identified in this systematic review are described. A majority (n = 7) had non-small-cell lung cancer (NSCLC) histology, CM as presenting manifestation (n = 6) and unilateral ocular involvement (n = 8). IV-Bev was used in a dose of either 1.25 mg/cycle (n = 5) or 2.5 mg/cycle (n = 4) with number of cycles varying from 2 to 14 and duration between cycles varying from 2 to 8 weeks. Of the nine patients treated with IV-Bev as the primary ocular treatment modality, six (all non-squamous NSCLC) had favorable ocular response. No short-term ocular complications related to therapy were noted. We suggest that IV-Bev is a promising and safe alternative to ocular radiation for initial treatment of CM from non-squamous NSCLC. However, we recommend against using it for patients with small-cell lung cancer.

Diffuse nesidioblastosis diagnosed on a Ga-68 DOTATATE positron emission tomography/computerized tomography.

The authors describe a 50 days old pre-term infant with persistent hyperinsulinemic hypoglycemia of infancy in whom Ga-68 DOTATATE positron emission tomography/computerized tomography scan showed diffusely increased tracer uptake in the entire pancreas with no abnormal tracer uptake anywhere else in the body, suggestive of a diffuse variant of nesidioblastosis.

Bone scintigraphic patterns in patients of tumor induced osteomalacia.

Tumor induced osteomalacia (TIO) or oncogenic osteomalacia is a rare condition associated with small tumor that secretes one of the phosphaturic hormones, i.e., fibroblast growth factor 23, resulting in abnormal phosphate metabolism. Patients may present with non-specific symptoms leading to delay in the diagnosis. Extensive skeletal involvement is frequently seen due to delay in the diagnosis and treatment. The small sized tumor and unexpected location make the identification of tumor difficult even after diagnosis of osteogenic osteomalacia. The bone scan done for the skeletal involvement may show the presence of metabolic features and the scan findings are a sensitive indicator of metabolic bone disorders. We present the bone scan findings in three patients diagnosed to have TIO.

Role of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the management of Askin's tumor.

A primitive neuroectodermal tumor (PNET) of the thoraco-abdominal region is one of a group of small round cell tumors usually found in children and young adults, originally described by Askin et al. Most cases arise in the soft-tissues of the thorax, but may rarely occur within the lung with the symptoms of chest wall pain, pleural effusion and dyspnea. The authors present two cases demonstrating the utility of F18 fluorodeoxyglucose positron-emission tomography/computed tomography in the staging and prognosis of PNET of the chest wall.

Extranodal manifestations of lymphoma on [¹8F]FDG-PET/CT: a pictorial essay.

Lymphoma is the seventh most common type of malignancy in both sexes. It is a neoplastic proliferation of lymphoid cells at various stages of differentiation and affects lymph nodes with infiltration into the bone marrow, spleen and thymus. However, extra nodal involvement is frequently seen in many cases. With the development of dedicated positron emission tomography (PET) scanners with fused computed tomographic (CT) systems in the same gantry, [18F]fluorodeoxyglucose (FDG)-PET/CT has become a major tool in the evaluation of lymphomas and it is inimitable in certain situations such as assessment of response to therapy. Extranodal lymphoma can present with diverse manifestations and sometimes mimics other organ-related pathologies. Knowledge of the protean manifestations of extranodal lymphoma is required to accurately detect the disease and differentiate it from the various physiologic and benign causes of FDG uptake in various organs. We present a case series of extranodal involvement of histologically proven cases of lymphomas detected on FDG-PET/CT at our institute to demonstrate the challenges in interpretation of extranodal lymphoma.

Association of angiotensin converting enzyme and angiotensin type 2 receptor gene polymorphisms with renal damage in posterior urethral valves.

OBJECTIVE: To examine the association with renal damage in patients with posterior urethral valves (PUV) of two renin-angiotensin system gene polymorphisms: angiotensin converting enzyme insertion/deletion (ACE I/D) and angiotensin type 2 receptor (AT2R A1332G), PATIENTS AND METHODS: In 120 patients with PUV, after stabilization, transurethral fulguration or a Blocksom vesicostomy was performed. Records were reviewed for age at diagnosis, biochemical renal function at diagnosis, results of urine cultures, voiding cystourethrograms, radiologic, sonographic and nuclear medicine scan findings, and follow-up data. ACE I/D genotypes were determined by the polymerase chain reaction using allele specific primers. RESULTS: The frequency of the ACE DD genotype was significantly higher in patients with chronic kidney disease (P=0.02) and renal scarring (P=0.05). These genotypes were also associated with a statistically higher incidence of vesicoureteral reflux, diurnal incontinence, proteinuria and hypertension. A significantly higher frequency of the AT2R GG genotype was found in PUV patients as compared to healthy unrelated control subjects (P=0.001), and in PUV patients with scarring (P=0.02). CONCLUSION: The ACE DD and AT2R GG genotypes are associated with chronic kidney disease and scarring in PUV patients. The GG genotype incidence is higher among PUV patients compared to the control population, and further studies in this area may help understanding of the genetic basis of PUV.

Lung scintigraphy in the diagnosis and follow-up of pulmonary thromboembolism in children with nephrotic syndrome.

Thromboembolic phenomenon and pulmonary embolism is quite frequent in children with nephrotic syndrome (NS). The incidence of pulmonary thromboembolism in children with NS is as common as in adults, and severity is also reported to be relatively high. The mortality rate in NS with thromboembolic complications may be significantly increased if not diagnosed and treated well in time. For establishing the diagnosis of pulmonary embolism, although the combined use of magnetic resonance venography and CT angiography has been proposed, V/Q scan is still the best modality. We performed serial lung perfusion scans in two young patients with NS who developed sudden onset tachypnea during their stay in the hospital. Initial lung perfusion scans showing marked perfusion defects and normal chest X-rays indicated a high probability for pulmonary embolism. The patients were treated with streptokinase, and the study was repeated. Marked improvement was seen in lung perfusion, thereby highlighting the importance of lung perfusion scan in the follow-up of such patients.