Varun Singh Dhull

68Ga-DOTANOC PET/CT for Baseline Evaluation of Patients with Head and Neck Paraganglioma

The purpose of this study was to evaluate the role of 68Ga-labeled DOTANOC PET/CT for baseline evaluation of patients with head and neck paragangliomas (HNPs). Methods: The data for 26 patients (mean age ± SD, 34.3 ± 10.4 y; 50% men) with known or suspected HNPs who underwent 68Ga-DOTANOC PET/CT for staging were retrospectively analyzed. PET/CT was performed after intravenous injection of 132–222 MBq of 68Ga-DOTANOC. The images were evaluated by 2 experienced nuclear medicine physicians in consensus, both qualitatively and quantitatively. The PET/CT findings were grouped as HNPs, paraganglioma at other sites (non-HNPs), and metastatic disease. The size and maximum standardized uptake values (SUVmax) were measured for all lesions. All of the patients also underwent whole-body 131I-metaiodobenzylgunanidine (131I-MIBG) scintigraphy and conventional imaging (CT/MR imaging) of the head and neck region. Their results were compared with those of 68Ga-DOTANOC PET/CT. Results: 68Ga-DOTANOC PET/CT findings were positive in all 26 patients, and 78 lesions were detected. PET/CT imaging demonstrated 45 HNPS, 10 non-HNPs, and 23 metastatic sites. Fifteen patients (57.6%) had more than one site of disease on PET/CT. Among 45 HNPs, 26 were carotid body tumors (CBTs), 15 glomus jugulare, 3 glomus tympanicum, and 1 laryngeal paraganglioma. A positive correlation was seen between size and SUVmax of HNPs (ρ = 0.323; P = 0.030). The SUVmax of the CBTs was higher than that of jugulotympanic paragangliomas (P = 0.026). No correlation was seen between size and SUVmax (ρ = 0.069; P = 0.854) of non-HNPs. The size and SUVmax of non-HNPs were significantly less than those of HNPs (P = 0.029 and 0.047, respectively). 131I-MIBG scintigraphy showed only 30 of the 78 lesions and was inferior to PET/CT (P < 0.0001). Conventional imaging (CT/MR imaging) was positive for 42 of 49 head and neck lesions and was inferior to PET/CT on direct comparison (P = 0.015). A combination of CT/MR imaging and 131I-MIBG scintigraphy detected only 53 of 78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001). Conclusion: 68Ga-DOTANOC PET/CT is useful for the baseline evaluation of patients with HNPs and can demonstrate synchronous paragangliomas at other sites and distant metastases. It is superior to 131I-MIBG scintigraphy and conventional imaging (CT/MR imaging) for this purpose.

Can hybrid SPECT-CT overcome the limitations associated with poor imaging properties of 131I-MIBG?: Comparison with planar scintigraphy and SPECT in pheochromocytoma.

Objective This study aimed to evaluate the incremental value of 131I-MIBG hybrid SPECT-CT over planar scintigraphy (PS) and SPECT alone in patients with clinical or biochemical suspicion of pheochromocytoma. Methods A total of 126 adrenals of 63 patients (mean [SD] age, 28.6 [15.7] years; male patients, n = 34; female patients, n = 29) with clinical or biochemical suspicion of pheochromocytoma were retrospectively evaluated. All patients had undergone 131I-MIBG SPECT-CT of adrenal region. The PS, SPECT, and SPECT-CT images were independently evaluated by 2 nuclear medicine physicians with 6 years (R1) and 2 years (R2) experience and in separate sessions 1 week apart. A scoring scale of 1 to 5 was used, in which 1 is definitely abnormal, 2 is probably abnormal, 3 is indeterminate, 4 is probably normal, and 5 is definitely normal. Sensitivity, specificity, predictive values were calculated taking a score 2 or less as abnormal. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Histopathology and/or clinical/imaging follow-up were taken as reference standard. Results Of the 126 adrenals evaluated, 29 were indeterminate on PS for R1 and 48 for R2, 39 were indeterminate on SPECT for both, and on SPECT-CT, 1 was indeterminate for R1 and 2 for R2. SPECT-CT correctly characterized 28 of 29 indeterminate adrenals on PS and 37 of 39 indeterminate adrenals on SPECT for R1. Similarly, for R2, SPECT-CT correctly characterized 45 of 48 indeterminate adrenals on PS and 33 of 39 indeterminate adrenals on SPECT. On ROC comparison, PS was inferior to SPECT (P = 0.040 for R1; P < 0.001 for R2) and SPECT-CT (P = 0.001 for R1; P < 0.001 for R2) for both the observers. Moreover, SPECT was inferior to SPECT-CT for both the observers (P = 0.017 for R1 and P = 0.001 for R2). Accuracy of SPECT-CT (R1, 97.6%; R2, 97.6%) was higher than PS (R1, 91.2%; R2, 84.1%) and SPECT (R1, 94.4%; R2, 86.5%). Interobserver agreement was highest for SPECT-CT (&kgr; = 0.966) as compared with PS (&kgr; = 0.815) and SPECT (&kgr; = 0.826). Conclusions 131I-MIBG hybrid SPECT-CT shows high sensitivity and specificity for characterizing adrenal lesions in patients with clinical or biochemical suspicion of pheochromocytoma and is superior to PS and SPECT alone. It will be especially useful in countries where 123I-MIBG is not available.

Diagnostic value of 18F-FDG PET/CT in paediatric neuroblastoma: comparison with 131I-MIBG scintigraphy.

PurposeThe aim of the study was to evaluate the diagnostic value of fluorine-18 fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in paediatric patients with neuroblastoma (NB) and compare the results with iodine-131 metaiodobenzylguanidine (131I-MIBG) scintigraphy. MethodsData on 40 paediatric patients (age, 5.5±5.6 years; male, 32; female, eight) with histopathologically proven NB who underwent 18F-FDG PET/CT (staging, 21 patients; restaging/response monitoring, 19 patients) were retrospectively evaluated. 131I-MIBG scintigraphy data were available for 28/40 patients (median interval, 15 days; staging, 20 patients; restaging/response monitoring, eight patients). 131I-MIBG scintigraphy and 18F-FDG PET/CT images were evaluated by two nuclear medicine physicians in consensus and in separate sessions. Histopathology (n=50 lesions) and/or clinical/imaging follow-up (n=90 lesions) data were taken as the reference standard. ResultsPatient-wise sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of 18F-FDG PET/CT were 100, 50, 91.89, 100 and 92.50%, respectively. A total of 140 lesions (primary, 37; lymph node, 31; bone, 50; bone marrow, 15; and others, seven) were detected on PET/CT. In 28 patients undergoing both imaging studies, the sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of 18F-FDG PET/CT were 100, 60, 92, 100 and 92.80%, respectively, and those of 131I-MIBG were 95.65, 60, 91.67, 75 and 89.20%, respectively. In these 28 patients, PET/CT detected 107 lesions (primary, 25; lymph node, 22; bone/bone marrow, 56; and others, four) and 131I-MIBG scintigraphy detected 74 lesions (primary, 24; lymph node, five; and bone/bone marrow, 45). On a patient-based comparison there was no significant difference between 18F-FDG PET/CT and 131I-MIBG (P=1.000), but 18F-FDG PET/CT was superior to 131I-MIBG on a lesion-based comparison (P<0.0001). Although no difference was noted for primary lesions (P=1.000), PET/CT was superior to 131I-MIBG scintigraphy for the detection of lymph nodal (P=0.001) and bone/bone marrow lesions (P=0.007). Conclusion18F-FDG PET/CT shows high accuracy in paediatric patients with NB and demonstrates more lesions as compared with 131I-MIBG scintigraphy.

Hybrid SPECT-CT for characterizing isolated vertebral lesions observed by bone scintigraphy: comparison with planar scintigraphy, SPECT, and CT

PURPOSE We aimed to assess the role of single photon emission computed tomography-computed tomography (SPECT-CT) for characterizing isolated vertebral lesions observed by bone scintigraphy compared to planar scintigraphy, SPECT, and CT, and to evaluate the impact of SPECT-CT on patient management. MATERIALS AND METHODS Data from 99 patients (mean age, 52.4±18.9 years; females, 58.5%) with 108 isolated vertebral lesions visible on planar bone scintigraphy, who had undergone SPECT-CT of a selected volume, were retrospectively analyzed. Planar scintigraphy, SPECT, CT, and SPECT-CT images were independently evaluated in separate sessions to minimize recall bias. A scoring scale of 1 to 5 was used, with 1 being definitely metastatic, 2 most likely metastatic, 3 indeterminate, 4 most likely benign, and 5 definitely benign. Sensitivity, specificity, and predictive values were calculated; a score ≤3 was defined as metastatic. The areas under the receiver operating characteristic curve were calculated and compared. Clinical and imaging followup with or without histopathology were used as a reference standard. RESULTS Among the 108 lesions, 49 were indeterminate on planar scintigraphy, 16 on SPECT, and one each on SPECT-CT and CT. SPECT-CT was superior to both planar scintigraphy (P < 0.001) and SPECT alone (P = 0.014), but not to CT (P = 0.302). CT was superior to planar scintigraphy (P < 0.001) but only slightly superior to SPECT (P = 0.063). SPECT-CT correctly characterized 96% of the indeterminate lesions observed by planar scintigraphy. SPECT-CT had an impact on the clinical management of 60.6% patients compared to planar scintigraphy and 18.1% compared to SPECT. CONCLUSION SPECT-CT is better than planar scintigraphy and SPECT alone, but not CT alone, for characterizing equivocal vertebral lesions that are observed by bone scintigraphy, thus SPECT-CT can have a significant impact on patient management.

Von Hippel-Lindau Syndrome: Demonstration of Entire Disease Spectrum with 68Ga-DOTANOC PET-CT

Von Hippel-Lindau (VHL) syndrome is a rare neoplastic disorder characterized by central nervous system (CNS) and visceral tumors. We here present 68Ga-labelled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-Nal3-Octreotide positron emission tomography computed tomography findings in a 52 year old female with VHL syndrome, demonstrating both CNS and visceral tumors.

Prospective Evaluation of 18F-Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography for Response Evaluation in Recurrent Carcinoma Cervix: Does Metabolic Response Predicts Survival?

Purpose This study aimed to assess the role of 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG PET-CT) in response assessment of patients with recurrent carcinoma cervix and in evaluating the predictive value of metabolic response for progression-free survival (PFS) and overall survival (OS). Methods Thirty-six patients with histopathologically or clinically evident recurrent cervical carcinoma underwent a pretherapy and a posttherapy 18F-FDG PET-CT for treatment response evaluation. Positron emission tomography–CT images were analyzed by 2 experienced nuclear medicine physicians. Response was categorized using European Organization for Research and Treatment of Cancer (EORTC) criteria into complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD). Clinical/imaging follow-up (minimum of 6 months) and/or histopathologic findings were taken as reference standard. Patients were categorized into 2 groups, those with PMD and those without PMD (ie, CMR, PMR, and SMD). Progression-free survival and OS based on PET-CT response were measured from the date of posttherapy PET-CT to the first documentation of progression of disease and death, respectively. Results On the basis of metabolic response on posttherapy PET-CT, 6 patients had CMR, 12 patients had PMR, 7 patients had SMD, and 11 patients had PMD. Progression-free survival for patients with cervical carcinoma ranged from 0.5 to 26.5 months (mean [SD], 6.7 [6.1] months). Median PFS for patients with PMD was 3.1 months, whereas median PFS for those without PMD was not reached. Patients who did not show PMD on posttherapy PET-CT had a significantly better PFS than those patients who showed PMD (P < 0.0001; HR, 0.14). There was no statistically significant difference in OS between the 2 groups (P = 0.187; HR, 0.39). Conclusions 18F-fluorodeoxyglucose PET-CT is an effective tool for treatment response evaluation in recurrent carcinoma cervix. Patients with metabolically progressive disease on posttherapy 18F-FDG PET-CT have a significantly shorter PFS.PurposeThis study aimed to assess the role of 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG PET-CT) in response assessment of patients with recurrent carcinoma cervix and in evaluating the predictive value of metabolic response for progression-free survival (PFS) and overall survival (OS). MethodsThirty-six patients with histopathologically or clinically evident recurrent cervical carcinoma underwent a pretherapy and a posttherapy 18F-FDG PET-CT for treatment response evaluation. Positron emission tomography–CT images were analyzed by 2 experienced nuclear medicine physicians. Response was categorized using European Organization for Research and Treatment of Cancer (EORTC) criteria into complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD). Clinical/imaging follow-up (minimum of 6 months) and/or histopathologic findings were taken as reference standard. Patients were categorized into 2 groups, those with PMD and those without PMD (ie, CMR, PMR, and SMD). Progression-free survival and OS based on PET-CT response were measured from the date of posttherapy PET-CT to the first documentation of progression of disease and death, respectively. ResultsOn the basis of metabolic response on posttherapy PET-CT, 6 patients had CMR, 12 patients had PMR, 7 patients had SMD, and 11 patients had PMD. Progression-free survival for patients with cervical carcinoma ranged from 0.5 to 26.5 months (mean [SD], 6.7 [6.1] months). Median PFS for patients with PMD was 3.1 months, whereas median PFS for those without PMD was not reached. Patients who did not show PMD on posttherapy PET-CT had a significantly better PFS than those patients who showed PMD (P < 0.0001; HR, 0.14). There was no statistically significant difference in OS between the 2 groups (P = 0.187; HR, 0.39). Conclusions18F-fluorodeoxyglucose PET-CT is an effective tool for treatment response evaluation in recurrent carcinoma cervix. Patients with metabolically progressive disease on posttherapy 18F-FDG PET-CT have a significantly shorter PFS.

Malignant melanoma with cavitary pulmonary metastasis: Diagnostic dilemma resolved by FDG PET/CT guided biopsy

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18F-FDG PET-CT for Evaluation of Cardiac Angiosarcoma: A Case Report and Review of Literature.

Cardiac angiosarcomas are rare neoplasms. We here present the case of a 24 year old male with a cardiac mass which was characterised as malignant on 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT). In addition 18F-FDG PET-CT also demonstrated pericardial infiltration and bone metastases. The tumor was confirmed to be angiosarcoma on biopsy and palliative chemotherapy was started. Here we have highlighted the potential role of 18F-FDG PET-CT in patients with cardiac angiosarcoma and presented a brief review.

68Ga-DOTANOC PET/CT imaging in glomus laryngicum.

Glomus laryngicum (laryngeal paraganglioma) are extremely rare neoplasm of the larynx. We here present the 68Ga-DOTANOC PET/CT images of a 40-year-old male patient with glomus laryngicum. In this report, we have highlighted the potential utility and limitations of 68Ga-DOTANOC PET/CT imaging in patients with glomus laryngicum.

Pineal gland involvement in Erdheim–Chester disease detected on 18F-FDG PET-CT imaging: a case report and review of literature

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis affecting multiple organ systems. The most common systemic manifestations are bone lesions, infiltration of the pituitary stalk sometimes leading to diabetes insipidus, pulmonary fibrosis, cardiac failure and exophthalmus. Neurological symptoms as the first clinical manifestations of ECD have been reported in less than one third of cases. We report a rare presentation of a patient of ECD on 18F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography which revealed abnormal (18)F-FDG accumulation in the region of pineal gland, pericardium and bilateral distal tibiae.