Tarun Kumar Jain

Utility of 18F-FDG PET-CT in staging and restaging of patients with malignant salivary gland tumours: a single-institutional experience

ObjectiveThe aim of this study was to evaluate the clinical utility of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography–computed tomography (PET-CT) in staging and restaging of patients with malignant primary salivary gland tumours. MethodsData pertaining to 30 patients (age: 43.8±16.8 years; male/female: 20/10) with histopathologically proven malignant primary salivary gland tumours who underwent 36 18F-FDG PET-CTs were retrospectively analysed. Ten PET-CTs were performed for staging and 26 for restaging. The primary site was the parotid gland in 22 patients, the submandibular gland in seven and the minor salivary gland in one patient. 18F-FDG PET-CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local disease, nodal disease and distant metastasis. Results were compared with those of conventional imaging modalities [CIM (CT/ultrasound/bone scintigraphy)] when available (n=28). Clinical or imaging follow-up (minimum 6 months) data along with histopathological information (when available) were taken as the reference standard. ResultsOverall, 25 PET-CTs were positive and 11 were negative for disease. 18F-FDG PET-CT showed local disease in 21 patients, nodal disease in 17 and distant metastasis in nine (lungs, four; liver, three; bones, four; and thyroid, one). Twenty-three PET-CTs were true positive, nine were true negative, two were false positive and two were false negative. The overall sensitivity of 18F-FDG PET-CT was 92%, specificity was 82%, positive predictive value was 92%, negative predictive value was 82% and accuracy was 89%. No significant difference was seen in the accuracy of PET-CT between the staging and restaging groups (100 vs. 85%; P=0.468). In patients for whom comparable CIM data were available (n=28), PET-CT did not show any significant advantage over CIM (P=0.012) but was more specific (71 vs. 43%). Conclusion 18F-FDG PET-CT shows high accuracy in staging and restaging of patients with malignant primary salivary gland tumours. It is more specific than CIM for this purpose.

Antenatal MRI Diagnosis of Massive Subchorionic Hematoma: A Case Report

Massive subchorionic hematoma is a large maternal blood clot, which separates the chorionic plate from the villous chorion [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. It is an uncommon condition associated with poor perinatal prognosis and intrauterine growth retardation [Tan WH, et al: Fetal Diagn Ther 1997;76:381–383, Nishijima K, et al: Fetal Diagn Ther 2005;20:23–26]. Ultrasound may not be able to differentiate this condition from other placental abnormalities [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. We report a case of massive subchorionic hematoma where the antenatal diagnosis was made on MRI.

Recurrent dermatofibrosarcoma protuberans with pulmonary metastases presenting twelve years after initial diagnosis: 18F-FDG PET/CT imaging findings.

Dermatofibrosarcoma protuberans is a rare cutaneous tumor that is locally aggressive and has a high rate of recurrence after surgical excision. The tumor grows slowly, typically over years. On rare occasions, metastasis to distant sites (especially the lung) or regional lymph nodes may occur. Here, we present F-FDG PET/CT imaging findings of a 52-year-old man with a local recurrence of dermatofibrosarcoma protuberans in the anterior abdominal wall with metastases to bilateral lungs.

68Ga-PSMA Expression in Pseudoangiomatous Stromal Hyperplasia of the Breast.

Ga-labeled prostate-specific membrane antigen ligand PET-CT has emerged as a promising technique to evaluate the extent of disease in patients with prostate carcinoma. We are reporting a 63-year-old man with prostatic carcinoma subjected to Ga-prostate-specific membrane antigen ligand PET-CT for initial staging. In addition to the radiotracer uptake in known primary site (prostate), focal increased radiotracer uptake was also noticed in the left breast. Subsequent biopsy of the breast lesion revealed PASH (pseudoangiomatous stromal hyperplasia), which is a benign mesenchymal proliferative lesion that may present clinically as palpable mass requiring further evaluation to rule out malignancy.

Comparison of single photon emission computed tomography-computed tomography, computed tomography, single photon emission computed tomography and planar scintigraphy for characterization of isolated skull lesions seen on bone scintigraphy in cancer patients

Purpose: The purpose of this study is to evaluate the added value of single photon emission computed tomography-computed tomography (SPECT-CT) over planar scintigraphy, SPECT and CT alone for characterization of isolated skull lesions in bone scintigraphy (BS) in cancer patients. Materials and Methods: A total of 32 cancer patients (age: 39.5 ± 21.9; male: female - 1:1) with 36 isolated skull lesions on planar BS, underwent SPECT-CT of skull. Planar BS, SPECT, CT and SPECT-CT images were evaluated in separate sessions to minimize recall bias. A scoring scale of 1-5 was used, where 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. With receiver operating characteristic analysis area under the curves (AUC) was calculated for each modality. For calculation of sensitivity, specificity and predictive values a Score ≤3 was taken as metastatic. Clinical/imaging follow-up and/or histopathology were taken as reference standard. Results: Of 36 skull lesions 11 lesions each were on frontal, parietal and occipital bone while three lesions were in the temporal bone. Of these 36 lesions, 16 were indeterminate (Score-3) on planar and SPECT, five on CT and none on SPECT-CT. The AUC was largest for SPECT-CT followed by CT, SPECT and planar scintigraphy, respectively. Planar scintigraphy was inferior to SPECT-CT (P = 0.006) and CT (P = 0.012) but not SPECT (P = 0.975). SPECT was also inferior to SPECT-CT (P = 0.007) and CT (P = 0.015). Although no significant difference was found between SPECT-CT and CT (P = 0.469), the former was more specific (100% vs. 94%). Conclusion: SPECT-CT is better than planar scintigraphy and SPECT alone for correctly characterizing isolated skull lesions on BS in cancer patients. It is more specific than CT, but provides no significant advantage over CT alone for this purpose.

Multiple hepatic lesions in a case of isolated hepatic tuberculosis simulating metastases on 18F-FDG PET/CT imaging

Hepatic tuberculosis is an unusual form of extrapulmonary tuberculosis and constitutes less than 1% of all cases of tuberculosis. Imaging studies for hepatic tuberculosis are nonspecific and mimic primary or metastatic carcinoma. Here we present ¹⁸F-FDG PET/CT images of a 25-year-old male patient with isolated hepatic tuberculosis.

18F-FDG PET/CT Imaging in Adrenal Cryptococcosis.

Cryptococcosis is a fungal infection, relatively rare in the absence of impaired immunity. Lung or brain may be involved. Cryptococcal dissemination is rare in absence of impaired immunity, and documentation of alone adrenal involvement without central nervous system involvement is rare. Here, we present a case of an immunocompetent patient presented with bilateral adrenal cryptococcosis with adrenal insufficiency, without central nervous system involvement and F-FDG PET/CT correctly identified the residual disease.

Gallbladder Carcinoma Metastasizing to Adrenal Gland: A Rare Site Demonstrated With 18F-FDG PET/CT

Adrenal metastases have commonly been reported in a wide variety of cancers but not in gallbladder cancer. We here present a case of a 45-year-old male patient with gallbladder carcinoma where left adrenal metastasis was detected on staging F-FDG PET/CT. This was confirmed histopathologically. F-FDG PET/CT can have a significant impact on management of patients with gallbladder carcinoma by demonstrating rare sites of metastasis.

Malignant Jugular Paraganglioma: Unusual Presentation on 68Ga DOTANOC PET/CT.

Metastatic jugular paraganglioma are rare tumors and account for less than 1% of the cases of head and neck tumors. We report a 40-year-old woman of jugular paraganglioma, presenting with right-sided neck swelling, hearing loss, and pulsatile tinnitus. Contrast-enhanced CT temporal bone revealed a mass in the right jugular foramina and extending inferiorly to internal jugular vein. Ga DOTANOC PET/CT was performed, which revealed somatostatin receptor expressing lesion in the right internal jugular vein and extension into sigmoid sinus and additional metastatic focus in the sacrum.

Carcinoma of unknown primary of neuroendocrine origin: Accurate detection of primary with 68 Ga-labelled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI3-Octreotide positron emission tomography/computed tomography enterography

68Ga-labelled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI3-Octreotide (68Ga-DOTANOC) positron emission tomography/computed tomography (PET/CT) is an excellent modality in patients with carcinoma of unknown primary of neuroendocrine origin. Most of the primary lesions are located in mid gut region where the lesions have poor resolution due to undistended and overlapping intestinal loops and motility-related artifacts. Although PET/CT enteroclysis, enterography and colonography have been described with 18F-fluorodeoxyglucose, PET/CT enterography with68Ga-DOTANOC has not been described in the literature. Here, we present a case where68Ga-DOTANOC PET/CT enterography was useful in identifying the primary neuroendocrine tumor lesion in small intestine with accurate delineation.