Bangkim Chandra Khangembam

Can 18F-FDOPA PET/CT predict survival in patients with suspected recurrent glioma? A prospective study

UNLABELLED Purpose of the present study was to evaluate the role of (18)F-FDOPA PET/CT for predicting survival in patients with suspected recurrent glioma. METHODS A total of 33 previously treated, histopathologically proven glioma patients with clinical and contrast enhanced MRI findings suspicious for recurrence were enrolled in this prospective study. All patients underwent (18)F-FDOPA PET/CT. Ratios of tumor uptake to normal tissue uptake were generated by dividing the tumor SUVmax with SUVmax of the contralateral normal brain tissue (T/N), normal striatum (T/S), normal white matter (T/W) and normal cerebellum (T/C). Patients were followed up clinically and by repeated imaging. Data was censored, if the patient died of disease or at the end of the study. Survival analysis was performed for the distributions of each variable and by multivariate analysis. RESULTS (18)F-FDOPA PET/CT was positive for recurrence in 25 patients and negative in 8. Death occurred in nineteen patients. Median follow up period was 20.2 months. Median survival in this study was 39.2 months. In univariate analysis significant association of survival was noted with results of (18)F-FDOPA PET/CT (P=0.007) and (18)F-FDOPA PET/CT quantitative parameters namely SUVmax (P=0.001), T/S (P=0.005), T/W (P=0.0004), T/N (P=0.001) and T/C (P=0.003) were found to be significant. On multivariate analysis, only MRI size of the recurrent tumor (P=0.002) and T/N ratio of (18)F-FDOPA PET/CT (P=0.005) were found to be independent predictors of survival. CONCLUSION T/N ratio on (18)F-FDOPA PET/CT is an independent predictor of survival in patients with suspected recurrent glioma, along with size of recurrent tumor on MRI.

68Ga DOTANOC PET/CT for accurate delineation of disease extent in a case of sinonasal small cell neuroendocrine carcinoma.

Neuroendocrine tumors constitute a heterogeneous group of neoplasms arising from the cells of the neural crest. We present a rare case of primary sinonasal neuroendocrine carcinoma in a 61-year-old male patient where somatostatin receptor PET/CT with 68Ga-DOTANOC correctly delineated the extent of primary tumor as compared to contrast-enhanced CT, thereby changing patient management.

Solitary breast metastasis from recurrent gallbladder carcinoma simulating a second primary on 18F-FDG PET/CT.

Gallbladder carcinoma is characterized by poor prognosis. It spreads by direct, lymphatic, vascular, neural, intraperitoneal, and intraductal routes. The most commonly involved organ is the liver followed by regional lymph nodes. Extra-abdominal metastases are comparatively rare. We present a case of solitary breast metastasis from recurrent gallbladder carcinoma mimicking a primary breast cancer in (18)F-FDG PET/CT.

Isolated cardiac metastasis in a patient with neuroendocrine carcinoma of pancreas discovered on 68Ga-DOTANOC PET/CT

We present an interesting image that demonstrates utility of 68Ga-DOTANOC PET/CT for demonstrating rare metastatic sites of neuroendocrime tumor.

Utility of 99m Tc-MDP SPECT-CT for the diagnosis of sesamoiditis as cause of metatarsalgia

Metatarsalgia is a general term for pain in the area of the metatarsophalangeal joints. Sesamoiditis is an uncommon cause of metatarsalgia. It is pain at the sesamoid bones beneath the head of the first metatarsal with inflammation or fracture. The diagnosis is usually clinical, with localized tenderness on palpation. Diagnosing the cause of metatarsalgia in patients without this classical sign is difficult. We present here such a case of a 37-year-old lady in whom sesamoiditis was diagnosed with technetium-99m (99mTc)-methylene diphosphonate (MDP) single photon emission tomography-computed tomography (SPECT-CT).

Schmorl's node mimicking metastasis in a patient with breast cancer: diagnosis with 99mTC methylene diphosphonate SPECT-CT.

Schmorls node (SN) is a common entity characterized by protrusion of intervertebral disc material through a break in the subchondral end plate of a vertebral body. They can show increased 99mTC methylene diphosphonate uptake on bone scintigraphy mimicking metastasis and can be symptomatic. Differentiation of SN from metastasis is essential for appropriate patient management. Here, we present a case where increased 99mTC methylene diphosphonate uptake in a dorsal vertebra was found to be because of SN by using single-photon emission computed tomography-computed tomography.

13N-Ammonia PET/CT for detection of recurrent glioma: a prospective comparison with contrast-enhanced MRI.

PurposeWe assessed the value of 13N-ammonia PET-computed tomography (PET/CT) in recurrent glioma and compared the results with those of contrast-enhanced MRI (CE MRI). Materials and methodsFifty-two (mean age, 39.8±11.6 years; male, 33; female, 19) histopathologically proven and previously treated glioma patients with clinical suspicion of recurrence were evaluated with 13N-ammonia PET/CT and CE MRI. PET/CT images were evaluated qualitatively and quantitatively (maximum standardized uptake value). Tumour to white matter (T/W), tumour to grey matter (T/G) and tumour to pituitary (T/P) ratios were calculated and cutoff levels were derived with receiver operating characteristic curve analysis. Sensitivity, specificity and predictive values were compared. A combination of clinical follow-up, repeat imaging and biopsy (when available) was taken as the reference standard. ResultsOn the basis of the reference standard, 23 out of 52 patients were seen to have recurrence. Overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 13N-ammonia PET/CT were 82.6, 86.2, 82.6, 86.2 and 84.6%, respectively, whereas those of CE MRI were 96.7, 48.3, 59.5, 93.3 and 69.2%, respectively. Overall, 13N-ammonia PET/CT was statistically superior to CE MRI (P=0.001). In low-grade tumours, 13N-ammonia PET/CT performed better than MRI with an accuracy of 86.8 versus 68.4% (P=0.003). In high-grade tumours, both the modalities had comparable performances with accuracies of 78.6% for 13N-ammonia PET/CT and 71.4% for CE MRI (P=0.250). Among the ratios, T/P was the most useful, with the largest area under the curve (0.825; P=0.0001). Conclusion13N-Ammonia PET/CT shows higher accuracy compared with contrast-enhanced MRI for detecting recurrent gliomas, particularly in low-grade tumours.

Intradiploic epidermoid cyst mimicking skull metastasis in a patient with primitive neuroectodermal tumor: Correct diagnosis with 99mTc-MDP hybrid SPECT-CT

A 14-year-old child was diagnosed with primitive neuroectodermal tumor (PNET) of pelvis. Baseline 99mTc-methtylene diphosphonate (MDP) bone scintigraphy done to know the extent of the disease, although of suboptimal quality, revealed involvement of right hemipelvis (A, arrowhead) (Fig. 1). Also, there was a focus of increased radiotracer uptake in the occipital bone (B, arrow). Since the patient had no history of trauma, in the clinical context the lesion was thought to be metastasis. The patient underwent chemotherapy and was again sent for bone scintigraphy, for response monitoring. The follow up planar bone scintigraphy done 6 weeks after completion of chemotherapy showed significant reduction in radiotracer uptake in the right hemipelvis (C, arrowhead), but the skull lesion still showed intense radiotracer uptake (D, arrow). To characterize the skull lesion, the patient underwent hybrid single photon emission tomography-computed

Lymphomatous involvement of epididymis: detection and response assessment with (18)F-FDG PET/CT.

Lymphomatous involvement of epididymis, primary or secondary to extensive extranodal disease, is a rare entity. We describe a case of extranodal non-Hodgkin lymphoma where staging F-FDG PET/CT demonstrated unsuspected lymphomatous involvement of epididymis and restaging FDG PET/CT showed complete response after chemotherapy.

Surgical Scar Site Recurrence in Patients With Cervical Cancer on 18F-FDG PET-CT: A Case-Control Study.

Purpose The purpose of this study was to assess the role of fluorine 18 (18F)-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in evaluating various parameters in patients with surgical scar site recurrence in cervical carcinoma. Methods Data of all patients with cervical cancer (n = 329) who underwent PET-CT at our institute between 2005 and 2013 was reviewed. Of these 329 patients, 132 patients who were surgically treated and underwent restaging/follow-up PET-CT were included in the present study for final analysis. Tumor recurrence at the abdominal surgical scar site was looked for. Abnormal uptakes suggestive of active disease at other sites were also noted. Maximum standardized uptake value was measured for all the lesions. Patients with scar site recurrence were taken as cases (n = 6), whereas the remaining patients served as controls (n = 126). Comparison with conventional imaging modalities was made wherever available. Histopathological examination was always sought for. Results The incidence of scar site recurrence after surgery was found to be 4.5% (6/117). A total of 56 of 132 patients had recurrent disease, including 6 patients with scar site recurrence. All of the patients with scar site recurrence also had recurrent disease at other sites (local, nodal, or distant). Conventional imaging modalities were available in 4 of these 6 patients and detected scar site recurrence in 3 of those 4 patients. In patients with scar site recurrence, the mean ± SD time to scar site recurrence was 14.0 ± 10.9 months (median, 10 months; range, 7–36 months). Significant difference was seen between cases and control for International Federation of Genecology and Oncology stage (P = 0.001) and nodal recurrence (P = 0.007). Additionally, age, nodal recurrence, distant recurrence, and scar site recurrence were significantly associated with death. Conclusions Scar site recurrence carries a poor prognosis, and the incidence is much higher than previously known when PET-CT is used as a modality for its detection.