Impact of Fluoro-Choline PET/CT in Reduction in Failed Parathyroid Localization in Primary Hyperparathyroidism.

INTRODUCTION: Accurate localization of the pathological parathyroid gland is a prerequisite for minimally invasive surgical management of hyperparathyroidism (HPT). Poor imaging or discordance in odd situations like ectopic adenomas, parathyroid hyperplasia, syndromic HPT results in localization dilemma thus causing failed parathyroidectomy. We studied the impact of Fluoro-Choline (FCH) PET/CT imaging in reduction in localization failure of parathyroid adenoma. MATERIALS AND METHODS: We did a retrospective observational study (2018-2021) of HPT among which 97 patients underwent focused parathyroidectomy (FP). All patients had undergone ultrasound imaging and 99mTc-sestaMIBI scan with early SPECT/CT (MIBI). When this preliminary imaging was doubtful or negative or multiple lesions were expected, FCH PET/CT was performed. We compared the localization accuracy of MIBI scan and FCH PET/CT with surgical outcomes as reference standard. RESULTS: MIBI scan showed overall lesion detection rate (LDR) of 88.65% in localization of pathological parathyroid gland in 97 patients. The addition of FCH PET/CT improved the overall lesion detection to 97.9%. The overall possible localization failure was reduced from 11.34 to 2.06% with the addition of FCH PET/CT (p < 0.05). Out of 97 patients of FP, 87 patients showed features of parathyroid adenoma. Single hyperplastic gland was seen in 7 patients, lipoadenoma was seen in 1 patient and 1 patient had features suggestive of parathyroiditis on histopathology. FCH PET/CT was a useful adjunct and showed significant reduction in localization failure of parathyroid adenoma.

Multi-time point imaging in 99m Tc-pertechnetate scintigraphy of ectopic gastric mucosa in duplication cysts: value-added services.

OBJECTIVES: The aim of our study was to describe the scintigraphic patterns of 99m Tc-pertechnetate uptake in patients who were referred to the department of nuclear medicine for evaluating and diagnosing ectopic gastric mucosa in foregut and midgut duplication cysts. MATERIALS AND METHODS: This hospital-based, retrospective cum prospective research spans a period of 8 years from April 2014 to January 2022. Previous hospital medical records were analyzed and subsequently, a database was prepared which included the age, sex, clinical indication of a 99m Tc-pertechnetate scan, and the planar and SPECT-computed tomography (CT) imaging findings. Postoperative histopathological reports were available for 21 patients. Dynamic and planar static imaging was performed. We included SPECT-CT in suspected duplication cysts to increase the sensitivity and specificity which is a tradeoff for a small amount of additional radiation exposure. A total of 69 patients were subjected to a 99m Tc-pertechnetate scan for suspected foregut or midgut duplication cysts. All were subjected to dynamic planar and delayed static images up to 24 h or until focal uptake of radiotracer was noted which corroborated the anatomical findings, whichever was earlier. SPECT-CT was performed along with the planar study in 31 patients which confirmed the findings. Previously performed CT scans were used for anatomical correlation in the remaining ones. RESULTS: Duplication cysts were localized in a total of 28 patients (19 foregut duplication cysts and 12 small bowel duplications - 3 patients had dual duplication cysts, both foregut, and midgut). Forty-one patients had no scintigraphic evidence of ectopic gastric mucosa. Of these 69 patients, histopathological diagnosis was available for 21 patients (22 lesions). The report was concordant with the scan findings in 15 patients (16 lesions) and 6 patients showed discordance in histopathological diagnosis and scan findings. CONCLUSION: In conclusion, multi-time point imaging is the key to diagnosing ectopic gastric mucosa of various sizes and in various locations. An abnormal radiotracer uptake in dynamic sequences, even before the appearance of the stomach in the region of the small bowel is indicative of intestinal duplication, and delayed radiotracer visualization in the region of the thorax is characteristic of intrathoracic foregut duplication cyst.

Designing and Comparing Performances of Image Processing Pipeline for Enhancement of I-131-metaiodobenzylguanidine Images.

OBJECTIVE: An image processing pipeline can have more than one image processing technique in sequence, and the output of the first technique becomes input for the next technique and so on. In this study, we have designed and compared the performances of image processing pipelines for enhancement of I-131-metaiodobenzylguanidine (mIBG) images. MATERIALS AND METHODS: Five different image processing pipelines (A [Gaussian filter, normalization], B [histogram specification (image 1), Gaussian filter, normalization], C [histogram specification (image 2), Gaussian filter, normalization], D [{histogram specification (image 3), Gaussian filter, and normalization], and E [histogram specification (image 4), Gaussian filter, normalization]) were designed and their performances were evaluated on I-131-mIBG images (n = 122). The image quality was assessed objectively using Perception-based Image Quality Evaluator (PIQE) score and subjectively (on scale 1-4) by two nuclear medicine physician. Sign test was applied to find the statistically significant difference between the image quality obtained using image processing pipelines. We applied test of proportion to compute difference in proportion of image quality score assigned to images obtained using image processing pipelines. RESULTS: Based on PIQE score, the quality of images obtained using all the five image processing pipelines were significantly better than that of input images (P < 0.001). The highest image quality score (=4) was assigned maximum number of times (n = 90) to the images obtained using image processing pipeline D and was significantly different from that of the second best image processing pipeline E (P = 0.015). CONCLUSIONS: The image processing pipeline D was found to be better for enhancement of I-131-mIBG images.

Fuzzy logic-based moving average filters for reducing noise from Tc-99m-sestamibi parathyroid images.

INTRODUCTION: The objective of the study was to use fuzzy logic-based moving average filters for reducing noise from Tc-99m-sestamibi parathyroid images and to compare its performance with classical moving average filters. METHODS: Sixty-eight Tc-99m-sestamibi parathyroid images (33 image zoom 1.0, 35 images zoom 2.0) were filtered using symmetric triangular fuzzy filters with the moving average (TMAV), asymmetric triangular fuzzy filters with the moving average (ATMAV) and classical moving average filter (MAV) with moving average within a square window of dimension N × N pixels (N=3,5,7,9,11). The relative filtering performance was compared both objectively (using Brisque score) and subjectively [by two nuclear medicine physicians on a 4-point scale (1 = nondiagnostic; 2 = diagnostic; 3 = good; and 4 = excellent image quality)]. The nonparametric two-sample Kolmogorov-Smirnov test was applied to find the statistically significant difference between the quality of input and their corresponding filtered images. RESULTS: The Brisque score assigned to MAV filtered zoom 2.0 images (MAV_3, median = -0.61) were significantly smaller than that of their input images (median = 53.84, at P = 1) and fuzzy filtered images (TMAV_3, median = 0.44, at P = 0.89 and ATMAV_3, median =8.26, at P = 0.97). The sum of average subjective image quality score for input, MAV_3, TMAV_3, TMAV_5, ATMAV_3, and ATMAV_5 were 148, 221, 221.5, 198,171,253 and 237.5, respectively. CONCLUSION: On the basis of subjective assessment, the performance of ATMAV_3 fuzzy filter was found to be better compared to the classical moving average filter in reducing noise from Tc-99m-sestambi parathyroid images.

Evaluation of CYFRA 21.1 as a Dedifferentiation Marker of Advanced Thyroid Cancer.

PURPOSE OF THE STUDY: Well-differentiated thyroid carcinomas have good prognosis, but as it de-differentiates, the survival rates go down. Early identification of such patients needs a marker which indicates the dedifferentiation process. CYFRA 21.1 has also shown to be increased in patients with 131I refractory thyroid cancer. We tested whether CYFRA 21.1 can differentiate between 131I avid and refractory tumors. METHODOLOGY: Well-differentiated thyroid cancer patients with known distant metastases were accrued and tested for stimulated and unstimulated thyroglobulin and CYFRA 21.1. All patients underwent 131I whole-body scan, 131I post therapy scan, and 18F-Fluorodeoxyglucose positron emission tomography-computed tomography. Those with even a single 131I nonavid lesion were considered 131I refractory disease. CYFRA 21.1 of both 131I avid and nonavid was compared, and CYFRA 21.1 levels against disease extent were analyzed. RESULTS: CYFRA 21.1 levels were significantly elevated in 131I refractory group. A cutoff value of 2.07 ng/ml distinguished between 131I avid and refractory disease with high sensitivity and specificity (88% and 89. 7%, respectively). However, CYFRA 21.1 levels were similar in patients when analyzed based on disease sites. CONCLUSION: CYFRA 21.1 can be utilized to differentiate between 131I avid and refractory diseases. Further long-term studies are required to use it as a predictive and prognostic marker.

Restoration of I-131 whole body image using a Wiener filter.

INTRODUCTION: The aim of the study was to restore I-131 whole body image using Wiener filter. MATERIAL AND METHODS: A set of 50 I-131 whole body images acquired using Symbia E dual head gamma camera with high energy general purpose collimator was used. The Gaussian point-spread function (PSF) characterised by the size (3, 5, 7, 9, 11, and 13 pixels) and corresponding standard deviation (0.5, 0.75, 1, 1.5, 1.75, and 2 pixels) and noise-to-signal power ratios (NSR: 0, 0.001, 0.01, 0.1, 0.2, 0.3, 0.4, and 0.5) were used as parameters for Wiener filter. Using the combinations of PSF and NSR, a total of 2450 images (50 × 49 = 2450 images, where 49 images include 1 input and 48 restored images for each input image) were generated and inspected by two nuclear medicine physicians. They selected one best image (the image which had less noise and better contrast between the lesion and background in comparison with the input image). Their results were analyzed. RESULTS: Compared to input image, the metastatic uptake in restored images was very easily perceived. The restored image obtained with PSF (size = 13, sigma = 2) and NSR = 0.3 had better signal-to-noise ratio in comparison to restored image obtained with PSF (size = 11, sigma = 1.75) and NSR = 0.2. CONCLUSION: The restored images with PSF (size = 13, sigma = 2) and NSR = 0.3 were found to have superior image quality in comparison with its input image.

Efficacy and Safety of 177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer Patients.

PURPOSE: The aim of this study was to evaluate the efficacy and safety of Lu-PSMA-617 radioligand therapy in metastatic castration-resistant prostate cancer (mCRPC). METHODS: In this prospective, single-arm, single-institutional study, 90 mCRPC patients with progressive disease (PD) on second-line hormonal therapy and/or docetaxel chemotherapy were recruited for the study. All patients underwent diagnostic Ga-PSMA-HBED-CC PET/CT, prior to inclusion for therapy. Included patients underwent Lu-PSMA-617 therapy at 8- to 12-weekly intervals. The primary end point was to assess the overall survival. The secondary and cosecondary end points included biochemical response assessment as per the Prostate Cancer Working Group 3 criteria, progression-free survival, radiological and molecular response criteria, clinical response, safety profile, and disease control rates. All the outcome parameters were evaluated in 90 patients except for the radiographic and molecular response, which was evaluated in 69 patients. RESULTS: The median age of patients was 66.5 years (range, 30-88 years). The median activity administered per cycle was 3.7 to 8 GBq ranging from 1 to 7 cycles, and patients were followed up over a median duration of 28 months. At 2- to 3-month interval after the first therapy and the end of the assessment, greater than 50% decline in prostate-specific antigen was observed in 32.2% and 45.5%, respectively. Univariate analysis did not reveal any variables such as prior therapies, laboratory parameters, concomitant hormonal therapy, and SUV patient parameters associated with prostate-specific antigen decline. Radiographic response by diagnostic CT revealed partial remission in 23% (16/69), stable disease in 54% (37/69), and PD in 23% (16/69) of patients. Molecular tumor response by PET Response Criteria in Solid Tumor 1 criteria revealed 19 (27.5%) of 69 patients with partial remission, 30 (43.5%) of 69 with stable disease, and 20 (29%) of 69 with PD. The disease control rates according to the radiographic and molecular response were 77% and 71%, respectively. The median overall survival and median progression-free survivals were 14 and 11.8 months, respectively. Toxicities related to radioligand therapy were low and transient with no serious adverse effects. CONCLUSIONS: Lu-PSMA-617 radionuclide therapy is a safe and effective approach to the treatment of mCRPC patients.

Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

PURPOSE OF THE STUDY: 99mTechnetium-methylene diphosphonate (99mTc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99mTc-MDP-bone scan images. MATERIALS AND METHODS: A set of 89 low contrast 99mTc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. RESULTS: This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t-test was applied, and a statistically significant difference in the input and processed image quality was found at P < 0.001 (with α = 0.05). However, further improvement in image quality is needed as per requirements of nuclear medicine physicians. CONCLUSION: GHE techniques can be used on low contrast bone scan images. In some of the cases, a histogram equalization technique in combination with some other postprocessing technique is useful.

Development of a Simple Image Processing Application that Makes Abdominopelvic Tumor Visible on Positron Emission Tomography/Computed Tomography Image.

INTRODUCTION: In this study, we have developed a simple image processing application in MATLAB that uses suprathreshold stochastic resonance (SSR) and helps the user to visualize abdominopelvic tumor on the exported prediuretic positron emission tomography/computed tomography (PET/CT) images. METHODS: A brainstorming session was conducted for requirement analysis for the program. It was decided that program should load the screen captured PET/CT images and then produces output images in a window with a slider control that should enable the user to view the best image that visualizes the tumor, if present. The program was implemented on personal computer using Microsoft Windows and MATLAB R2013b. RESULTS: The program has option for the user to select the input image. For the selected image, it displays output images generated using SSR in a separate window having a slider control. The slider control enables the user to view images and select one which seems to provide the best visualization of the area(s) of interest. CONCLUSION: The developed application enables the user to select, process, and view output images in the process of utilizing SSR to detect the presence of abdominopelvic tumor on prediuretic PET/CT image.

Identification of optimal mask size parameter for noise filtering in 99mTc-methylene diphosphonate bone scintigraphy images.

Tc-methylene diphosphonate (Tc-MDP) bone scintigraphy images have limited number of counts per pixel. A noise filtering method based on local statistics of the image produces better results than a linear filter. However, the mask size has a significant effect on image quality. In this study, we have identified the optimal mask size that yields a good smooth bone scan image. Forty four bone scan images were processed using mask sizes 3, 5, 7, 9, 11, 13, and 15 pixels. The input and processed images were reviewed in two steps. In the first step, the images were inspected and the mask sizes that produced images with significant loss of clinical details in comparison with the input image were excluded. In the second step, the image quality of the 40 sets of images (each set had input image, and its corresponding three processed images with 3, 5, and 7-pixel masks) was assessed by two nuclear medicine physicians. They selected one good smooth image from each set of images. The image quality was also assessed quantitatively with a line profile. Fisher's exact test was used to find statistically significant differences in image quality processed with 5 and 7-pixel mask at a 5% cut-off. A statistically significant difference was found between the image quality processed with 5 and 7-pixel mask at P=0.00528. The identified optimal mask size to produce a good smooth image was found to be 7 pixels. The best mask size for the John-Sen Lee filter was found to be 7×7 pixels, which yielded Tc-methylene diphosphonate bone scan images with the highest acceptable smoothness.

Development and Validation of the Suprathreshold Stochastic Resonance-Based Image Processing Method for the Detection of Abdomino-pelvic Tumor on PET/CT Scans.

PURPOSE: The detection of abdomino-pelvic tumors embedded in or nearby radioactive urine containing 18F-FDG activity is a challenging task on PET/CT scan. In this study, we propose and validate the suprathreshold stochastic resonance-based image processing method for the detection of these tumors. METHODS: The method consists of the addition of noise to the input image, and then thresholding it that creates one frame of intermediate image. One hundred such frames were generated and averaged to get the final image. The method was implemented using MATLAB R2013b on a personal computer. Noisy image was generated using random Poisson variates corresponding to each pixel of the input image. In order to verify the method, 30 sets of pre-diuretic and its corresponding post-diuretic PET/CT scan images (25 tumor images and 5 control images with no tumor) were included. For each sets of pre-diuretic image (input image), 26 images (at threshold values equal to mean counts multiplied by a constant factor ranging from 1.0 to 2.6 with increment step of 0.1) were created and visually inspected, and the image that most closely matched with the gold standard (corresponding post-diuretic image) was selected as the final output image. These images were further evaluated by two nuclear medicine physicians. RESULTS: In 22 out of 25 images, tumor was successfully detected. In five control images, no false positives were reported. Thus, the empirical probability of detection of abdomino-pelvic tumors evaluates to 0.88. CONCLUSION: The proposed method was able to detect abdomino-pelvic tumors on pre-diuretic PET/CT scan with a high probability of success and no false positives.

Utility of a questionnaire tool (QUARAS) for localizing and lateralizing seizures in the epilepsy monitoring unit (EMU).

OBJECTIVES: An accurate description of the seizure semiology improves the recognition of the ictal onset zone and helps in hypothesizing the possible epileptogenic zone (EZ). Semiology based on a reliable description of seizures may be as good as investigative modalities, as has been shown by numerous studies. The main objective of this study was to apply a questionnaire-tool for auras and semiology (QUARAS) in refractory epilepsy cohort and compare its yield to that of standard history-taking. METHODS: A drug refractory epilepsy cohort of 139 subjects was selected, based on inclusion and exclusion criteria. All subjects underwent routine history-taking, and a structured interview with QUARAS (in Hindi language) about 3-6 months later when they were admitted for pre-surgical work-up (Video-EEG, MRI, SPECT and PET), by an epilepsy nurse. Seizures were localised and lateralised at the each step separately, in a blinded manner; concordance with the final hypothesis was checked, after the epilepsy-surgery case-conference, and statistical significance of the difference calculated. RESULTS: Auras were reported in significantly more number of patients after administration of QUARAS (p<0.001); there was also higher concordance between the final hypothesis and the localization and lateralization based on QUARAS than an unstructured history (p<0.001). CONCLUSION: Administering a structured questionnaire in the native language of patients by trained personnel leads to better localisation and lateralisation and may help arrive at a hypothesis about the EZ.

Can ictal-MEG obviate the need for phase II monitoring in people with drug-refractory epilepsy? A prospective observational study.

PURPOSE: To determine if ictal-magnetoencephalography (ictal-MEG) source localization (SL) added information towards delineating the ictal-onset zone (IOZ), whether and how it helped final decision-making in epilepsy-surgery. METHODS: Definite focal clusters on ictal-MEG were available for 32 DRE-patients, data was analyzed (single equivalent current dipole (ECD) model), SL done. Clinical history, long-term video-EEG (VEEG) monitoring, epilepsy-protocol MRI, FDG-PET, ictal-SPECT and interictal-MEG were discussed at the multispeciality Epilepsy Surgery Case-conference (ESC). Cases were reviewed with ictal-MEG SL presented only at the last ESC (after decision using other available modalities). Patients were grouped as VEEG localization and MRI-lesion concordant (Group-A), discordant (Group-B), and no MRI-lesion (Group-C). Final hypothesis or decision, surgical outcome in those operated, and how ictal-MEG data influenced them were recorded. RESULTS: Five lesion-negative patients had identification of lesions after review of MRI with ictal-MEG SL. The difference between numbers of patients cleared for surgery without and with ictal MEG data was statistically significant (p=0.0044); but the difference in those cleared for phase II monitoring was not (p=1.00). Ictal MEG influenced decisions on possibility of surgery in 9 and converted decisions of phase II monitoring in 11 patients to electrocorticography-guided lesionectomy (20 in all; Group A-11, Group B-4, Group C-5); five were operated, with good seizure-control on follow-up. CONCLUSIONS: Delineation of IOZ by ictal-MEG helped convert DRE patients unsuitable for surgery or planned for phase II monitoring into candidates suitable for surgery, even ECoG-guided resections, and resulted in favorable outcomes in those who were operated.

Endoscopic-Assisted (Through a Mini Craniotomy) Corpus Callosotomy Combined With Anterior, Hippocampal, and Posterior Commissurotomy in Lennox-Gastaut Syndrome: A Pilot Study to Establish Its Safety and Efficacy.

BACKGROUND: Corpus callosotomy is a palliative procedure especially for Lennox-Gastaut semiology without localization with drop attacks. OBJECTIVE: To describe endoscopic-assisted complete corpus callosotomy combined with anterior, hippocampal, and posterior commissurotomy. METHODS: Patients with drug refractory epilepsy having drop attacks as the predominant seizure type, bilateral abnormalities on imaging, and moderate to severe mental retardation were included. All underwent a complete workup (including magnetic resonance imaging). RESULTS: Patients (n = 16, mean age 11.4 ± 6.4 years, range 6-19 years) had a mean seizure frequency of 24.5 ± 19.8/days (range 1-60) and a mean intelligence quotient of 25.23 ± 10.71. All had syndromic diagnosis of Lennox-Gastaut syndrome, with the following etiologies: hypoxic insult (10), lissencephaly (2), bilateral band heterotropia (2), and microgyria and pachygyria (2). Surgery included complete callosotomy and the section of anterior and posterior commissure by microscopic approach through a mini craniotomy (11) and endoscopic-assisted approach (5). Complications included meningitis (1), hyperammonemic encephalopathy (2), and acute transient disconnection (5). There was no mortality or long-term morbidity. Mean follow-up was 18 ± 4.7 months (range 16-27 months). Drop attacks stopped in all. Seizure frequency/duration decreased >90% in 10 patients and >50% in 5 patients, and increased in 1 patient. All patients attained presurgical functional levels in 3 to 6 months. Child behavior checklist scores showed no deterioration. Parental questionnaires reported 90% satisfaction attributed to the control of drop attacks. The series was compared retrospectively with an age/sex-matched cohort (where a callosotomy only was performed), and showed better outcome for drop attacks (P < .003). CONCLUSION: This preliminary study demonstrated the efficacy and safety of complete callosotomy with anterior, hippocampal, and posterior commissurotomy in Lennox-Gastaut syndrome (drop attacks) with moderate to severe mental retardation.

Impact of intraoperative MRI on outcomes in epilepsy surgery: preliminary experience of two years.

PURPOSE: To determine the impact of intraoperative magnetic resonance imaging (iMRI) in epilepsy surgeries on the extent of surgical resection and seizure outcome along with its feasibility and limitations. METHODS: Patients with pharmacoresistant epilepsy (PRE), who underwent surgeries in operating theater equipped with high-field 1.5-Tesla MRI, were evaluated for extent of resection, operative time, scanning time, pathologies, resultant extra resection, and seizure outcomes. RESULTS: Thirty-nine patients with mean age of 18 (range: 3-65) years with PRE underwent surgical intervention. Mean duration of epilepsy was 10.2 years. Surgical interventions included tumor resection (31%), resection of focal cortical dysplasia (28%), mesial temporal lobe surgeries (18%), and disconnection surgeries (23%). iMRI alone, apart from navigation and electrophysiology, improved resection rates in 13% (5 out of 39) of these patients. In lesional group, iMRI modified operative strategy resulting in increased resections in 21% (5/23) patients. Complete resection was observed in 87% of patients. iMRI scanning time constituted 25% (mean: 72 ± 21 min) of time spent under anesthesia by the patient. Major and minor complications were observed in 2.5% and 7.5% of patients, respectively. The mean follow-up was 14 months. Favorable postoperative seizure control (Engel Classes I and II) was achieved in 85% and complete seizure freedom was achieved in 77% of patients (Engel Class IA) at 1-year follow-up. CONCLUSIONS: iMRI increases the extent of resection mainly in lesional epilepsy surgeries translating into good seizure outcomes but not found to be much beneficial in prototype mesial temporal sclerosis surgeries and disconnection surgeries.

Evaluation of gastroesophageal reflux before and after sleeve gastrectomy using symptom scoring, scintigraphy, and endoscopy.

BACKGROUND: The effect of laparoscopic sleeve gastrectomy (SG) on gastroesophageal reflux disease (GERD) has been a controversial issue. There have been limited studies on this aspect and most of the published studies are retrospective. Therefore, a prospective study was designed to objectively assess the problem. The objective of this study was to assess the impact of SG on symptoms of gastroesophageal reflux using questionnaire, endoscopy, and radionuclide scintigraphy. METHODS: Thirty-two patients undergoing laparoscopic sleeve gastrectomy were assessed for gastroesophageal reflux using Carlsson Dent Questionnaire and GERD questionnaire before and after surgery at three monthly intervals. They were also subjected to upper GI endoscopy (UGIE) and radionuclide scintigraphy both pre- and postoperatively. RESULTS: Mean preoperative weight and body mass index were 126.5 kg and 47.8 kg/m2, respectively. Mean percent excess weight loss at 12 months was 64.3 ± 18.4. Both the Carlsson Dent Score (CDS) and Severity Score (SS) exhibited a decline from 2.88 to 1.63 (p<0.05) and 2.28 to 1.06 (p<0.05), respectively after 12 months. Radionuclide scintigraphy revealed a significant rise of GERD from 6.25% to 78.1% in the postoperative period (p<0.001). UGIE showed a rise in incidence of esophagitis from 18.8% to 25%; however, there was improvement in all patients except one in terms of reduction of severity of esophagitis. CONCLUSION: Presence of GERD may not be considered as a contra-indication for sleeve gastrectomy. There is improvement of GERD as assessed by symptom questionnaires, as well as improvement in grade of esophagitis. The new onset GERD detected on scintigraphy may not be pathologic as there is a decrease in total acid production postsurgery; however, it still remains an important issue and needs long-term follow-up.

Dual tracer functional characterization of metastatic gastric carcinoid.

Because of the increasing clinical importance of gastric carcinoids and the difficulty in diagnosing them, the need for non-invasive diagnostic methods is growing. Currently, the only reliable method is upper gastrointestinal endoscopy with biopsy. We report the case of a 32-year-old male where a combination of functional imaging studies ((18)F-fluorodeoxyglucose-positron emission tomography/computed tomography [PET/CT] and (68)Ga-DOTA-NOC PET/CT) not only helped in the correct staging, but also highlighted certain important biological aspects of these tumors, which are important from the management point of view and can prognosticate the patients.

11C-methionine PET for grading and prognostication in gliomas: a comparison study with 18F-FDG PET and contrast enhancement on MRI.

UNLABELLED: The aim of this study was to compare the grading and prognostic value of l-[methyl-(11)C]-methionine ((11)C-MET) PET in glioma patients with (18)F-FDG PET and contrast-enhanced MRI. METHODS: Patients (n = 102) with histopathologically confirmed gliomas were followed up for an average of 34.6 ± 3.8 mo after PET. The median survival was 18 ± 4.7 mo in the high-grade glioma group and 58 ± 27 mo in the low-grade glioma group. Patients underwent (18)F-FDG PET, (11)C-MET PET, and MRI in the diagnostic and preoperative stage. The ratio of the mean standardized uptake value in the tumor to mean standardized uptake value in contralateral normal cortex (T/N ratio) was calculated. Kaplan-Meier survival analysis and ANOVA were performed. RESULTS: T/N ratios for (11)C-MET PET and (18)F-FDG PET were significantly higher in high-grade gliomas than in low-grade gliomas (2.15 ± 0.77 vs. 1.56 ± 0.74, P < 0.001, and 0.85 ± 0.61 vs. 0.63 ± 0.37, P < 0.01, respectively). Median survival was 19 ± 5.4 mo in patients with a T/N ratio greater than 1.51 for (11)C-MET PET and 58 ± 26.7 mo in those with a T/N ratio less than 1.51 (P = 0.03). Among the LGGs, median survival was lower in patients with a mean T/N ratio greater than 1.51 for (11)C-MET PET (16 ± 10 mo; 95% confidence interval, 1-36 mo) than in those with a T/N ratio less than 1.51 (P = 0.04). No significant difference in survival in LGGs was based on (18)F-FDG uptake and MRI contrast enhancement. CONCLUSION: (11)C-MET PET can predict prognosis in gliomas and is better than (18)F-FDG PET and MRI in predicting survival in LGGs.

68Ga-DOTANOC PET/CT in patients with carcinoma of unknown primary of neuroendocrine origin.

OBJECTIVE: To evaluate the role of 68Ga-DOTANOC (68Gallium-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI³-octreotide) PET/CT for localization of the primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin. MATERIAL AND METHODS: Twenty patients (median age, 55 years; male 10) with histopathologically proven metastatic neuroendocrine tumor and no localization of primary tumor on conventional imaging were included in the study. PET/CT was done after injection of 132-222 MBq (4-6 mCi) of 68Ga-DOTANOC. Images were evaluated by 2 experienced nuclear medicine physicians both qualitatively as well as quantitatively (maximum standardized uptake value). Histopathology (when available) and/or follow-up imaging with biochemical markers were taken as reference standard. RESULTS: 68Ga-DOTANOC PET/CT localized the primary tumor in 12/20 (60%) patients. Midgut was the most common site of primary tumor (n = 9); duodenum (4), ileum (4), and colon (1). In 1 patient each the primary was localized to the pancreas, stomach, and lung. In these 12 patients, significant correlation was found between maximum standardized uptake value of primary tumor and metastasis (ρ = 0.615; P = 0.041). Even in patients in whom no primary tumor was localized, additional sites of metastatic disease were observed when compared with conventional imaging, mostly in lymph nodes and bones. There was a change in management in 3/20 patients (15%), who underwent surgery. In the remaining 17 patients, demonstration of somatostatin receptor expression by PET/CT made them suitable candidate for peptide receptor radionuclide therapy. CONCLUSION: 68Ga-DOTANOC PET/CT seems to be a promising modality for detecting primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin.

Role of FDG PET-CT in detecting recurrence in patients with uterine sarcoma: comparison with conventional imaging.

PURPOSE: The purpose of the present study was to evaluate the role of 18F-fluorodeoxyglucose (FDG) PET-CT in detecting recurrent disease in posttherapy patients of uterine sarcoma and compare the same with conventional imaging (CI). METHODS: A total of 15 FDG PET-CT studies were acquired in 12 posttherapy uterine sarcoma patients. The images were evaluated by two experienced nuclear medicine physicians in consensus. Clinical/imaging follow-up (minimum 6 months) and histopathology were taken as the reference standard. All the patients had also undergone CI (CT or MRI or ultrasonography) of the chest, abdomen, and pelvis. The diagnostic accuracy of FDG PET-CT was calculated and compared with that of CI. RESULTS: The median age of the patients was 51.5 years (interquartile range: 47.5-53). Histopathology was leiomyosarcoma in six, carcinosarcoma in five, and endometrial stromal sarcoma in one patient. Six FDG PET-CT studies were carried out for suspected recurrence and nine for posttherapy surveillance. Six FDG PET-CTs were positive and nine were negative for recurrence. The sensitivity, specificity, and accuracy of FDG PET-CT were 85.7, 100, and 93.3%, respectively, on per study-based analysis, and 80, 100, and 83.3% on per lesion-based analysis. PET-CT showed higher sensitivity and specificity compared with CI for both study-based and lesion-based analysis. However, no significant difference was found between FDG PET-CT and CI either in the study-based or in the lesion-based analysis (P not significant). CONCLUSION: FDG PET-CT is a highly sensitive and specific modality for detecting recurrence in posttherapy patients with uterine sarcoma. However, it provides no significant advantage over CI for this purpose.