Πέμπτη, 20 Ιουνίου 2019

Nuclear Medicine

Evaluation of positron emission tomography and contrast-enhanced computed tomography scan in nodal staging of early operable uterine cancers
Anand A Zade, Venkatesh Rangarajan, Nilendu C Purandare, Sneha A Shah, Archi R Agrawal

Indian Journal of Nuclear Medicine 2019 34(3):183-187

Introduction: In early operable stages of cervical an endometrial malignancies, surgical staging of lymph nodes is advocated as contrast-enhanced computed tomography (CECT) has limited sensitivity and accuracy. Although fluorine-18 (F-18) fluorodeoxyglucose (FDG)/positron emission tomography (PET)-CT has potential to identify subcentimeter-sized nodal metastases, higher prevalence of pelvic inflammatory disease in developing countries could result in lower accuracy. The present study was undertaken to assess the incremental value of PET scan over CECT for nodal staging before radical surgery. Methods: Forty-four patients with the International Federation of Gynecology and Obstetrics (FIGO) Stage IA2–IIb carcinoma cervix and 28 patients of FIGO Stage I–II carcinoma endometrium underwent F-18 FDG-PET-CECT scan. A SUVmaxvalue >2.5 g/ml based on body weight was considered as positive. An enhancing node with >1 cm size in the shortest dimension, with loss of fatty hilum was considered positive on CT images. The histological findings were considered the gold standard against which the two modalities were compared. Results: All 1226 pelvic nodes were dissected, of which 65 were found to be metastatic (i.e., 5.3%). Of the 72 patients, 15 (20.83%) had pelvic nodal metastases. The overall accuracy of PET and CECT for assessment of pelvic nodal metastases was comparable (i.e., 86% vs. 85%). Conclusion: PET and CECT scans have similar accuracy in pelvic nodal staging of operable uterine malignancies. Granulomatous inflammation may not be a major cause of false-positive results. The sensitivity and negative predictive values are not high enough to obviate need of surgical nodal staging. 

Ga-68 DOTATATE positron emission tomography-computed tomography imaging in oncogenic osteomalacia: Experience from a Tertiary Level Hospital in South India
Junita Rachel John, Julie Hephzibah, Regi Oommen, Nylla Shanthly, David Mathew

Indian Journal of Nuclear Medicine 2019 34(3):188-193

Aim: Utility of Ga68 DOTATATE PETCT imaging to localise cause for oncogenic osteomalacia (OOM). Materials and Methods: Retrospective analysis between March 2015 to March 2018 of all patients with a clinical diagnosis (based on a combination of clinical history, hypophosphatemia and elevated FGF-23 values) of OOM who underwent Ga-68 DOTATATE PET/CT. Results: Total of 27 patients had undergone Ga-68 DOTATATE PET/CT imaging in our centre from March 2015 to March 2018. Of these 16 patients with clinically suspected oncogenic osteomalacia were included in our study. Age range 18-61 years of which 12 were males. Total of 13 (81.25%) patients were found to be positive on imaging for a possible mesenchymal tumour. Most common site of tumour was the lower limb (76%). Most common presenting symptom was bone pain (81%) followed by muscle weakness (19%). Overall, 10 patients underwent surgery, all of whose biopsy was reported as phosphaturic mesenchymal tumour. During the three month follow up, serum phosphorous measured in 15/16, post-surgical/ medical treatment had normalised in all except two patients who had undergone only medical therapy with neutral phosphate. Fall in FGF-23 was more pronounced in surgically treated patients as compared to those who received medical treatment. Conclusion: Ga68-DOTATE PET/CT is a useful investigatory modality for localizing cause for oncogenic osteomalacia. 

Gastric emptying scintigraphy: Beyond numbers – An observational study to differentiate between various etiologies and a step toward personalized management
Manish Ora, Aftab Hasan Nazar, Ashutosh Parashar, Subhash Kheruka, Sanjay Gambhir

Indian Journal of Nuclear Medicine 2019 34(3):194-200

Aim: Gastric emptying (GE) scintigraphy is commonly used as a standard diagnostic procedure for the assessment of functional dyspepsia (FD). Results of the study are often reported as either normal or delayed GE times. The aim of this study was to recognize various patterns of scintigraphy among both normal and abnormal emptying times. Materials and Methods: Fifty patients with suspected FD were included in the study. GE study was performed with a standardized vegetarian solid meal. Results: Out of 50 patients, 33 patients had deranged GE. Thirty patients had delayed GE. Three patients demonstrated gastric hurrying. Five different patterns were demonstrated in patients having similar emptying and retention times such as reduced fundus compliance, decreased fundic accommodation, antral dysmotility, gastric hurrying, and gastroesophageal reflux. Conclusion: According to our findings, it may be suggested that visual assessment of GE and identification of various pattern is a very important aspect of the GE study. It not only subcategorized patients but also decreases the number of “normal” studies. This finding may have an impact on patient management in the era of personalized medicine. 

Comparison of image quality of different radionuclides technetium-99m, samarium-153, and iodine-123
Youssef Bouzekraoui, Farida Bentayeb, Hicham Asmi, Faustino Bonutti

Indian Journal of Nuclear Medicine 2019 34(3):201-204

Introduction: The choice of the radionuclide has a key role in nuclear medicine which appearing the lowest scatter fraction. In addition, the presence of penetrated and scattered photons from collimator in single-photon emission computed tomography images degrades resolution and contrast. Thus, image quality depends on sensitivity and resolution of the collimator–detector system. The goal of this study was to compare the image quality that can be achieved by three radionuclides: technetium-99 m (Tc-99 m), iodine-123 (I-123), and samarium-153 (Sm-153). Materials and Methods: Tc-99 m and Sm-153 were imaged with low-energy high resolution (LEHR) collimator, while I-123 was imaged with medium-energy (ME) collimator. We modeled the Siemens Symbia Medical system using Monte Carlo simulation code SIMIND. The imaging characteristics of each radionuclide were investigated by simulated data: point spread function, sensitivity (Cps/MBq) and geometric, penetration and scattering distribution. Results: Tc-99 m and Sm-153 give best and results with LEHR collimator for spatial resolution (full width at half maximum [FWHM] = 3.19 mm; full width at tenth maximum [FWTM] = 6.73 mm) and (FWHM = 3.22 mm; FWTM = 7.39 mm), respectively. Whereas, I-123 provided with ME collimator a lower resolution (FWHM = 4.89 mm; FWTM = 9.89 mm). The sensitivity recorded by Tc-99 m, Sm-153, and I-153 were (31.21 Cps/MBq), (10.16 Cps/MBq), and (51.22 Cps/MBq), respectively. Conclusion: Tc-99 m and Sm-153 give the best and generally similar imaging properties with LEHR. For I-123, the ME collimator helps lowering the influence of high-energy gamma rays. 

Cutaneous metastasis from visceral organs: 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan aiding in localizing primary site
Nitin Gupta, Dharmender Malik, Ritu Verma, Ethel Shangne Belho, Anisha Manocha

Indian Journal of Nuclear Medicine 2019 34(3):205-208

Skin metastases are rare from systemic malignancy, and incidence reported is between 0.7% and 9% in various malignancies and usually occur in advanced stage. Here, we report three cases, one each of carcinoma esophagus, carcinoma breast, and carcinoma lung, where patients presented with metastatic cutaneous lesions and positron-emission tomography-computed tomography (PET-CT) scan whole body helped in localizing the primary site. Whole-body fluorodeoxyglucose PET-CT scan helps in scanning whole body at once and detect occult primary and metastatic sites. 

Fibrodysplasia ossificans progressiva – A rare genetic disorder and the role of Technetium-99m methylene diphosphonate bone scan
Nitin Gupta, Ankur Pruthi, Suneel Kumar, Ritu Verma, Ethel Shangne Belho

Indian Journal of Nuclear Medicine 2019 34(3):209-212

Fibrodysplasia ossificans progressiva is a rare genetic disease believed to occur in approximately 1 in 2 million people worldwide and is characterized by progressive extraosseous ossification over the course of a lifetime in an inevitable and unpredictable episodic manner, with most patients being confined to a wheelchair by the third decade of life and requiring life-long care. The extraosseous calcification involves ligaments, tendons, muscles, and connective tissue leading to severe restriction of movements. Another hallmark of this condition is abnormal great toes. The diagnosis is often made on clinical and radiological examination, but Technetium-99m methylene diphosphonate (Tc-99m MDP) bone scan is usually indicated to determine the extent of the disease. We hereby present a case series comprising of four patients suffering from this debilitating illness who underwent Tc99m MDP bone scan for initial diagnosis and localizing sites of heterotopic ossification. 

Upcoming role of prostate specific membrane antigen positron emission tomography-computed tomography in detecting occult metastases in prostate cancer
Parul Gupta, Rohini Mishra, Manoj Gupta, Partha Sarthi Choudhury

Indian Journal of Nuclear Medicine 2019 34(3):213-215

Prostate cancer (PCa) is the second most frequent malignancy in men. Most common sites of disease involvement other than the prostate gland include abdominopelvic lymph nodes and the skeleton. The detection of nodal metastases is of utmost importance to determine prognosis and choice of treatment in patients with PCa. Conventional imaging focuses on morphologic information and takes size criteria for decision-making. Early detection of metastases is further relevant in terms of prognosis and therapy management. Molecular imaging of PCa with Ga-68 prostate-specific membrane antigen (PSMA) positron emission tomography–computed tomography (PET-CT) has recently received significant attention and frequently used with a signature to PCa-specific remark. We presented the case of a 69-year-old male presenting with biochemical recurrence after undergoing surgery and in remission for about a year, where Ga-68 PSMA PET-CT identified additional sites of disease apart from the expected regional bed. 

Mesenteric tuberculosis masquerading as carcinoid tumor on conventional imaging and DOTANOC positron emission tomography/computed tomography: Uncommon presentation of a common disease
Abdul Razik, Anand Narayan Singh, Shambo Guha Roy, Kumble Seetharama Madhusudhan

Indian Journal of Nuclear Medicine 2019 34(3):216-219

Carcinoid tumor of the mesentery has a classical imaging morphology. A specific diagnosis can often be provided on the basis of clinical history, elevated serum neuroendocrine markers, and uptake on somatostatin receptor-based radiotracer studies. Although a number of inflammatory and neoplastic conditions may mimic carcinoid tumor on many of these modalities, uptake on 68Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) is considered specific. We report a case of a 28-year-old male presenting with a mesenteric mass along with elevated serum neuroendocrine markers and uptake on DOTANOC PET/CT, all suggestive of carcinoid tumor. However, the histopathologic examination after surgical resection revealed necrotizing granulomas consistent with tuberculosis (TB). This case highlights the great masquerader that TB can be and stresses the importance of keeping a high index of suspicion for TB, especially in endemic areas. 

Thyroid cartilage metastases on F-18 Fluorodeoxyglucose positron emission tomography-computed tomography: A tale of two cases with a brief review of literature
Sarthak Tripathy, Girish Kumar Parida, Abhinav Singhal, Shamim Ahmed Shamim, Rakesh Kumar

Indian Journal of Nuclear Medicine 2019 34(3):220-222

Metastases to thyroid cartilage are rare entities and can often easily be missed on computed tomography (CT) scan alone. Positron emission tomography (PET)-CT imaging has overcome this diagnostic dilemma due to its ability to provide for both anatomical and functional imaging. We report two rare cases of thyroid cartilage metastases on F-18 fluorodeoxyglucose PET-CT from breast and papillary thyroid malignancies as primaries. 

Camurati-Engelmann disease with good treatment response to Losartan
Mansoor Cherumkuzhiyil Abdulla

Indian Journal of Nuclear Medicine 2019 34(3):223-225

Camurati–Engelmann disease (CED) or progressive diaphyseal dysplasia is a rare autosomal dominant inherited condition which belongs to the group of craniotubular hyperostosis. A 24-year-old man presented with insidious onset, progressive pain over both legs, and forearms for 3 years. He was born as the second child of a nonconsanguineous union by vaginal delivery at term without any complications. The clinical, radiological, and histopathological features were suggestive of CED. Transforming growth factor-β1 sequence analysis revealed a missense mutation (c.652C>T; p. Arg218Cys) confirming the diagnosis. He had a good response to treatment with Losartan. CED should be considered in the differential diagnosis of patients presenting with nonspecific limb pains and radiological features of skeletal dysplasia. Early recognition and diagnosis play a crucial role in management. This case discuss regarding the potential benefits of the drug losartan in the management of a rare bone disease for which the evidence from previous literature is scarce. 

Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos

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