Nuclear Medicine

Ethical conundrum in nuclear medicine research in India Kanhaiyalal Agrawal, Bikash Ranjan Meher, Biswa Mohan Padhy Indian Journal of Nuclear Medicine 2019 34(2):83-85

Phase analysis: A new armamentarium in nuclear cardiology Dharmender Malik Indian Journal of Nuclear Medicine 2019 34(2):86-87

Equilibrium radionuclide angiography in evaluation of left ventricular mechanical dyssynchrony in patients with dilated cardiomyopathy: Comparison with electrocardiographic parameters and speckle-tracking echocardiography Abhinav Singhal, Bangkim Chandra Khangembam, Sandeep Seth, Chetan Patel Indian Journal of Nuclear Medicine 2019 34(2):88-95 Purpose of the Study: The purpose of this study was to study the role of equilibrium radionuclide angiography (ERNA) in the assessment of left ventricular (LV) mechanical dyssynchrony in patients with dilated cardiomyopathy (DCM), by correlating the findings with electrocardiographic parameters and speckle-tracking echocardiography (STE). Methods: This was a prospective observational study. A total of 55 patients with a mean age 42.5 ± 11 years (range: 19–61 years) diagnosed with DCM underwent ERNA and echocardiography sequentially. On ERNA, phase images of LV were obtained, and standard deviation of LV mean phase angle (SD LVmPA) was derived to quantify intra-LV mechanical dyssynchrony (ILVD). Similarly, on STE, “dyssynchrony index” was calculated as the standard deviation of time-to-peak systolic circumferential strain (SDCS) of the six mid-LV segments. The cutoff values used to define mechanical dyssynchrony were SD LVmPA >13.2° (or >27.1 ms) and SDCS >74 ms on ERNA and STE, respectively. The results obtained from the two modalities were then compared. Results: Speckle-tracking analysis could be done on the echocardiographic data of only 42 patients. Paired data from ERNA and STE studies of these 42 patients (26 males and 16 females) were compared, which showed no significant difference in the detection of ILVD (P = 0.125). The two modalities showed good agreement with Cohen's kappa value of 0.78 (P < 0.0001). SD LVmPA and SDCS values showed moderately strong linear correlation (ρ = 0.69; P < 0.0001). No significant association of mechanical dyssynchrony on ERNA or STE was found with QRS duration and with the presence or absence of left bundle branch block. ILVD was also found to be negatively correlated with LV ejection fraction. Conclusion: ERNA is comparable to STE for the assessment of LV mechanical dyssynchrony.

Unilateral graves' disease: The lesser known Ranadheer Gupta Manthri, Nimmagadda Ajit, Suresh Vaikakkara, B Vijayalakshmi Devi, Tekchand Kalawat Indian Journal of Nuclear Medicine 2019 34(2):96-98 Background: Here, we present a retrospective study conducted from 2009 to 2018, which showed the presence of unilateral uptake of radioactive tracer on 99mTc thyroid scintigraphy scan in 15 patients with Graves' disease. Materials and Methods: All these patients had either clinical features of Graves' disease or elevated thyroid hormone levels along with ultrasonographic features, showing either normal thyroid gland or diffuse thyroiditis. The scintigraphic features revealed increased uptake in one lobe of the thyroid gland with the other lobe being normal. Results: Of the 15 patients, 13 were females and two were males. The mean age of the patients was 47 years with standard deviation of 3.4 years (range 26–70 years). Eight of the 15 patients had increased uptake on the right lobe and seven had increased uptake in the left lobe. Conclusion: This study shows that there exists an entity called unilateral Graves' disease which should be further evaluated.

Single-photon emission computed tomography myocardial ischemia detection in high-risk asymptomatic patients: correlation with coronary calcium score and high-sensitivity C-reactive protein Irena Mitevska, Elizabeta Srbinovska, Lily Stojanovska, Emilija Antova, Vasso Apostolopoulos, Marijan Bosevski Indian Journal of Nuclear Medicine 2019 34(2):99-106 Background: The association between myocardial ischemia in high-risk patients with coronary calcium score (CCS) and high-sensitivity C-reactive protein (hs-CRP) is not well established. Aims: We evaluated the correlation between hs-CRP, CCS, and myocardial ischemia in asymptomatic high-risk patients without known coronary artery disease (CAD). Materials and Methods: We prospectively assessed 68 asymptomatic high-risk outpatients without known CAD. One-day rest-stress Tc-99m single-photon emission computed tomography (SPECT) myocardial perfusion imaging and multislice computed tomography were performed. Multivariate regression analysis was performed for the assessment of predictors of myocardial ischemia. Standard risk factors and hs-CRP values were analyzed. Results: CCS >0 Agatston score was observed in 26 patients (46.4%). Seven patients had CCS between 10 and 99 AU, 8 patients between 100 and 400 AU, and 11 patients had CCS >400 AU. Mild ischemia was noted in 11 patients, moderate ischemia in 10 patients, and severe ischemia in 6 patients. Hs-CRP was >1 mg/L in 39 patients, of whom 8 patients had CCS >0, 13 patients had normal SPECT results, 6 patients had mild ischemia, and 12 patients had moderate and severe ischemia. Multivariate regression analysis showed independent predictors for increased CCS: low-density lipoprotein cholesterol (odds ratio [OR]: 2.891; P = 0.001); age >70 years (OR: 2.568; P = 0.001); and smoking (OR: 1.931; P = 0.001). We found hs-CRP to be an independent predictor of myocardial ischemia (OR: 4.145; 95% confidence interval: 1.398–7.471, P = 0.001). Conclusion: hs-CRP was an independent predictor of myocardial ischemia. hs-CRP might improve the selection of high-risk asymptomatic patients for myocardial SPECT imaging.

Tc-99m glucoheptonate single photon emission computed tomography-computed tomography for detection of recurrent glioma: A prospective comparison with N-13 ammonia positron emission tomography-computed tomography Bangkim Chandra Khangembam, Abhinav Singhal, Rajeev Kumar, Chandrasekhar Bal Indian Journal of Nuclear Medicine 2019 34(2):107-117 Purpose of the Study: To assess the efficacies of Tc-99m glucoheptonate single photon emission computed tomography-computed tomography (Tc-99m GHA SPECT-CT) and N-13 ammonia positron emission tomography-computed tomography (N-13 NH3PET-CT) in detecting recurrent glioma. Materials and Methods: Fifty-five consecutive, histologically proven, and previously treated glioma patients (age, 38.9 ± 12.2 years; 61.8% males) presenting with clinical suspicion of recurrence were evaluated with Tc-99m GHA SPECT-CT and N-13 NH3PET-CT. Images were evaluated both qualitatively and semiquantitatively. A combination of clinicoradiological follow-up, repeat imaging, and/or biopsy (when available) was considered as the reference standard. Results: Based on the reference standard, 28/55 (50.9%) patients had recurrence. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy of Tc-99m GHA SPECT-CT, and N-13 NH3PET-CT were 85.7%, 85.2%, 85.7%, 85.2%, 85.5% and 78.6%, 88.9%, 88.0%, 80.0%, 83.6%, respectively (concordant findings in 46 patients). The performances of the two modalities were equivalent both in overall and subgroup McNemar analyses (P = 0.508, overall; P = 0.687, low grade; P = 1.000, high grade). Conclusion: Tc-99m GHA SPECT-CT is an alternative imaging modality equally efficacious as N-13 NH3PET-CT in detecting recurrent glioma.

Value of the postablative thyroglobulin measurements for assessment of disease-free status in patients with differentiated thyroid cancer Nahla Dessoki, Ibrahim Nasr, Ahmed Badawy, Ismail Ali Indian Journal of Nuclear Medicine 2019 34(2):118-124 Aim: The aim of the study is to evaluate the value of thyroid-stimulating hormone (TSH)-stimulated thyroglobulin (sTg) measurements by the end of the 1st-year postablation in differentiated thyroid cancer (DTC) patients with biochemical non complete response (indeterminate and incomplete response). Patients and Methods: One hundred patients with DTC underwent near-total thyroidectomy and radioactive remnant ablation by iodine-131 (I131) with regular follow-up every 6 months during the first 2 years and at 6–12-month intervals thereafter by I131 whole-body scan (WBS), neck ultrasound, and sTg measurement in the hypothyroid state (TSH >30 mU/L). Patients were divided according to the imaging findings and sTg level into three groups: excellent response (ER) – no evidence of disease by imaging and sTg <1 ng/mL, indeterminate or acceptable response (AR) – nonspecific findings on imaging studies and sTg < 10 ng/mL, and incomplete response (IR) – patients with incomplete structural and/or incomplete biochemical response (sTg > 10 ng/mL). Results: The follow-up at 6-month postablation showed ER in 3 (3%) patients, AR in 29 (29%) patients, and IR in 68 (68%) patients. The second follow-up at 9–12-month postablation showed dramatic biochemical response with ER, indeterminate, and IR in 50 (50%), 34 (34%), and 16 (16%) patients, respectively, and 14 (14%) patient had structural recurrence. This change is highly statistically significant (P = 0.00). In the last follow-up (ranges from 3 to 10 years), 53 (55.8%) patients achieved ER, 42 (44.2%) AR and no patient with non complete response. The change in patients with IR between the second and the last follow-up is also statistically significant (P = 0.001). Conclusion: sTg measurement by the end of the 1st year is more reliable in the follow-up of patients with DTC and biochemical non complete response and considered significant predictor of disease-free status. Patients with biochemical IR still have the chance to achieve ER or AR by the passage of time without additional therapies.

Energy window and contrast optimization for single-photon emission computed tomography bremsstrahlung imaging with yttrium-90 Youssef Bouzekraoui, Farida Bentayeb, Hicham Asmi, Faustino Bonutti Indian Journal of Nuclear Medicine 2019 34(2):125-128 Purpose: In yttrium-90 (Y-90) single-photon emission computed tomography (SPECT) imaging, the choice of the acquisition energy window is not trivial, due to the continuous and broad energy distribution of the bremsstrahlung photons. In this work, we investigate the effects of the energy windows on the image contrast to noise ratio (CNR), in order to select the optimal energy window for Y-90 imaging. Materials and Methods: We used the Monte Carlo SIMIND code to simulate the Jaszczak phantom which consists of the six hot spheres filled with Y-90 and ranging from 9.5 to 31.8 mm in diameter. Siemens Symbia gamma camera fitted with a high-energy collimator was simulated. To evaluate the effect of the energy windows on the image contrast, five narrow and large energy windows were assessed. Results: The optimal energy window obtained for Y-90 bremsstrahlung SPECT imaging was 120–150 keV. Furthermore, the results obtained for CNR indicate that the high detection is only for the three large spheres. Conclusion: The optimization of energy window in Y-90 bremsstrahlung has the potential to improve the image quality.

Quintessential role of 18fluorine fluorodeoxyglucose positron emission tomography/computed tomography in differentiation of viable tumor tissue and nondisease desmoplastic residue Vatturi Venkata Satya Prabhakar Rao, Vijaya Aditya Yadaraju, Aditya Narayan, Muralidhar Bora, Praveen Adusumalli, Sweta Sinha Indian Journal of Nuclear Medicine 2019 34(2):129-133 The authors report a series of cases of treated nodal, solid malignancies showing persisting physical residue after completion of treatment with 18-F fluorodeoxyglucose positron emission tomography-computerized tomography showing non-avid status conjuring a nondisease desmoplastic residue over morphological disease.

Papillary carcinoma thyroid metastases presenting as thyrotoxicosis post thyroidectomy - A case report Kanala Sai Krishnaja, Ramya Priya Rallapeta, Mehabunnisa Shaik, Ranadheer Manthri, Suresh Vaikkakara, TC Kalawat Indian Journal of Nuclear Medicine 2019 34(2):134-136 Thyrotoxicosis can occur in the setting of differentiated thyroid cancer due to functioning metastases. Here, we report a case of a 63 year old woman with papillary carcinoma thyroid who underwent total thyroidectomy and defaulted for further scheduled treatment with high dose radioactive iodine therapy. 2 years after total thyroidectomy, she presented with signs and symptoms of thyrotoxicosis and a scalp swelling on the right side of frontal region. Excision biopsy revealed metastatic deposits of papillary carcinoma thyroid. Even after withdrawal of thyroxine, her serum thyrotropin did not rise and thyroglobulin levels were high, raising the suspicion of high volume tumour burden. I-131 whole body scan was done and it revealed radio iodine avid cervical lymph nodes along with functioning lung and skeletal metastases.