فهرست مطالب

Nuclear Medicine - Volume:26 Issue: 1, 2018
  • Volume:26 Issue: 1, 2018
  • تاریخ انتشار: 1396/11/20
  • تعداد عناوین: 12
|
  • Davood Beiki * Pages 1-1
  • Hojjat Ahmadzadehfar, Kamran Aryana, Elahe Pirayesh, Saeed Farzanehfar, Majid Assadi, Babak Fallahi, Babak Shafiei, Narjess Ayati, Mahasti Amoui * Pages 2-8
    Prostate-specific membrane antigen (PSMA) is a type II transmembrane protein, which is anchored in the cell membrane of prostate epithelial cells. It is highly expressed on prostate epithelial cells and strongly up-regulated in prostate cancer. Although, 177Lu-PSMA has been recently introduced for radionuclide therapy of metastatic castration-resistant prostate cancer (mCRPC) with continuously increasing interest and use worldwide. This guideline is intended to assist nuclear medicine physicians in evaluating and managing patients with mRCPC for whom radioligand therapy (RLT) using 177Lu-PSMA is a promising treatment option. In addition, more information could be provided by subsequent investigative studies in the field of RLT.
    Keywords: Prostatic neoplasms, Neoplasm metastasis, Radionuclide therapy, 177Lu, PSMA, Radioligand therapy
  • Yasmin Yaraghi, Iraj Jabbari *, Ali Akhavan, Pardis Ghaffarian, Shahram Monadi, Mohsen Saeb Pages 9-15
    Introduction
    Tumor volume delineation is the most important step in the radiation treatment planning. In this study the impact of PET/CT data on the tumor delineation precision of non-small cell lung cancer (NSCLC) was investigated.
    Methods
    PET/CT images of 20 patients with primary NSCLC were obtained and imported to the treatment planning system for image fusion, contouring and radiation treatment planning. For each patient two separate gross tumor volumes were delineated based on CT and PET/CT images as GTVCT and GTVPET/CT, respectively. In addition, three different indices including conformity index (CI), geographic miss index (GMI) and geographic include index (GII) were calculated to quantify the match and mismatches degree between derived volumes. Then, for each patient an appropriate 3D conformal treatment plan was made based on the PTVCT and then these plans were applied on the PTVPET/CT. Afterwards, the dose coverage of PTVPET/CT was estimated through several dosimetric parameters.
    Results
    The GTVPET/CT was larger than GTVCT for majority of cases. The 25% exceeded volumetric alterations were observed in 8 of all cases (40%). Mean values of CI, GMI and GII were 0.43, 0.42 and 0.34, respectively. Also, dosimetric parameters indicated inadequate dose coverage of PTVPET/CT in CT-based RT plans for most of the patients.
    Conclusion
    Incorporating PET data into tumor delineation process had a great potential to improve the quality of radiation treatment planning for NSCLC.
    Keywords: PET, CT, Lung Cancer, Tumor volume delineation, Radiation treatment planning
  • Hadi Malek, Fahimeh Rayegan, Hassan Firoozabadi, Fereidoon Rastgoo, Majid Haghjoo, Hooman Bakhshandeh, Ahmad Bitarafan-Rajabi, Nahid Yaghoobi * Pages 16-21
    Introduction
    Myocardial perfusion imaging using gated SPECT and phase analysis is an effective tool in evaluation of mechanical dyssynchrony. The purpose of this study was to determine the normal ranges of global and regional phase parameters.
    Methods
    A total of 100 patients with normal resting and stress electrocardiograms, low pretest likelihood for coronary artery disease and a normal gated MPI study were recruited in the study. All of the patients underwent a standard 2-day stress/rest gated MPI study according to standard protocols. The reconstructed images were further analyzed by Cedar-Sinai’s quantitative gated SPECT. Left ventricular phase indices were provided both globally and regionally for both genders and the normal interquartile range of these parameters were defined.
    Results
    Normal ranges of global and wall-based regional phase parameters are presented both in unisex and in gender-specific formats. Both global (P
    Conclusion
    Normal ranges of phase indices are defined in this article by using Cedar-Sinai’s QGS software. As normal ranges of phase dyssynchrony parameters are gender-specific and are related to LV volume, stress or resting state and stress type, the need for careful incorporation of these data is indicated in interpretation of phase studies.
    Keywords: Myocardial perfusion gated SPECT, Myocardial perfusion imaging, Left ventricular dyssynchrony, Phase analysis
  • Parvaneh Darkhor, Babak Mahmoudian, Esmaeil Gharepapagh, Seyed Rasoul Zakavi, Jalil Pirayesh Islamian * Pages 22-29
    Introduction
    Myocardial perfusion SPECTby 99mTc-Sestamibi and 99mTc-Tetrofosmin radiopharmaceuticals usually presents a false significant increase in the radiotracer uptake in the inferior myocardium due to the uptake in organs such as liver, bowel, stomach and biliary system. The present study evaluated a suitable Slit angle for differentiating extra-cardiac activities by Slit Slat collimation.
    Methods
    The Siemens E.CAM gamma camera equipped with a Low Energy High Resolution (LEHR) collimator was simulated with the Simulating Medical Imaging Nuclear Detectors (SIMIND) Monte Carlo program. Following the verification of the simulation, a Slit Slat collimator was simulated for SPECT imaging of a NURBS-based Cardiac Torso (NCAT) phantom with different Slit angels ranged from 0 to 30 degrees. The reconstructed images were qualitatively assessed with blinded observer method by three nuclear medicine specialists.
    Results
    The improved differentiation of the bowel activity from the cardiac was obtained by a Slit-Slat collimator with the Slit angle of 7 degree. While for gastric activity differentiation an angle of 15 degree for the Slit was useful.
    Conclusion
    The results showed that Slit Slat collimation with 7 and 15 Slit angle provide a suitable differentiation of the bowel and gastric activities from the cardia, respectively.
    Keywords: Myocardium, NCAT, SPECT, Slit Slat collimator, SIMIND Monte Carlo
  • Leila Zarifmahmoudi, Hossein Shabahang, Vahid Reza Dabbagh Kakhki, Ramin Sadeghi * Pages 30-34
    Introduction
    One of the major problems of lymphoscintigraphy is the time of patient presence in the nuclear medicine wards. The operating room schedule can be compromised if the patients stay longer than usual in the nuclear medicine departments. However, too early imaging can be falsely negative for sentinel node visualization and delayed imaging may be required. The aim of the current study is to determine a time beyond which lymphoscintigraphy imaging does not yield more information and imaging can be terminated.
    Methods
    One hundred and fifty women with proven clinically axillary node negative breast cancer entered the study For each patient 0.5 mCi Tc-99m phytate in the 0.2 cc volume was intradermally injected in periareolar region to raise a wheal. Lymphoscintigraphy imaging was done in the following time intervals: 5, 10, 30, 45, 60, 90 minutes post injection. In case of sentinel node visualization at any time, the imaging was terminated.
    Results
    Sentinel nodes were first detected on 5, 10, 30, 45, 60, and 90 minute images in 31 (20.6%), 45 (30%), 46 (30.6%), 15 (10%), 1 (0.6%), and 0 patients. Median number of the detected sentinel nodes per patient was 1. At least one hot sentinel node could be identified in all 138 patients with observed sentinel nodes of whom, 45 had pathologically involved sentinel nodes and axillary lymph node dissection was done. In 12 patients, no sentinel node was visualized even on the 90 minute images. All of these patients had axillary node involvement and no sentinel node could be harvested intra-operatively either.
    Conclusion
    Considering the rather slow movement of Tc-99m phytate in the lymphatic system, lymphoscintigraphy imaging of the breast cancer patients should be continued for 45 minutes in case of sentinel node detection failure. On the other hand imaging beyond 45 minutes does not seem to be necessary as the diagnostic yield is very low.
    Keywords: Phytate, Particle size, Breast cancer, Lymphoscintigraphy, Delayed imaging
  • Zahra Etemadi, Pardis Ghafarian *, Ahmad Bitarafan-Rajabi, Hadi Malek, Arman Rahmim, Mohammad Reza Ay Pages 35-46
    Introduction
    Metallic artifacts due to pacemaker/ implantable cardioverter defibrillator (ICD) leads in CT images can produce artifactual uptake in cardiac SPECT/CT images. The aim of this study was to determine the influence of the metallic artifacts due to pacemaker and ICD leads on myocardial SPECT/CT imaging.
    Methods
    The study included 9 patients who underwent myocardial perfusion imaging (MPI). A cardiac phantom with an inserted solid defect was used. The SPECT images were corrected for attenuation using both artifactual CT and CT corrected using metal artifact reduction (MAR). VOI-based analysis was performed in artifactual regions.
    Results
    In phantom studies, mean-of-relative-difference in white-region, between artifact-free attenuation-map without/with MAR were changed from 9.2 and 2.1 to 3.7 and 1.2 for ICD and pacemaker lead, respectively. However, these values for typical patient were 9.7±7.0 and 3.8±2.4 for ICD and pacemaker leads respectively, in white-region. MAR effectively reduces the artifacts in white-regions while this reduction is not significant in black-regions.
    Conclusion
    Following application of MAR, visual and quantification analyses revealed that while quality of CT images were significantly improved, the improvements in the SPECT/CT images were not as pronounced or significant. Therefore cardiac SPECT images corrected for attenuation using CT in the presence of metallic-leads can be interpreted without correction for metal artefacts.
    Keywords: Cardiac SPECT, CT, Metal artifact reduction, Virtual sonogram, Pacemaker, ICD
  • Masoud Moslehi, Ali Mahmoud-Pashazadeh, Rahim Tahmasebi, Majid Assadi * Pages 47-53
    Introduction
    Retention of I-131 in the body of patients with differentiated thyroid carcinoma (DTC) has a direct effect on therapeutic outcome of radioiodine therapy. There are several factors that may influence retention time of radioiodine in the body of these patients. In this study we are going to assess effects of administered radioiodine activity, serum thyroid stimulating hormone (TSH) level and also admission/administration number on the retention of I-131 in the body of DTC patients.
    Methods
    Number of 92 DTC patients, with different TSH levels ranged from 32 mIU/ml to 250 mIU/ml, was treated with different I-131 activities ranged from 1850 MBq to 7400 MBq. They received one, two or three sessions of radioiodine therapy based on severity of cancer. Post-therapy dosimetry for all the patients was performed immediately, 6 hours, 12 hours, 24 hours and one week after the administration of activity to calculate clearance rate of the I-131.
    Results
    Basedon our observations,there wasa direct correlation between administered radioiodine activities to the patients and clearance rate of the activity from their bodies. Also, those patients who had been admitted for the third time to receive their third radioiodine administration had higher clearance rate as compared to those who had their first or second admissions. TSH level above 32 mIU/ml did not show any effect on clearance rate of I-131.
    Conclusion
    Based on our findings, clearance rate of I-131 is affected by amount of administered radioiodine activities to the patients and number of radioiodine therapy sessions, but serum TSH level above 32 mIU/ml had no effect on this quantity.
    Keywords: Thyroid carcinoma, TSH, Dosimetry, Clearance rate, Radiation dose rate, I, 131
  • Joon Hyouk Choi, Chang Lim Hyun, Heesung Song * Pages 54-57
    Diffusely increased glucose metabolic activity in the right and left ventricles using 2-deoxy-2-(F-18) fluoro-D-glucose positron emission tomography/computed tomography (18F-FDGPET/CT) and global left ventricular hypokinesia at echocardiography can be evident in acute myocarditis. But, there has been no case report that the ventricular 18F-FDGuptake remains unchanged even after recovery of ventricular hypokinesia. A 60-year-old female with primary pleural effusion lymphoma underwent echocardiography and electrocardiography due to fever and elevated cardiac marker after chemotherapy. The electrocardiography showed global hypokinesia suggesting heart failure and the managements were performed. After 20 days 18F-FDGPET/CT for assessing the extent of lymphoma demonstrated that newly appeared high 18F-FDGuptake in the myocardium suggesting pathologic lesions. To evaluate malignancy a cardiac biopsy was performed. Myocarditis was confirmed pathologically. Three months later, improved ventricular function was confirmed by echocardiography, but the metabolic activity in the ventricles was not decreased at follow-up 18F-FDGPET/CT.
    Keywords: myocarditis, chemotherapy, fluorodeoxyglucose
  • Yalda Salehi, Maryam Naseri, Saeed Farzanefar, Mehrshad Abbasi * Pages 58-61
    A 45-year-old woman presented with a headache and visual complaints. Brain MRI revealed a large mass in the right occipital cortex. The tumor was surgically removed and pathological examination showed papillary carcinoma originating from thyroid gland. She had a history of thyroid surgery 27 years ago indicating papillary thyroid cancer with central neck lymph node involvement followed by no additional treatments. CT scan showed a mass in the right kidney and multiple liver cysts. She was referred and treated with curative dose of radioiodine. A post therapeutic iodine scan showed accumulation of the tracer in the right kidney and disseminated uptake in the lungs and neck, with no focal uptake in the liver. To increase iodine accumulation in the lungs with curative intention, the right kidney was surgically resected. Forty-five days after nephrectomy, the patient received her second dose of radioiodine. In the second post therapy scan, the uptake in the lungs and neck was significantly enhanced. The ratio of lungs to whole body uptake was 17.2% and 46.2% in the first and second post therapeutic scan, respectively. Not only unilateral kidney metastasis from PTC is rare incidentally noticed non-metastatic multiple liver cysts in this patient are interesting to report, also the benefit from metastasectomy of asymptomatic visceral metastasis is documented. Such a visceral metastasectomy could result in optimal radiation to other sites, being lung metastases in this case.
    Keywords: Papillary thyroid carcinoma, Kidney metastasis, Metastasectomy, Dosimetry
  • Zehra Pinar Koc *, Pelin Ozcan Kara, Ahmet Dag, Mustafa Berkesoglu Pages 62-65
    Novel surgical applications include radioguided procedures in parathyroidectomy operations. In order to investigate the feasibility of usage of the portable gamma camera in parathyroidectomy operations; intraoperative radioguided parathyroidectomy operation was performed in three hyperparathyroidism patients with inconclusive preoperative parathyroid scintigraphy results. Intraoperative portable gamma camera did not reveal additional benefit over gamma probe in the patients with preoperative inconclusive parathyroid scintigraphy results that have parathyroid adenomas in close proximity to the thyroid lobes. However this modality might be evaluated by future studies regarding the ability to replace frozen section analysis or quick PTH analysis in the verification of the excision of the parathyroid adenoma.
    Keywords: Portable gamma camera, Gamma probe, Radioguided, Parathyroid, Scintigraphy
  • Somayeh Ghahremani, Mahsa Sabour, Sarah Ghahremani, Ahmad Bazrafshan, Ramin Sadeghi * Pages 66-67
    A 23 day old infant patient underwent 99mTc-denatured RBC scanning for locating possible ectopic spleen in our department. The scan showed no tracer activity in normal splenic bed in the left upper quadrant and an ectopic spleen was shown on the right side of abdomen inferior to the liver. 99mTc-denatured RBC scan is an easy and available method for splenic localization in pediatric patients.
    Keywords: Spleen, Ectopic, Denatured RBC, Scintigraphy