Asia Oceania Journal of Nuclear Medicine & Biology
Volume:6 Issue: 1, Winter 2018

The current management of coronary artery disease (CAD) relies on three major therapeutic options, namely medication, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). However, severe CAD that is not indicated for PCI or CABG still bears a poor prognosis due to the lack of effective treatments. In 2006, extracorporeal cardiac shock wave (SW) therapy reported on human for the first time. This treatment resulted in better myocardial perfusion as evaluated by dipyridamole stress thallium scintigraphy, angina symptoms, and exercise tolerance. The aim of the present study was to investigate myocardial perfusion images and evaluate the relationship between the ischemia improvement and symptom amelioration by SW therapy.
We treated ten patients (i.e., nine males and one female) with cardiac SW therapy who had CAD but not indicated for PCI or CABG and aged 63–89 years old. After the SW therapy, all patients were followed up for three months to evaluate any amelioration of the myocardial ischemia based on symptoms, adenosine stress thallium scintigraphy, transthoracic echocardiography, and blood biochemical examinations.
The changes in various parameters were evaluated before and after cardiac SW therapy. The cardiac SW therapy resulted in a significant improvement in the symptoms as evaluated by the Canadian Cardiovascular Society [CCS] class score (P=0.016) and a tendency to improve in summed stress score (SSS) (P=0.068). However, no significant improvement was observed in the summed rest score (SRS), summed difference score (SDS), left ventricular wall motion score index (LVWMSI), N-terminal pro-brain natriuretic, and troponin I. The difference of CCS class score (ΔCCS) was significantly correlated with those of SSS (ΔSSS) and SDS (ΔSDS) (r=0.69, P=0.028 and r=0.70, P=0.025, respectively). There was no significant correlation between ΔCCS and other parameters. Furthermore, no significant difference was observed between the CCS improved and non-improved groups in terms of the baseline characteristics.
The current study demonstrated the potential efficacy and safety of Cardiac SW therapy in CAD patients. As the findings indicated, symptom amelioration was associated with ischemia improvement by extracorporeal shock wave therapy for the CAD patients.

Controversy exists about the localization of non-palpable breast lesions. In many countries, the gold standard for the diagnosis of these lesions is needle localization due to its accuracy. This study sought to compare the ultrasoundand radio-guided occult lesion localization (ROLL) as a simple method with the conventional procedures in terms of their diagnostic power.
This study was conducted on 94 patients with non-palpable breast lesions detected by ultrasonography and localized by the combination of ultrasonography and using radiopharmaceuticals. One to ten hours prior to surgery, 0.1-0.2 ml (equivalent to 0.5-1 mCi) of Tc-99m-phytate was injected to the lesion under the guidance of ultrasonography. Then, the lesion was localized using a hand-held gamma probe, and excision of the lesion was performed according to its radioactivity signal. Data analysis was performed using SPSS, version 16.
Benign and malignant pathologic results were observed in 77 (81.9%) and 17(18.1%) of the patients, respectively, and the mean volume of the excised tissue was 26.29±27 mm³. 79 patients had a solitary lesion (84%), 55 in the left breast (58.5%) and 39 in superolateral quadrant (41.5%). The mean size of the lesions was 15.7 mm in diameter (ranging from 4 to 34 mm). Additionally, there was a need to secondary surgery in 3 (3.2%) patients and inappropriate localization in 6 (6.4%) patients (subcutaneous or intra-ductal spread of radiodrug).
Combination of ultrasound- and radio-guided localization methods for localizing non-palpable breast lesions is a simple and acceptable method for localization with no significant complications. For radio-drug spread and subsequent excessive excised tissue volume, subcutaneous and intra-ductal lesions are not suitable indication for ROLL.

The aim of this study is to examine the effect of different smoothing filters on the image quality and SUVmax to achieve the guideline recommended positron emission tomography (PET) image without harmonization.
We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was filled with 18F solution with a background activity of 2.65 kBq/mL and a sphere-to-background ratio of 4. PET images obtained with the Biograph mCT PET scanner were reconstructed using the ordered subsets-expectation maximization (OSEM) algorithm with time-of-flight (TOF) models (iteration, 2; subset, 21); smoothing filters including the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters with various full width at half maximum (FWHM) values (1-15 mm) were applied. The image quality was physically assessed according to the percent contrast (QH,10), background variability (N10), standardized uptake value (SUV), and recovery coefficient (RC). The results were compared with the guideline recommended range proposed by the Japanese Society of Nuclear Medicine and the Japanese Society of Nuclear Medicine Technology. The PET digital phantom was developed from the digital reference object (DRO) of the NEMA IEC body phantom smoothed using a Gaussian filter with a 10-mm FWHM and defined as the reference image. The difference in the SUV between the PET image and the reference image was evaluated according to the root mean squared error (RMSE).
The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that satisfied the image quality of the FDG-PET/CT standardization guideline criteria were 8-12 mm, 9-11 mm, 9-13 mm, 10-13 mm, 9-11 mm, and 12- 15 mm, respectively. The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that provided the smallest RMSE between the PET images and the 3D digital phantom were 7 mm, 8 mm, 8 mm, 8 mm, 7 mm, and 11 mm, respectively.
The suitable FWHM for image quality or SUVmax depends on the type of smoothing filter that is applied.

Yttrium-90 (90Y) is a beta particle nuclide used in targeted radionuclide therapy which is available to both single-photon emission computed tomography (SPECT) and time-of-flight (TOF) positron emission tomography (PET) imaging. The purpose of this study was to assess the image quality of PET and Bremsstrahlung SPECT by simulating PET and SPECT images of 90Y using Monte Carlo simulation codes under the same conditions and to compare them.
In-house Monte Carlo codes, MCEP-PET and MCEP-SPECT, were employed to simulate images. The phantom was a torso-shaped phantom containing six hot spheres of various sizes. The background concentrations of 90Y were set to 50, 100, 150, and 200 kBq/mL, and the concentrations of the hot spheres were 10, 20, and 40 times of those of the background concentrations. The acquisition time was set to 30 min, and the simulated sinogram data were reconstructed using the ordered subset expectation maximization method. The contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were employed to evaluate the image qualities.
The CRC values of SPECT images were less than 40%, while those of PET images were more than 40% when the hot sphere was larger than 20 mm in diameter. The CNR values of PET images of hot spheres of diameter smaller than 20 mm were larger than those of SPECT images. The CNR values mostly exceeded 4, which is a criterion to evaluate the discernibility of hot areas. In the case of SPECT, hot spheres of diameter smaller than 20 mm were not discernable. On the contrary, the CNR values of PET images decreased to the level of SPECT, in the case of low concentration.
In almost all the cases examined in this investigation, the quantitative indexes of TOF-PET 90Y images were better than those of Bremsstrahlung SPECT images. However, the superiority of PET image became critical in the case of low activity concentrations.

In recent years, the application of radiopharmaceuticals in nuclear medicine has increased substantially. Following the diagnostic procedures performed in nuclear medicine departments, such as myocardial perfusion imaging, patients generally receive considerable doses of radiation. Normally, radiation-induced DNA damages are expected following exposure to a low-dose ionizing radiation. In order to detect molecular changes, high-sensitivity techniques must be utilized. The aim of this study was to assess the effect of a low-dose (below 10 mSv) gamma ray on gene expression using quantitative real-time polymerase chain reaction (qRT-PCR).
Blood samples were obtained from 20 volunteer patients who underwent myocardial perfusion imaging. They were given various doses of Technetium99-m methoxyisobutylisonitrile (99mTc-MIBI). After that, peripheral blood mononuclear cells (PBMNs) were derived, and then total RNA was extracted and reverse-transcribed to cDNA. Finally, the expression levels of xeroderma pigmentosum complementation group-A (XPA) and ferredoxin reductase (FDXR) genes were determinded through qRT-PCR technique using SYBR Green.
XPA and FDXR expression levels were obtained following a very low-dose ionizing radiation. A significant up-regulation of both genes was observed, and the gene expression level of each individual patient was different. If differences in the administered activity and radiosensitivity are taken into account, the observed differences could be justified. Furthermore, gender and age did not play a significant role in the expression levels of the genes under study.
The up-regulation of FDXR after irradiation revealed the high-sensitivity level of this gene; therefore, it could be used as an appropriate biomarker for biological dosimetry. On the other hand, the up-regulation of XPA is an indication of DNA repair following radiation exposure. According to linear no-threshold model (LNT) and the results obtained from this study, a very low dose of ionizing radiation could bring about adverse biological effects at molecular level in the irradiated person.

Studies have indicated advantageous properties of [DOTA-DPhe1 , Tyr3 ] octreotide (DOTATOC) in tumor models and labeling with gallium. Breast cancer is the second leading cause of cancer mortality in women, and most of these cancers are often an adenocarcinoma. Due to the importance of target to non-target ratios in the efficacy of diagnosis, the pharmacokinetic of 68Ga-DOTATOC in an adenocarcinoma breast cancer animal model was studied in this research, and the optimized time for imaging was determined.
68Ga was obtained from 68Ge/68Ga generator. The complex was prepared at optimized conditions. Radiochemical purity of the complex was checked using both HPLC and ITLC methods. Biodistribution of the complex was studied in BALB/c mice bearing adenocarcinoma breast cancer. Also, PET/CT imaging was performed up to 120 min post injection.
The complex was produced with radiochemical purity of greater than %98 and specific activity of about 40 GBq/mM at optimized conditions. Biodistribution of the complex was studied in BALB/c mice bearing adenocarcinoma breast cancer indicated fast blood clearance and significant uptake in the tumor. Significant tumor:blood and tumor:muscle uptake ratios were observed even at early times postinjection. PET/CT images were also confirmed the considerable accumulation of the tracer in the tumor.
Generally, the results proved the possible application of the radiolabelled complex for the detection of the adenocarcinoma breast cancer and according to the pharmacokenitic data, the suitable time for imaging was determined as at least 30 min after injection.

We developed a simple non-invasive I-123-N-isopropyl-p-iodoamphetamine (123I-IMP) quantification method by analyzing chest RI-angiography and single photon emission computed tomography (SPECT) images based on the microsphere model (SIMS method). Theoretically, the SIMS method could be changed to the simple non-invasive ARG (SIARG) method by modifying the integrated washout ratio (WR) to one-point WR. If the regional cerebral blood flow (rCBF) values derived from the SIARG and ARG methods correlate well, the facilities employing the ARG method can easily switch to the SIARG method. The purpose of this study was to develop the SIARG method by modifying the SIMS method and to confirm the feasibility of this method.
The correlation between the input counts of the SIARG method and the blood counts was determined by linear regression analysis. The rCBF values determined by the SIARG method were compared with the values obtained with the ARG and SIMS methods.
There was a good linear correlation between the SIARG counts and the arterial blood counts obtained by the ARG method (r = 0.85, p The rCBF values obtained by the ARG, SIARG, and SIMS methods correlated very well. Therefore, the SIARG method is potentially useful for examinations in routine clinical practice.

Extraosseous accumulation of technetium-99m-methyl diphosphonate (99mTc-MDP) on bone scan is not common. This phenomenon is often attributed to abnormality of calcium metabolism and has been reported in a variety of conditions including metabolic diseases and malignancies.
A five years old boy is presented here, who was admitted to the pediatric emergency suffering from fatigue, respiratory symptoms, weight loss, intermittent fevers, anorexia, nausea and vomiting, edema of legs and abdominal distension for one month. The initial laboratory analysis revealed hypercalcemia. The patient was referred for whole body bone scan with suspicion of malignancy and bone metastasis. The bone scan revealed highly increased radiotracer uptake in both lungs in the perfusion and blood pool phases. Delayed images also showed increased activity in lungs and gastric wall. The skeleton was not seen clearly. Bone marrow aspiration was done and established the diagnosis of ALL. The patient deceased due to respiratory failure 20 days later.
Diffuse lung uptake in this patient was consistent with respiratory failure and poor prognosis. It is reported that bone scan may be useful for assessment of the extent of metastatic calcification and may establish suitable management to prevent organ failure.

A 76-year-old man with symptomatic bone metastases from castrationresistant prostate cancer underwent Radium-223-dichloride (Ra-223) therapy. Before Ra-223 therapy, he had normal peripheral blood cell counts. Ra-223 therapy relieved his shoulder and low back pain. The elevation of the serum prostate-specific antigen (PSA), doubling every month during Ra-223 therapy, suggested a PSA flare or relapse. Some lesions showed decrease and some lesions showed increase on Tc-99m hydroxymethylene diphosphonate bone scintigraphy at two weeks after the third injection of Ra-223 therapy. Ra-223 therapy was discontinued due to thrombocytopenia that was getting worse rapidly. After treatment discontinuation, namely four weeks after the third injection of Ra-223, F-18 fluorodeoxyglucose (FDG) Positron Emission Tomography (PET)/CT and a biopsy were performed to evaluate for metastases, and bone marrow metastases were found. Ra-223 was effective for osteoblastic lesions, but not for bone marrow metastases. FDG PET/CT, but not a Tc-99m based bone scan, detected diffuse bone marrow involvement by cancer. This case report is the first to clarify the utility of FDG PET for the detection of bone marrow metastases confirmed by pathological examination in Ra-223 therapy for progressive castration-resistant prostate cancer.

Nuclear Medicine was established in Myanmar in 1963 by Dr Soe Myint and International Atomic Energy expert Dr R. Hochel at Yangon General Hospital. Nuclear medicine diagnostic and therapeutic services started with Probe Scintillation Detector Systems and rectilinear scanner. In the early stage, many Nuclear Medicine specialists from the International Atomic Energy Agency (IAEA) spent some time in Myanmar and made significant contributions to the development of Nuclear Medicine in our country. The department participated in various IAEA technical cooperation projects and regional cooperation projects. By the late 1990s, new centers were established in Mandalay, Naypyidaw, and North Okkalapa Teaching Hospital of University of Medicine 11, Yangon. The training program related to Nuclear Medicine includes a postgraduate master’s degree (three years) at the University of Medicine. Currently, all centers are equipped with SPECT, SPECT-CT, PET-CT, and cyclotron in Yangon General Hospital. Up until now, the International Atomic Energy Agency has been playing a crucial role in the growth and development of Nuclear Medicine in Myanmar. Our vision is to provide a wide spectrum of nuclear medicine services at a level compatible with the international standards to become a Center of Excellence.

This mage-based series comprises of a quiz pertaining to the identification of salient and important anatomical structures and landmarks expected to be seen at a given level on the computed tomography (CT). The representative image is followed by a series of images showing the examples of different commonly encountered pathological entities that can be seen at this level in a routine clinical practice. Readers are encouraged to identify the highlighted anatomical structures and landmarks in all the images and appreciate the alterations in the appearance of the normal structures resulting from the presence of a pathology. It is expected that this series will assist in improving the confidence of the nuclear physicians in the interpretation of the CT component of the single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies.