Iranian Journal of Nuclear Medicine
Volume:29 Issue: 2, Summer-Autumn 2021

Nipple discharge is the third most common complaint of the breast diseases following the breast mass and the breast pain. The majority of the lesions causing pathological nipple discharge (PND) consist of non-palpable breast lesions (NPBLs). When non-operative diagnostic tools are inadequate to distinguish the diagnosis, the pathological duct should be removed to obtain definitive diagnosis. In this study, we aimed to present the results of radioguided surgery for NPBLs in patients with PND. Patients with PND who underwent radioguided occult lesion localization (ROLL) and excision in our tertiary care referral center were included in this study. Patients were evaluated in detail for age, gender, clinical data, radiological data, marking procedure, surgical results, pathological results, complication rates, local recurrence rates and follow-up period. A total of 66 patients (98.5%) were able to successfully localize the lesion with ROLL. Lesions were marked with ultrasonography (USG) in 81.8% patients (n=54), while the rate of marking with mammography (MMG) was 18.2% (n=12). The mean time duration of preoperative marking was 14±4.3 minutes. The mean operation time was determined as 35 ± 12 minutes. Malignancy was detected in 19.7% of the patients (n=13).  Surgical margin negativity was achieved in 92.3% (n=12) of patients with malignancy. No local recurrence was detected during the follow-up period (median 62(12-116) months). In our study, it has been shown that radioguided occult lesion localization and excision can be easily performed technically for non-palpable breast lesions in patients with pathological nipple discharge and provides sufficient safe surgical margins with acceptable cosmetic results.

This study introduces a novel polyvinyl chloride (PVC)/tungsten composites with characterization of their shielding properties by employing different techniques. The PVC/tungsten composites were produced by employing various weight fractions of tungsten micro-particles including 0, 20, and 40 % wt via melt blending method. In the next step, the linear attenuation coefficients of prepared composite samples were experimentally measured at 662 keV γ-ray, and then were compared to the data estimated using MCNP simulation code and XCOM software. Also the shielding properties of samples were evaluated experimentally with an X-ray tube at 40 kVp. Recorded results showed that by increasing the weight percentage of the tungsten micro-particles, the coefficient of linear attenuation and also the absorbed dose values were increased dramatically. Samples containing 20, and 40% wt of tungsten micro-particles reached to 89.60 and 92.26 %of dose absorption, respectively. Interestingly the proposed composition were approximately 2.3 lighter than the commercial shields. The linear attenuation coefficient of the composite shields has been calculated to be 0.20 cm-1, which was comparable with commercial Pb-based shields. Tungsten micro-particles addition to PVC matrix can increase the absorbed dose value. Plasticized PVC has suitable flexibility and low stiffness value, therefore it can be a good alternative for commercial aprons and other Pb-based shields in low energy voltages.

Traditional citation analysis has been greatly criticized because the process of citation accumulation requires considerable time after publication. So, the term “altmetrics” was proposed in 2010 to measure the scientific and social impact of a paper.We performed a search for certain nuclear medicine topics using the altmetrics approach to report the correlation between the altmetrics index and the number of citations. In this descriptive-analytical study, we retrieved the articles entitled with a few nuclear medicine keywords that published from 2010 to 2019 in the Web of Science (WoS). The number of 730 original papers included in this study. Altmetrics data were derived via an altmetrics bookmarklet. Statistical analysis was performed to measure the correlation between the altmetrics score and the citation count of nuclear medicine papers. Mendeley and Twitter had the highest score of attention on social media platforms. Demographic information revealed that the most number of tweets and Mendeley's attention in nuclear medicine belonged to the United States (US). Moreover, researchers had the highest rate of shares in Mendeley. The correlation between the altmetrics score and citation index was significant (p <0.05). The authors have to pay more attention to social activities on the web for wide dissemination and proper evaluation of their scientific publications.

The applicability of sentinel lymph node biopsy for early detection of metastasis in patients with renal cell carcinoma (RCC) is still in the validation phase and under investigation, which might be due to the unpredictability of the lymphatic pattern in RCC. In this study, we aimed to evaluate the feasibility and accuracy of sentinel node biopsy in patients with renal masses. In this prospective study, twenty-one candidates for open radical nephrectomy with T1-T3 renal tumors, were included consecutively. Sentinel nodes were sought using a hand-held gamma probe following the injection of radiotracer. The validity of sentinel node biopsy procedure as our index test was compared with lymphadenectomy as the standard method for staging and detecting the regional lymph nodes metastasis. At least one sentinel lymph node was detected in thirteen of the patients using a hand-held gamma probe, and the detection rate was 61%. There was no patient with positive pathological involvement of the regional lymph nodes despite the negative involvement of the sentinel lymph node; so, the false-negative rate was 0%. Although sentinel lymph node biopsy was feasible in patients with RCC, sentinel node detection failure was high in our study. More prospective studies with a larger sample size are needed for standardization of the radiotracer injecting aspects and mapping method to increase the detection rate and to evaluate the false negative rate more accurately.

Internal radiation dosimetry is important from a radiation protection point of view and can help to optimize the radiation dose delivered to the workers, public, and patients. It has a rather simple protocol but needs a large amount of data. Therefore, it is difficult to do on a routine basis. The use of computer programs makes internal radiation dosimetry simpler and less time consuming and also decreases the possibility of human errors. The photon’s specific absorbed fractions for two versions of Oak Ridge National Laboratory phantoms were calculated using MCNPX code and a Python code was used to calculate the S-values for selected radionuclides. Then calculated S-values transferred to an excel spreadsheet. The program’s GUI was developed with the Tkinter module of Python programming language. A user-friendly program for internal radiation dosimetry was developed using Python programming language. This program allows the user to calculate the absorbed dose for 20 source organs in 23 target organs for two phantoms. Also, it is possible to compare the results of the two phantoms. Originally, 40 radionuclides were included in the program. This program can be a useful tool for the assessment of organ absorbed doses for individuals dealing with radiation such as patients and workers. It decreases the time of dose calculation and helps to avoid human mistakes.

Gamma cameras are proposed for online range verification and treatment monitoring in proton therapy.  An Analytical formula was derived and validated for sensitivity of a slit collimator based on the photon fluence concept. Fluence formulation was generalized for photons distribution function and solved for high-energy point sources. The effect of the collimator slit size and source off-axis position on the sensitivity of the collimator were included in the formula. The analytically calculated sensitivities of the slit collimator were in good agreement with Monte Carlo results according to the Bland-Altman agreement test and Pearson correlation (r =0.998) statistical analysis with   . The mean relative error between calculated sensitivities with the derived formula and Monte Carlo was up to 0.8%. Moreover, we found that under certain conditions, the established formula is converted to the Anger equation for the pinhole collimator. The analytical formula developed in this research can estimate the slit collimator sensitivity with an acceptable accuracy. The derived closed-form sensitivity formula can be applied in KE collimator design and optimization studies.

Various iodine isotopes are undergoing radioactive decay except Iodine-127 (I-127. Iodine I-131 is unsealed radioactive material used in nuclear medicine for both diagnostic and therapeutic procedures in Royal Hospital since 2006. In radiotoxic classification, I-131 is in group 2 element. I-131 is highly reactive element due to its volatilization nature. Currently, commercial Radio-active wash spray method used for I-131 decontamination in nuclear medicine. Violated fumes from stable Iodine I-127 after heating in fume hood were exposed to starch powder and sugar to verify the starch affinity in trapping iodine reaction and compare with sugar. Then, decontaminate two areas, one by applying starch powder with alkaline and the other area was decontaminated using commercial Radio-active wash spray. Wipes were taken from both areas after each decontamination attempts and measured using well counter (Capintec, CRC-55-tW, and USA).The I-131 decontamination attempts measurements were plotted for both starch powder and Radio-active wash. The starch has affinity of trapping Iodine permanently, while the sugar did not have this property. The effectiveness of starch in case of Iodine-131 contamination was assessed practically. The reduction in contamination by cleaning up using starch powder was more effective compared to the commercial Radio-active wash. This technical note explains the starch effect on I-131 decontamination compare to usual method which is commercial Radio-active wash. Using starch powder for trapping is an efficient and cost effective technique for decontamination of I-131.

Adrenal lesions are commonly observed during 18F-FDG PET/CT studies. Although, most of these lesions are considered benign, an important consideration in oncologic patients is metastasis. Benign lesions, such as adenomas usually present with low 18F-FDG uptake, although overlap with malignant lesions exist and clear SUV cut-off for distinguishing adrenal adenomas has not been established. Different criteria have been proposed to further characterize adrenal lesions, as benign or metastatic. Conventional imaging modalities have additional value when the degree of uptake is equivocal. In this review, we go through some of the common adrenal lesions, as well as discerning features that favor either benign or malignant etiology.

Melioidosis is a potentially fatal infectious disease occurring predominantly in the tropics, caused by a Gram-negative, motile, rod shaped obligatory aerobic non-spore forming bacillus, Burkholderia pseudomallei. It can produce localised or disseminated disease largely affecting immunocompromised patients. It is a challenge to identify melioidosis early as this disease can manipulate host’s cellular immune response to escape detection. Although musculoskeletal involvement in melioidosis is said to be the predominant manifestation, reports have shown widespread involvement in the form of abscesses in lung, liver and spleen etc. It predominantly occurs in patients with diabetes mellitus or those suffering from chronic alcohol abuse, cirrhosis, smoking, chronic lung disease or patients on longstanding corticosteroid use. We present a 43-year-old diabetic male with fever and headache of 5 months duration, abdominal and left sided hip pain with difficulty in walking for 3 weeks. 99mTc-MDP three phase bone scan revealed increased tracer uptake in left femur leading to a diagnosis of focal osteomyelitis. In view of dull aching, intermittent abdominal pain, further investigation was carried out. Contrast enhanced CT abdomen showed hepatosplenomegaly with rim enhancing tiny lesions scattered in liver and spleen suggesting possibility of micro abscesses.  Serial blood cultures grew Gram-negative bacilli, which was later identified as B.pseudomallei. Patient was subsequently started on meropenem, doxycycline and cotrimoxazole. Bone scan was the first investigation to identify the pathology and mooted further investigation to identify visceral involvement guiding appropriate management. He was followed up for a period of 6 months and had an uneventful recovery.

A 68 years old man with prostate carcinoma was referred for 68Ga-PSMA PET/CT scan because of recent significant rise of PSA. He complained of muscle weakness and fatigue, since 3 weeks before the scan, without dyspnea or shortness of breath. In his 68Ga-PSMA-611 PET/CT study, widespread skeletal metastasis, as well as liver involvement were noticed. Also, multiple bilateral patchy areas of ground glass opacities were noticed in peripheral areas of both lung fields, which showed typical pattern of covid-19 pneumonia. These lung lesions showed relatively significant PSMA uptake which were about twice of the liver uptake. Serology test which was performed later, confirmed covid-19 infection.

Primary malignant melanoma of uterine cervix is extremely rare malignancy with very few case published reports. This neoplasm is having poor prognosis, so early diagnosis, staging and treatment is of extreme importance. 18F-FDG PET-CT (18F-labeled fluoro-2-deoxyglucose positron emission computed tomography) scan is an established modality to determine exact extent of disease in malignant melanoma thus determining the treatment protocol. In this reported case, PET-CT is showing primary lesion in uterine cervix with extension in to the vagina and involvement of left inguinal lymph nodes. No other abnormal 18F-FDG avid lesion or distant metastases noted in the scanned region of the body.