فهرست مطالب

Nuclear Medicine & Biology - Volume:7 Issue:2, 2019
  • Volume:7 Issue:2, 2019
  • تاریخ انتشار: 1398/03/11
  • تعداد عناوین: 12
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  • Abdullah Al, Zaghal, Dani Yellani, Esha Kothekar, Thomas Werner, Poul H&Oslash, Ilund, Carlsen, Abass Alavi * Pages 108-114
    Objective(s)
    This study was undertaken to determine the role of computed tomography (CT)-based methodology to segment the SI joint and quantify the metabolic activity using positron emission tomography (PET). We measured tracer uptake in the right and left SI joints independently to look for differences between the two sides. Further, we correlated tracer uptake with BMI and studied the inter-observer variation with regard to estimated tracer uptake in the SI joints.
    Methods
    In this retrospective study, a total of 103 subjects (48 females, 55 males) from the CAMONA study database collected 2012-2016 at Odense University Hospital in Denmark were included. Mean age was 48±14.59 years, mean BMI was 26.68±4.31 kg/m2. The SI joints were segmented on fused PET/CT images using a 3D growing algorithm with adjustable upper and lower Hounsfield Units (HU) thresholds. The metabolic activities on the two sides were correlated with BMI.
    Results
    For FDG, we found a higher average SUVmean on the right side (right: 1.3±0.33, left: 1.13±0.30; P<0.0001). Similarly, for NaF, the uptake was higher on the right side (right: 5.9±1.29, left: 4.27±1.23; P<0.0001). Positive correlations were present between BMI and FDG uptake (P<0.01) as well as NaF uptake (P<0.01).
    Conclusion
    The PET-based molecular imaging probes along with the CT-based segmentation techniques revealed a significant difference in the metabolic activity between the two SI joints with higher inflammation and reactive bone formation on the right side. FDG and NaF uptakes correlated significantly and positively with BMI.
    Keywords: FDG, NaF, Sacroiliac, Laterality, Leg-Dominance
  • Hiroshi Wakabayashi *, Takahiro Konishi, Hiroto Yoneyama, Anri Inaki, Tomo Hiromasa, Takafumi Yamase, Norihito Akatani, Satoru Watanabe, Hiroshi Mori, Daiki Kayano, Seigo Kinuya Pages 115-120
    Objective(s)
    Single-photon emission computed tomography (SPECT) using metaiodobenzylguanidine (MIBG) is an important diagnostic tool for the treatment of refractory pheochromocytoma and paraganglioma (PPGL). Owing to the difficulty of SPECT quantification, the tumour-to-background ratio (TBR) is used to assess disease activity. However, the utility of TBR is limited owing to the background setting. A quantification technique of SPECT/computed tomography (CT) would facilitate image interpretation. This study aimed to assess the relationship between 123I-MIBG maximum standardized uptake value (SUVmax) and TBR and levels of urinary catecholamines and metabolites in patients with refractory PPGL.
    Methods
    This study included 15 patients with refractory PPGL who underwent 131I-MIBG therapy. Overall, 27 123I-MIBG SPECT/CT images were acquired before and after the therapy. Lesions observed on whole-body images were analysed; the maximum number of lesions per scan was 10. 123I-MIBG SUVmax was semi-automatically calculated using Q. Metrix package (GE Healthcare). TBR was manually calculated according to the following formula: (max count in lesion − max count in background)/max count in background. Background was set in the contralateral area. When a background region of interest could not be set in the area, it was set in the thigh area. Urine was sampled for 24 h to measure catecholamine and metabolite levels. Increases of ≥3-fold were considered abnormal. TBR, 123I-MIBG SUVmax and urinary catecholamine and metabolite levels were compared using linear regression analysis.
    Results
    All patients had MIBG-avid lesions, as seen on 123I-MIBG SPECT/CT. A significant relationship between 123I-MIBG SUVmax and TBR was observed (correlation coefficient [r] =0.84, P < 0.0001). In 27 SPECT/CT examinations, normetanephrine (NMN) level was abnormally increased in 51% (14/27), but other catecholamine and other metabolites were abnormally increased in < 26% (7/27). 123I-MIBG SUVmax strongly correlated with NMN (r=0.76, P < 0.01) and log NMN (r=0.74, P < 0.01).
    Conclusion
    123I-MIBG SUVmax demonstrated similar trends as TBR and reflected urinary NMN in patients with refractory PPGL. Semi-automatic quantification of SPECT/CT could be a useful tool for the evaluation of disease activity
    Keywords: 123I-MIBG, refractory pheochromocytoma, paraganglioma
  • Manabu Nakamura *, Masahisa Onoguchi, Takayuki Shibutani Pages 121-128
    Objective(s)
    In heart failure, the heart-to-mediastinum (H/M) ratio of the delayed image and washout rate (WR) are well-known as a powerful cardiac event predictors. H/M ratio quantifies the accumulation rate of MIBG in the myocardium and WR quantifies reduction of meta-iodobenzylguanidine (MIBG) accumulation in the heart from the early planar image to the delayed planar images in the 123I-MIBG scintigraphy. The present study was conducted to estimate the role of the parameters of cardiac sympathetic imaging by 123I-MIBG myocardial scintigraphy in subacute phase of acute myocardial infarction (AMI) in the prediction of cardiac events, particularly in patients who are successfully responded to reperfusion therapy.
    Methods
    This study was conducted on 145 patients with initial AMI who underwent 123I-MIBG myocardial scintigraphy and myocardial single-photon emission computed tomography (SPECT) after successful response to reperfusion therapy. The 123I-MIBG myocardial scintigraphy was averagely performed 16±5.8 days after the onset of AMI. The early image was taken 15 min after the intravenous administration of 123I-MIBG. Three hours after 123I-MIBG administration, an anterior planar delayed SPECT image was obtained. The H/M ratio and WR were calculated based on planar images. In addition, the average WR, defect volume, and extent were calculated from the SPECT image. The end points of the cardiac event was defined as hospitalization due to unstable angina, heart failure progression, myocardial infarction recurrence, malignant arrhythmia and cardiac death.
    Results
    The follow-up period was 18.4±8.5 months on average, during which 38 (26.2%) cases experienced cardiac events. The results revealed a significant difference between the groups with and without cardiac events in terms of WR and WR (SPECT). Based on the multivariate analysis, WR was the only relevant factor predicting cardiac events. The cumulative event-free rate was significantly lower in the group with the delayed H/M ratio of < 1.74. The cumulative event-free rate were significantly lower in the groups with WR and WR (SPECT) more than 25% and 21.8%, respectively. There was no significant relationship between the cumulative event-free survival rate and the defect size.
    Conclusion
    In the subacute phase of myocardial infarction, the increased WR of 123I-MIBG from the myocardium in planar scintigraphy and SPECT is the predictor of heart failure and cardiac events such as myocardial infarction and recurrence of unstable angina.
    Keywords: Acute myocardial infarction, long-term cardiac event, heart-to-mediastinum ratio, washout rate, 123I-MIBG imaging
  • Babak Fallahi, Reyhaneh Manafi, Farid, Mohammad Eftekhari, Armaghan Fard, Esfehani, Alireza Emami, Ardekani, Parham Geramifar, Mehdi Akhlaghi, Amir Pejman Hashemi Taheri, Davood Beiki * Pages 129-140
    Objective(s)
    In view of somatostatin receptor (SSR) expression on cell membranes of the majority of neuroendocrine tumors (NETs), functional imaging exploiting analogs of SSR alongside the anatomical imaging is the mainstay of this diagnostic modality. In this prospective study, we assessed and directly compared the diagnostic parameters of 68Ga-DOTATATE PET/CT and 99mTc-Octreotide SPECT/CT, as well as CT/MRI.
    Methods
    Twenty-five NET patients, either histologically proven or highly suspicious for NET, who were referred for Octreotide Scan were enrolled in this prospective study. They all underwent 99mTc-Octreotide SPECT/CT and then 68Ga-DOTATATE PET/CT. A blind interpretation was conducted for each imaging as well as for the previously obtained conventional imaging (CT or MRI). The patient-based and lesion-based analysis were conducted and the results of the three modalities were compared. The histopathologic confirmation or follow-up data were considered as the gold standard. Also, the impact of 68Ga-DOTATATE PET/CT on the patient’s management was assessed.
    Results
    Overall, 77 lesions in 14 patients, 135 in 19 and 86 in 16 were detected on 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. On patient-based analysis, the sensitivity was 65%, 90% and 71% for 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. Also, the specificity was 80%, 80% and 75% for 99mTc-Octreotide SPECT/CT, 68Ga-DOTATATE PET/CT and CT/MRI, respectively. The correlation between 68Ga-DOTATATE PET/CT and 99mTc-Octreotide SPECT/CT results was significant (P=0.02; kappa value=0.57), no correlation, however, was depicted with CI (P=0.07; kappa value=0.35). On lesion-based analysis, 68Ga-DOTATATE PET/CT found more organs (P=0.02) and lesions (P=0.001) in comparison with 99mTc-Octreotide SPECT/CT and also more lesions in comparison with CT/MRI (P=0.003). In addition, comparing with 99mTc-Octreotide SPECT/CT and CT/MRI, 68Ga-DOTATATE PET/CT revealed more data in 44% and 36% of the patients, resulting in management modification in 24% and 20%, respectively.
    Conclusion
    Comparing with 99mTc-Octreotide SPECT/CT and CT/MRI, 68Ga- DOTATATE PET/CT provided more sensitivity and specificity in patients with NETs showing more involved organs as well as tumoral lesions. Also, 68Ga-DOTATATE PET/ CT led to change of management in up to one-fourth of the patients, especially in a sub-group re-evaluated for recurrence.
    Keywords: Neuroendocrine tumor, 68Ga-DOTATATE PET, CT, 99mTc-Octreotide SPECT, Conventional Imaging
  • Halil Komek *, Tansel Ansal Balci, Canan Can Pages 141-148
    Objective(s)
    The aim of this study was to determine metastasis rate in patients with well-differentiated grade1 (G1) and grade 2 (G2) gastroenteropancreatic neuroendocrine tumors (GEP NETs) using the gallium-68 DOTATATE positron emission tomography/computed tomography (68Ga-DOTATATE PET/CT). This study was also targeted toward investigating the relationship of maximum standardized uptake value (SUVmax) with mitotic count, histological grade, and Ki-67 index.
    Methods
    This retrospective study included 38 patients (i.e., 17 males and 21 females) with G1 or G2 GEP NETs who underwent 68Ga-DOTATATE PET/CT in Diyarbakir Gazi Yasargil training and research hospital between November 2014 and March 2018. The patients had at least one positive lesion that was approved by two nuclear medicine specialists with a minimum of 10 years of experience.
    Results
    The median age of the patients was 50 years (age range: 27-80 years), and their mean age was 52±15 years. Out of 38 patients, 1 (2.6%), 2 (5.2%), 2 (5.2%), 3 (7.8%), 10 (28.5%), and 19 (50%) patients had primary hepatic, primary mesenteric, colon, duodenal, gastric, and pancreatic NETs, respectively. In addition, the liver metastasis, local lymph node invasions, distant lymph node metastasis, bone metastasis, peritoneal involvement, and lung metastasis were observed in 42%, 21%, 15.7%, 13%, 7.8%, and 5% of the cases, respectively. The SUVmax median values of G1 and G2 tumors were 9.45 (range: 4.2-43.6) and 34.9 (range: 4.1-103), respectively (P=0.003). The Ki-67 index showed a negative correlation with the SUVmax value of the liver metastases and the highest SUVmax value (P=0.001 and P=0.002, respectively). There was also a negative correlation between mitosis count and the highest SUVmax value (P=0.011).
    Conclusion
    Based on the findings, although [68Ga]DOTATATE PET/CT is successfully used to diagnose primary GEP NETs and their metastases, the SUVmax value obtained from DOTATATE PET/CT showed a negative correlation with Ki-67 and mitotic count.
    Keywords: Gastro-Entero-Pancreatic (GEP), Neuroendocrine Tumor (NET), [68Ga]DOTATATE, PET, CT
  • Sabina Sevcenco, Bernhard Grubmuller, Charlotte Sonneck, Koenne, Yasaman Ahmadi, Peter Knoll, Andreas Floth, Wolfgang Pokieser, Shahin Zandieh, Hans, Christoph Klingler, Shahrokh Shariat, Siroos Mirzaei * Pages 149-152
    Objective(s)
    Prostate cancer (PC) is the most common cancer in men over 50 years of age. Bone scintigraphy is still performed in many institutions at the time of primary diagnosis. We aimed to evaluate the role of bone scan in the primary staging of PC in regard of different risk groups.
    Methods
    A retrospective analysis of bone scans in 296 patients (mean age 64±6 y) acquired at the time of primary diagnosis was performed in our institution. The median prostate specific antigen (PSA) was 6.73 ng/ml, all patients had a Gleason score of >5.
    Results
    Only 11/296 patients had a positive bone scan, 1 being in the intermediate risk group, 10 in the high-risk group and none in the low-risk group according to D’Amico classification.
    Conclusion
    Our results support the few published studies that less than 10% of patients with newly diagnosed PC by biopsy would develop bone metastasis, all in the intermediate or high-risk groups. Therefore, a staging by bone scan can only be recommended in patients with intermediate or high-risk, or symptomatic patients only.
    Keywords: Bone scintigraphy, Prostate cancer, Prostate specific antigen, PSA, Gleason score
  • Susan Shafiei, Reza Bagheri *, Ramin Sadeghi, Vahid Reza Dabbagh Kakhki, Amir Hosein Jafarian, Reza Afghani, Davood Attaran, Reza Basiri, Shahrzad M Lari Pages 153-159
    Objective(s)
    Lymph node metastases are the most significant prognostic factor in localized non-small cell lung cancer (NSCLC). Identification of the first nodal drainage site (sentinel node) may improve detection of metastatic nodes. Extended surgeries, such as lobectomy or pneumonectomy with lymph node dissection, are among the therapeutic options of higher acceptability. Sentinel node biopsy can be an alternative approach to less invasive surgeries. The current study was conducted to evaluate the accuracy of sentinel node mapping in patients with NSCLC using an intraoperative radiotracer techniques.
    Methods
    This prospective study was conducted on 21 patients with biopsy-proven NSCLC who were candidates for sentinel node mapping during 2012-2014. All patients underwent thoracoabdominal computed tomography, based on which they had no lymph node involvement. Immediately after thoracotomy and before mobilizing the tumor, peritumoral injection of 2mCi/0.4 mL Tc-99m- phytate was performed in 4 corners of tumor. After mobilization of the tumoral tissues, the sentinel nodes were searched for in the hillar and mediastinal areas using hand-held gamma probe . Any lymph node with in vivo count twice the background was considered as sentinel node and removed and sent for frozen section evaluation. All dissected nodes were evaluated by step sectioning and hematoxylin and eosin staining (H&E).The recorded data included age, gender, kind of pathology, site of lesion, number of dissected sentinel nodes, number of sentinel nodes, and site of sentinel nodes. Data analysis was performed in SPSS software (version 22).
    Results
    The mean age of the patients was 58.52±11.46 years with a male to female ratio of 15/6. The left lower lobe was the most commonly affected site (30.09%). Squamous cell carcinoma and adenocarcinoma were detected in 11 and 10 subjects, respectively. A total of 120 lymph nodes were harvested with the mean number of 5.71±2.9 lymph nodes per patient. At least one sentinel node was identified in each patient, resulting in a detection rate of 95.2%. The mean number of sentinel nodes per patient was 3.61±2. Frozen section results showed 100% concordance with the results of hematoxylin and eosin staining.
    Conclusion
    Based on the findings, sentinel node mapping can be considered feasible and accurate for lymph node staging and NSCLC treatment.
    Keywords: Non-Small Cell Lung Cancer, Radiotracer, Sentinel node
  • Changyin Wang *, Yanfen Zhao, Ying Shen Pages 160-171
    Objective(s)
    The aim of this study was to explore the accuracy of thyroid to background uptake ratio (UR) in the evaluation of 99mTc-pertechnetate thyroid uptake (TcTU) and establishment of an improved algorithm.
    Methods
    This study was conducted on the thyroid images of 322 patients with thyroid diseases and 67 controls. For the purpose of the study, URs of the images were calculated, and then corrected by standardized thyroid area size to establish a corrected uptake ratio (CUR). Subsequently, the accuracy between UR and CUR was compared.
    Results
    The results of linear regression using weighted least squares (using TcTU as a dependent variable and CUR, UR, or thyroid area size as independent variables) showed that CUR (t=105.5, P=0.000), UR (t=31.9, P=0.000), and thyroid area size (t=15.9, P=0.000) are influential factors of TcTU. Furthermore, the standardized coefficient of CUR (β=0.983) was obviously higher than those of UR (β=0.851) and thyroid area size (β=0.629). The linear goodness-of-fit between CUR and TcTU (R=0.983) was better than that between UR and TcTU (R=0.851). In addition, the total concordance rate between CUR and TcTU (96.7%) was significantly higher than that between UR and TcTU (83.0%; χ2=42.9, P=0.000). Discordance rates of CUR in large thyroid area (1.4% vs. 13.4%, χ2=17.0, P=0.000) and small thyroid area (3.3% vs. 42.2 %, χ2=44.3, P=0.000), were significantly lower than that of UR. In the abnormal thyroid areas, the discordance rates of UR obviously increased as compared to those of CUR. The UR overestimated the thyroid uptake in small thyroid areas and underestimated it in large thyroid areas.
    Conclusion
    Based on the findings, CUR is more accurate than UR in measuring 99mTcO4ˉ thyroid uptake; accordingly, it is more significant in the diagnosis of thyroid disease.
    Keywords: Quantitative analysis, Sodium pertechnetate Tc-99m, Thyroid gland, Thyroid uptake, Uptake ratio of thyroid-to-background
  • Maryam Mazaheri Tehrani, Mostafa Erfani *, Nour Amirmozafari, Taher Nejadsattari Pages 172-180
    Objective(s)
    Despite recent advances in treatment modalities, cancer remains a major source of morbidity and mortality throughout the world. Currently, the development of sensitive and specific molecular imaging probes for early diagnosis of cancer is still a problematic challenge. Previous studies have been shown that some of the antimicrobial peptides (AMPs) exhibit a broad spectrum of cytotoxic activity against cancerous cells in addition to their antimicrobial activities. MicrocinJ25 (MccJ25) is an antimicrobial peptide that is produced by Escherichia coli (E. coli) strain. The aim of this study was to investigate the potential of a new peptide radiopharmaceutical derived from MccJ25 for diagnosis of melanoma tumor bearing C57BL/6 mice.
    Methods
    A 14 amino acid analog of MccJ25 was labeled with technetium-99m (99mTc) through hydrazinonicotinamide (HYNIC) chelator and tricine as coligand. In vivo tumor uptake and tissue distribution were evaluated. The in vivo biodistribution studies were determined in C57BL/6 mice bearing B16F10 tumor.
    Results
    The amount of non-peptide related 99mTc-impurities that measured by thin layer chromatography (TLC) did not exceed 5% of the total radioactivity. The in vitro binding to B16F10 cells was 30.73 ± 0.9% after 1 h incubation at 37°C, and saturation binding experiments showed good affinity for radio-complex (Kd=47.98±6.25 nM). The melanoma tumor was clearly visible up 1 h post-injection by gamma camera imaging.
    Conclusion
    The results showed that 99mTc-labeld peptide could be a promising candidate as a targeting radiopharmaceutical for melanoma tumor imaging in mice.
    Keywords: 99m Tc-MccJ25, Radiotracer, B16F10, Tumor
  • Hamideh Abbasian, Ramin Sadeghi, Farshad Emami, Vahidreza Dabbagh Kakhki * Pages 181-184
    Carcinosarcoma is a rare type of cancer that is composed of a mixture of sarcomatous and carcinomatous elements. Pulmonary carcinosarcoma has a 25% five-year survival rate with a prognosis poorer than other non-small cell lung carcinomas. Herein, we report a case of pulmonary carcinosarcoma and its 18F-FDG PET/CT findings. A 61-year-old male patient presented with brain symptoms, including headache, nausea, right hemiplegia, and few attacks of seizures. He underwent brain computed tomography (CT) scan showing a brain lesion in the left parietal lobe. The patient underwent excisional biopsy, and brain lesion was removed. The results of tissue sampling were indicative of carcinosarcoma. Based on anatomical imaging and evidence of pulmonary lesion, the patient underwent 18FDG PET/CT that revealed a heterogeneous mass on the upper lobe of the left lung. An intense FDG uptake was observed along the rim of the mass; however, no FDG uptake was observed in the center of the mass. There were multiple mediastinal lymph nodes with a high FDG uptake. Pulmonary carcinosarcoma was confirmed by tissue sampling.
    Keywords: Carcinosarcoma, FDG PET, Lung cancer, Brain metastasis
  • Saurabh Arora, Nishikant Avinash Damle *, Averilicia Passah, Animesh Ray, Manish Soneja, Sayantan Banerjee, Seema Kaushal, Manisha Jana, Madhavi Tripathi, Chandrasekhar Bal Pages 185-187
    18F-labeled fluoro-2-deoxyglucose positron emission tomography/ computed tomography (18F-FDG PET/CT) is an important imaging modality in the clinical workup of patients with chronic inflammatory disorders which present quite often with a fever of unknown origin. Sarcoidosis is a multisystem chronic inflammatory disorder with a wide clinical spectrum that can involve different organs. The diagnosis of sarcoidosis is usually based on the observation of noncaseating granulomas in biopsy specimens and exclusion of other granulomatous diseases. Skin involvement can occur in 20-25% of sarcoidosis cases. However, scar involvement in sarcoidosis is a rare condition. Herein, we present a case of multisystem sarcoidosis in a 45-year-old woman, who was previously treated with steroids and was in remission for 8 months. The patient presented with multiple skin nodules on the chest and back, a history of intermittent fever, headache, and mild itching at the abdominal scar site for 3 months. Blood investigations revealed elevated serum angiotensin-converting enzyme levels. The 18F-FDG PET/CT revealed a metabolically active involvement of the cutaneous tissue (posthysterectomy scar), apart from other sites of involvement. Biopsy of the scar site revealed multiple epithelioid cell granulomas with giant cells surrounding the collagenous fibers of the scar tissue
    Keywords: Scar sarcoidosis, 18F-FDG PET, CT, cutaneous sarcoidosis
  • Rashid Hashmi *, Adil Lathif Pages 188-193
    In this series we present a quiz about identification of salient and important anatomical landmarks present at a given level on the computed tomography (CT) image. The representative image is followed by further images showing examples of various commonly encountered pathologies that can be seen at this level in clinical practice. Readers are expected to identify highlighted structures in all the images and appreciate how a given abnormality can alter the appearance of normal structures. The aim of this series is to foster understanding and interpretation of the CT component of the single photon emission computed tomography (SPECT) and positron emission tomography (PET) studies help nuclear physicians in interpretation by the nuclear medicine professionals.
    Keywords: Anatomy, Computed Tomography, Heart