فهرست مطالب

Nuclear Medicine - Volume:29 Issue: 1, Winter-Spring 2021

Iranian Journal of Nuclear Medicine
Volume:29 Issue: 1, Winter-Spring 2021

  • تاریخ انتشار: 1399/11/06
  • تعداد عناوین: 12
|
  • Mohammad Eftekhari, Davood Beiki* Page 1
  • Mohamad Aminudin Bin Said *, Hairil Rashmizal Bin Abdul Razak, Marianie Musarudin Pages 2-7
    Introduction
    In Peptide Receptor Radionuclide Therapy (PRRT), the administration of radionuclide such as Lu-177 label with a pharmaceutical agent useful to destroy the lesion. The amount of Lu-177 radioactivity administered to the patients is still not standardize and generally not more than 7.4 GBq per session due to the patient’s safety issues. The first cycle of Lu-177 is an excellent technique to estimate radionuclide uptake for organs at risk. This study aims to simplify five SPECT-CT scanning points into less scanning points to estimate absorbed dose to the organ at risk.
    Methods
    Ten patients who have neuroendocrine tumors enrolled in 177Lu-Dotatate therapy dosimetry. The serial SPECT-CT done after 2, 4, 24, 48 and 72 hours to acquired time disintegration for organ at risk. Partik’s categorical grading criteria is relevantly used in this study to convert the numeric value of Lin’s concordance coefficient into an ordinal scale.
    Results
    Our current result demonstrated an excellent agreement between three and five scanning with LSA exponential fit method. These excellent results presented for kidney, liver and spleen. However, the bladder shows poor results due to the urinary system.
    Conclusion
    Three data point of SPECT-CT images is the best option to estimate absorbed dose to the lesion and organ at risk for 177Lu-Dotatate dosimetry technique.
    Keywords: 177Lu-Dotatate, Dosimetry, SPECT-CT
  • Zahra Pourhabib, Hassan Ranjbar *, Ali Bahrami Samani, Bagher Azizkalantari Pages 8-14
    Introduction
    The palliative care in patients with bone metastasis includes variety of techniques such as conventional analgesics, surgery, external beam radiotherapy, hormone therapy, chemotherapy and using bone-seeking radiopharmaceuticals. Even some of the recent works used combined methods like chemotherapy and radionuclide therapy or using radionuclide therapy as adjuvant to external beam therapy or even using tandem 2 separate radiopharmaceuticals. In line with combined methods, due to the improved efficacy of two radioisotopes with complementary properties in treatment, in this study we proposed using compositional radiopharmaceuticals as a new idea. In this study as a new idea the combined radionuclide therapy have been investigated with utilizing 188Re and 186Re complementary features in the 188/186Re-HEDP cocktail to achieve the maximum efficacy.
    Methods
    186Re and 188Re have been produced simultaneously with identical activities by natural rhenium irradiation. Produced 188/186Re-HEDP with high radiochemical purity was administered intravenously to rats. Biodistribution data were collected at 2, 4, 24, 48 and 72 hours post injection and scintigraphic images were taken at 24 hours after administration of radiopharmaceutical.
    Results
    188/186Re-HEDP was prepared with radiochemical purity of nearly 99%. Its biodistribution data showed high uptake and durability in the skeletal tissues without significant uptake in other major organs.
    Conclusion
    The study results demonstrate that the combination of 186Re and 188Re in cocktail radiopharmaceutical form is achievable and safe. The complementary features of 188Re and 186Re, due to their different energies, half-lives and penetration ranges can lead to more efficacy in bone metastases treatment.
    Keywords: 188, 186Re–HEDP, Cocktail radiopharmaceutical, Radionuclide therapy, Pain palliation, Bone metastasis
  • Manjit Sarma *, Subramanyam Padma, Palaniswamy Shanmuga Sundaram Pages 15-22
    Introduction
    Clinical examination and even anatomical imaging may fail to identify primary site of malignancy in patients presenting with cervical nodal metastasis. 18F-Fluorodeoxyglucose Positron Emission Computed Tomography (18F-FDG PET-CT) is known to overcome the limitations of anatomic imaging.
    Methods
    Sixty-three (63) patients (male:female=55:8, age range=32-83 years, mean age=61.14 ±12.6 years) with one or more metastatic neck node (s) from occult primary underwent 18F-FDG PET-CT. Nodal cytological/biopsy findings, IHC of cervical nodal biopsy (whenever available), scan findings, subsequent biopsy findings (PET guided/ directed)  of suggested occult primaries were correlated. Subsequent detection of any primary malignancy in whom 18F-FDG PET-CT failed to localize a primary was also documented.
    Results
    Malignancy was confirmed in eighteen (18) out of those twenty-four (24) patients in whom site of possible occult primary malignancy was suggested out of total sixty-three (63) patients. In five (5) patients out of remaining thirty-nine (39) patients, a site of primary malignancy was detected or a site of primary malignancy was considered based on IHC subsequently. The detection rate of occult primary, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and false positivity rate was calculated to be 28.5%, 78.2%, 85%, 75%, 87.1% and 15% respectively. 18F-FDG PET-CT also detected other lymph nodal and organ metastases in 46% and 23.8% patients respectively.
    Conclusion
    18F-FDG PET-CT is a useful modality for detecting unknown primary and other nodal /distant metastases in patients presenting with neck nodal metastases.
    Keywords: Metastatic neck nodes, Carcinoma of unknown primary, 18F-FDG PET-CT
  • Bahare Saidi, Babak Fallahi *, Mohammad Eftekhari, Najme Karamzade Ziarati, Armaghan Fard Esfahani Pages 23-27

    Management of locally advanced colon cancer metastases is challenging and operation carries an increased risk of morbidity and mortality. The knowledge of exact sites of involvement can aid the surgeon to make a decision regarding complete resection or palliative therapy. PET/CT scan is an advantage in this setting because metabolic alterations often precede the anatomic changes; moreover, it can show unexpected metastases. In addition, PET/CT scan can differentiate adhesions and scar from local invasion of tumor.  We report a rare case of locally advanced colon cancer metastases to mesentery with extension to liver, chest wall and mediastinum depicted on PET/CT scan. The patient was treated with resection of the involved sites. The pathology report confirmed a poorly differentiated adenocarcinoma mainly involving the mesentery with extension to surrounding organs including the liver. Unfortunately, the patient’s condition deteriorated following surgical intervention. Although there is a trend toward complete resection of primary tumor and involved sites in patients with metastatic colon carcinoma to improve overall patient survival by eliminating any residual disease, in more advanced stages of the disease, palliative therapy might be the preferred approach. PET/CT has invaluable complimentary role to improve surgical planning in advanced oncological situations.

    Keywords: Colon cancer, Metastasis, Chest wall
  • Yasaman Fakhar, Vahid Roshanravan, Mohammad Esmatinia, Somaye Barashki, Ramin Sadeghi * Pages 28-31

    Incidental extra-osseous uptake of 99mTc-MDP on bone scintigraphy has been frequently reported in the literature; however, calcification of the psoas muscle is a rare condition, which has been reported on magnetic resonance (MR) and computed tomography (CT) imagings. Here we report a 67-year-old woman with acute paraplegia and low back pain who was referred for a 99mTc-MDP bone scintigraphy. A destructive lesion in lumbar vertebrae was identified; which was compatible with the findings on CT scan. The planar images also showed focally increased activity in the right pelvis, which was confirmed as extra osseous MDP uptake in psoas muscle on the SPECT/CT images.

    Keywords: Bone scintigraphy, Psoas muscle, Extra osseous uptake, Tuberculosis
  • Forough Kalantari *, Ghasemali Divband, Mohsen Beheshti, Elham Kalantari, Nahid Yaghoobi Pages 32-34

    A 67 years old woman was referred to nuclear medicine center for myocardial perfusion imaging (MPI) for assessment of ischemic heart dieses (IHD).She had a history of atypical chest pain and dyspnea since about 10 days before admission. The MPI SPECT/CT was performed by stress/redistribution Tl-201 protocol. MPI was interpreted as relatively good coronary flow with no appreciable stress induced ischemia. SPECT-CT images revealed multifocal, bilateral and peripheral ground-glass opacities in lungs with subtle background uptake of Tl-201. Considering Covid-19 outbreak, the first diagnosis based on chest CT was Covid-19. This case emphasizing importance of attention to non-cardiac findings in patients undergoing myocardial perfusion imaging, especially review of lung window images in SPECT/CT protocols in the era of covid-19.

    Keywords: Covid-19, Myocardial perfusion imaging, Tl-201, SPECT, CT
  • Elahe Pirayesh * Pages 35-37

    Myocardial perfusion SPECT is one of the most common imaging techniques performed in nuclear medicine departments. To avoid misleading interpretation, it is necessary to address the quality control and technical problems. The truncation artifact occurs when the patient size is large relative to the field of view of the camera, causing false perfusion defects in the LV myocardium, misinterpreted as myocardial perfusion abnormality. It usually happens in obese patients, who may deviate from the detector field. Here, we present a skinny patient showing myocardial truncation artifact, proved to be because of technical issues.

    Keywords: Artifacts, Myocardial perfusion imaging, SPECT, Truncation
  • Susan Shafiei, Kamran Aryana, Seyed Rasoul Zakavi, Abolghasem Allahyari, Atena Aghaee * Pages 38-40

    A 50 years old woman with history of pancreatic neuroendocrine tumor diagnosed 2 years ago, which has not been surgically removed,was referred to our department for a 99mTc-Octreotate in order to evaluate the somatostatin receptor status. She was treated with regular sandostatin injections and chemotherapy. Her CT scan which was previously performed confirmed lung, adrenal and hepatic metastases. In her original pancreatic mass biopsy, well-differentiated neuroendocrine tumor of the pancreas with 3% rate of KI-67 positivity was reported. Whole body 99mTc-Octreotate scan was obtained 4 hours post-intravenous injection of 20 mCi of the radiotracer showed multiple areas of increased tracer uptake in the pancreas, left adrenal, both breasts and left axillary region. Considering the fact that metastasis of the pancreatic NET to the breast is extremely rare, we recommended mammographic correlation and tissue biopsy. Her CT scan images and mammography confirmed breast masses and the biopsy revealed metastatic NET from the pancreatic origin.

    Keywords: Neuroendocrine tumor, Breast, Metastasis, 99mTc-Octreotate
  • Bahare Saidi, Babak Fallahi *, Fatemeh Haghighi, Leila Aghaghazvini, Elham Mirzaian, Mohammad Eftekhari Pages 41-44

    Pigment villondular synovitis (PVNS) is a rare synovial condition. The nature of this disorder is usually characterized as benign; however, malignant transformation has also been reported. MRI is the diagnostic modality of choice in evaluating this entity, revealing low T1 and T2 weighted signals and blooming artifact on gradient echo sequences.  Three-phase 99mTc-MDP bone scan has been infrequently used to assess these lesions; and a varied pattern on three phase bone scans has been reported. In the present case, we report a case of diffuse type PVNS lesion of the knee, evaluated with three-phase 99mTc-MDP bone scan.  This lesion had a progressive nature. Flow and blood pool images revealed minimal activity in the lesion, with increased radiotracer uptake on delayed images. After surgical resection, the patient’s diagnosis of a PVNS was confirmed. Although, the pattern of PVNS has been characterized as more prominent on vascular and blood pool images, other patterns such as limited arterial and venous perfusion, as observed in our case, is also possible. In addition, SPECT-CT as in this case, provided valuable information regarding the extent of joint involvement.

    Keywords: Synovitis, Bone scan, SPECT-CT, 99mTc-MDP
  • Elahe Pirayesh * Pages 45-48

    99mTc-octreotide scintigraphy, performed during the following up a 58-year old man with neuroendocrine tumor demonstrated massive hepatomegaly demonstrating multiple areas of increased and decreased uptake. Due to severe hepatomegaly concurrence of any other abdominal soft tissue lesions could not be excluded. A 99mTc-sulfur colloid scan was done and thoroughly compared with 99mTc-octreotide scintigraphy showing mismatched lesions compatible with liver metastases. Our case demonstrates the importance of multimodality imaging and highlights the forgotten role of 99mTc-Sulfur colloid liver and spleen scan as useful supplementary technique especially when SPECT/CT is not available.

    Keywords: Neuroendocrine tumor, 99mTc-octreotide, 99mTc-Sulfur colloid, SPECT
  • Anurag Jain, Abhishek Mahato *, Deepak Kumar Jha, Vigneshwaran M Pages 49-51

    Pachygyria or incomplete lissencephaly is a developmental condition due to abnormal migration of neurons. The association of seizures in this condition warrants investigation like electroencephalogram (EEG) and magnetic resonance imaging (MRI). 18F-flurodeoxyglucose positron emission topography computed topography (18F-FDG PET/CT) has a potential role in commenting of wide distribution of abnormal metabolism in affected brain parenchyma as well as hypermetabolic epileptogenic focus during ictal phase. Scan during interictal phase will give an idea of affected regions in brain in the form of hypometabolic areas. Although treatment is long-term antiepileptic drugs however if the epileptogenic foci are localized to same region then surgical interventions like hemispherectomies are the options. We present a case in which 18F-FDG PET/CT proved beneficial in pachygyria with seizure disorder.

    Keywords: Pachygyria, Seizure, Epileptogenic focus, 18F-FDG PET, CT