Indian Journal of Nuclear Medicine最新文献

Prostate-specific membrane antigen (PSMA) is a widely accepted and used tracer in staging and biochemical recurrences of prostate cancer. PSMA is extensively expressed in normal prostatic epithelial cells and prostate cancer cells, with some amount of expression also in nonprostatic cells. False-positive PSMA uptake in nonmalignant lesions creates ambiguity in disease detection. In such cases, histopathological correlation and radiological follow-up assist in clinical decision-making. In this case series, we illustrate a few cases where PSMA uptake was incidentally found in some of the commonly occurring benign conditions.

Background: Infertility is a significant aspect of reproductive health and evaluating degree of tubal pathology is essential for determining appropriate management plans.

Aims and objectives: To assess the role of hysterosalpingoscintigraphy (HSSG) as a tubal patency test in nuclear medicine and compare it with hysterosalpingography (HSG) in radiology in infertile women and study pain perception in both tests as well.

Materials and methods: A prospective study was conducted on 50 infertility patients undergoing infertility evaluation at a tertiary care hospital. Both HSG and HSSG procedures were performed during proliferative phase of menstrual cycle.

Results: Our study demonstrated the potential of HSSG as a tool for evaluating tubal patency in infertility workup. It showed good accuracy in detecting tubal patency compared to HSG.

Conclusion: HSG is a radiological procedure valued for its ability to provide detailed anatomical information of uterus and patency of fallopian tubes. In contrast, HSSG provides dynamic information on the functional aspects of the reproductive system using nuclear medicine techniques. Both HSG and HSSG are vital tools in the diagnostic armamentarium for assessing female reproductive health, offering complementary information that aids in comprehensive patient management.

Primary leiomyosarcoma of bone (PLB) is a rare tumor, constituting <0.7% of all primary bone malignancies. It is clinically aggressive with heterogeneous presentation and a dismal prognosis. The most common presentation is pain with swelling and pathological fracture at times. Limited literature is available on PLB and only about 150 cases have been reported to date with only a few case reports defining the utility of 18F-fluorodeoxyglucose (18-F FDG) positron emission tomography/computed tomography (PET-CT) in its management. We hereby present a case of primary leiomyosarcoma of the right distal femur and the role of FDG-PET-CT in its management.

Background: Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra. SPECT imaging using technetium-99m [^99mTc] labeled trodat is the choice of imaging to differentiate PD from its other forms like drug-induced PD.

Aims and objectives: The main objective of our study was to prepare in-house sterile formulation of [^99mTc]Tc-trodat and use in clinics.

Materials and methods: The labeling of trodat was standardized using glucoheptonate sodium salt (GHA), stannous chloride dihydrate (in 0.05 N HCl), and ethylenediaminetetraacetic acid (Na-EDTA). The preparation was mixed and autoclaved at 15 psi for 15 min. The standardised formulation was stored at 4°C, -20°C and -80°C and labeling with ^99mTc was tested for up to 6 days. The radiochemical purity, chemical impurities, and endotoxin levels were tested. The frozen formulation was tested in swiss mice (n = 3) for biodistribution studies at 4 h. Around 18 ± 2 mCi was injected intravenously in each patient (n = 5) and the image was acquired at 4 h post-injection.

Results: The radiochemical purity of the preparation was 98.3 ± 1.4% with a retention time of 16.8 ± 1.5 min as compared to 4.0 ± 0.5 min for free ^99mTc. Animal distribution showed highest uptake in liver and dual excretion via hepatobiliary and renal system. [^99mTc]Tc-trodat imaging was able to differentiate both caudate and putamen.

Conclusions: In-house frozen preparation was advantageous, as it has decreased the chance of manual error as compared to daily make up formulations and economical as compared to commercially available kits.

Artifacts in nuclear medicine imaging are not uncommon. We are aware of some of these, for which we follow necessary protocols to avoid them. However, there are some unusual and unavoidable artifacts that we come across in daily imaging, which may be of concern and need to be detected and corrected on time. Hence, sharing a few such unusual artifacts we encountered while performing routine studies on positron emission tomography-computed tomography and gamma cameras, evaluating the cause and possible precautions.

Introduction: Type 2 deiodinase (DIO2) enzyme plays a vital role in peripheral T4 to T3 conversion and in the negative feedback regulation of pituitary thyroid-stimulating hormone (TSH) secretion. Thr92Ala polymorphism (rs225014) is a common single-nucleotide polymorphism (SNP) that lowers DIO2 activity and is associated with diverse physiological disorders. Differentiated thyroid cancer (DTC) patients are given L-T4 therapy after total thyroidectomy and ¹³¹I treatment to suppress TSH levels.

Aim: The aim of the study was to determine the frequency of rs225014 in DTC patients and to investigate its effect on the thyroid function tests (TFTs) and L-T4 dose required to suppress TSH levels.

Materials and methods: The study included a DTC patient group and a control group. TFTs were estimated by RIA/IRMA kits. Genomic DNA of all the subjects was screened for rs225014 SNP by polymerase chain reaction.

Results: The frequency of Thr/Thr (wild type), Thr/Ala (heterozygous mutant), and Ala/Ala (homozygous mutant) genotypes in the DTC patients' group was 0.21, 0.52, and 0.27, respectively. T3 levels and T3/T4 ratio were significantly low in the Ala/Ala genotype in the DTC group indicating impaired DIO2 activity. L-T4 dose requirement to suppress TSH levels in the DTC patients harboring rs225014 SNP was not statistically different from the wild-type genotype.

Conclusion: The SNP rs225014 was observed to be associated with T3 and T3/T4 ratio but not with the L-T4 dose in DTC harboring SNP suggesting the presence of a compensatory pathway to overcome DIO2 impairment. However, it is essential to study the genetic makeup of DTC patients showing reduced response to TSH suppression to enable quicker decision-making in the implementation of personalized L-T4 dose to prevent any adverse effects.

Exertion and exercise increase glucose metabolism within the skeletal muscles causing increased fludeoxyglucose (FDG) uptake on ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT). Here, we present findings of ¹⁸F-FDG PET/CT in a patient with acute viral hepatitis A-induced liver failure with multiple foci of pyoderma and incessant itching resulting in increased FDG uptake in the muscles of the bilateral forearm, producing the "bilateral hot forearm sign."

A 67-year-old female presented with shortness of breath, weight loss, abdomen, and back pain for 2 months. Ultrasound of the abdomen revealed multiple focal liver lesions. ¹⁸F-Fluorodeoxyglucose whole-body positron emission tomography/computed tomography revealed a hypermetabolic lesion in the suprahepatic inferior vena cava extending into the right atrium. Multiple hypermetabolic lesions were seen in liver, bones, and abdominal lymph nodes, suggestive of metastases. Histopathology and immunohistochemistry of the lesions revealed it to be metastatic leiomyosarcoma.

Background: Lymphoma is a common malignant proliferative disease in which bone marrow infiltration will upstage the disease and thus affect prognosis of the disease. As of now bone marrow biopsy is considered as a reference standard to find out bone marrow involvement in lymphoma. Performing an invasive and painful intervention in all newly diagnosed lymphoma patients is controversial. PET-CT is a non-invasive technique that gives functional information about the cells using the glucose metabolism. It can detect early bone marrow and extra medullary organ involvement which can lead to restaging of the disease. These advantages make PET-CT a valuable adjunct in diagnosis of lymphoma.

Aims and objectives: Our study aims to evaluate the usefulness of 18 F-FDG PET-CT, a non-invasive, semi quantitative whole body imaging technique for detection of early bone marrow and extra medullary organ involvement in lymphoma patients which in turn can obviate the need for bone marrow study (BMS). The primary objective of study is to categorise FDG uptake in bone marrow as diffuse /unifocal /multifocal / no uptake and to correlate pattern of FDG uptake to bone marrow study. Our study also assesses the role of FDG PET/CT in staging of lymphoma.

Materials and methods: Thirty patients with newly diagnosed lymphoma in the age group 18 to 75 years of both sexes within 3 months of diagnosis and who have not been started on any treatment was included in the study. Marrow uptake on FDG PET/CT has been categorized as diffuse, unifocal, multifocal and no uptake. Agreement between bone marrow study and FDG PET/CT has been assessed by reliability analysis using Cohen's kappa. Sensitivity, specificity, PPV, NPV of PET/CT in detecting marrow involvement have been calculated.

Results: The sensitivity, specificity, PPV, NPV and accuracy of 18 F-FDG PET-CT in detecting marrow involvement of lymphoma cases are 86.6%, 77.7%, 68.4%, 91.3% and 80.9% respectively. 18 F-FDG PET-CT detected bone marrow involvement in 86.6% (13 out of 15 total positive cases) cases of lymphoma which included both HL and NHL. Reliability analysis using Cohen's kappa is used to test the agreement between bone marrow study and ¹⁸F-FDG PET/CT. k value of 0.6 was obtained which showed a moderate agreement between bone marrow study and ¹⁸F-FDG PET/CT in marrow assessment.

Conclusion: 18F-FDG PET/CT is a highly sensitive imaging modality which can pick up extra-nodal organ and BMI in patients with lymphoma and can upstage the disease and alter treatment strategies. PET-CT cannot completely replace the bone marrow study. However, being an invasive painful procedure, BMB can be avoided in cases with unifocal or multifocal marrow involvement on PET-CT.