NUCLEAR MEDICINE REVIEW最新文献

Prostate-specific membrane antigen (PSMA) - based radiopharmaceuticals are promising for the evaluation of PSMA-positive non-prostate cancers. In this case study, 18F-BF3-Cy3-ACUPA and 68Ga-PSMA positron emission tomography/magnetic resonance imaging (PET/MRI) were compared in a patient with metastatic colon cancer. Both 18F-BF3-Cy3-ACUPA and 68Ga-PSMA PET/MRI showed biopsy-proven metastatic left external iliac adenopathy, highlighting the feasibility of PSMA uptake in PET/MRI of metastatic nodal disease from colon cancer. Along with imaging evaluation, PSMA-based radiopharmaceuticals may also be used as a surrogate imaging tracer for potential theranostic applications using alpha or beta emitters in the context of PSMA-directed radiopharmaceutical therapy in advanced and progressive colorectal cancer.

Background: Ductal carcinoma in-situ (DCIS) often coexists with invasive ductal carcinoma (IDC) of the breast. DCIS is considered as a non-obligate precursor of IDC when both coexist. 18F-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) imaging is commonly used in the staging and follow-up assessment of breast cancer. In this study, we aimed to assess if there is any correlation between primary tumor PET and histopathology findings and histopathological features of the coexisting DCIS.

Material and methods: FDG PET/CT images and histopathology results of the patients with newly diagnosed breast cancer (IDC) with coexisting DCIS were analyzed in this retrospective study. The grade and size of the primary tumor and histopathological features of the coexisting DCIS (nuclear grade and architectural pattern) were obtained from the postoperative histopathology results. Maximum standardized uptake values (SUV: SUVmax and SULmax) of the primary tumor normalized by weight and lean body mass were measured. Statistical analysis was performed to assess the correlation between various parameters of IDC and DCIS.

Results: This study included sixty-two (62) patients with IDC-DCIS. Primary tumor grade was significantly correlated and associated with the nuclear grade of the coexisting DCIS (polychoric correlation r = 0.736, and Fisher exact test, PV < 0.001, respectively). Primary tumor SUV was not correlated with the nuclear grade and architectural pattern of the coexisting DCIS (polyserial correlation r = 0.172, PV = 0.155, and Point Bi-Serial correlation r = -0.009, PV = 0.955, respectively). Median primary tumor size was marginally significantly different among DCIS nuclear grades but it was not significantly different in comedo and non-comedo cases (Kruskal-Wallis test PV = 0.053, and Mann-Whitney U test PV = 0.890, respectively).

Conclusions: Primary tumor grade is correlated with the nuclear grade of the coexisting DCIS. SUV of primary tumor does not seem to be correlated with the histopathological features of coexisting DCIS (nuclear grade and architectural pattern) but this may be further studied in a larger number of patients.

Background: Since melatonin is a non-toxic compound with proven radioprotective effects, we aimed to investigate its efficacy in an in-vivo setting in hyperthyroid patients who are treated with iodine-131. This double-blind placebo-controlled study was conducted on hyperthyroid patients referred to nuclear medicine centers in Babol, Iran. We excluded patients suffering from hypertension treated with warfarin, autoimmune diseases, genetic diseases, cancers, smokers, chemical wounded, radiology and radiotherapy workers, and those who were treated with chemotherapy agents. Patients were randomly assigned to receive a capsule containing 300 mg of melatonin powder or a placebo. Just before receiving iodine-131, blood samples were taken from individuals. All 52 female patients received 10 to 20 mCi iodine-131 for treating hyperthyroidism. A second blood sample was taken one hour after the administration of iodine-131.

Material and methods: To determine the chromosomal damages before and after receiving radioiodine, we performed the cytokinesis- block micronucleus assay. Also, at phase 2, 6 months follow-up was performed, in which patients' positive responses to treatment were compared.

Results: The findings of this study indicate that the difference in micronucleus formation between the placebo and melatonin groups is not significant. However, a significant difference in the 6 months follow-up revealed that 61.5% and 85.7% of patients had a positive response to treatment in the placebo and melatonin groups, respectively.

Conclusions: As one of the first studies dealing with the human in-vivo assessment on the radioprotective effects of melatonin, it was concluded that melatonin has a non-significant positive impact on reducing the rate of chromosomal damages in hyperthyroid patients treated with iodine-131. Nevertheless, the outcome of treatment was significantly higher by melatonin compared to the placebo group.

We report a case of incidental diagnosis of COVID-19 pneumonia by parathyroid scintigraphy. A 53-year-old woman who had severe fatigue, and mild dyspnea underwent parathyroid scintigraphy due to increased serum parathyroid hormone (PTH) and serum calcium levels. Parathyroid scan was negative for abnormal parathyroid tissue. Although the patient had three negative results of COVID-19 PCR tests, significant 99m Tchexakis-2-methoxyisobutylisonitrile ([99mTc]MIBI) uptake is noticed in both lungs that was suspicious for Covid-19 pneumonia. The patient underwent CT scan of the chest for further evaluation. Diffuse groundglass opacities were identified in both lungs which were interpreted as typical feature for COVID-19 pneumonia.

Background: Ovarian cancer relapse can be diagnosed by serum tumor markers measurements and 18F-fluorodoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) findings. The aim of our study was to analyze the potential relationship between cancer antigen 125 (CA-125) and PET/CT results in patients affected by ovarian cancer.

Material and methods: Ninety-two [18F]FDG PET/CT scans in sixty-one patients with diagnosis of ovarian cancer were analyzed and compared to CA-125 values. PET/CT results were compared to other imaging modalities, histology or follow-up data in order to define its diagnostic accuracy. PET/CT studies were analyzed qualitatively and semiquantitatively by measuring the maximum and mean standardized uptake value body weight max (SUVbw max, SUVbw mean), maximum SUV lean body mass (SUVlbm), maximum SUV body surface area (SUVbsa), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of hypermetabolic lesions. All measurements were compared with CA-125 values.

Results: Twenty PET/CT studies were true negative, sixty-three true positive, five false positive and four false negative with sensitivity of 94%, specificity of 80%, negative predictive value of 83%, positive predictive value of 93% and accuracy of 90%. CA-125 levels were significantly correlated with PET/CT results and all PET/CT semiquantitative parameters. CA-125 cutoff values of 17 UI/mL is the best compromise between sensitivity and specificity in discriminating between positive and negative PET/CT result.

Conclusions: [18F]FDG PET/CT has good accuracy in evaluating patients with relapse or persistance of ovarian cancer. CA-125 levels were significantly correlated with metabolic PET/CT parameters.

Background: 99mTc-hydrazinonicotinyl-Tyr3-octreotide ([99mTc]-HYNIC-TOC [Tektrotyd]) is a radiopharmaceutical used for the diagnosis of lesions with overexpression of somatostatin receptors. The purpose of this study was to optimize the method and estimate normal ranges for standardized uptake values of Tektrotyd in healthy livers.

Material and methods: An analysis of standardized uptake value (SUVs) normal ranges was performed for images acquired in a selected "healthy group" of 42 patients evaluated for neuroendocrin tumors. The "pathological group" comprised 20 patients with liver lesions detected by scintigraphic imaging. Normal ranges for radiopharmaceutical uptake values were estimated based on the quantitative analysis of images acquired with a GE Healthcare NM/CT 850 gamma camera.

Results: The method for healthy liver segmentation in single photon emission computed tomography/computed tomography (SPECT/CT) was optimized. The normal range of SUVs for the liver was: standardized uptake value body weight (SUVbw) max [5.2-14.0] g/mL and standardized uptake value lean body mass (SUVlbm) [3.5-9.5] g/mL. The relative standard error (relative SE) of activity concentration estimated in the phantom study for the largest hot spheres was: ϕ = 37 mm - 5.9%, ϕ = 28 mm - 7.1%, ϕ = 22 mm - 11.4%, and ϕ = 17 mm - 22%.

Conclusions: Segmentation in the mid-coronal computed tomography (CT) image, at one-fourth of the height of the liver measured from the top, with a medium-sized volume of interest (VOI) outlined on a given transverse SPECT slice was regarded as the optimal method for estimating normal ranges for standardized uptake values. It is necessary to standardize quantification methods in the SPECT/CT studies. Our work is a step forward in obtaining standardization of SPECT/CT SUV calculation methods. Calculations for radiopharmaceutical uptake in tumors with volumes smaller than 5 mL are biased with a significant measurement error.

We present a case report of incidental detection of breast cancer in a female patient referred for 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) due to primary hyperparathyroidism. This imaging method was recently shown as more sensitive for the detection of metabolically hyperactive parathyroid glands than neck ultrasound and (2-metoksyizobutyloizonitryl labeled with technetium-99m) [99mTc]MIBI. Increased accumulation of FCH was found in the hyperactive parathyroid gland and unexpectedly in the right breast lesion. The surgery confirmed parathyroid adenoma. One month later right upper medial quadrantectomy confirmed breast carcinoma - a combination of invasive ductal carcinoma and intracystic papillary breast carcinoma. To the best of our knowledge, this is the first reporting of simultaneous detection of parathyroid adenoma and breast cancer by using 18F-fluorocholine PET/CT.

Background: The aim of this study is to find the sensitivity of the [18F]FDG PET/CT and the classification of the primary sites of carcinoma of unknown primary (CUP) as a single-center experience.

Material and methods: Sixty-eight patients with a mean age of 62.43 ± 12.78 years were included in this study retrospectively. Sixty-five patients had biopsy or surgery after PET/CT, which revealed pathological diagnoses of malign primary tumors, while primary tumor site could not be detected in three patients with histopathological examination. We evaluated the primary site of CUP with [18F]FDG PET/CT.

Results: Primary sites of three patients were not determined by histopathological examination. Malign lesions indicating the primary site of tumor were identified in 52 of 68 patients with PET/CT correctly. The primary tumor was lung cancer in 14 patients, cholangiocellular cancer in 9 patients, lymphoma in 9 patients, pancreas cancer in 6 patients, gastric cancer in 4 patients, ovary cancer in 4 patients, colon cancer in 4 patients, breast cancer in 3 patients, hepatocellular cancer in 2 patients, rectal cancer in 2 patients, sarcoma in 2 patients, esophagus, renal cell cancer, squamous cell cancer, endometrium cancer, malign melanoma, and multiple myeloma in 1 patient with histopathological examination. PET/CT was false positive in one patient. There were 13 patients in whom primary tumor could not be localized by PET/CT, but was diagnosed by histopathological evaluation.

Conclusions: PET/CT should be the first-line diagnostic tool for CUP, other diagnostic imaging tools should be applied after a negative whole-body PET/CT.

Background: In differentiated thyroid cancer (DTC) patients, cervical nodal metastasis is a negative prognostic factor. Preoperative imaging plays an important role in treatment planning for nodal metastasis and recurrence. The aim of the study is to compare the diagnostic performance of the diffusion-weighted magnetic resonance imaging (DW-MRI) and the F-18 flurodeoxyglucose positron emission computed tomography ([18F]FDG PET/CT) in detection of cervical nodal deposits in DTC patients.

Materal and methods: The study was conducted on 30 patients, each performed both modalities just before the surgery. The gold standard was the pathological specimens with post-operative clinico-radiological follow-up, to assess the diagnostic performance of each modality.

Results: Based on pathological and post-operative clinico-radiological follow up data. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were 84%, 80%, 50%, 95% and 83% for PET/CT compared to 84%, 60%, 42.8%, 91.3% and 80% for DW-MRI. On comparing the diagnostic performance of combined DW-MRI and PET/CT to each modality alone, the sensitivity and NPV were improved to 96% and 80% respectively.

Conclusions: [18F]FDG PET/CT study is a valuable diagnostic modality for the assessment of cervical nodal deposits in DTC patients, surpassing DW-MRI. Combined PET/CT and DW-MRI techniques seemed to have synergistic performance, mainly in terms of sensitivity and NPV, for detection of nodal metastases.

Background: The frequency of bone metastases in individuals increases at advanced stages of cancer, mostly in patients suffering from lung, breast, or prostate cancer. The study aims to evaluate the effectiveness of bone metastases diagnosis of nuclear medicine, CT scan, and MRI in detecting bone metastases among patients with lung, breast, and prostate carcinoma.

Material and methods: Retrospective study design was adopted for the analysis of 120 recruited patients (with the presence of bone metastasis) following a series of examinations and tests.

Results: Better sensitivity (73.33%) and specificity (94.66%) for MRI as compared to SPECT. MRI also proved to be more sensitive (68%) and specific (95.74%), as compared to the findings of the CT scan.

Conclusions: The results conclude that MRI provided favorable diagnostic performance for bone metastasis. It emphasizes that diagnosis using MRI may enable practitioners to devise optimal carcinoma treatment strategies. The healthcare practitioners need to assess the MRI findings to determine improved treatment plans.