NUCLEAR MEDICINE REVIEW最新文献

Background: Bone metastases are complications of many cancers, including colon cancer. Whole body bone scan is commonly used to detect bone metastases in these patients. Bone scan findings are sensitive for detecting metastases but with less experience and especially without the use of single photon emission computed tomography/computed tomography (SPECT/CT) images, they are less specific. This means that while bone scans are effective at identifying areas of abnormal bone activity, they may not always distinguish between bone metastases and other conditions, such as fractures, infections, or benign bone diseases such as a rare condition like osteopetrosis, leading to potential false positives. This 52-year-old male patient was referred for a whole-body bone scan for evaluation of bone metastasis. At first glance, the scan pattern with multiple foci of increased radiotracer uptake seemed to indicate bone metastases due to the patient's colon cancer. However, upon closer inspection of the bone scan and careful attention to details such as bone deformities and cortical thickening, along with obtaining a more detailed patient history and reviewing other radiological records, the diagnosis of osteopetrosis was made.

Conclusions: This case demonstrates the importance of carefully interpreting bone scan findings when diagnosing metastasis. It highlights that other benign diseases, including rare conditions such as osteopetrosis, can mimic the appearance of bone metastases on scans. Therefore, it is crucial to pay close attention to any abnormal patterns, like cortical thickening and bone deformity, and to thoroughly review the patient's medical history and other relevant clinical data and imaging findings. This comprehensive approach helps avoid misdiagnosis and ensures accurate interpretation of the scan results.

Background: Neuroendocrine tumours (NETs) are a group of cancers that can produce hormones and other metabolically active compounds. The majority of NETs have specific tissue characteristics, such as the expression of somatostatin receptors (SSTR). Metabolic testing with [99mTc]Tc-EDDA/HYNIC-Tyr3-octreotide ([99mTc]Tc-EDDA/HYNIC-TOC) can be used in patients with NETs to visualize the presence of receptors in different locations of pathological lesions, including the skeletal system. The study aimed to calculate the body weight maximum standardized uptake value (SUVbwmax) of pathological bone lesions and healthy bone tissues, estimate the size of lesions, and identify a relationship between the SUVbwmax of the bone tissues, age and body mass of the study participants.

Material and methods: The somatostatin receptor scintigraphies (SRS) with [99mTc]Tc-EDDA/HYNIC-TOC were carried out at the Department of Nuclear Medicine, University Clinical Hospital No. 1, Pomeranian Medical University (PMU) in Szczecin from 2019 to 2022. Whole body and single photon emission computed tomography/computed tomography (SPECT/CT) scans were performed four hours after the injection of 700-800 MBq of [99mTc]Tc-EDDA/HYNIC-TOC in 344 patients with neuroendocrine tumours of various primary lesion locations. In 19 patients, who showed foci of increased radiopharmaceutical accumulation in bone location, the SUVbwmax was measured. The SUVbwmax of pathological bone lesions and healthy tissues were determined on SPECT/CT cross-sectional images using Xeleris 4 software.

Results: The total number of foci with increased SSTR expression in bone regions seen on scintigraphic images was 89. Among them, 32 bone lesions were visible on the corresponding CT scans. The mean SUVbwmax of these lesions was 31.39 [standard deviation (SD) 34.31]. For the other 57 lesions that were not visible on corresponding CT scans, the mean SUVbwmax was 19.12 (SD 24.24). The smallest bone lesion detected on the scintigram and visible on the corresponding CT location was 5 mm × 5 mm, measured in cross-section, and was located in the Th8 vertebral body; the largest, measuring 20 mm × 22 mm, was detected in the L3 vertebral body. The SUVbwmax of these lesions was 24.70 and 142.40, respectively.

Conclusions: Bone lesions seen on SPECT/CT in [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy can be quantitatively analysed using the SUV index. Even a very small pathological bone lesion can be detected on [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy. It was shown that in cases where bone lesions were visible on CT scans, the SUVbwmax of bone tumour lesions was higher than when lesions were not visible on CT. Body mass does not affect the SUVbwmax of bone lesions. SUVbwmax of healthy bone tissue decreased with age.

Muir-Torre syndrome (MTS) is a rare genetic disorder, considered a subtype of Lynch syndrome, that causes sebaceous cutaneous tumors and increases the risk of internal visceral tumors. We present a case of a 63-year-old male with a history of MTS with sebaceous tumors, colorectal, and urothelial cancers who underwent fluorine-18-deoxyglucose positron emission tomography/ computed tomography [18F]FDG PET/CT to follow-up on multiple [18F]FDG avid skin lesions and right pelvic lymph nodes. Although few reports are available detailing the utility of [18F]FDG PET/CT in this rare disease, this modality appears useful, and superior, to computed tomography in the diagnosis and follow-up of MTS.

Background: As in disease recurrence, providing clinicians with the exact extent of the disease at the time of initial diagnosis is key in the management and individual treatment of prostate cancer (PC) patients. Intending to examine the usefulness of gallium- 68 PSMA-11 positron emission tomography/computed tomography ([68Ga]Ga-PSMA-11 PET/CT) and to determine if there is a correlation between prostate-specific antigen (PSA) serum values, WHO/ISUP (World Health Organization/International Society of Urological Pathology's) grade group of the tumor and SUVmax (maximized standardized uptake value) values we retrospectively analyzed PET/CT studies performed for initial staging of the disease.

Patients and methods: We retrospectively evaluated 34 studies of patients who underwent [68Ga]Ga-PSMA-11 PET/CT as part of the initial staging of prostate cancer. All patients had prostate cancer confirmed by histological assessment after biopsy and had Gleason score and PSA serum values obtained. The mean PSA value was 33.8 ± 40.9 nmol/L (range 2.2-232).

Results: Nineteen patients had extended disease (55.9%). The mean SUVmax in prostate lesions was 19.5 ± 12.6. The mean value of SUVmax of PET studies in the high-risk group was significantly higher than those of low risk (23.5 ± 13.2 and 10.6 ± 5.4, p < 0.05). A positive correlation was observed between the ISUP group and SUVmax value of prostate lesions (Pearson's r = 0.557, p < 0.01). A positive correlation was also found in the comparison between PSA values and SUVmax (Pearson's r = 0.34, p < 0.05).

Conclusions: In our study, [68Ga]Ga-PSMA-11 PET/CT scans detected the extended disease in more than half of the patients. Locating disease beyond the prostate gland allowed better informed clinical decisions and modified treatment. A positive correlation was found between intraprostatic SUVmax values and the ISUP group of prostate cancer. High-risk patients had SUVmax values that were significantly higher than those of low-risk patients. The correlation between the Gleason score and SUVmax value can be explained by the increased intensity of PSMA expression as the tumor grade increases.

Background: Nuclear medicine uses radionuclides in medicine for diagnosis, staging, therapy, and monitoring the response to therapy. The application of radiopharmaceutical therapy for the treatment of certain diseases is well-established, and the field is expanding. Internal dosimetry is multifaceted and includes different workflows, as well as various calculations based on patient- specific dosimetry.

Aim: The objective of this study was to introduce the technical issues which might occur during iodine-131 (¹³¹I) dosimetry performed in nuclear medicine departments.

Material and methods: Retrospective analysis was performed on a group of 44 patients with papillary thyroid cancer who between May 2021 and October 2021 underwent a 131I treatment: 80-100 mCi (2200-3700 MBq, based on the previous medical history and stage of the disease). Patients underwent a series of ¹³¹I therapy scans using gamma camera Discovery NM 670 CT. Whole body scan (WBS) was performed 2, 4, 24 and 48 hours after ¹³¹I administration. Additionally, after 24 hours of single photon emission computed tomography/ computed tomography, two fields of view (SPECT/CT 2-FOV) were performed from the mid-head to the bladder.

Results: During the dosimetry procedure, several issues arise. Firstly, after receiving therapeutic doses of ¹³¹I, patients should remain in their rooms until the appropriate activity is achieved before being transported to the diagnostic room. Secondly, the walls between examination rooms meet the requirements for accurate diagnosis but not for therapy, leading to the occurrence of artefacts in patients examined behind the wall, potentially influencing the examination results. Thirdly, personnel in the control room also experience additional exposure (10 times greater than in the case of standard diagnostic procedure).

Conclusions: The dosimetry in patients in whom therapeutic procedures are performed with the use of isotopes is mandatory according to Polish and European law, technical issues which occur during the dosimetry procedures might influence the organization of the work in departments.

Background: Therapeutic radiopharmaceuticals [¹⁷⁷Lu]Lu-DOTA-TATE and [⁹⁰Y]Y-DOTA-TATE are used in peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors. One of the factors determining the efficacy of such therapy is administering the radiopharmaceutical dose to the patients in a way consistent with treatment planning. This paper evaluates the loss of [¹⁷⁷Lu]Lu-DOTA-TATE and [⁹⁰Y]Y-DOTA-TATE and their mixed doses during the administration to the patient either by direct infusion or by gravity method.

Material and methods: The loss of [¹⁷⁷Lu]Lu-DOTA-TATE and [⁹⁰Y]Y-DOTA-TATE, was assessed in tests simulating the administration procedures and during infusion to the patients performed at four clinical centres. One clinical centre used a direct infusion, and three others used a gravity method to administer radiopharmaceuticals to the patient.

Results: In the direct infusion the highest radioactivity loss was 3.88% ± 0.49% (n = 3) and 3.76% ± 0.83% (n = 3) for [¹⁷⁷Lu] Lu-DOTA-TATE infusion with radioactivity of 3.71 GBq ± 0.08 GBq (n = 3) and 1.06 GBq ± 0.08 GBq (n = 3), respectively, and 4.04% ± 0.40% (n = 5) for infusion of [⁹⁰Y]Y-DOTA-TATE dose of 1.98 GBq ± 0.05 GBq (n = 5). In the gravity method administration of [¹⁷⁷Lu]Lu-DOTA-TATE generated losses of up to 1.31% ± 0.46% (n = 16) for a dose of 7.45 GBq ± 0.06 GBq (n = 16) and 2.93% ± 1.64% (n = 8) for a dose of 3.78 GBq ± 0.05 GBq (n = 8). However, the infusion of the lowest doses of 0.95 GBq ± 0.01 GBq (n = 4) [¹⁷⁷Lu]Lu-DOTA-TATE and 1.96 GBq ± 0.03 GBq (n = 8) [⁹⁰Y]Y-DOTA-TATE resulted in higher loss of radiopharmaceuticals up to 6.00% ± 0.97% (n = 4) and 4.00% ± 1.57% (n = 8), respectively.

Conclusions: Both investigated methods of radiopharmaceutical administration are associated with the loss of the radioactivity of radiopharmaceutical.

A 75-year-old man underwent a positron emission tomography/computed tomography (PET/CT) scan with fluorine-18-prostate specific membrane antigen ([¹⁸F]F-PSMA-1007) for initial staging of prostate adenocarcinoma. The scan showed lung infiltrates predominantly in both lower lobes with moderate uptake, in addition to a bilateral pulmonary hilar lymph node uptake. CT images revealed ground-glass opacities and a reticular pattern, suggesting COVID-19 pneumonia, which was confirmed by reverse transcription polymerase chain reaction (RT-PCR). Similar incidental findings have been reported in patients undergoing PET/CT scans with other radiotracers. In this case, the probable lung angiogenesis linked to COVID-19 infection can be potencially demonstrated by [¹⁸F]F-PSMA-1007, which helps ensure timely diagnosis and appropriate care for cancer patients.

Background: In radioembolization therapy for hepatic malignancies, the accurate estimation of lung shunt fraction (LSF) is crucial to minimize the risk of radiation-induced pneumonitis and fibrosis due to hepatopulmonary shunting of yttrium-90 (90Y)-microspheres. This study aimed to compare the accuracy and precision of LSF estimation using technetium-99m macroaggregated albumin single photon emission computed tomography ([99mTc]Tc-MAA SPECT) LSF, [99mTc]Tc-MAA planar LSF, and 90Y PET LSF in patients undergoing 90Y-radioembolization.

Material and methods: A retrospective study was conducted involving 15 patients diagnosed with hepatocellular carcinoma (HCC) or liver metastases and planned to undergo transarterial radioembolization with 90Y SirSpheres after multidisplinary team discussion. LSF values were calculated using [99mTc]Tc-MAA SPECT LSF, [99mTc]Tc-MAA planar LSF, and 90Y PET LSF. The accuracy of these methods was assessed through paired t-tests and correlation analysis.

Results: The paired t-test revealed a statistically significant difference between SPECT LSF and planar LSF (t-statistic = -4.81, p-value = 0.0003), indicating that planar imaging tends to overestimate LSF values. However, no significant difference was observed between [99mTc]Tc-MAA SPECT LSF and 90Y PET LSF (t-statistic = -0.98, p-value = 0.343), suggesting a high degree of agreement between these two methods. Correlation analysis showed a very strong positive correlation between [99mTc]Tc-MAA SPECT LSF and 90Y PET LSF (r = 0.999), while strong correlations were also found between SPECT LSF and planar LSF, and between planar LSF and 90Y PET LSF (r = 0.841).

Conclusions: The findings suggest that 90Y PET LSF aligns closely with [99mTc]Tc-MAA SPECT LSF, making them both reliable for LSF estimation in radioembolization therapy. In contrast, planar imaging tends to overestimate LSF, potentially leading to inaccurate dosimetric planning. Incorporating [99mTc]Tc-MAA SPECT/CT and 90Y PET/CT into routine clinical practice could enhance the accuracy of LSF estimation, thereby improving patient outcomes. Further research with larger cohorts is recommended to validate these findings.

A 61-year-old woman with diffuse large B-cell lymphoma received a fluorine-18-deoxyglucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) for staging. Because of the obvious uptake of [¹⁸F]FDG in the spinal cord and brain, a positron emission tomography/magnetic resonance imaging (PET/MRI) was performed after the positron emission tomography/computed tomography (PET/CT). The images showed diffuse [¹⁸F]FDG uptake of the spinal cord and increased T2 signal intensity on MRI, which was suspected to be lymphoma involvement. The patient was diagnosed with diffuse large B-cell lymphoma involving the right maxillofacial region, right cervical lymph nodes, cervix, brain and spinal cord (stage IV of non-germinal center B-cell origin). After chemotherapy, the spinal [¹⁸F]FDG uptake level decreased significantly, which was considered to be a partial metabolic response. Our case was different from prior, which indicated the pattern of spinal cord involvement by lymphoma was focal.

Glucagonoma is a rare pancreatic neuroendocrine tumor (panNET) that can be characterized by increased secretion of glucagon and distinguishing symptoms - glucagonoma syndrome with a typical dermatosis, necrolytic migratory erythema, being its most common manifestation. While surgery and somatostatin analogs remain first-line therapeutic options in panNETs, radioligand therapy with [177Lu]Lu-DOTA-TATE is a recommended second-line palliative treatment in advanced, metastatic cases. However, its prospects and efficacy are still not vastly researched in less frequent neuroendocrine neoplasms. Here, we present an extraordinary case of a metastatic glucagonoma treated with [177Lu]Lu-DOTA-TATE used as a second-line treatment in progressive disease.