MATERIALS AND METHODS: Six patients (M:F = 5:1, age range 28-56 years) with immunohistochemically proven neuroendocrine liver metastases but inconclusive initial CT work-up were retrospectively analysed. Clinical finding, histopathology, comparative imaging and follow-up were used to validate the results when ethically justified.
RESULTS: (68)Ga-DOTATATE PET/CT identified the primary tumour in five out of six (83.3 %) patients: pancreas (n = 4) and stomach (n = 1). Out of three patients with indeterminate primary on initial CT, two patients were confirmed by (68)Ga-DOTATATE PET/CT. Absence of uptake in indeterminate primary of one patient was later confirmed negative by histopathology. In another three patients with undetected primary on initial CT, primary site was demonstrated in all patients with unsuspected metastases in two patients on (68)Ga-DOTATATE PET/ CT. No further work-up was done to confirm the primary in patients with distant metastases. Change of management was observed in three out of six (50 %) patients.
CONCLUSION: Our small study indicates that (68)Ga-DOTATATE PET/CT is a promising diagnostic option in the multimodality approach to neuroendocrine liver metastases of unknown primary origin.
METHODS: From Jan 2020 to Jan 2021, 30 consecutive patients (M:F = 8:22; median age = 52 year (21-89)) suspected of having acute pulmonary embolism (PE) or chronic thromboembolic pulmonary hypertension (CTEPH) were referred for non-contrasted Q-SPECT/CT. All patients were COVID-19 PCR negative. MSKCC Q-SPECT/CT and/or PISAPED criteria were used to determine the presence of thromboembolic disease in Q-SPECT/CT. Final diagnosis was made based on composite reference standards that included at least 2-month clinical cardiorespiratory assessment and follow-up imaging.
RESULTS: Q-SPECT/CT was positive in 19 patients: indeterminate in 1 and 10 were negative. Three false positive cases were observed during follow-up. Of the remaining 16 true positives, all patients' cardiorespiratory symptom were improved or stabilised after treatment with anticoagulants. The overall sensitivity, specificity, PPV, NPV and accuracy of Q-SPECT/CT were 100% (95% CI, 79.41-100%), 78.57% (95% CI, 49.20-95.34%), 84.21% (95% CI, 66.41-93.57%), 100% and 90.00% (95% CI, 73.47-97.89%) respectively.
CONCLUSIONS: In the current COVID-19 pandemic, Q-SPECT/CT can be an alternative modality to detect pulmonary thromboembolic disease. Normal Q-SPECT/CT excludes pulmonary thromboembolic disease with high degree of certainty. However, false positive has been observed.
METHODS: Twenty-six patients on HD underwent US and CT scans on the same day, postdialysis session. QMT for rectus femoris (RF) and vastus intermedius (VI) muscles was taken at the midpoint (MID) and two-thirds (2/3) of both thighs and CSA of the RF muscle (RFCSA ), respectively. Correlation between US and CT measurements was determined by intraclass correlation coefficient (ICC) and Bland-Altman plot.
RESULTS: ICC (95% CI) computed between US and CT was 0.94 (0.87-0.97), 0.97 (0.93-0.99), 0.94 (0.87-0.97), 0.94 (0.86-0.97), and 0.92 (0.83-0.97) for RFMID , VIMID, RF2/3, VI2/3 , and RFCSA , respectively (all P < 0.001). Bland-Altman analysis indicated no bias in agreement between both methods.
CONCLUSION: The US imaging offers a valid and quick bedside assessment approach to assess muscle wasting in HD patients.
Materials and Methods: A cross-sectional study was performed to review the impact of 68Ga-DOTA-peptide (68Ga-DOTATATE or 68Ga-DOTATOC) PET/CT on patients with biopsy-proven GI-NET between January 2011 and December 2015. Suspected NET was excluded. Demographic data, tumoral characteristics, change of disease stage, pre-PET intended management and post-PET management were evaluated.
Results: Over a 5-year period, 82 studies of 68Ga-DOTA-peptide PET/CT were performed on 44 GI-NET patients. The most common primary site was the rectum (50.0%) followed by the small bowel, stomach and colon. Using WHO 2010 grading, 40.9% of patients had low-grade (G1) tumour, 22.7% intermediate (G2) and 4.5% high (G3). Of ten patients scheduled for pre-operative staging, 68Ga-DOTA-peptide PET/CT only led to therapeutic change in three patients. Furthermore, false-negative results of 68Ga-DOTA-peptide PET/CT were reported in one patient after surgical confirmation. However, therapeutic changes were seen in 20/36 patients (55.6%) scheduled for post-surgical restaging or assessment of somatostatin analogue (SSA) eligibility. When 68Ga-DOTA-peptide PET/CT was used for monitoring disease progress during systemic treatment (sandostatin, chemotherapy, everolimus and PRRT) in metastatic disease, impact on management modification was seen in 19/36 patients (52.8%), of which 84.2% had inter-modality change (switch to everolimus, chemotherapy or PRRT) and 15.8% had intra-modality change (increased SSA dosage).
Conclusions: 68Ga-DOTA-peptide PET/CT has a significant impact on management decisions in GI-NET patients as it can provide additional information on occult metastasis/equivocal lesions and supply the clinician an opportunity to select patients for targeted therapy.
METHODS: The administered activity of 177 Lu-DOTATATE was 7.99 ± 0.36 GBq. SPECT/CT images were acquired 0.5, 4, 24, and 48 h after injection in Sunway Medical Centre. For the multiple VSV method, VSV kernels of 177 Lu in media with various densities were generated by Geant4 Application for Emission Tomography (GATE) simulation first. The second step involved the convolution of the time-integrated activity map with each kernel to produce medium-specific dose maps. Third, each medium-specific dose map was masked using binary medium masks, which were generated from CT-based density maps. Finally, all masked dose maps were summed to generate the final dose map. VSV methods with four different VSV sets (1, 4, 10, and 20 VSVs) were compared. Voxel-wise density correction for the single VSV method was also performed. The absorbed doses in the kidneys, bone marrow, and tumors were analyzed, and the relative errors between the VSV and Monte Carlo simulation approaches were estimated. Organ-based dosimetry using Organ Level INternal Dose Assessment/EXponential Modeling (OLINDA/EXM) was also compared.
RESULTS: The accuracy of the multiple VSV approach increased with the number of dose kernels. The average dose estimation errors of a single VSV with density correction and 20 VSVs were less than 6% in most cases, although organ-based dosimetry using OLINDA/EXM yielded an error of up to 123%. The advantages of the single VSV method with density correction and the 20 VSVs over organ-based dosimetry were most evident in bone marrow and bone-metastatic tumors with heterogeneous medium properties.
CONCLUSION: The single VSV method with density correction and multiple VSV method with 20 dose kernels enabled fast and accurate radiation dose estimation. Accordingly, voxel-based dosimetry methods can be useful for managing administration activity and for investigating tumor dose responses to further increase the therapeutic efficacy of 177 Lu-DOTATATE.
METHODS: In this pictorial review, we present six different scenarios of using 18F-FDG PET-CT in the management of suspicious pulmonary nodule or mass. The advantages and limitations of 18F-FDG PET-CT and Herder model are discussed.
RESULTS: 18F-FDG PET-CT with risk assessment using Herder model provides added value in characterising indeterminate pulmonary nodules. Besides, 18F-FDG PET-CT is valuable to guide the site of biopsy and provide accurate staging of lung cancer.
CONCLUSION: To further improve its diagnostic accuracy, careful history taking, and CT morphological evaluation should be taken into consideration when interpreting 18FFDG PET-CT findings in patients with these nodules.