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(1) Background: In 90Y-TARE treatments, lung-absorbed doses should be calculated according to the manufacturer's instructions, using the MIRD-scheme. This scheme is derived from the assumption that 90Y-microspheres deliver the dose in a water-equivalent medium. Since the density of the lungs is quite different from that of the liver, the absorbed dose to the lungs could vary considerably, especially at the liver/lungs interface. The aim of this work is to compare the dosimetric results obtained by two dedicated software packages implementing a water-equivalent dose calculation and a Monte Carlo (MC) simulation, respectively. (2) Methods: An anthropomorphic IEC phantom and a retrospective selection of 24 patients with a diagnosis of HCC were taken into account. In the phantom study, starting from a 90Y-PET/CT acquisition, the liver cavity was manually fixed with a uniform activity concentration on PET series, while the lung compartment was manually expanded on a CT series to simulate a realistic situation in which the liver and lungs are adjacent. These steps were performed by using MIM 90Y SurePlan. Then, a first simulation was carried out with only the liver cavity filled, while a second one was carried out, in which the lung compartment was also manually fixed with a uniform activity concentration corresponding to 10% lung shunt fraction. MIM 90Y SurePlan was used to obtain Voxel S-Value (VSV) approach dose values; instead, Torch was used to obtain MC approach dose values for both the phantom and the patients. (3) Results: In the phantom study, the percentage mean dose differences (∆D%) between VSV and MC in the first and second simulation, respectively were found to be 1.2 and 0.5% (absolute dose variation, ∆D, of 0.7 and 0.3 Gy) for the liver, −56 and 70% (∆D of −0.3 and −16.2 Gy) for the lungs, and −48 and −60% (∆D of −4.3 and −16.5 Gy) for the Liver/Lungs Edge region. The patient study reports similar results with ∆D% between VSV and MC of 7.0%, 4.1% and 6.7% for the whole liver, healthy liver, and tumor, respectively, while the result was −61.2% for the left lung and −61.1% for both the right lung and lungs. (4) Conclusion: Both VSV and MC allowed accurate radiation dose estimation with small differences (<7%) in regions of uniform water-equivalent density (i.e., within the liver). Larger differences between the two methods (>50%) were observed for air-equivalent regions in the phantom simulation and the patient study. [ABSTRACT FROM AUTHOR]

Purpose: Although multiple radiopharmaceuticals are currently available for sentinel node (SN) biopsy, 99mTc-tilmanocept is of particular interest due to its low molecular weight and specific binding capability for the mannose receptors of lymphatic reticuloendothelial cells. In the current systematic review and meta-analysis, we aimed to provide an update from a European expert panel on the performance of 99mTc-tilmanocept for SN biopsy. Methods: A systematic literature search of the PubMed/Medline and Embase databases was performed to identify studies on the use of 99mTc-tilmanocept for SN identification in oncological patients. The articles' methodological quality was assessed before inclusion. The pooled estimates of the pre-/intraoperative detection rates (DR; proportion of patients with ≥ 1 SN identified) and/or pN + sensitivity (SN + /pN + patients ratio), with 95% confidence intervals (CIs), were calculated for breast cancer, melanoma, and head and neck cancer. Results: Twenty-four articles were included in the systematic review, and twenty-one provided data for the meta-analysis. According to data availability, the 99mTc-tilmanocept-estimated pooled preoperative and intraoperative DRs were 0.94 (95%CI, 0.88–1.01) and 0.99 (0.98–1.00) for breast cancer, 0.98 (0.96–0.99) and 1.00 (0.99–1.00) for melanoma, and 0.97 (0.93–1.02) and 0.99 (0.96–1.01) for head and neck carcinoma. Finally, the pooled sensitivity for nodal metastasis in melanoma was 0.97 (95% CI, 0.92–1.03). Conclusion: 99mTc-tilmanocept is a promising radiotracer for SN mapping in patients with breast cancer, melanoma, or head and neck cancer. We strongly believe that multicenter trials are still needed to assess if 99mTc-tilmanocept is superior to other radiotracers used in clinical routine. [ABSTRACT FROM AUTHOR]