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IntroductionGrowing data support the safe and efficacious use of ablative radiotherapy in the setting of liver metastases, with some studies suggesting that patients with metastatic breast cancer (MBCa) do better than patients with metastases from other cancers. This study aims to retrospectively review clinical outcomes of patients with MBCa following liver radiotherapy (RT).Materials and MethodsPatients with MBCa who received liver hypo fractionated ablative RT between 2004 – 2020 were classified according to metastatic classification and treatment intent (i.e., oligo-metastatic (OM) or oligo-progressive (OP)). Demographics, disease characteristics and treatment characteristics were collated. Primary outcome was local control (LC) of treated metastases. Secondary outcomes included overall survival (OS), progression-free survival (PFS), and time to next line systemic therapy (ST), analyzed by univariate (UVA) and multi-variable analysis (MVA).ResultsThirty MBCa patients with 50 liver metastases treated with 5 – 10 fraction ablative intent RT were identified for analysis. Median follow-up was 14.6 months (range 0.9 - 156.2 months). Mean age was 55.6 years (range 32.1 - 79.3 years); 53% were ER+/HER2-ve and 33% HER2+ve. Class of metastatic disease was described as – induced (12 patients, 40%), repeat (15 patients, 50%) and de novo (3 patients, 10%) (1 synchronous, 2 metachronous). Indication of treatment was OP (73%) and OM (27%). Median size of treated liver metastases (LM) was 3.1 cm (range 1cm – 8.8 cm) and the median dose delivered was 40Gy (range 30Gy-60Gy). 1 and 3-year LC rates were 100%. Median OS was 57.7-months with size of treated liver metastases predictive of overall survival (HR 1.35, p=0.023) on UVA. Median time to progression post treatment was 4.8 months (0.8 – 114.7). Patients with induced OMD had a significantly higher rate of progression (HR 4.77, p=0.01) on UVA compared to others, which trended to significance on MVA (HR 3.23, p=0.051).ConclusionHypo-fractionated ablative liver RT in patients with MBCa provides safe, tolerable treatment with excellent LC. Further studies assessing the impact, ideal sequencing, and indications of RT in each metastatic class in MBCa are required.

Background: Cardiac and respiratory motions in clinical positron emission tomography (PET) is a major contributor to inaccurate PET quantification and lesion characterisation. In this study, an elastic motion-correction (eMOCO) technique based on mass preservation optical flow is adapted and investigated for PET/MR applications. Methods: The eMOCO technique was investigated in a motion management QA phantom and in twenty-four patients who underwent PET/MR for dedicated liver imaging and nine patients for cardiac PET/MR evaluation. Data were acquired and then reconstructed with different gating modes and motion correction techniques and compared to static images. Standardized uptake value (SUV), signal-to-noise ratio (SNR) of lesions activities from each gating mode and correction technique were measured and there means/standard deviation (STD) were compared using 2-ways ANOVA analysis and post-hocTukey’s test.Results: Lesions’ s SNR are highly recovered from phantom and patient studies. The STD of the SUV resulted from the eMOCO technique was statistically significantly less (p) than the STD resulted from conventional gated and static SUVs at the liver, lung and heart.Conclusions: The eMOCO technique was successfully implemented in PET/MR imaging in a clinical setting and produced the lowest STD compared to gated and static images, and hence provided the least noisy PET images. Therefore, the eMOCO technique can potentially be used on PET/MRI for improved respiratory and cardiac motion correction.

Introduction: Stereotactic body radiation therapy (SBRT) for the treatment of hepatocellular carcinoma (HCC) remains a challenge due to high rates of toxicity in patients with impaired liver function or tumors not amenable to thermal ablation. We performed a single-arm prospective phase II clinical trial utilizing a novel treatment paradigm optimizing the utility of SBRT based on the individual patient’s probability for tumor control traded off against the risk of liver injury. We hypothesized that maximizing the utility of treatment would decrease toxicity while achieving the same tumor control rate as standard therapy. Methods: Patients with Child-Pugh (CP) A to B7 disease with tumors >3.5 cm, or CP ≥ B8 with any size tumor were prospectively enrolled on an IRB approved clinical trial to undergo SBRT with baseline dose optimization and mid-treatment response adaptation. Optimization and adaptation were based on the expected utility of treatment, calculated as a weighted average of the probability of 4 combinations of toxicity and efficacy outcomes. These calculations were based on the individual patient’s baseline indocyanine green retention at 15 minutes or albumin-bilirubin score (ALBI), CP score, intended dose and fractionation, and mean liver dose with the goal of maximizing the difference between the probability of local control compared to the probability of treatment-related toxicity. Primary endpoints were rate of liver decompensation as measured by ≥2 point change in CP score within 6 months, and lesion-specific local control. Overlap weighting was used to compare patients treated on protocol with patients receiving conventional SBRT at another high-volume cancer center. Results: 56 patients with 80 tumors met inclusion criteria and had a median follow-up of 11.2 months. 44 tumors with a median size of 3.8 cm were treated in CP-A to B7 patients, while 36 tumors with a median size of 2.1 cm were treated in CP ≥ B8 patients. Optimization resulted modification of initial dose for 38% of patients. Sixty-eight percent of patients underwent mid-treatment adaptation with either omission or dose reduction of the final two treatments based on change in expected utility. The 1 year freedom from local progression was 94%. A total of 21% of patients experienced a ≥ 2 point change in CP score within 6 months. Overlap weighted analysis revealed similar local control (HR 0.69, 95% CI [0.25-1.91], p = 0.48), and overall survival (HR 1.45, 95% CI [0.69-3.0], p = 0.33), with decreased toxicity (OR 0.26, 95% CI [0.07 - 0.99], p = 0.048) compared to conventional SBRT. Conclusion: SBRT for HCC patients with large tumors or poor liver function can be optimized via an individualized, utility-based treatment paradigm which may decrease treatment-related toxicity while maintaining tumor control. Citation Format: Daniel J. Herr, Chang Wang, Mishal Mendiratta-Lala, Martha Matuszak, Charles S. Mayo, Yue Cao, Neehar Parikh, Randy Ten Hanken, Dawn Owen, Teodor Stanescu, Michael Yan, Laura A. Dawson, Matthew Schipper, Theodore S. Lawrence, Kyle C. Cuneo. A phase II study of optimized individualized adaptive radiation therapy for hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT151.

Nowadays, automation systems for naval propulsion groups with gas turbines use programmable logic controllers for a precise and reliable control. The automation system is designed so as to be able to connect using signal cables to the transducers monitoring the engine’s parameters, via adapters, so that the command and regulation functions to be fully automatized. These signals are managed by means of the software program implemented in the PLC, and subsequent data acquisition. One of the important problems is the available resource of the propulsion group, until capital repair is required. The remaining lifetime depends on the operating regimes of the gas turbine engine. This problem is more pronounced in the propulsion groups equipping navy ships, where the dynamic regimes of gas turbine engines are much more demanding, and hence the pre-established operating limits may be exceeded. The automation configuration presented herein ensures the accurate computation and precise control of essential parameters for which the direct measurement is not possible using transducers. These parameters are the exhaust gas temperature, the power developed by the engine and implicitly the torque developed at propeller shaft.

Magnetic resonance imaging (MRI) is gaining widespread use in radiation therapy planning, patient setup verification, and real-time guidance of radiation delivery. Successful implementation of these technologies relies on the development of simple and efficient methods to characterize and monitor the geometric distortions arising due to system imperfections and gradient nonlinearities. To this end, the authors present the theory and validation of a novel harmonic approach to the quantification of system-related distortions in MRI.The theory of spatial encoding in MRI is applied to demonstrate that the 3D distortion vector field (DVF) is given by the solution of a second-order boundary value problem (BVP). This BVP is comprised of Laplace's equation and a limited measurement of the distortion on the boundary of a specified region of interest (ROI). An analytical series expansion solving this BVP within a spherical ROI is obtained, and a statistical uncertainty analysis is performed to determine how random errors in the boundary measurements propagate to the ROI interior. This series expansion is then evaluated to obtain volumetric DVF mappings that are compared to reference data obtained on a 3 T full-body scanner. This validation is performed within two spheres of 20 cm diameter (one centered at the scanner origin and the other offset +3 cm along each of the transverse directions). Initially, a high-order mapping requiring measurements at 5810 boundary points is used. Then, after exploring the impact of the boundary sampling density and the effect of series truncation, a reduced-order mapping requiring measurements at 302 boundary points is evaluated.The volumetric DVF mappings obtained from the harmonic analysis are in good agreement with the reference data. Following distortion correction using the high-order mapping, the authors estimate a reduction in the mean distortion magnitude from 0.86 to 0.42 mm and from 0.93 to 0.39 mm within the central and offset ROIs, respectively. In addition, the fraction of points with a distortion magnitude greater than 1 mm is reduced from 35.6% to 2.8% and from 40.4% to 1.5%, respectively. Similarly, following correction using the reduced-order mapping, the mean distortion magnitude reduces to 0.45-0.42 mm within the central and offset ROIs, and the fraction of points with a distortion magnitude greater than 1 mm is reduced to 2.8% and 1.5%, respectively.A novel harmonic approach to the characterization of system-related distortions in MRI is presented. This method permits a complete and accurate mapping of the DVF within a specified ROI using a limited measurement of the distortion on the ROI boundary. This technique eliminates the requirement to exhaustively sample the DVF at a dense 3D array of points, thereby permitting the design of simple, inexpensive phantoms that may incorporate additional modules for auxiliary quality assurance objectives.