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Most patients with p16-positive oropharynx cancer (p16+OPC) receive contralateral elective nodal radiation therapy that improves regional control but increases acute and long-term toxicity. We hypothesize a validated volume reduction in the contralateral neck is effective with an improved toxicity profile in patients with p16+OPC receiving definitive or adjuvant radiation therapy. Patients with newly diagnosed p16+OPC without contralateral nodal involvement treated with primary proton or photon-based (chemo)radiation or adjuvant (chemo)radiation following Transoral Robotic Surgery (TORS) were eligible for enrollment. The reduced contralateral nodal volume included regions of level II and III based on high risk locations for contralateral nodal disease. The primary endpoint was elective out-of-field contralateral nodal failure. Dosimetric comparisons between standard versus reduced elective nodal volumes were analyzed. Acute toxicity was collected using CTCAE v4.0. Fifty-two patients were enrolled of which 36 (69.2%) received definitive (chemo)radiation. Sixteen (30.8%) patients underwent adjuvant radiation following TORS of which 5 (31.2%) received concurrent platinum-based chemotherapy for high risk features. Proton therapy was used in 38 (73.1%) patients. There were no contralateral nodal failures at a median follow up of 15 months (range 1-24 months). For the first 20 patients enrolled, dosimetric comparison of the reduced contralateral elective nodal volumes to consensus elective nodal volumes demonstrated a decrease in the mean dose (18.5 Gy to 14.1 Gy [p<0.05]) and V30 Gy (21.3% to 11.6% [p<0.01]) of the contralateral parotid dose. Significant differences were independent of radiation modality or technology. Acute grade 3 toxicity was observed in 13 (25%) patients including 6 (11.5%) who received a PEG tube during treatment. There were no grade 4-5 acute toxicities, and at 6 months follow up no patients had retained a PEG tube. S elective a voidance of nodal v olum e s at minimal r isk in the N0 contralateral neck of patients with p16-positive oropharynx cancer can be safely performed while maintaining excellent regional control. Both dose to contralateral organs at risk and toxicities were favorable. Maturation of follow-up is ongoing to further support this de-intensification strategy. [ABSTRACT FROM AUTHOR]

Purpose: Combined micro-PET/CT scanners are widely employed to investigate models of brain disorders in rodents using PET-based coregistration. We examined if CT-based coregistration could improve estimates of brain dimensions and consequently estimates of nondisplaceable binding potential (BP ND ) in rodent PET studies., Procedures: PET and CT scans were acquired on 5 female and 5 male CD-1 mice with 3-[ 18 F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([ 18 F]FPEB), a radiotracer for the metabotropic glutamate receptor subtype 5 (mGluR5). In the proposed PET/CT (PTCT) approach, the tracer-specific standard volume was dimension-customized to each animal using the scaling factors from CT-to-standard CT coregistration to simplify PET-to-standard PET coregistration (i.e., 3 CT- and 6 PET-derived parameters). For comparison, conventional PET-based coregistration was performed with 9 (PT9) or 12 (PT12) parameters. PET frames were transferred to the standard space by the three approaches (PTCT, PT9, and PT12) to obtain regional time-activity curves (TACs) and BP ND in 14 standard volumes of interest (VOIs). Lastly, CT images of the animals were transferred to the standard space by CT-based parameters from PTCT and with the scaling factors replaced with those from PET-based PT9 to evaluate agreement of the skull to the standard CT., Results: The PET-based approaches showed various degrees of underestimations of scaling factors in the posterior-anterior-direction compared to PTCT, which resulted in negatively proportional overestimation of radioactivity in the cerebellum (reference region) up to 20%, and proportional, more prominent underestimation of BP ND in target regions down to -50%. The skulls of individual animals agreed with the standard skull for scaling factors from PTCT but not for the scaling factors from PT9, which suggested inaccuracy of the latter., Conclusions: The results indicated that conventional PET-based coregistration approaches could yield biased estimates of BP ND in proportion to errors of brain dimensions when applied to tracers for which the cerebellum serves as reference region. The proposed PTCT provides evidence of a quantitative improvement over PET-based approaches for brain studies using micro-PET/CT scanners., Competing Interests: Declarations. Ethical approval: All experimental protocols and procedures used in this study were reviewed and approved by the Johns Hopkins School of Medicine Animal Care and Use Committee. Consent for publication: Not indicated., (© 2024. The Author(s), under exclusive licence to World Molecular Imaging Society.)

Background: This study evaluates a novel multidisciplinary program providing expanded access to hepatitis C virus (HCV) treatment for rural Appalachian patients in South Carolina. This program identified patients via an opt-out emergency department screening program, and it aimed to achieve HCV cure by using community paramedics (CPs) to link and monitor patients from treatment initiation through 12-week sustained virologic response (SVR)., Methods: Patients aged ≥18 years who were HCV RNA positive were eligible for enrollment if they failed to appear for a scheduled HCV appointment or reported barriers to accessing office-based treatment. CPs provided home visits (initial and 4, 12, and 24 weeks) using a mobile Wi-Fi hotspot to support telemedicine appointments (compliant with the Health Insurance Portability and Accountability Act) and perform focused physical assessments, venipuncture, and coordinated home delivery of medications. Statistics described participant characteristics, prevalence of SVR, and patient satisfaction results at 12 weeks posttreatment., Results: Thirty-four patients were eligible for SVR laboratory tests by 31 August 2023; the majority were male (61.7%) and White (64.7%) with an average age of 56 years (SD, 11.7). Twenty-eight (82.4%) completed treatment and achieved 12-week SVR. Six (17.6%) were lost to follow-up. Two-thirds strongly agreed that they were satisfied with the overall care that they received, and half strongly agreed that their overall health had improved., Conclusions: This CP-augmented treatment program demonstrated success curing HCV for rural patients who lacked access to office-based treatment. Other health care systems may consider this novel delivery model to treat hard-to-reach individuals who are HCV positive., Competing Interests: Potential conflicts of interest. A. H. L. has served on advisory board for Merck Pharmaceuticals, AbbVie and Gilead Sciences. A. H. L. has received research grants from Merck Pharmaceuticals and Gilead Sciences. P. M. has received research grants from Gilead Sciences. No other authors declared any conflict of interest related to this work., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Purpose: Combined micro-PET/CT scanners are widely employed to investigate models of brain disorders in rodents using PET-based coregistration. We examined if CT-based coregistration could improve estimates of brain dimensions and consequently estimates of nondisplaceable binding potential (BP ND ) in rodent PET studies., Procedures: PET and CT scans were acquired on 5 female and 5 male CD-1 mice with PET and CT scans were acquired on 5 female and 5 male CD-1 mice with 3-[ 18 F]fluoro-5-(2-pyridinylethynyl)benzonitrile ([ 18 F]FPEB), a radiotracer for the metabotropic glutamate receptor subtype 5 (mGluR5). In the proposed PET/CT (PTCT) approach, the tracer-specific standard volume was dimension-customized to each animal using the scaling factors from CT-to-standard CT coregistration to simplify PET-to-standard PET coregistration (i.e., 3 CT- and 6 PET-derived parameters). For comparison, conventional PET-based coregistration was performed with 9 (PT9) or 12 (PT12) parameters. PET frames were transferred to the standard space by the three approaches (PTCT, PT9, and PT12) to obtain regional time-activity curves (TACs) and BP ND in 14 standard volumes of interest (VOIs). Lastly, CT images of the animals were transferred to the standard space by CT-based parameters from PTCT and with the scaling factors replaced with those from PET-based PT9 to evaluate agreement of the skull to the standard CT., Results: The PET-based approaches showed various degrees of underestimations of scaling factors in the posterior-anterior-direction compared to PTCT, which resulted in negatively proportional overestimation of radioactivity in the cerebellum (reference region) up to 20%, and proportional, more prominent underestimation of BP ND in target regions down to -50%. The skulls of individual animals agreed with the standard skull for scaling factors from PTCT but not for the scaling factors from PT9, which suggested inaccuracy of the latter., Conclusions: The results indicated that conventional PET-based coregistration approaches could yield biased estimates of BP ND due to erroneous estimates of brain dimensions when applied to tracers for which the cerebellum serves as reference region. The proposed PTCT provides evidence of a quantitative improvement over PET-based approaches for brain studies using micro-PET/CT scanners., Competing Interests: Declarations The authors have no conflicts of interest to declare.