Evaluation of setup and intrafraction motion for surface guided whole-breast cancer radiotherapy.

Surface Guided Radiotherapy (SGRT) is a relatively new technique for positioning patients and for monitoring patient movement during treatment. SGRT is completely non-invasive since it uses visible light for determining the position of the patient surface. A reduction in daily imaging for patient setup is possible if the accuracy of SGRT is comparable to imaging. It allows for monitoring of intrafraction motion and the radiation beam can be held beyond a certain threshold resulting in a more accurate irradiation. The purpose of this study was to investigate setup uncertainty and the intrafraction motion in non-gated whole breast cancer radiotherapy treatment using an integrated implementation of AlignRT (OSMS) system as SGRT. In initial setup, SGRT was compared to three-point setup using tattoos on the patient and orthogonal kV imaging. For the investigation of intrafraction motion, OSMS monitored the patient with six degrees of freedom during treatment. Using three-point setup resulted in a setup root-mean-square error from the isocenter of 5.4 mm. This was improved to 4.2 mm using OSMS. For the translational directions, OSMS showed improvements in the lateral direction (P = 0.0009, Wilcoxon rank-sum), but for the longitudinal direction and rotation it was not possible to show improvements (P = 0.96 and P = 0.46, respectively). The vertical direction proved more accurate for three-point setup than OSMS (P = 0.000004). Intrafraction motion was very limited with a translational median of 1.1 mm from the isocenter. While OSMS showed marked improvements over laser and tattoo setup, the system did not prove accurate enough to replace the daily orthogonal kV images aligned to bony anatomy.

Exploring death scenes and circumstances in fatal opioid poisonings: Insights for preventive strategies using forensic autopsy cases in Western Denmark.

INTRODUCTION: Fatal opioid poisoning is a growing global issue. This study aims to describe circumstances surrounding fatal opioid poisonings by examining death scenes, demographics, and information from bystanders with the goal of informing prevention efforts. METHODS: We extracted data from the autopsy reports of 327 forensic autopsy cases with fatal poisoning involving methadone and/or morphine from 2013-2020. RESULTS: Fatal opioid poisonings occurred in both rural and urban areas. Death scene was the decedent's own home and a relative's or friend's home in 62% and 21%, respectively. The decedent died alone in 64% of the cases while other people were staying at the same address while death occurred in 30%. Decedents aged 15-34 years were more likely to die with other people staying at the same address than persons aged > 44 years (OR±SD: 2.3 ± 0.9, p = 0.005), and had lower postmortem blood methadone concentrations compared to persons > 34 years (Median [interquartile range]: 0.36 [0.23-0.62] vs 0.63 [0.28-1.2] mg/kg, p = 0.002). Female sex was more prevalent, and persons using illegal drugs were less prevalent in decedents aged > 44 years compared to those with age 15-44 years (29% vs 20%, p = 0.05% and 67% vs 89%, p < 0.001, respectively). Other psychoactive drugs were detected in 97% of decedents, mainly benzodiazepines (80%). CONCLUSIONS: Preventive strategies based on our findings include the need for harm reduction initiatives in both urban and rural areas, recognizing symptoms of fatal poisoning, and awareness of low tolerance among younger age groups. Urgent attention should be given to avoiding opioid use alone, particularly among older individuals, including women using prescribed opioids. Conveying the risks of polydrug use to all age groups is essential, especially co-use of sedative drugs.

Radiation exposure to surgical staff during hyperthermic isolated limb perfusion with 99m Technetium labeled red blood cells.

PURPOSE: Hyperthermic isolated limb perfusion (HILP) is an effective method in the treatment of recurrent melanomas and soft tissue sarcomas. To avoid systemic toxicity, leakage from the limb perfusate into the systemic circulation is real-time monitored by administration of a radioactive agent to the limb circuit. This has made HILP safe for the patient. However, the radiation exposure to the surgical staff has never been measured and could be a limiting factor for the use of HILP. The purpose of the present study was to measure and evaluate the radiation exposure to the surgical staff performing HILP with (99m)Technetium labeled red blood cells. MATERIALS AND METHODS: Thirteen patients had HILP performed in 11 lower limbs and two upper limbs at our inpatient clinic between October 2006 and February 2007. The surgeon and nurse had thermoluminescence dosimetry (TLD) chips attached to the finger pulp and to the ring area of the left fourth finger, as well as an electronic dosimeter attached to the anterior lining of the trousers. The anesthesiologist and perfusion technologist also carried electronic dosimeters. RESULTS: The surgeon had the highest radioactive exposure with an average dose per procedure to the finger pulp of 16.2 microSv, to the ring area of 8.5 microSv, and to the abdominal wall of 4.2 +/- 0.6 microSv. CONCLUSIONS: HILP with (99m)technetium-labeled red blood cells does not constitute a safety risk to the operating team with respect to radioactive exposure. Routine dose monitoring of the staff or special precautions for fertile women are not necessary.

Radiation exposure for medical staff performing quantitative coronary perfusion PET with 13N-ammonia.

PURPOSE: To evaluate radiation doses to medical staff performing quantitative (13)N-ammonia myocardial perfusion positron emission tomography (PET). METHODS: Seventeen PET examinations were performed. Nine examinations consisted of two PET scans (one during rest and one after pharmacological stress with dipyridamole) and eight examinations consisted of three PET scans (additionally a scan after cold pressor testing). The two nuclear technologists and the physician attending the examinations were equipped with an electronic dosemeter over the chest and thermoluminescent dosimetry chips on the right index finger and wrist. RESULTS: The highest mean equivalent dose per examination for a staff member was 453 microSv (417-490 microSv) to the right index finger, 138 microSv (127-149 microSv) to the right wrist and 13 +/- 0.8 microSv to the chest. CONCLUSIONS: Myocardial perfusion PET with (13)N-ammonia exposes the staff to radiation doses that are comparable to doses from (18)F-fluoro-deoxy-glucose scans and the annual doses are well within the recommended upper limits for radiation workers.