The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.
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http://dx.doi.org/10.1088/0031-9155/58/17/5821 | DOI Listing |
Int J Radiat Oncol Biol Phys
January 2025
Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
Purpose: Randomized trials have demonstrated similar local tumor control in patients treated with accelerated partial-breast irradiation (APBI) compared with whole-breast irradiation. However, the optimal APBI dose for maximizing tumor control and minimizing toxicity is uncertain.
Methods And Materials: We enrolled patients ≥18 years of age with grade 1 or 2 ductal carcinoma in situ or stage I invasive breast cancer and resection margins ≥2 mm between 2003 and 2011 to a sequential dose-escalation trial using 3-dimensional conformal external beam APBI giving twice daily 4 Gy fractions with total doses of 32 Gy, 36 Gy, and 40 Gy.
J Med Radiat Sci
January 2025
Royal Adelaide Hospital, Adelaide, South Australia, Australia.
This letter critically evaluates the conclusions drawn by Li et al. (https://doi.org/10.
View Article and Find Full Text PDFCancers (Basel)
January 2025
Department of Thoracic Surgery, Ruhrlandklinik, University of Duisburg-Essen, 45239 Essen, Germany.
Objective: Ewing sarcoma (EWS) of the mediastinum is extremely rare, with only a few cases reported in the literature. We aimed to gain a better understanding of primary mediastinal EWS, describing patients treated within two international, multicenter, prospective, randomized EWS trials.
Methods: Data from patients with primary mediastinal EWS were retrieved from the database of the EURO-E.
Psychooncology
January 2025
Department of Nursing, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai, China.
Objective: Influenced by their life stage and socio-cultural background, young and middle-aged cancer patients in China may experience unique psychological distress. Therefore, this study investigated the severity, problems, and associated factors of psychological distress among young and middle-aged cancer patients.
Methods: We conducted a cross-sectional study on young and middle-aged cancer patients aged 18-59 who were treated at a radiotherapy center from February 2022 to September 2023.
Radiat Oncol
January 2025
Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200025, P.R. China.
Aim: To characterize the differences of dynamic changes for absolute lymphocyte count (ALC) among esophageal squamous cell carcinoma (ESCC) patients treated with neoadjuvant chemoradiotherapy (nCRT) with or without pembrolizumab, as well as to investigate the clinical and lymphocyte-related organs dosimetric parameters that would impact ALC nadir during nCRT.
Materials And Methods: A total of 216 ESCC patients who received nCRT (with pembrolizumab 144; without pembrolizumab: 72) were identified from a prospective cohort. Weekly and 1-month post-nCRT ALC were identified.
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