Effects of dose and dose-averaged linear energy transfer on pelvic insufficiency fractures after carbon-ion radiotherapy for uterine carcinoma.

Background And Purpose: The correlation between dose-averaged linear energy transfer (LETd) and its therapeutic or adverse effects, especially in carbon-ion radiotherapy (CIRT), remains controversial. This study aimed to investigate the effects of LETd and dose on pelvic insufficiency fractures after CIRT.

Material And Methods: Among patients who underwent CIRT for uterine carcinoma, 101 who were followed up for > 6 months without any other therapy were retrospectively analyzed.

Pelvic insufficiency fractures following carbon-ion radiotherapy for uterine carcinomas.

Background And Purpose: There is growing evidence on the role of carbon-ion radiotherapy (C-ion RT) for gynaecological tumours. Pelvic insufficiency fracture (PIF) decreases the quality of life after photon beam radiotherapy (RT). However, there is little information on PIF after C-ion RT.

Unresectable Chondrosarcomas Treated With Carbon Ion Radiotherapy: Relationship Between Dose-averaged Linear Energy Transfer and Local Recurrence.

Background/aim: The local control rate of chondrosarcomas treated with carbon-ion radiotherapy (CIRT) worsens as tumour size increases, possibly because of the intra-tumoural linear energy transfer (LET) distribution. This study aimed to evaluate the relationship between local recurrence and intra-tumoural LET distribution in chondrosarcomas treated with CIRT.

Patients And Methods: Thirty patients treated with CIRT for grade 2 chondrosarcoma were included.

Dose-averaged linear energy transfer per se does not correlate with late rectal complications in carbon-ion radiotherapy.

Background And Purpose: Several studies have focused on increasing the linear energy transfer (LET) within tumours to achieve higher biological effects in carbon-ion radiotherapy (C-ion RT). However, it remains unclear whether LET affects late complications. We assessed whether physical dose and LET distribution can be specific factors for late rectal complications in C-ion RT.

Commissioning of a respiratory gating system involving a pressure sensor in carbon-ion scanning radiotherapy.

This study reports the commissioning methodology and results of a respiratory gating system [AZ - 733 V/733 VI (Anzai Medical Co., Japan)] using a pressure sensor in carbon-ion scanning radiotherapy. Commissioning includes choosing a location and method for pressure sensor installation, delay time measurement of the system, and the final flow test.

Dose constraints in the rectum and bladder following carbon-ion radiotherapy for uterus carcinoma: a retrospective pooled analysis.

Background: Carbon-ion radiotherapy (C-ion RT) provides better dose distribution in cancer treatment compared to photons. Additionally, carbon-ion beams provide a higher biological effectiveness, and thus a higher tumor control probability. However, information regarding the dose constraints for organs at risk in C-ion RT is limited.

Effect of patient positioning on carbon-ion therapy planned dose distribution to pancreatic tumors and organs at risk.

Purpose: Pancreatic tumor treatment dose distribution variations associated with supine and prone patient positioning were evaluated.

Methods: A total of 33 patients with pancreatic tumors who underwent CT in the supine and prone positions were analyzed retrospectively. Gross tumor volume (GTV), planning target volume (PTV), and organs at risk (OARs) (duodenum and stomach) were contoured.

Modelling of organ-specific radiation-induced secondary cancer risks following particle therapy.

Background And Purpose: Radiation-induced cancer is a serious late effect that may follow radiotherapy. A considerable uncertainty is associated with carcinogenesis from photon-based treatment, and even less established when including relative biological effectiveness (RBE) for particle therapy. The aim of this work was therefore to estimate and in particular explore relative risks (RR) of secondary cancer (SC) following particle therapy as applied in treatment of prostate cancer.

Estimation of late rectal normal tissue complication probability parameters in carbon ion therapy for prostate cancer.

Purpose: The aim of this study was to estimate normal tissue complication probability (NTCP) parameters for late rectal complications after carbon ion radiotherapy (C-ion RT) for prostate cancer.

Methods And Materials: A total of 163 patients were used to derive NTCP parameters. These patients were treated with relative biological effectiveness (RBE)-weighted dose ranging from 57.

Application of a radiophotoluminescent glass dosimeter to nonreference condition dosimetry in the postal dose audit system.

Purpose: The purpose of this study was to obtain a set of correction factors of the radiophotoluminescent glass dosimeter (RGD) output for field size changes and wedge insertions.

Methods: Several linear accelerators were used for irradiation of the RGDs. The field sizes were changed from 5 × 5 cm to 25 × 25 cm for 4, 6, 10, and 15 MV x-ray beams.

A new method for tracking organ motion on diagnostic ultrasound images.

Purpose: Respiratory-gated irradiation is effective in reducing the margins of a target in the case of abdominal organs, such as the liver, that change their position as a result of respiratory motion. However, existing technologies are incapable of directly measuring organ motion in real-time during radiation beam delivery. Hence, the authors proposed a novel quantitative organ motion tracking method involving the use of diagnostic ultrasound images; it is noninvasive and does not entail radiation exposure.

[Development of the 60Co gamma-ray standard field for therapy-level dosimeter calibration in terms of absorbed dose to water (N(D,w))].

A primary standard for the absorbed dose rate to water in a 60Co gamma-ray field was established at National Metrology Institute of Japan (NMIJ) in fiscal year 2011. Then, a 60Co gamma-ray standard field for therapy-level dosimeter calibration in terms of absorbed dose to water was developed at National Institute of Radiological Sciences (NIRS) as a secondary standard dosimetry laboratory (SSDL). The results of an IAEA/WHO TLD SSDL audit demonstrated that there was good agreement between NIRS stated absorbed dose to water and IAEA measurements.