scholarly journals Dosimetry audits in Taiwan radiotherapy departments

BJR|Open ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 20210002
Author(s):  
An-Cheng Shiau ◽  
Shih-Ming Hsu ◽  
Pei-Yun Huang ◽  
Chiu-Ping Chen ◽  
Yi-Ting Huang ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Electron Beams ◽  
Beam Quality ◽  
Quality Measurement ◽  
High Dose Rate ◽  
Site Quality ◽  
Regulation System ◽  
High Dose ◽  
Photon Beams ◽  
Core Item

Objectives: This study examines the practice of the regulation of Standards for Medical Exposure Quality Assurance (SMEQA) in Taiwan based on on-site quality audit for radiation therapy systems from 2016 to 2019. Methods: 81 radiation therapy departments, 141 linacs, 9 γ knife systems, 34 high dose rate brachytherapy systems, 20 Tomotherapys, and 6 Cyberknives were audited yearly. Data collection and analysis for each institute’s documents including QA procedure, ion chamber and electrometer calibration reports, and a questionnaire relating to machine type and staffing, were requested first and reviewed by auditors. On-site SMEQA core item measurements, including beam output, beam profile and energy constancy for external beam therapy systems, and the source strength, positioning, and timer accuracy for brachytherapy systems were audited second. More than 300 photon beams and more than 400 electron beams were measured each year. Results: There were approximately 8.9 radiotherapy units per million population, and 1.2 medical physicists per unit in Taiwan. For the output measurements, more than 78 and 75% of the photon beams and electron beams, respectively, from linacs were with deviations within ±1.0%. Photon beams have lower beam quality measurement deviations than electron beams. Including in-plane and cross-plane measurements, more than 90 and 85% photon and electron beams, respectively, were with flatness consistency within 1.0%. All audit measurements were within the SMEQA acceptance criteria. Conclusions: According to SMEQA regulations on-site QA audits were successfully carried out from 2016 to 2019 for all Taiwan radiotherapy units. The measurement results showed high quality machine performance in Taiwan. Advances in knowledge: Dosimetry audits with directly acquired measurement readings have lower uncertainties; allow immediate feedback, discussion, and adjustment in a timely manner. In addition to regulation system establishment and education and training implementation, the machine quality is closely related to machine maintenance implementation.

scholarly journals Radiotherapy Dosimetry Audits in Taiwan Hospitals

2020 ◽  
Author(s):  
An-Cheng Shiau ◽  
Shih-Ming Hsu ◽  
Pei-Yun Huang ◽  
Chiu-Ping Chen ◽  
Yi-Ting Huang ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Radiation Treatment ◽  
Electron Beams ◽  
Beam Quality ◽  
Ion Beam ◽  
Quality Measurement ◽  
High Dose Rate ◽  
Site Quality ◽  
High Dose ◽  
Photon Beams

Abstract Purpose: This study examines the practice of the regulation of Standards for Medical Exposure Quality Assurance (SMEQA) in Taiwan based on on-site quality audit for radiation therapy systems from 2016 to 2019. Methods and Materials: about 81 radiation therapy departments, 141 medical linear accelerators, 9 gamma knifes, 34 high dose rate brachytherapy systems, 20 Tomotherapys and 6 Cyberknives were audited yearly. The inspection was implemented in two stages. Data collection and analysis for each institute’s documents including QA operating procedure, ion chamber and electrometer calibration reports, and a questionnaire relating to machine type and staffing, were requested first and reviewed by specially trained auditors. On-site measurements of SMEQA core items, including beam output, beam profile and energy constancy for external beam therapy systems, and the source strength, positioning and timer accuracy for brachytherapy systems were audited second. More than 300 photon beams were measured from linacs, Gamma knives, Cyberknives and Tomotherapys, and more than 400 electron beams from linacs each year.Results: The radiation treatment resource is about 8.9 therapy machines or 7.5 MV/MeV/ion beam therapy machines per million population, respectively, and there are on average about 1.20 medical physicists per radiation therapy unit in Taiwan. There were more than 78% and 75% of photon and electron beams respectively from linacs with deviations measured to the stated reference-point dose within 1.0%. Photon beams have lower beam quality measurement deviations than electron beams, and more than 90% of photon beams from linacs were within 1.0%. Including in-plane and cross-plane measurements, more than 90% and 85% of photon and electron beams respectively with flatness consistency within 1.0%. Beam symmetry as an absolute value has more than 75% of measurements within 1.0%. All audit measurements in this study were within the SMEQA acceptance criteria.Conclusions: On-site machine QA audits have been implemented from 2016 to 2019 for all radiation therapy units each year. The measurement results have shown a high quality machine performance in Taiwan.

Radiobiological characterization of the very high dose rate and dose per pulse electron beams produced by an IORT (intra operative radiation therapy) dedicated linac

2017 ◽  
Vol 6 (S5) ◽  
pp. S761-S768 ◽  
Author(s):  
Paola Scampoli ◽  
Carmela Carpentieri ◽  
Marco Giannelli ◽  
Vera Magaddino ◽  
Lorenzo Manti ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Dose Rate ◽  
Electron Beams ◽  
High Dose Rate ◽  
High Dose ◽  
Pulse Electron ◽  
Very High

PET Image-guided Dose Escalation in High-dose Rate Radiation Therapy

2010 ◽  
Vol 78 (3) ◽  
pp. S415
Author(s):  
E.K. Lee ◽  
F. Yuan ◽  
A. Templeton ◽  
R. Yao ◽  
J.C. Chu
Keyword(s):  
Radiation Therapy ◽  
Dose Rate ◽  
Dose Escalation ◽  
High Dose Rate ◽  
High Dose ◽  
Image Guided

scholarly journals Back to the Future: Very High-Energy Electrons (VHEEs) and Their Potential Application in Radiation Therapy

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4942
Author(s):  
Maria Grazia Ronga ◽  
Marco Cavallone ◽  
Annalisa Patriarca ◽  
Amelia Maia Leite ◽  
Pierre Loap ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Current Knowledge ◽  
High Energy ◽  
High Dose Rate ◽  
Point Of View ◽  
High Dose ◽  
Dose Rates ◽  
High Energy Electrons ◽  
Very High Energy ◽  
Very High

The development of innovative approaches that would reduce the sensitivity of healthy tissues to irradiation while maintaining the efficacy of the treatment on the tumor is of crucial importance for the progress of the efficacy of radiotherapy. Recent methodological developments and innovations, such as scanned beams, ultra-high dose rates, and very high-energy electrons, which may be simultaneously available on new accelerators, would allow for possible radiobiological advantages of very short pulses of ultra-high dose rate (FLASH) therapy for radiation therapy to be considered. In particular, very high-energy electron (VHEE) radiotherapy, in the energy range of 100 to 250 MeV, first proposed in the 2000s, would be particularly interesting both from a ballistic and biological point of view for the establishment of this new type of irradiation technique. In this review, we examine and summarize the current knowledge on VHEE radiotherapy and provide a synthesis of the studies that have been published on various experimental and simulation works. We will also consider the potential for VHEE therapy to be translated into clinical contexts.

scholarly journals Implementation of High Dose Rate Brachytherapy in Cancer Treatment

2021 ◽  
Vol 1 (3) ◽  
pp. 77-106
Author(s):  
Amir Shahabaz ◽  
Muhammad Afzal
Keyword(s):  
Radiation Therapy ◽  
Side Effects ◽  
Dose Rate ◽  
Radiation Source ◽  
Cancer Recurrence ◽  
High Dose Rate ◽  
High Dose ◽  
Hdr Brachytherapy ◽  
Short Treatment ◽  
High Dose Rate Brachytherapy

A technique of radiation therapy delivery in which the radioactive sources are placed very close or even inside the target volume is called Brachytherapy (BT). Brachytherapy is a type of radiation therapy. It destroys cancer cells by making it hard for them to multiply. In this technique, a radiation source is placed directly into or near a tumour. High dose-rate brachytherapy is also known as HDR brachytherapy, or temporary brachytherapy. It is a type of internal radiotherapy. HDR was developed to reduce the risk of cancer recurrence while shortening the amount of time it takes to get radiation treatment. HDR also limits the dose of radiation (associated side effects) to surrounding normal tissue. The important benefits of HDR brachytherapy include extremely precise radiation therapy delivered internally, used alone or after surgery to help prevent cancer recurrence, convenient treatments that are usually pain-free, and a reduction in the risk of common short- and long-term side effects. Currently, tumour dose, as well as doses of the surrounding normal structures, can be evaluated accurately, and high-dose-rate brachytherapy enables three-dimensional image guidance. The biological disadvantages of high-dose-rate were overcome by fractional irradiation. In the definitive radiation therapy of cervical cancer, high-dose-rate brachytherapy is most necessary. Most patients feel little discomfort during brachytherapy. There is no residual radioactivity when the treatment is completed. A patient may be able to go home shortly after the procedure, resuming his normal activities with few restrictions. An advantage of brachytherapy is to deliver a high dose to the tumour during treatment and save the surrounding normal tissues. High-dose-rate (HDR) brachytherapy has great promise with respect to proper case selection and delivery technique because it eliminates radiation exposure, can be performed on an outpatient basis and allows short treatment times. Additionally, by varying the dwell time at each dwell position, the use of a single-stepping source allows optimization of dose distribution. As the short treatment times do not allow any time for correction of errors, and mistakes can result in harm to patients, so the treatments must be executed carefully by using HDR brachytherapy. Refinements will occur primarily in the integration of imaging (computed tomography, magnetic resonance imaging, intraoperative ultrasonography) and optimization of dose distribution and it is expected that the use of HDR brachytherapy will greatly expand over the next decade. Various factors in the development of well-controlled randomized trials addressing issues of efficacy, quality of life, toxicity and costs-versus-benefits will ultimately define the role of HDR brachytherapy in the therapeutic armamentarium. Surrounding healthy tissues are not affected by the radiation due to the ability to target radiation therapy at high dose rates directly to the tumour. Treatment to be delivered as an outpatient in as few as one to five sessions is also allowed by this targeted high dose approach. HDR brachytherapy is the most precision radiation therapy, even better than carbon ion therapy. At the time of invasive placement of the radiation source into the tumour area, brachytherapy requires the skills and techniques of radiation oncologists.

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