A multi-institutional dosimetry audit of rotational intensity-modulated radiotherapy

Clark, Catharine H.; Hussein, Mohammad; Tsang, Yatman; Thomas, Russell; Wilkinson, Dean; Bass, G A; Snaith, J A D; Gouldstone, C.; Bolton, Steve; Nutbrown, R F; Venables, Karen; Nisbet, Andrew

doi:10.1016/j.radonc.2014.11.015

Cited by 50 publications

(52 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[16][17][18]20,22,23,27,49,50,53,57,60,61 It is beyond the scope of this overview to review all of these and their results, so the following section limits discussion to two areas only. The first is that of beam calibration audit, being the fundamental reference dosimetry level affecting all patients on any specific machine or in any specific centre; and therefore beam calibration audit is also the most widely carried out audit, by number of beams or by repetitions at different times.…”

Section: Results Of Dosimetry Auditsmentioning

confidence: 99%

“…Whilst maintaining audits of reference dose, NPL has broadened its involvement in dosimetry audit to cover clinical dose delivery of typical treatment modalities, via the use of its alanine measurement system, including the national rotational IMRT audit, [47][48][49] stereotactic ablative body radiotherapy (SABR) audit and brachytherapy audit, in some cases in collaboration with the RTTQA group to support centre accreditation for inclusion in clinical trials. From the point of view of a standards laboratory, benefits of involvement in audit include ensuring the correct implementation of the traceability chain to the patient and closer interaction and understanding of the end users' requirements.…”

Section: The National Physical Laboratory's Involvement In Auditmentioning

confidence: 99%

“…The RTTQA Group has co-operated with other groups on projects such as the national rotational IMRT audit 48,49 (NPL, Royal Surrey County Hospital NHS Foundation Trust, RTTQA and IPEM) and the recent national high dose rate (HDR) brachytherapy audit 57 (NPL, Portsmouth Hospitals NHS Trust). The Outlining and Imaging Subgroup has also involved co-operation with the NCRI positron emission tomography (PET) group.…”

Section: Streamlining Trial Audit Processesmentioning

confidence: 99%

“…The audit also developed a novel approach to audit 48 of using an array of ion chambers such that multiple dose points could be measured simultaneously and results could be given during the on-site visit. 49 Point dose differences gave a mean 6 SD of 0.1 6 2.6% and 0.2 6 2.0% for a specially designed generic test (3D TPS) 47 and the clinical trial plans, respectively. 42 of 43 centres passed their clinical trial plan with .95.0% of the measured points passing 3%/3 mm criteria, suggesting that in the UK, TPS modelling and delivery can achieve high accuracy for rotational IMRT.…”

Section: Recent National Radiotherapy Dosimetry Audits For More Advanmentioning

confidence: 99%

“…A statistically significant difference in gamma pass rates was seen between planning systems where rotational IMRT modelling had been designed for the manufacturer's own treatment delivery system and those designed by different manufacturers to be independent of the rotational IMRT delivery equipment. 49 Other novel techniques which have been recently audited include intraoperative radiotherapy, using compact mobile kilovoltage X-ray sources for the treatment of breast and other cancers. All seven current clinical sites in the UK were audited by a single visiting group and set of measurement equipment.…”

Section: Recent National Radiotherapy Dosimetry Audits For More Advanmentioning

confidence: 99%

See 4 more Smart Citations

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

Clark

Aird

Bolton

et al. 2015

BJR

Self Cite

View full text Add to dashboard Cite

Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed.

show abstract

Section: Results Of Dosimetry Auditsmentioning

confidence: 99%

Section: The National Physical Laboratory's Involvement In Auditmentioning

confidence: 99%

Section: Streamlining Trial Audit Processesmentioning

confidence: 99%

Section: Recent National Radiotherapy Dosimetry Audits For More Advanmentioning

confidence: 99%

Section: Recent National Radiotherapy Dosimetry Audits For More Advanmentioning

confidence: 99%

See 3 more Smart Citations

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

Clark

Aird

Bolton

et al. 2015

BJR

Self Cite

View full text Add to dashboard Cite

show abstract

Remote dosimetric auditing of clinical trials: The need for vendor specific models to convert images to dose

Miri

Vial

Greer

2018

J Applied Clin Med Phys

View full text Add to dashboard Cite

IntroductionA previous pilot study has demonstrated the feasibility of a novel image‐based approach for remote dosimetric auditing of clinical trials. The approach uses a model to convert in‐air acquired intensity modulated radiotherapy (IMRT) images to delivered dose inside a virtual phantom. The model was developed using images from an electronic portal imaging device (EPID) on a Varian linear accelerator. It was tuned using beam profiles and field size factors (FSFs) of a series of square fields measured in water tank. This work investigates the need for vendor specific conversion models for image‐based auditing. The EPID measured profile and FSF data for Varian (vendor 1) and Elekta (vendor 2) systems are compared along with the performance of the existing Varian model (VM) and a new Elekta model (EM) for a series of audit IMRT fields measured on vendor 2 systems.Materials and methodsThe EPID measured beam profile and FSF data were studied for the two vendors to quantify and understand their relevant dosimetric differences. Then, an EM was developed converting EPID to dose in the virtual water phantom using a vendor 2 water tank data and images from corresponding EPID. The VM and EM were compared for predicting vendor 2 measured dose in water tank. Then, the performance of the new EM was compared to the VM for auditing of 54 IMRT fields from four vendor 2 facilities. Statistical significance of using vendor specific models was determined.ResultsObserved dosimetry differences between the two vendors suggested developing an EM would be beneficial. The EM performed better than VM for vendor 2 square and IMRT fields. The IMRT audit gamma pass rates were (99.8 ± 0.5)%, (98.6 ± 2.3)% and (97.0 ± 3.0)% at respectively 3%/3 mm, 3%/2 mm and 2%/2 mm with improvements at most fields compared with using the VM. For the pilot audit, the difference between gamma results of the two vendors was reduced when using vendor specific models (VM: P < 0.0001, vendor specific models: P = 0.0025).ConclusionA new model was derived to convert images from vendor 2 EPIDs to dose for remote auditing vendor 2 deliveries. Using vendor specific models is recommended to remotely audit systems from different vendors, however, the improvements found were not major.

show abstract

Comparison of Rapid Arc and Intensity Modulated Radiotherapy in a True Beam Linear Accelerator for 6 MV: Application of AAPM TG‐119 tests in treatment planning and quality assurance

Roy,

Sarkar,

Pradhan

2023

Precision Radiation Oncology

View full text Add to dashboard Cite

ObjectiveWe developed rapid arc (RA) and intensity‐modulated radiotherapy (IMRT) plans based on the American Association of Physicists in Medicine Task Group‐119 (AAPM TG‐119) proposals and compared the planning and quality assurance results.Materials and MethodsTwo treatment plans were used for each study patient: one using 7–9 IMRT fields and the other using the two full‐arc RA methods. Plan optimization and dose calculations were performed using 6 MV photons and EclipseTM with the anisotropic analytical algorithm (AAA). Task group (TG)‐119 described the planning objectives used to evaluate the treatment plans generated for this study. Point dose, planar fluence measurement, and trajectory log file analysis are used for quality assurance.ResultsThe conformity index (CI) for treatment plans varied between 0.76–0.91 when using IMRT and 0.75–0.93 when using RA. The homogeneity index (HI) was approximately 0.10–0.24 (IMRT) and 0.07–0.23 (RA). The ratio of the total number of monitor units required for IMRT to that required for RA was between 0.87 and 2.14. The treatment log files exhibited higher gamma passing with RA than with IMRT.ConclusionRA plans were more effective than IMRT plans in achieving the test goals. Point dose measurements and electronic portal imaging device (EPID)‐based planar fluence measurements showed statistically insignificant differences between the IMRT and RA plan quality assurance (QA) results. However, the trajectory log file analysis exhibited better gamma‐passing results for RA than for IMRT.

show abstract

A multi-institutional dosimetry audit of rotational intensity-modulated radiotherapy

Cited by 50 publications

References 17 publications

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

Remote dosimetric auditing of clinical trials: The need for vendor specific models to convert images to dose

Comparison of Rapid Arc and Intensity Modulated Radiotherapy in a True Beam Linear Accelerator for 6 MV: Application of AAPM TG‐119 tests in treatment planning and quality assurance

Contact Info

Product

Resources

About