A statistical approach to IMRT patient‐specific QA

Palaniswaamy, Geethpriya; Brame, R. Scott; Yaddanapudi, S; Rangaraj, D; Mutic, Sasa

doi:10.1118/1.4768161

Cited by 27 publications

(18 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the anatomic parameters discussed herein, other parameterizations, such as portions of OAR outside the primary target fields and tumor site, can be easily considered. 6,11 Beam information, such as beam angles and field arrangements, can also be included. However, given that there are many such planning parameters, external factors, and anatomic parametrizations that could be included in this framework, an exhaustive model considering all risk factors is outside of the scope of this proof of concept.…”

Section: Discussionmentioning

confidence: 99%

“…Individual, moving-range, standard deviation (SD), and exponentially weighted moving average (EWMA) charts were used to detect unusual trends in dose deviations between the TPS and delivered dose. 5,6 Alternatively, Nordström et al 7 found control charts to be effective for the continuous verification of monitor units and derived control limits that agree with international guidelines. However, the use of control charts for treatment plan evaluation has been limited due to planning process variability for each patient, including patient-and treatment-specific risk factors.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

A Risk-Adjusted Control Chart to Evaluate Intensity Modulated Radiation Therapy Plan Quality

Roy

Cutright

Gopalakrishnan

et al. 2020

Advances in Radiation Oncology

View full text Add to dashboard Cite

This study aimed to develop a quality control framework for intensity modulated radiation therapy plan evaluations that can account for variations in patient-and treatment-specific risk factors. Methods and Materials: Patient-specific risk factors, such as a patient's anatomy and tumor dose requirements, affect organs-at-risk (OARs) dose-volume histograms (DVHs), which in turn affects plan quality and can potentially cause adverse effects. Treatment-specific risk factors, such as the use of chemotherapy and surgery, are clinically relevant when evaluating radiation therapy planning criteria. A risk-adjusted control chart was developed to identify unusual plan quality after accounting for patient-and treatment-specific risk factors. In this proof of concept, 6 OAR DVH points and average monitor units serve as proxies for plan quality. Eighteen risk factors are considered for modeling quality: planning target volume (PTV) and OAR cross-sectional areas; volumes, spreads, and surface areas; minimum and centroid distances between OARs and the PTV; 6 PTV DVH points; use of chemotherapy; and surgery. A total of 69 head and neck cases were used to demonstrate the application of risk-adjusted control charts, and the results were compared with the application of conventional control charts. Results: The risk-adjusted control chart remains robust to interpatient variations in the studied risk factors, unlike the conventional control chart. For the brainstem, the conventional chart signaled 4 patients with unusual (out-of-control) doses to 2% brainstem volume. However, the adjusted chart did not signal any plans after accounting for their risk factors. For the spinal cord doses to 2% brainstem volume, the conventional chart signaled 2 patients, and the adjusted chart signaled a separate patient after accounting for their risk factors. Similar adjustments were observed for the other DVH points when evaluating brainstem, spinal cord, ipsilateral parotid, and average monitor Sources of support: This work had no specific funding. Disclosures: The data used in this study are from de-identifiable Digital Imaging and Communications in Medicine files.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

A Risk-Adjusted Control Chart to Evaluate Intensity Modulated Radiation Therapy Plan Quality

Roy

Cutright

Gopalakrishnan

et al. 2020

Advances in Radiation Oncology

View full text Add to dashboard Cite

show abstract

“…5 Additionally, using a 90% passing rate threshold to decide whether a plan is acceptable has also been identified as a significant limitation to detecting clinically relevant errors, and the development of site specific thresholds has been suggested. 11 The 90% threshold for all plans with composite analysis and global normalization was derived in Task Group 119, assuming that gamma failing rates followed a Gaussian distribution and determining what threshold will include 95% of plans passing QA. 12 With today's level of accuracy, however, this threshold is easily met by most plans if proper commissioning has been performed.…”

Section: Introductionmentioning

confidence: 99%

A mathematical framework for virtual IMRT QA using machine learning

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Thus, the tolerance limit can be established from the trend of the patient-specific QA result in each institution. However, few reports have been published about applying statistical methods to patient-specific QA [10–12]. For example, no recommendations about the management method for patient-specific QA exist, though Pulliam et al .…”

Section: Introductionmentioning

confidence: 99%

A management method for the statistical results of patient-specific quality assurance for intensity-modulated radiation therapy

Nakamura¹,

Okamoto²,

Wakita³

et al. 2016

Journal of Radiation Research

View full text Add to dashboard Cite

There are many reports concerning patient-specific quality assurance (QA) for intensity-modulated radiation therapy (IMRT). However, reports about the statistical results of QA are lacking. Management methods for the results of the QA are needed, even though we have the ESTRO group recommendation that a tolerance limit of 1.96 standard deviation (SD) be established in each institution. The purpose of this study was to establish a management method for determining the tolerance limit and to report the statistical results of patient-specific QA. From April 2006 to March 2015, five linacs in the National Cancer Center, Tokyo, Japan, were used to treat 1185 patients with IMRT. Patient-specific QA was performed using an ion chamber, films, and some detectors. To establish a management method for the results, differences between the measured and calculated doses in the ion chamber were analyzed for each linac, each phantom, and each treatment site. The overall mean dose difference was 0.5 ± 1.3%, and the mean dose difference in each linac was 0.6 ± 1.2%, 0.9 ± 1.3%, −0.4 ± 1.4%, −0.1 ± 1.2% and −0.1 ± 0.9%. The difference between linacs and between treatment sites was significant (P < 0.001 and 0.01, respectively). The proportion of the dose difference within ±3% was 97.7%, and that was improved from 2006 to 2014. The results of the patient-specific QA should be managed for each linac and each treatment site in order to decide the suitable tolerance limit. Reports of statistical results will be helped if a new tolerance limit and action level will be considered.

show abstract

A statistical approach to IMRT patient‐specific QA

Cited by 27 publications

References 14 publications

A Risk-Adjusted Control Chart to Evaluate Intensity Modulated Radiation Therapy Plan Quality

A Risk-Adjusted Control Chart to Evaluate Intensity Modulated Radiation Therapy Plan Quality

A mathematical framework for virtual IMRT QA using machine learning

A management method for the statistical results of patient-specific quality assurance for intensity-modulated radiation therapy

Contact Info

Product

Resources

About