Quality Control Of High-Dose-Rate Brachytherapy: Treatment Delivery Analysis Using Statistical Process Control

Able, C; Bright, Megan; Frizzell, Bart; Graham, Ashley

doi:10.1016/j.brachy.2010.02.100

Cited by 3 publications

(3 citation statements)

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“…Statistical process control is used in multiple fields of medicine, including infectious disease and preventive medicine [20,21], orthopedics [22], pediatrics [23], and for improving bio-pharmaceutical manufacturing processes and operations [24]. In radiation oncology, it was described in multiple publications, including investigating energy variations in tomotherapy [25], and for assessing the quality of high-dose-rate (HDR) brachytherapy treatment delivery [26]. In this study, control charts were used in prostate LDR brachytherapy permanent seed implants to identify cases that did not meet the expected level of performance based on the historical record of our implant process for RV 100 , V 100 , and D 90 , and to determine whether the identified variation was associated with clinical observations.…”

Section: Purposementioning

confidence: 99%

Control charts for evaluation of quality of low-dose-rate brachytherapy for prostate cancer

Nasser¹,

Saibishkumar²,

Wang³

et al. 2022

jcb

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Purpose: Variations in dosimetric outcomes among patients treated with low-dose-rate brachytherapy for prostate cancer exist, even when implants are within dose constraints. Here, we used control charts to investigate reasons for intra-patient dosimetric variability.Material and methods: Univariate and multivariate control charts for prostate V 100 (percentage of prostate volume that received 100% of prescribed radiation dose), D 90 (radiation dose to 90% of prostate volume), and RV 100 (rectal wall volume that received 100% of prescribed radiation dose) were generated for 212 consecutive prostate cancer patients implanted with iodine-125 ( 125 I) radioactive seeds at the Princess Margaret Cancer Centre. Control limits were calculated based on the first fifty implants. Data points that were out of control were identified, and their pre-treatment and post-treatment dosimetric and clinical parameters were compared to data points that were in-control, using Student's t-test.Results: All implants were clinically acceptable. Twelve data points exceeded multivariate control limits. Ten of those points fell below the lower control limit of V 100 control chart. Average prostate edema in the 10 out-of-control patients on both multivariate and V 100 charts was 8.3%, as compared to 0.4% for in-control patients (p < 0.04). Two patients were observed to be out-of-control on multivariate control chart, but not on V 100 control chart, and were found to have a reduction in prostate volume of 19.1% and 20.1% at one month after seed implant, compared to prostate volumes of pre-implantation evaluations.Conclusions: Control charts helped in identifying cases with out-of-control variability in post-plan prostate dosimetry. Post-treatment prostatic edema and contraction are important factors predicting variability in patients treated with 125 I permanent seed brachytherapy.

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Section: Purposementioning

confidence: 99%

Control charts for evaluation of quality of low-dose-rate brachytherapy for prostate cancer

Nasser¹,

Saibishkumar²,

Wang³

et al. 2022

jcb

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“…In recent years several groups have published work which illustrates how SPC can be applied to the different systems controlled by medical physicists in the various radiotherapy processes related to linear particle accelerator (linac) monitoring (Pawlicki et al, 2005;Able et al, 2011;de la Vega et al, 2012;Sanghangthum et al, 2013b;Létourneau et al, 2014;López-Tarjuelo et al, 2015), image guided radiation therapy (IGRT; Ung and Wee, 2011), monitor-unit verifications (Nordström et al, 2012), high-dose rate (HDR) brachytherapy treatments (Able et al, 2013), proton therapy beams (Rah et al, 2014), and different aspects of intensity-modulated treatment quality assurance (Breen et al, 2008;Pawlicki et al, 2008a;Pawlicki et al, 2008b;Gérard et al, 2009;Sanghangthum et al, 2013c;Sanghangthum et al, 2013a;Gagneur and Ezzell, 2014).…”

Section: Introductionmentioning

confidence: 99%

What can statistical process control show us about ionization chamber stability?

López-Tarjuelo

Quirós-Higueras

Bonaque-Alandí

et al. 2016

Radiation Measurements

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“…In this study we seek to characterize the process of medical linear accelerator beam steering and demonstrate, retrospectively, the ability to provide a level of control using the statistical process control (SPC) methodology [ 3 - 11 ]. For a generalized system, process performance data varies naturally.…”

Section: Introductionmentioning

confidence: 99%

Initial investigation using statistical process control for quality control of accelerator beam steering

et al. 2011

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BackgroundThis study seeks to increase clinical operational efficiency and accelerator beam consistency by retrospectively investigating the application of statistical process control (SPC) to linear accelerator beam steering parameters to determine the utility of such a methodology in detecting changes prior to equipment failure (interlocks actuated).MethodsSteering coil currents (SCC) for the transverse and radial planes are set such that a reproducibly useful photon or electron beam is available. SCC are sampled and stored in the control console computer each day during the morning warm-up. The transverse and radial - positioning and angle SCC for photon beam energies were evaluated using average and range (Xbar-R) process control charts (PCC). The weekly average and range values (subgroup n = 5) for each steering coil were used to develop the PCC. SCC from September 2009 (annual calibration) until two weeks following a beam steering failure in June 2010 were evaluated. PCC limits were calculated using the first twenty subgroups. Appropriate action limits were developed using conventional SPC guidelines.ResultsPCC high-alarm action limit was set at 6 standard deviations from the mean. A value exceeding this limit would require beam scanning and evaluation by the physicist and engineer. Two low alarms were used to indicate negative trends. Alarms received following establishment of limits (week 20) are indicative of a non-random cause for deviation (Xbar chart) and/or an uncontrolled process (R chart). Transverse angle SCC for 6 MV and 15 MV indicated a high-alarm 90 and 108 days prior to equipment failure respectively. A downward trend in this parameter continued, with high-alarm, until failure. Transverse position and radial angle SCC for 6 and 15 MV indicated low-alarms starting as early as 124 and 116 days prior to failure, respectively.ConclusionRadiotherapy clinical efficiency and accelerator beam consistency may be improved by instituting SPC methods to monitor the beam steering process and detect abnormal changes prior to equipment failure.PACS numbers: 87.55n, 87.55qr, 87.56bd

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Quality Control Of High-Dose-Rate Brachytherapy: Treatment Delivery Analysis Using Statistical Process Control

Cited by 3 publications

References 0 publications

Control charts for evaluation of quality of low-dose-rate brachytherapy for prostate cancer

Control charts for evaluation of quality of low-dose-rate brachytherapy for prostate cancer

What can statistical process control show us about ionization chamber stability?

Initial investigation using statistical process control for quality control of accelerator beam steering

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