Statistical Analysis of Interfraction Dose Variations of High-Risk Clinical Target Volume and Organs at Risk for Cervical Cancer High-Dose-Rate Brachytherapy

Washington, Brien; Randall, Marcus E.; Fabian, Denise; Cheek, D; Luo, W.

doi:10.1016/j.adro.2022.101019

Cited by 1 publication

(7 citation statements)

References 33 publications

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“…The left-skewed Beta distribution was the best-fit HRCTV IDV uncertainty distribution with an RSS score = 1.16 • 10 −2 . The left-skewed generalized extreme value (GEV) distribution was the second-best-fit distribution with an RSS score = 1.37 • 10 −2 and an Anderson-Darling p-value > 0.251, consistent with our previous study's findings [22]. The Beta distribution's Anderson-Darling p-value was estimated to be > 0.251 based on the GEV.…”

Section: Hrctv and Oar Idv Uncertaintysupporting

confidence: 85%

“…They found that IDV uncertainty has a minor effect on LC if one assumes IDV uncertainty is a Gaussianrandom variable. In our previous study on adaptive HDR brachytherapy dosimetry, we found evidence suggesting IDV uncertainty may not be considered a Gaussian-random variable [22]. Instead, IDV uncertainty in cervical cancer HDR brachytherapy was a nonnormal, left-skewed distribution yielding a 30.0% probability of under-dosing the HRCTV.…”

Section: Introductionmentioning

confidence: 85%

“…In this study, IDV uncertainty was defined as the percent difference between the delivered equivalent dose in a 2 Gy fraction (EQD 2 ) and the prescribed or expected EQD 2 (Equation ( 1)). In our previous study, IDV uncertainty was defined as the mean dose variation from the prescribed dose over a course of HDR adaptive brachytherapy [22]. Using the EQD 2 to calculate IDV uncertainty incorporates interfraction dose fluctuations by the definition of EQD 2 , and is more appropriate to use with TCP and NTCP models since they are derived using EQD 2 .…”

Section: Calculating Idv and Determining Idv Uncertainty Distributionsmentioning

confidence: 99%

“…Determining the best-fit HRCTV IDV distribution was described in detail in our previous study [22]. In brief, Python 3.7 s DistFit package was used to fit the IDV distributions to 89 different probability density functions (PDF) with limited dependence on distribution bin width.…”

Section: Idv Uncertaintymentioning

confidence: 99%

“…The uncertainty distributions of OAR IDVs were calculated with respect to OAR IDV correlations with HRCTV IDVs [22]. If the OAR IDVs were not correlated via linear regression (p < 0.05) to HRCTV IDVs, then that structure was not used in the simulation model.…”

Section: Idv Uncertaintymentioning

confidence: 99%

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Effects of Interfraction Dose Variations of Target and Organs at Risk on Clinical Outcomes in High Dose Rate Brachytherapy for Cervical Cancer

Washington,

Cheek,

Fabian

et al. 2023

Cancers

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Meeting dose prescription is critical to control tumors in radiation therapy. Interfraction dose variations (IDVs) from the prescribed dose in high dose rate brachytherapy (HDR) would cause the target dose to deviate from the prescription but their clinical effect has not been widely discussed in the literature. Our previous study found that IDVs followed a left-skewed distribution. The clinical effect of the IDVs in 100 cervical cancer HDR patients will be addressed in this paper. An in-house Monte Carlo (MC) program was used to simulate clinical outcomes by convolving published tumor dose response curves with IDV distributions. The optimal dose and probability of risk-free local control (RFLC) were calculated using the utility model. The IDVs were well-fitted by the left-skewed Beta distribution, which caused a 3.99% decrease in local control probability and a 1.80% increase in treatment failure. Utility with respect to IDV uncertainty increased the RFLC probability by 6.70% and predicted an optimal dose range of 83 Gy–91 Gy EQD2. It was also found that a 10 Gy dose escalation would not affect toxicity. In conclusion, HRCTV IDV uncertainty reduced LC probabilities and increased treatment failure rates. A dose escalation may help mitigate such effects.

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Section: Hrctv and Oar Idv Uncertaintysupporting

confidence: 85%

Section: Introductionmentioning

confidence: 85%

Section: Calculating Idv and Determining Idv Uncertainty Distributionsmentioning

confidence: 99%

Section: Idv Uncertaintymentioning

confidence: 99%

Section: Idv Uncertaintymentioning

confidence: 99%

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