Uncertainty analysis for 3D image-based cervix cancer brachytherapy by repetitive MR imaging: Assessment of DVH-variations between two HDR fractions within one applicator insertion and their clinical relevance

A comprehensive evaluation of adaptive daily planning for cervical cancer HDR brachytherapy

“…Lang et al (23) found similar results in their study with systematic variations being small and within 6%. The adaptive plan, although accounting for organ motion, still resulted in dose variations for the same patient due to the trade‐offs between high target dose and low OAR dose.…”

“…The adaptive plan, although accounting for organ motion, still resulted in dose variations for the same patient due to the trade‐offs between high target dose and low OAR dose. Lower variations in $\text{HR}‐\text{CTV}{\mathrm{D}}_{90}$ compared to $\text{OAR}{\mathrm{D}}_{2\text{cc}}$ indicates that the HR‐CTV dose remains more consistent than OAR doses and this may mainly be attributed to the fact that the brachytherapy applicator is fixed to the HR‐CTV (23) . SP resulted in higher physical dose variations in ${\mathrm{D}}_{2\text{cc}}$ and ${\mathrm{D}}_{90}$ than ADP, strongly suggesting that ROIs receive more predictable doses from ADP due to the consideration of interfractional organ motion in the treatment plan.…”

“…MATLAB was used to calculate these dose parameters (${\mathrm{D}}_{0.1\text{cc}},{\mathrm{D}}_{2\text{cc}}$, and ${\mathrm{D}}_{90}$) for each plan from the cumulative DVHs. ${\mathrm{D}}_{2\text{cc}}$ and ${\mathrm{D}}_{90}$ were used to calculate physical dose variations, defined as the ratio of mean dose change between fractions to mean dose of the first fraction, as described previously, to quantify variations from the initial plan (23) . Physical doses were converted to biological doses through the linear‐quadratic model for sublethal cell damage repair with the tissue parameter value $\alpha /\beta =3\text{Gy}$ for OARs and $\alpha /\beta =10\text{Gy}$ for HR‐CTV (33) .…”

Intra-fraction uncertainties of MRI guided brachytherapy in patients with cervical cancer

“…Several groups have recently published the impact of changing anatomy on the delivered dose [1][2][3][4]. In these studies, MR-imaging was performed both after applicator insertion for treatment planning, and prior to dose delivery.…”

In vivodosimetry: trends and prospects for brachytherapy

“…41 Organ-applicator movements occurring between patient imaging and treatment delivery stages have been identified as a major source of uncertainty 33,[47][48][49][50][51][52][53] and their impact further analysed. [54][55][56][57] In cervical cancer BT, inter-and intrafraction uncertainties owing to organ movements and deformations account for 20-25% of the D 2cm3 parameter (minimum dose to the most irradiated 2 cm 3 ) per fraction and is the most essential component in the uncertainty budget for OARs. 5 …”