Evaluation of deformable image registration algorithm for determination of accumulated dose for brachytherapy of cervical cancer patients

Purpose: This study was designed to assess the dose accumulation (DA) of bladder and rectum between brachytherapy fractions using hybrid-based deformable image registration (DIR) and compare it with the simple summation (SS) approach of GEC-ESTRO in cervical cancer patients.Material and methods: Patients (n = 137) with cervical cancer treated with 3D conformal radiotherapy and three fractions of high-dose-rate brachytherapy were selected.CT images were acquired to delineate organs at risk and targets according to GEC-ESTRO recommendations.In order to determine the DA for the bladder and rectum, hybrid-based DIR was done for three different fractions of brachytherapy and the results were compared with the standard GEC-ESTRO method.Also, we performed a phantom study to calculate the uncertainty of the hybrid-based DIR algorithm for contour matching and dose mapping.Results: The mean ± standard deviation (SD) of the Dice similarity coefficient (DICE), Jaccard, Hausdorff distance (HD) and mean distance to agreement (MDA) in the DIR process were 0.94 ±0.02, 0.89 ±0.03, 8.44 ±3.56 and 0.72 ±0.22 for bladder and 0.89 ±0.05, 0.80 ±0.07, 15.46 ±10.14 and 1.19 ±0.59 for rectum, respectively.The median (Q1, Q3; maxi mum) Gy EQD2 differences of total D 2cc between DIR-based and SS methods for the bladder and rectum were reduced by -1.53 (-0.86, -2.98; -9.17) and -1.38 (-0.80, -2.14; -7.11), respectively.The mean ± SD of DICE, Jaccard, HD, and MDA for contour matching were 0.98 ±0.008, 0.97 ±0.01, 2.00 ±0.70 and 0.20 ±0.04, respectively for large deformation.Maximum uncertainty of dose mapping was about 3.58%. Conclusions:The hybrid-based DIR algorithm demonstrated low registration uncertainty for both contour matching and dose mapping.The DA difference between DIRbased and SS approaches was statistically significant for both bladder and rectum and hybrid-based DIR showed potential to assess DA between brachytherapy fractions.

Abstract licence: CC BY-NC-SA

1. 5.

   A framework for deformable image registration validation in radiotherapy clinical applications · 2013

2. 6.

   Review of clinical brachytherapy uncertainties: Analysis guidelines of GEC-ESTRO and the AAPM · 2014

38 more references, whose wording the paper’s licence keeps private.

A person counts once a day per paper. We keep no cookie and no address: a reader is a hash that changes every day. Any month under five reads shows no number.