Ultrasound versus Cone-beam CT image-guided radiotherapy for prostate and post-prostatectomy pretreatment localization

To evaluate the accuracy of an intra-modality trans-abdominal ultrasound (TA-US) device against soft-tissue based Cone-Beam Computed tomography (CBCT) registration for prostate and post-prostatectomy pre-treatment positioning.

The differences between CBCT and US shifts were calculated on 25 prostate cancer patients (cohort A) and 11 post-prostatectomy patients (cohort B), resulting in 284 and 106 paired shifts for cohorts A and B, respectively. As a second step, a corrective method was applied to the US registration results to decrease the systematic shifts observed between TA-US and CBCT results. This method consisted of subtracting the mean difference obtained between US and CBCT registration results during the first 3 sessions from the US registration results of the subsequent sessions. Inter-operator registration variability (IOV) was also investigated for both modalities.

After initial review, about 20% of the US images were excluded because of insufficient quality. The average differences between US and CBCT were: 2. 8 ± 4. 1 mm, -0. 9 ± 4. 2 mm, 0. 4 ± 3. 4 mm for cohort A and 1. 3 ± 5. 0 mm, -2. 3 ± 4. 6 mm, 0. 5 ± 2. 9 mm for cohort B, in the anterior-posterior (AP), superior-inferior (SI) and lateral (LR) directions, respectively. After applying the corrective method, only the differences in the AP direction remained significant (p < 0. 05). The IOV values were between 0. 6-2. 0 mm and 2. 1-3. 5 mm for the CBCT and TA-US modalities, respectively.

Based on the obtained results and on the image quality, the TA-US imaging modality is not safely interchangeable with CBCT for pre-treatment repositioning. Treatment margins adaptation based on the correction of the systematic shifts should be considered.

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB). 2015 Sep 25 [Epub ahead of print]

Marie Fargier-Voiron, Benoît Presles, Pascal Pommier, Alexandre Munoz, Simon Rit, David Sarrut, Marie-Claude Biston

CREATIS, Université de Lyon, Lyon, France; CNRS UMR5220, Lyon, France; Inserm U1044, Lyon, France; INSA-Lyon, Lyon, France; Université Lyon 1, Lyon, France; Centre Léon Bérard, Lyon, France. , CREATIS, Université de Lyon, Lyon, France; CNRS UMR5220, Lyon, France; Inserm U1044, Lyon, France; INSA-Lyon, Lyon, France; Université Lyon 1, Lyon, France; Centre Léon Bérard, Lyon, France. , Léon Bérard Cancer Center, University of Lyon, F-69373 Lyon, France. , Léon Bérard Cancer Center, University of Lyon, F-69373 Lyon, France. , CREATIS, Université de Lyon, Lyon, France; CNRS UMR5220, Lyon, France; Inserm U1044, Lyon, France; INSA-Lyon, Lyon, France; Université Lyon 1, Lyon, France; Centre Léon Bérard, Lyon, France. , CREATIS, Université de Lyon, Lyon, France; CNRS UMR5220, Lyon, France; Inserm U1044, Lyon, France; INSA-Lyon, Lyon, France; Université Lyon 1, Lyon, France; Centre Léon Bérard, Lyon, France. , CREATIS, Université de Lyon, Lyon, France; CNRS UMR5220, Lyon, France; Inserm U1044, Lyon, France; INSA-Lyon, Lyon, France; Université Lyon 1, Lyon, France; Centre Léon Bérard, Lyon, France.  

PubMed

E-Newsletters

Newsletter subscription

Free Daily and Weekly newsletters offered by content of interest

The fields of GU Oncology and Urology are rapidly advancing. Sign up today for articles, videos, conference highlights and abstracts from peer-review publications by disease and condition delivered to your inbox and read on the go.

Subscribe