Identification of a rectal subregion highly predictive of rectal bleeding in prostate cancer IMRT

Dréan, Gwenola Le; Acosta, Oscar; Ospina, Juan David; Fargeas, A.; Lafond, C.; Corrégé, Gwénaëlle; Lagrange, Jean-L.éon; Créhange, G.; Simon, Antoine; Haigron, Pascal; Crevoisier, R. de

doi:10.1016/j.radonc.2016.04.023

Cited by 43 publications

(75 citation statements)

References 41 publications

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“…The dosimetric analysis [23] of the anatomical subregions showed that rectal bleeding is associated with V70 of the anorectal region, fecal incontinence with V15 of external sphincter, and V55 of the iliococcygeal muscle, whereas stool frequency with V40 of the levator ani and V45 of the iliococcygeal muscle. In the prospective study of Dréan et al [24], rectal subregions at risk have been delineated, and the authors have found that the exposure of the subprostatic anterior hemirectum and the upper part of the anal canal was 4 Gy higher in patients developing rectal bleeding. Technological advances allowing rectal sparing include endorectal balloons filled with air or water, reducing the exposure of the posterior rectal wall by moving away the prostate from it, depending on the volume of the balloons [25].…”

Section: Discussionmentioning

confidence: 99%

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

Kószó

Varga

Fodor

et al. 2018

Pathol. Oncol. Res.

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The presence of normal tissues in the irradiated volume limits dose escalation during pelvic radiotherapy (RT) for prostate cancer. Supine and prone positions on a belly board were compared by analyzing the exposure of organs at risk (OARs) using intensity modulated RT (IMRT). The prospective trial included 55 high risk, localized or locally advanced prostate cancer patients, receiving definitive image-guided RT. Computed tomography scanning for irradiation planning was carried out in both positions. Gross tumor volume, clinical and planning target volumes (PTV) and OARs were delineated, defining subprostatic and periprostatic rectal subsegments. At the height of the largest antero-posterior (AP) diameter of the prostate, rectal diameters and distance from the posterior prostate wall were measured. IMRT plans were generated. Normal tissue exposure and structure volumes were compared between supine and prone plans using paired t-test. In the volumes of the prostate, PTV, colon and small bowel, no significant differences were found. In prone position, all rectal volumes, diameters, and rectum-prostate distance were significantly higher, the irradiated colon and small bowel volume was lower in dose ranges of 20-40 Gy, and the exposure to all rectal segments was more favorable in 40-75 Gy dose ranges. No significant difference was found in the exposure of other OARs. Prone positioning on a belly board is an appropriate positioning method aiming rectum and bowel protection during pelvic IMRT of prostate cancer. The relative reduction in rectal exposure might be a consequence of the slight departure between the prostate and rectal wall.

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Section: Discussionmentioning

confidence: 99%

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

Kószó

Varga

Fodor

et al. 2018

Pathol. Oncol. Res.

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“…Moreover, the reported dose volume values discard dose distribution information that may be crucial for adaptive BT planning, e.g. local characteristics of dose distribution on the rectum are related to rectum toxicity (Buettner et al 2009, Lee et al 2012, Wortel et al 2015, Drean et al 2016.…”

Section: Introductionmentioning

confidence: 99%

“…Although most current studies focus on statistical analysis of the underlying relationship between the OARs' toxicity and the extracted 1D dose volume parameters (ICRU 2013), or 2D/3D localized dose distribution features (Wortel et al 2015, Drean et al 2016, our ultimate interest lies in the possibility of employing the dose distribution information for induced OAR toxicity prediction. The recent revival of deep learning techniques highlighted by the success of deep convolutional neural networks (CNN) (LeCun et al 2015) has brought more alternatives and opportunities for dose-toxicity prediction modeling.…”

Section: Introductionmentioning

confidence: 99%

Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study

et al. 2017

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Better understanding of the dose-toxicity relationship is critical for safe dose escalation to improve local control in late-stage cervical cancer radiotherapy. In this study, we introduced a convolutional neural network (CNN) model to analyze rectum dose distribution and predict rectum toxicity. Forty-two cervical cancer patients treated with combined external beam radiotherapy (EBRT) and brachytherapy (BT) were retrospectively collected, including twelve toxicity patients and thirty non-toxicity patients. We adopted a transfer learning strategy to overcome the limited patient data issue. A 16-layers CNN developed by the visual geometry group (VGG-16) of the University of Oxford was pre-trained on a large-scale natural image database, ImageNet, and fine-tuned with patient rectum surface dose maps (RSDMs), which were accumulated EBRT + BT doses on the unfolded rectum surface. We used the adaptive synthetic sampling approach and the data augmentation method to address the two challenges, data imbalance and data scarcity. The gradient-weighted class activation maps (Grad-CAM) were also generated to highlight the discriminative regions on the RSDM along with the prediction model. We compare different CNN coefficients fine-tuning strategies, and compare the predictive performance using the traditional dose volume parameters, e.g. D , and the texture features extracted from the RSDM. Satisfactory prediction performance was achieved with the proposed scheme, and we found that the mean Grad-CAM over the toxicity patient group has geometric consistence of distribution with the statistical analysis result, which indicates possible rectum toxicity location. The evaluation results have demonstrated the feasibility of building a CNN-based rectum dose-toxicity prediction model with transfer learning for cervical cancer radiotherapy.

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“…In prostate radiotherapy, the correlation between dose to rectum and toxicity has been the focus of many research studies [1], [2], [3], [4], [5], [6], [7]. The rectum is one of the dose-limiting organs when planning intensity-modulated radiotherapy (IMRT) to the prostate due to the risk of radiation-induced adverse effects.…”

mentioning

confidence: 99%

“…Methods have included dose–surface histograms [1], [5], [13], [14], dose–surface maps [1], [5], [15], dose–line histograms [14], principal component-based pattern analysis [16], and voxel-based approaches for identifying rectal subregions [2], [6], [7]. These studies have been limited in their analysis by the availability of planned dose data only, based on a single anatomical snapshot in time.…”

mentioning

confidence: 99%

Delivered dose can be a better predictor of rectal toxicity than planned dose in prostate radiotherapy

Shelley

Scaife

Romanchikova

et al. 2017

Radiotherapy and Oncology

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Background and purposeFor the first time, delivered dose to the rectum has been calculated and accumulated throughout the course of prostate radiotherapy using megavoltage computed tomography (MVCT) image guidance scans. Dosimetric parameters were linked with toxicity to test the hypothesis that delivered dose is a stronger predictor of toxicity than planned dose.Material and methodsDose–surface maps (DSMs) of the rectal wall were automatically generated from daily MVCT scans for 109 patients within the VoxTox research programme. Accumulated-DSMs, representing total delivered dose, and planned-DSMs, from planning CT data, were parametrised using Equivalent Uniform Dose (EUD) and ‘DSM dose-width’, the lateral dimension of an ellipse fitted to a discrete isodose cluster. Associations with 6 toxicity endpoints were assessed using receiver operator characteristic curve analysis.ResultsFor rectal bleeding, the area under the curve (AUC) was greater for accumulated dose than planned dose for DSM dose-widths up to 70 Gy. Accumulated 65 Gy DSM dose-width produced the strongest spatial correlation (AUC 0.664), while accumulated EUD generated the largest AUC overall (0.682). For proctitis, accumulated EUD was the only reportable predictor (AUC 0.673). Accumulated EUD was systematically lower than planned EUD.ConclusionsDosimetric parameters extracted from accumulated DSMs have demonstrated stronger correlations with rectal bleeding and proctitis, than planned DSMs.

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Identification of a rectal subregion highly predictive of rectal bleeding in prostate cancer IMRT

Cited by 43 publications

References 41 publications

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

Deep convolutional neural network with transfer learning for rectum toxicity prediction in cervical cancer radiotherapy: a feasibility study

Delivered dose can be a better predictor of rectal toxicity than planned dose in prostate radiotherapy

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