Adaptive radiation dose escalation in rectal adenocarcinoma: a review

Wickle, J.D. Van; Paulson, E.S.; Landry, Jerome C.; Erickson, Beth; Hall, William A.

doi:10.21037/jgo.2017.07.06

Cited by 21 publications

(14 citation statements)

References 67 publications

(71 reference statements)

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“…The incidence of rectal adenocarcinoma has been reported to be increasing year by year in many Asian countries [ 4 ]. Despite significant advances in screening and surgery with chemotherapy, overall survival rates for patients diagnosed with advanced rectal adenocarcinoma remain low [ 5 ]. The outcomes of patients with rectal adenocarcinoma rely on the time of diagnosis, and targeted treatment is beneficial for this [ 6 , 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

MYL6B drives the capabilities of proliferation, invasion, and migration in rectal adenocarcinoma through the EMT process

Wang

Sun

2020

Open Life Sciences

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ObjectiveThis study was designed to explore the biological significance of myosin light chain 6B (MYL6B) in rectal adenocarcinoma.MethodsProfiles on the Oncomine dataset, GEPIA website, and UALCAN-TCGA database were searched to assess the MYL6B expression level in rectal adenocarcinoma tissues and normal tissues. After MYL6B knockdown using siRNA strategy, cell counting kit-8 (CCK-8) and transwell assays were conducted to measure cell proliferation, migration and invasion, respectively. Flow cytometry analysis was conducted to assess cell apoptosis. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot were performed to detect the expression level of mRNAs and proteins.ResultsThe data showed that overexpression of MYL6B was observed in rectal adenocarcinoma tissues and correlated with a poor prognosis of patients. Functional in vitro experiments revealed that MYL6B knockdown could inhibit proliferation, migration, and invasion of rectal adenocarcinoma cells, while promote cell apoptosis. Moreover, western blot analysis suggested that increased expression of E-cadherin and decreased expression of N-cadherin and Vimentin were induced by si-MYL6B.ConclusionIn summary, this study elaborated on the promoting effect of MYL6B in rectal adenocarcinoma progression, thus providing novel insight for strategies of clinical diagnosis and drug application in the future clinical study.

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Section: Introductionmentioning

confidence: 99%

MYL6B drives the capabilities of proliferation, invasion, and migration in rectal adenocarcinoma through the EMT process

Wang

Sun

2020

Open Life Sciences

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“…[19] This advantage combined with the daily adaptive planning tool lies the foundations for a margin reduction policy that can be considered as another way to optimize PTV coverage without compromising OARs constraints. [20,21] Some experiences already described the use of reduced PTV margins of 1 or 2 mm on the CyberKnife system, but this would often require the use of implanted ducial markers. [22,23] This invasive procedure may not be necessary for MR-linacs, since MR-guided online adaptive radiotherapy itself allows to correct for inter-fraction motion of the PTV without the need of implanted ducial markers as a reference point.…”

Section: Discussionmentioning

confidence: 99%

Mitigation on bowel loops daily variations by 1.5-T MR-guided daily-adaptive SBRT for abdomino-pelvic lymph-nodal oligometastases

Cuccia

Rigo

Gurrera

et al. 2021

J Cancer Res Clin Oncol

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We report preliminary dosimetric data concerning the use of 1.5-T MR-guided daily-adaptive radiotherapy for abdomino-pelvic lymph-nodal oligometastases. We aimed to assess the impact of this technology on mitigating daily variations for both target coverage and organs-at-risk (OARs) sparing. MethodsA total of 150 sessions for 30 oligometastases in 23 patients were analyzed. All patients were treated with MR-guided stereotactic body radiotherapy (SBRT) for a total dose of 35Gy in 5 fractions. For each fraction, a quantitative analysis was performed for PTV volume, V35Gy and Dmean. Similarly, for OARs we assessed daily variations of volume, Dmean, Dmax. Any potential statistically signi cant change between baseline planning and daily-adaptive sessions was assessed using the Wilcoxon signed-rank test, assuming a p-value< 0.05 as signi cant. ResultsAverage baseline PTV, bowel, bladder and single intestinal loop volumes were respectively 8.9cc (range, 0.7-41.2cc), 1176cc (119-3654 cc), 95cc (39.7-202.9 cc), 18.3cc (9.1-37.7 cc). No signi cant volume variations were detected for PTV (p=0.21) bowel (p=0.36), bladder (p=0.47), except for single intestinal loops, which resulted smaller (p=0.026).Average baseline V35Gy and Dmean for PTV were respectively 85.6% (72-98.8%) and 35.6 Gy (34.6-36.1 Gy). We recorded a slightly positive trend in favor of daily-adaptive strategy vs baseline planning for improved target coverage, although not reaching statistical signi cance. (p=0.11 and p=0.18 for PTV-V35Gy and PTV-Dmean).Concerning OARs, a signi cant difference was observed in favor of daily-adapted treatments in terms of single intestinal loop Dmax [23.05 Gy (13.2-26.9 Gy) at baseline vs 20.5 Gy (12.1-24 Gy); p-value=0.0377] and Dmean [14.4 Gy (6.5-18 Gy) at baseline vs 13.0 Gy (6.7-17.6 Gy); p-value=0.0003].Speci cally for bladder, the average Dmax was 18.6 Gy (0.4-34.3 Gy) at baseline vs 18.3 Gy (0.7-34.3 Gy) for a p-value=0.28; the average Dmean was 7.0 Gy (0.2-16.6 Gy) at baseline vs 6.98 Gy (0.2-16.4 Gy) for a p-value=0.66. Concerning the bowel, no differences in terms of Gy) vs 5.6 Gy (1.4-10.5 Gy); p-value=0.23] were observed between after daily-adapted sessions. A statistically signi cant difference was observed for bowel Dmax [26.4 Gy (7.7-34 Gy) vs 25.8 Gy (7.8-33.1 Gy); p-value=0.0086]. ConclusionsDaily-adaptive MR-guided SBRT reported a signi cantly improved single intestinal loop sparing for lymphnodal oligometastases. Also bowel Dmax was signi cantly reduced with daily-adaptive strategy. A minor

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“…Tumor volume decreases during RCT offer the option to adapt treatment volumes for a better sparing of the surrounding tissues-at-risk with a potential impact on acute and late radiogenic toxicities as well as perioperative morbidity [15]. There is an increasing interest in tailoring neoadjuvant treatments more closely to the extent of tumor regression during RCT based on MRI examinations [32]. Therefore, MR parameters have to be defined for reliable differentiation between good and moderate or poor responders during neoadjuvant treatment [15,16].…”

Section: Discussionmentioning

confidence: 99%

Exploring MR regression patterns in rectal cancer during neoadjuvant radiochemotherapy with daily T2- and diffusion-weighted MRI

et al. 2020

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Background: To date, only limited magnetic resonance imaging (MRI) data are available concerning tumor regression during neoadjuvant radiochemotherapy (RCT) of rectal cancer patients, which is a prerequisite for adaptive radiotherapy (RT) concepts. This exploratory study prospectively evaluated daily fractional MRI during neoadjuvant treatment to analyze the predictive value of MR biomarkers for treatment response. Methods: Locally advanced rectal cancer patients were examined with daily MRI during neoadjuvant RCT. Contouring of the tumor volume was performed for each MRI scan by using T2-and diffusion-weighted-imaging (DWI)-sequences. The daily apparent-diffusion coefficient (ADC) was calculated. Volumetric and functional tumor changes during RCT were analyzed and correlated with the pathological response after surgical resection. Results: In total, 171 MRI scans of eight patients were analyzed regarding anatomical and functional dynamics during RCT. Pathological complete response (pCR) could be achieved in four patients, and four patients had a pathological partial response (pPR) following neoadjuvant treatment. T2-and DWI-based volumetry proved to be statistically significant in terms of therapeutic response, and volumetric thresholds at week two and week four during RCT were defined for the prediction of pCR. In contrast, the average tumor ADC values widely overlapped between both response groups during RCT and appeared inadequate to predict treatment response in our patient cohort. Conclusion: This prospective exploratory study supports the hypothesis that MRI may be able to predict pCR of rectal cancers early during neoadjuvant RCT. Our data therefore provide a useful template to tailor future MRguided adaptive treatment concepts.

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Adaptive radiation dose escalation in rectal adenocarcinoma: a review

Cited by 21 publications

References 67 publications

MYL6B drives the capabilities of proliferation, invasion, and migration in rectal adenocarcinoma through the EMT process

MYL6B drives the capabilities of proliferation, invasion, and migration in rectal adenocarcinoma through the EMT process

Mitigation on bowel loops daily variations by 1.5-T MR-guided daily-adaptive SBRT for abdomino-pelvic lymph-nodal oligometastases

Exploring MR regression patterns in rectal cancer during neoadjuvant radiochemotherapy with daily T2- and diffusion-weighted MRI

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