Oncology patients were found to understand and accept the Trials within Cohorts design.

Background And Objective: The Trials within Cohorts design aims to reduce recruitment difficulties and disappointment bias in pragmatic trials. On cohort enrollment, broad informed consent for randomization is asked, after which cohort participants can be randomized to interventions or serve as controls without further notification. We evaluated patients' recollection, understanding, and acceptance of broad consent in a clinical oncology setting.

The trials within cohorts design facilitated efficient patient enrollment and generalizability in oncology setting.

Objectives: The trials within cohorts (TwiCs) design aims to improve recruitment efficiency. We conducted the first TwiCs in radiation oncology and described efficiency of the design and generalizability of the results.

Study Design And Setting: In two radiotherapy centers, patients with rectal cancer were asked to participate in a prospective cohort study and to provide broad consent for randomization and patient-reported outcomes (PROs).

Health-related quality of life in rectal cancer patients undergoing neoadjuvant chemoradiation with delayed surgery versus short-course radiotherapy with immediate surgery: a propensity score-matched cohort study.

Background: Neoadjuvant chemoradiation with delayed surgery (CRT-DS) and short-course radiotherapy with immediate surgery (SCRT-IS) are two commonly used treatment strategies for rectal cancer. However, the optimal treatment strategy for patients with intermediate-risk rectal cancer remains a discussion. This study compares quality of life (QOL) between SCRT-IS and CRT-DS from diagnosis until 24 months after treatment.

MRI-based tumor inter-fraction motion statistics for rectal cancer boost radiotherapy.

Background: In patients diagnosed with rectal cancer, dose escalation is currently being investigated in a large number of studies. Since there is little known on gross tumor volume (GTV) inter-fraction motion for rectal cancer, a wide variety in margins is used. Purpose of this study is to quantify GTV inter-fraction motion statistics on different timescales and to give estimates of planning target volume (PTV) margins.

Utility Scores and Preferences for Surgical and Organ-Sparing Approaches for Treatment of Intermediate and High-Risk Rectal Cancer.

Background: Organ-sparing approaches, including wait-and-see and local excision, are increasingly being offered to patients with rectal cancer following a good response to neoadjuvant therapy. Preferences regarding these treatment strategies are yet unknown.

Objective: This study aimed to determine the preferences and utility scores for rectal cancer treatment approaches.

Effect of Neoadjuvant Therapy and Rectal Surgery on Health-related Quality of Life in Patients With Rectal Cancer During the First 2 Years After Diagnosis.

Introduction: Rectal cancer surgery with neoadjuvant therapy is associated with substantial morbidity. The present study describes the course of quality of life (QOL) in rectal cancer patients in the first 2 years after the start of treatment.

Patients And Methods: We performed a prospective study within a colorectal cancer cohort including rectal cancer patients who were referred for neoadjuvant chemoradiation or short-course radiotherapy and underwent rectal surgery.

Does setup on rectal wall improve rectal cancer boost radiotherapy?

Background: Rectal cancer patients that show a pathological complete response (pCR) after neo-adjuvant chemo-radiotherapy, have better prognosis. To increase pCR rates several studies escalate the tumor irradiation dose. However, due to lacking tumor contrast on online imaging techniques, no direct tumor setup can be performed and large boost margins are needed to ensure tumor coverage.

The impact of postoperative complications on health-related quality of life in older patients with rectal cancer; a prospective cohort study.

Objectives: As result of the aging population and increasing rectal cancer incidence, more older patients undergo treatment for rectal cancer. This study compares treatment course, postoperative complications, and quality of life (QOL) between older and younger patients with rectal cancer and evaluates the impact of postoperative complications on QOL in the elderly.

Materials And Methods: Patients with rectal cancer participating in a prospective colorectal cancer cohort and referred for radiotherapy between 2013 and 2016 were included.

Inter-observer agreement of MRI-based tumor delineation for preoperative radiotherapy boost in locally advanced rectal cancer.

Background: While surgery remains the cornerstone of rectal cancer treatment, organ-preservation is upcoming. Therefore, neo-adjuvant treatment should be optimized. By escalating doses, response can be increased.

Evolution of motion uncertainty in rectal cancer: implications for adaptive radiotherapy.

Reduction of motion uncertainty by applying adaptive radiotherapy strategies depends largely on the temporal behavior of this motion. To fully optimize adaptive strategies, insight into target motion is needed. The purpose of this study was to analyze stability and evolution in time of motion uncertainty of both the gross tumor volume (GTV) and clinical target volume (CTV) for patients with rectal cancer.

Impact of radiotherapy boost on pathological complete response in patients with locally advanced rectal cancer: a systematic review and meta-analysis.

Purpose: We conducted a systematic review and meta-analysis to quantify the pathological complete response (pCR) rate after preoperative (chemo)radiation with doses of ⩾60Gy in patients with locally advanced rectal cancer. Complete response is relevant since this could select a proportion of patients for which organ-preserving strategies might be possible. Furthermore, we investigated correlations between EQD2 dose and pCR-rate, toxicity or resectability, and additionally between pCR-rate and chemotherapy, boost-approach or surgical-interval.