An observational study in Rectal Cancer, sponsored by Maastricht Radiation Oncology. Recruiting at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by Maastricht Radiation Oncology · Observational
This registry will collect data from all patients treated with the MAASTRO HDR applicator. The goal is to deepen knowledge about dose-response relationships in rectal cancer boosting, which is essential for improving future treatment approaches and patient selection.
Standard treatment for rectal cancer usually involves surgical removal of the tumor. Depending on the tumor's characteristics, patients may first receive neoadjuvant therapy such as radiotherapy, chemoradiotherapy, or total neoadjuvant treatment (TNT). These treatments aim to improve oncological outcomes and can lead to a complete response (CR) in about 10-40% of patients. When a CR occurs, patients may choose a watch-and-wait strategy, which avoids surgery and improves quality of life by preventing complications such as incontinence or the need for a stoma.
Increasing the radiation dose improves the chance of achieving a CR. Endoluminal boost techniques-high-dose-rate (HDR) brachytherapy and contact X-ray radiotherapy (CXRT)-allow a highly localized radiation boost. CXRT has shown higher CR rates than external beam radiotherapy (EBRT) boosts (81% vs. 60%). However, widespread use of endoluminal boosting is limited by the high cost of CXRT equipment and the less favorable dose distribution of HDR brachytherapy.
To overcome these limitations, MAASTRO, in collaboration with Varian Inc., developed a new HDR rectal brachytherapy applicator that delivers a dose profile similar to CXRT. The applicator has received CE certification and is now available for clinical use. A recent clinical trial confirmed that treatment with this applicator is clinically feasible. As a result, MAASTRO HDR treatment is now part of standard care.
To improve understanding of treatment outcomes and optimize future strategies, a prospective observational cohort study has been initiated.This project is designed to continuously include new patients and will provide an ongoing source for multiple future studies
2,400 studies on the registry are indexed under Rectal Neoplasms; 587 are open to participants now.
This study's planned enrollment of 999 is above the median of 161 across 498 observational studies indexed under Rectal Neoplasms.
Browse Rectal Neoplasms studies →Maastricht Radiation Oncology is the lead sponsor of 106 studies on the registry; 9 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients being treated with the MAASTRO HDR rectal applicator
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Treatment with the MAASTRO HDR rectal applicator
Efficacy of Maastro applicator endoluminal HDR contact brachytherapy boosting in functional organ sparing of the rectum.
Number of patients with clinical complete respons. Number of patients with treatment related adverse events as assessed by CTCAE v 4.0
Time frame: From enrollment to the end of FU at 10 years
Percentage of planned interventional Maastro procedures that could be conducted successfully from a procedural point of view.
Percentage of planned interventional Maastro procedures that could be conducted successfully from a procedural point of view.
Time frame: During treatment
Duration of the application procedure.
Duration of the application procedure.
Time frame: During treatment
Clinical complete response rate up to 5 years after treatment.
Clinical complete response rate up to 5 years after treatment.
Time frame: From end of treatment until 5 years after treatment
Rectal toxcity up to 3 year after treatment
Rectal toxicity scored according to CTCAE v. 5 up to 3 years after treatment
Time frame: From start treatment until 3 years after the end of treatment
Disease status up to 10 years after treatment
Local and locolregional recurrence rate and metastatic rate up to 10 years after treatment
Time frame: from enrollment until 10 years after treatment
Salvage surgery
Salvage surgery rate after treatment.
Time frame: From end of treatment until 5 years after treatment
Overall and disease specific survival rate
Overall and disease specific survival rate up to 10 year after treatment.
Time frame: from enrollment until 10 years after treatment
Discomfort/pain
Discomfort/pain during endorectal irradiation using NRS (Numeric Rating Scale 0-10) painscore
Time frame: From baseline up to 2 weeks after last fraction
Toxcity up to 3 year after treatment
Rectal and genitourinary toxicity scored according to CTCAE v. 5 up to 3 years after treatment
Time frame: From start treatment until 3 years after the end of treatment
Genitourinary toxicity up to 3 years after treatment
Genitourinary toxicity scored according to CTCAE v 5 up to 3 years after treatment
Time frame: From start treatment until 3 years after the end of treatment
Health status
Separate informed consent will be asked to measure the health status and quality of life by QLQ-C30 ( EORTC Quality of Life Questionaires, Core 30) , QLQ-CR29 ( EORTC Quality of Life Questionaires ColoRectal 29 and EQ-5D ( EuroQoL-5D)
Time frame: From enrollment until 5 years after treatment
Long-term rectal functional outcome
Separate informed consent will be asked to measure the Long-term rectal functional outcome by LARS score (Low Anterior Resection Syndrome - scale 0-42)
Time frame: From enrollment until 5 years after treatment
Quality of life questionnaires
Separate informed consent will be asked to measure the quality of life by QLQ-C30 ( EORTC Quality of Life Questionaires, Core 30).
Time frame: From enrollment until 5 years after treatment
Plan to share: Undecided
No publications or documents are linked to this record.
Started Mar 2026 (actual). Primary completion is estimated for Apr 2034, 96 months after the start.
Of 213 non-industry observational studies under Rectal Neoplasms, half reached primary completion within 47 months of starting (the median), counting those still running; a quarter within 24 and three quarters within 116. This study's planned 96 months is above that.
Counting every sponsor, half of 228 studies reached it within 45 months; a quarter within 24 and three quarters within 116.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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