An interventional study of Intensity modulated proton therapy in Locally Advanced Rectal Cancer and Rectal Adenocarcinoma, sponsored by University of Aarhus. Not yet recruiting at 8 sites in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by University of Aarhus · Not applicable, Interventional, and Treatment
This prospective national multicentre feasibility study evaluates dose-escalated short-course proton radiotherapy followed by total neoadjuvant chemotherapy in patients with primary high-risk locally advanced rectal adenocarcinoma. The study will assess willingness to participate and travel for proton therapy, completion of planned treatment, early clinical complete response, safety, patient-reported outcomes, and feasibility of circulating cell-free and tumour DNA sampling. Patients with a clinical complete response may enter a watch-and-wait programme; other patients will undergo surgery according to national guidelines.
Standard short-course radiotherapy for locally advanced rectal cancer is 25 Gy in 5 fractions. Dose escalation may increase tumour response and the probability of organ preservation but may also increase radiation exposure of adjacent normal tissues. Proton therapy may permit dose escalation while limiting dose to organs at risk.
Participants will receive intensity-modulated proton therapy with 35 Gy(RBE) in 5 fractions to the tumour target and 25 Gy(RBE) in 5 fractions to the elective target. Radiotherapy will be followed, approximately 2 weeks later, by 4 cycles of CAPOX or FOLFOX according to national guidelines. Response will be assessed 20-22 weeks after the start of radiotherapy by multidisciplinary review of digital rectal examination, endoscopy, and pelvic MRI. Patients with a clinical complete response may be managed by watch-and-wait; surgery and subsequent follow-up will otherwise follow national guidelines.
Toxicity, patient-reported symptoms, quality of life, and oncological outcomes will be followed for up to 60 months. Blood for exploratory cfDNA/ctDNA analyses will be collected at baseline, at the end of radiotherapy, and at the 20-22-week response assessment.
2,400 studies on the registry are indexed under Rectal Neoplasms; 587 are open to participants now.
This study's planned enrollment of 30 is below the median of 65 across 1,751 interventional studies indexed under Rectal Neoplasms.
Browse Rectal Neoplasms studies →University of Aarhus is the lead sponsor of 1,300 studies on the registry; 189 are open to participants now.
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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.
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Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
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.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
One-armed feasibility study where patients will be treated with dose-escalated IMPT 35Gy in 5 fractions
Radiation: Intensity modulated proton therapy
Dose-escalated IMPT
Feasibility of recruitment
Proportion of eligible patients who are willing to participate i trial and travel proton facility
Time frame: 2 year inclusion expected
Start is estimated for Nov 2026; primary completion for Nov 2029, 36 months later.
Of 329 non-industry interventional studies with no phase under Rectal Neoplasms, half reached primary completion within 51 months of starting (the median), counting those still running; a quarter within 23 and three quarters within 78. This study's planned 36 months is below that.
Counting every sponsor, half of 336 studies reached it within 51 months; a quarter within 23 and three quarters within 78.
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 ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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