Defining target volume for radiation boosting in rectal cancer

DETECT: Defining the Target Volume for Endoluminal Radiation Boosting in Patients With Rectal Cancer

This study is trying to understand how rectal cancer spreads in order to improve radiation treatment for patients who still have cancer after their initial therapy.

Quick facts

• Study type: Observational
• Enrollment: 50 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Maastricht Radiation Oncology (other)
• Drugs / interventions: radiation
• Locations: 3 sites (Maastricht, Limburg and 2 other locations)
• Trial ID: NCT04927897 on ClinicalTrials.gov

What this trial studies

This observational study aims to gather prospective data on the microscopic spread of rectal cancer tumors to better define the target volume for endoluminal radiation boosting. It involves a multicenter cohort of at least 50 patients with residual rectal adenocarcinoma after neoadjuvant treatment. Patients will undergo standard workup procedures, including flexible endoscopy and MRI, along with additional endorectal ultrasound and rigid rectoscopy. The study will analyze tumor spread in all directions and develop a tissue deformation model to translate findings back to in vivo imaging.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with confirmed residual rectal adenocarcinoma after neoadjuvant therapy.

Not a fit: Patients who have received brachytherapy as part of their neoadjuvant treatment will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could improve the precision of radiation therapy for rectal cancer, potentially leading to better treatment outcomes.

How similar studies have performed: While similar studies have explored tumor spread and radiation targeting, this specific approach to defining target volumes for endoluminal radiation boosting is novel.

Eligibility criteria

Inclusion Criteria:

* ≥18 years of age and capable of giving informed consent.
* ycT1-3N0(\*) residual(\*\*) histology confirmed rectal adenocarcinoma after neoadjuvant radiotherapy or long-course chemoradiotherapy for which patients will undergo TME surgery.
* Minimal interval between end of neoadjuvant chemoradiotherapy or radiotherapy: 6 weeks.

(\*)= as determined by clinical assessment (digital rectal examination, endoscopy with or without biopsy) and/or MRI. Biopsy/histology around the time of diagnosis is adequate; no biopsy/histology is needed after neoadjuvant therapy.

(\*\*)= including tumor regrowths/local recurrence after an initial clinical complete response and a "watch and wait" approach. These patients will also be included after the local recurrence has been determined using endoscopy and/or MRI.

Exclusion Criteria:

* Patient has received brachytherapy as part of neoadjuvant treatment.
* \<18 years of age or incapable of giving informed consent.
* Patient has not been treated with neoadjuvant radiotherapy or long-course chemoradiotherapy.
* Patient will not undergo TME surgery for a ycT1-3N0 residual histology confirmed rectal adenocarcinoma.
* Interval between end of neoadjuvant therapy and surgery is \<6 weeks.

Where this trial is running

Maastricht, Limburg and 2 other locations

• Maastro — Maastricht, Limburg, Netherlands (RECRUITING)
• Maastricht University Medical Center — Maastricht, Limburg, Netherlands (RECRUITING)
• Catharina Hospital — Eindhoven, North Brabant, Netherlands (RECRUITING)

Study contacts

• Principal investigator: Maaike Berbée, MD, PhD — Maastro
• Study coordinator: Maaike Berbée, MD, PhD

Conditions: Rectal Cancer, Microscopic Tumor Spread, Target Volume Definition, Endoluminal Radiation Boosting