the Efficacy of MR-guided Online Adaptive Radiotherapy for Locally Advanced Rectal Cancer

Launched by CANCER INSTITUTE AND HOSPITAL, CHINESE ACADEMY OF MEDICAL SCIENCES · Jul 14, 2025

Keywords

ClinConnect Summary

This clinical trial is studying a new type of radiation treatment called MR-guided online adaptive radiotherapy (MRgART) for people with locally advanced rectal cancer, which means cancer that is more developed but hasn’t spread to distant parts of the body. The goal is to see if this treatment can better target the cancer while protecting healthy tissue, improve the chances of the cancer completely responding to therapy, and help patients keep their organs intact without needing surgery. The study will also look at how safe and tolerable the treatment is, as well as long-term outcomes like cancer returning, survival rates, and quality of life over three years.

People who might be eligible are adults aged 18 to 75 with a specific stage of rectal cancer confirmed by scans and exams. They must not have had previous treatments like surgery or radiation for their cancer and need to be in generally good health with normal blood and organ function. The trial excludes anyone with certain medical conditions, active infections, or who cannot have MRI scans due to metal implants or claustrophobia. If you join the study, you can expect regular MRI-guided radiation sessions that adjust the treatment based on daily changes in the tumor, along with careful monitoring to understand how well the cancer is responding and to watch for side effects. This approach aims to improve treatment precision and outcomes, potentially offering a better chance to avoid surgery and maintain quality of life.

Gender

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Eligibility criteria

• Inclusion Criteria:
• • 1. Age 18-75 years, regardless of gender;
• • 2. Staged as II/III (cT3-T4N0 or cT2-4N+, no distant metastasis) by MRI or endoscopic ultrasound (according to the AJCC Cancer Staging Manual, 8th Edition);
• • 3. Fibrocolonoscopy or digital rectal examination confirms the lower border of the lesion is ≤10 cm from the anal verge;
• • 4. Pathologically confirmed or reviewed diagnosis of rectal adenocarcinoma;
• • 5. ECOG performance status of 0-1;
• • 6. Laboratory test results meeting the following criteria: Hemoglobin ≥ 90 g/L, white blood cells ≥ 3.5×10⁹/L; Neutrophils ≥ 1.5×10⁹/L, platelets ≥ 100×10⁹/L; Creatinine ≤ 1.0× upper normal limit (UNL), blood urea nitrogen (BUN) ≤ 1.0× UNL; Alanine aminotransferase (ALT) ≤ 1.5× UNL; Aspartate aminotransferase (AST) ≤ 1.5× UNL; Alkaline phosphatase (ALP) ≤ 1.5× UNL; Total bilirubin (TBIL) ≤ 1.5× UNL; Urine protein (-); normal bleeding and clotting time.
• • 7. No history of allergy to 5-Fu drugs or platinum-based drugs;
• • 8. Primary rectal cancer patients must not have undergone surgery (except palliative colostomy), chemotherapy, or other antitumor treatments from diagnosis to enrollment;
• • 9. No prior radiation therapy to the intended treatment site;
• • 10. Signed informed consent form.
• Exclusion Criteria:
• • 1. Presence of MRI-incompatible metal implants or claustrophobia;
• • 2. Previous treatment with anti-PD-1/L1, anti-CTLA-4 immunotherapy, or other experimental immunotherapeutic drugs;
• • 3. History of severe autoimmune diseases, including active inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis), rheumatoid arthritis, scleroderma, systemic lupus erythematosus, autoimmune vasculitis (e.g., Wegener's granulomatosis), etc.;
• • 4. Symptomatic interstitial lung disease or active infectious/non-infectious pneumonia;
• • 5. Risk factors for intestinal perforation, such as active diverticulitis, intra-abdominal abscess, gastrointestinal (GI) obstruction, abdominal malignancies, or other known predisposing conditions;
• • 6. History of other malignancies, except for curable non-melanoma skin cancer or cervical carcinoma in situ;
• • 7. Active infections, heart failure, myocardial infarction within the past 6 months, unstable angina, or unstable arrhythmia;
• • 8. Physical examination or clinical findings that, in the investigator's judgment, may interfere with results or increase the patient's risk of treatment complications, or other uncontrolled medical conditions;
• • 9. Women who are pregnant or breastfeeding;
• • 10. Congenital or acquired immunodeficiency disorders, including human immunodeficiency virus (HIV) infection, or history of organ transplantation or allogeneic stem cell transplantation.
• • 11. Active hepatitis B virus (HBV) infection (HBV-DNA ≥2000 U/mL), hepatitis C virus (HCV) infection, or active tuberculosis infection;
• • 12. Prior administration of a cancer vaccine or receipt of any other vaccine within 4 weeks before treatment initiation.
• • (Note: Inactivated vaccines, such as seasonal flu shots, are permitted, whereas live attenuated vaccines, such as intranasal formulations, are prohibited.)
• • 13. Concurrent use of other immunomodulators, chemotherapy, investigational drugs, or long-term corticosteroid therapy will exclude the patient from enrollment.
• • 14. Patients with psychiatric disorders, substance abuse, or social issues that may compromise compliance, as assessed by the investigator, will be excluded.
• • 15. Patients with a known allergy or contraindication to the study treatment.