Online Adaptive Radiotherapy With Sequential BoostConventional Non-Adaptive IMRTCapecitabineCAPEOXTotal Mesorectal Excision
Online Adaptive Radiotherapy With Sequential Boost: MR- or CBCT-guided online adaptive radiotherapy with daily imaging, target and organ-at-risk review, and plan reoptimization. A sequential boost of 9 Gy in 3 fractions or 10 Gy in 2 fractions is delivered to GTVp and GTVn, followed by 50 Gy in 25 fractions to the pelvic CTV.
Conventional Non-Adaptive IMRT: Conventional non-adaptive intensity-modulated radiotherapy to the pelvic CTV at 50 Gy in 25 fractions without dose escalation.
Capecitabine: Capecitabine 825 mg/m² orally twice daily during long-course chemoradiotherapy.
CAPEOX: Consolidation chemotherapy consisting of capecitabine 1000 mg/m² orally twice daily on days 1-14 plus oxaliplatin 130 mg/m² intravenously on day 1 every 3 weeks for 3-4 cycles after chemoradiotherapy.
Total Mesorectal Excision: Total mesorectal excision planned after completion of neoadjuvant treatment according to standard surgical principles.
Study summary
This prospective, single-center, randomized controlled trial evaluates whether online adaptive radiotherapy (ART) with a sequential boost to both the primary rectal tumor and clinically involved lymph nodes improves pathologic complete response in patients with high-risk, node-positive locally advanced rectal cancer. Participants were randomly assigned 1:1 to online ART with a sequential boost or conventional non-adaptive intensity-modulated radiotherapy (IMRT). Both groups received concurrent capecitabine during long-course chemoradiotherapy, followed by 3-4 cycles of CAPEOX consolidation chemotherapy and planned total mesorectal excision. The planned sample size was 128 participants. Enrollment was discontinued after an interim review after 76 participants had been randomized; long-term follow-up of enrolled participants is ongoing.
Eligibility
Sex
ALL
Min age
18 Years
Max age
75 Years
Healthy volunteers
No
Inclusion Criteria
1. Age 18 years or older.
2. ECOG performance status of 0 or 1.
3. Histologically confirmed rectal adenocarcinoma.
4. Primary tumor located within 10 cm of the anal verge by pelvic MRI and/or rigid sigmoidoscopy.
5. Clinically involved regional lymph nodes (cN1-2) according to the AJCC 8th edition.
6. At least one additional high-risk feature: cT4 disease, cN2 disease, extramural vascular invasion, mesorectal fascia involvement, lateral pelvic lymph-node involvement, tumor deposits, or low rectal cancer (≤5 cm from the anal verge).
7. Baseline locoregional staging with contrast-enhanced pelvic MRI and chest/abdominal imaging excluding distant metastases.
8. Treatment-naïve with respect to systemic therapy and pelvic radiotherapy for the index rectal cancer and suitable for total mesorectal excision.
9. Adequate organ function and no medical contraindication to chemoradiotherapy.
10. Written informed consent before study-specific procedures.
Exclusion Criteria
1. Prior pelvic radiotherapy.
2. Prior rectal surgery for the index cancer, including local excision or transanal procedures.
3. Radiologically or pathologically confirmed distant metastasis.
4. Locally recurrent rectal cancer.
5. Active inflammatory bowel disease.
6. History of another primary malignancy within the preceding 5 years, except adequately treated non-melanoma skin cancer or carcinoma in situ.
7. Pregnancy or lactation.
8. Severe or uncontrolled medical condition contraindicating chemoradiotherapy or surgery.
9. Clinically significant hypersensitivity to protocol systemic therapy that precludes treatment.
Primary outcome measure(s)
pCR — At total mesorectal excision after completion of neoadjuvant therapy, up to approximately 6 months after randomization Proportion of participants achieving ypT0N0, defined as absence of viable tumor cells in the resected primary tumor and regional lymph nodes after neoadjuvant treatment.
Trial sites (1)
Facility
City
Region
Status
Department of Radiation Oncology, Shandong Cancer Hospital and Institute
Jinan
Shandong
More Shandong Cancer Hospital and Institute trials in China
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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