A Phase 2 interventional study of GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost) and GTV 50 Gy/25 fractions(Simultaneous Integrated Boost) in Locally Advanced Rectal Adenocarcinoma, sponsored by Peking Union Medical College Hospital. Recruiting at 1 site in China. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-21.
Sponsored by Peking Union Medical College Hospital · Phase 2, Interventional, and Treatment
The goal of this clinical trial is to learn whether new adjuvant radiotherapy with gross tumor volume(GTV) escalated to 58.75 Gy can improve complete response (CR) rates compared with GTV dose of 50 Gy in adult patients (18-79 years) with locally advanced rectal adenocarcinoma (T3-T4/N+, M0) located ≤10 cm from the anal verge.The main questions it aims to answer are:
Participants will:
This study is a randomized controlled trial designed to evaluate the clinical efficacy and safety of simultaneous integrated boost (SIB) dose escalation in the neoadjuvant treatment of locally advanced rectal cancer (LARC).Standard neoadjuvant chemoradiotherapy (nCRT) typically utilizes a dose of 50 Gy to the gross tumor volume (GTV). This trial investigates whether escalating the radiation dose specifically to the GTV to 58.75 Gy, delivered in 25 fractions, can significantly enhance tumor downstaging and increase the rates of pathologic complete response (pCR) or sustained clinical complete response (cCR).Study Arms and Radiation Technique:Participants are randomized into two arms. Both arms receive intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) with concurrent fluoropyrimidine-based chemotherapy.Experimental Arm: The planned target volume of the GTV (PGTV) receives a total dose of 58.75 Gy in 25 fractions ($2.35 \text{ Gy/fraction}$), while the elective lymphatic drainage areas (PTV) receive 45-50 Gy.Control Arm: The PGTV receives a total dose of 50 Gy in 25 fractions ($2.0 \text{ Gy/fraction}$), consistent with standard-of-care protocols.Clinical Workflow:Following the completion of neoadjuvant therapy, patients will undergo a mandatory restaging assessment 6-12 weeks post-radiation. This evaluation includes digital rectal examination (DRE), pelvic multiparametric MRI (mpMRI), and endoscopy.Surgical Intervention and Organ Preservation:Patients achieving a cCR may be offered a "Watch-and-Wait" (W\&W) strategy with intensive surveillance, aiming for organ preservation.Patients with a good but incomplete response may undergo local excision (LE) or total mesorectal excision (TME).The primary endpoint is the combined complete response (CR) rate, defined as pCR for those undergoing surgery and cCR (sustained for at least 6 months) for those entering the W\&W protocol.Secondary Objectives:The study will also perform a comparative analysis of progression-free survival (PFS), local control (LC) rates, and the distribution of Tumor Regression Grade (TRG). Safety profiles will be rigorously monitored using the Common Terminology Criteria for Adverse Events (CTCAE), focusing on acute and late gastrointestinal and genitourinary toxicities.
Peking Union Medical College Hospital is the lead sponsor of 1,115 studies on the registry; 463 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Radiotherapy: long course simultaneous integrated boost radiotherapy * Gross tumor volume (GTV): A total dose of 58.75Gy delivered in 25 fractions using a simultaneous integrated boost approach. * CTV: 45Gy/25f * Mesorectum lymph node(GTVnd1):58.75Gy/25f * Lateral lymph node（GTVnd2）：60Gy/25f Concurrent Chemotherapy: Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment.
Radiation: GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost) · Drug: Concurrent Chemotherapy · Procedure: Total mesorectal excision (TME) surgery or non-operative management
Radiotherapy: long course simultaneous integrated boost radiotherapy Gross tumor volume (GTV): A total dose of 50Gy delivered in 25 fractions using a simultaneous integrated boost approach. CTV: 45Gy/25f Mesorectum lymph node(GTVnd1):58.75Gy/25f Lateral lymph node（GTVnd2）：60Gy/25f Concurrent Chemotherapy: Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment.
Radiation: GTV 50 Gy/25 fractions(Simultaneous Integrated Boost) · Drug: Concurrent Chemotherapy · Procedure: Total mesorectal excision (TME) surgery or non-operative management
Patients will receive neoadjuvant long course radiotherapy using VMAT or IMAT with daily image guided. Gross tumor volume (GTV): A total dose of 58.75Gy delivered in 25 fractions using a simultaneous integrated boost approach; CTV: 45Gy/25f; Mesorectum lymph node(GTVnd1):58.75Gy/25f ; Lateral lymph node（GTVnd2）：60Gy/25f;
Patients will receive neoadjuvant radiotherapy with GTV 50 Gy in 25 fractions , delivered with IMRT or VMAT technique. CTV: 45Gy/25f; Mesorectum lymph node(GTVnd1):58.75Gy/25f; Lateral lymph node（GTVnd2）
Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy.
After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment.
CR
primary tumor achieved pathological complete response or clinical complete response.
Time frame: 1 year
3-year disease free suvival rate
The proportion of patients from the initiation of surgery to tumor recurrence or death within 3 years
Time frame: 3 years
3-year local control rate
The proportion of patients absence of pelvic tumor progression, including primary tumor regrowth or regional lymph node progression, within 3 years after randomization.
Time frame: 3 years
Tumor Regression Grade
Pathological tumor regression grade (TRG) according to CAP criteria.
Time frame: 1 year
Number of participants with treatment-related adverse events as assessed by CTCAE v5.0
Acute and late adverse events will be graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
Time frame: 3 years
Organ Preservation Rate
The proportion of patients who retain anal sphincter function without permanent stoma, including watch-and-wait, Dixon procedure or sphincter-preserving resection.
Time frame: 1 year
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Peking Union Medical College Hospital