IMRT Versus 3DCRT for Locally Advanced Rectal Cancer, Prospective Phase II Study.

Study Overview
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Brief Summary
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The goal of this prospective phase II study was to determine whether personalized planning-based nCRT for LARC would indeed decrease small bowel dose, and whether selected plans, specifically prioritizing lower dose to small bowel, would result in lower rates of acute GI toxicity compared with previously reported rates.

Detailed Description
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The standard of care for locally advanced rectal cancer is neoadjuvant chemoradiotherapy. However, acute gastrointestinal (GI) toxicity is common. Some retrospective studies suggested that Intensity Modulated Radiation Therapy( IMRT) reduces acute bowel toxicity compere to 3D conformal radiotherapy (3DCRT).The aim of this prospective phase II study to determine whether the use of IMRT planning in neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer can decrease small bowel irradiation dose compared to commonly used 3D conformal techniques ,and the rate of acute GI toxicity. Patients (pts) with clinical stage II-III rectal adenocarcinoma were enrolled in a prospective phase II study of preoperative chemoradiation. For each patient two radiation plans were performed: IMRT and 3DCRT. After comparing two DVH (dose volume histogram) plans for organs at risk (OARs), such as small bowel and bladder, pts were treated according to the plan with maximal critical organs sparing. All Patients received 45 Gy in 25 fractions to the rectum and draining lymph nodes, followed by boost to the tumor, with concurrent capecitabine or 5- Fluorouracil .Weekly follow up was performed to assess acute toxicity. The investigators hypothesize that the use of IMRT in neoadjuvant chemoradiation for locally advanced rectal cancer may reduce the small bowel and bladder irradiated volume and consequently reduce acute toxicity.

Official Title
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Evaluation of Preoperative Chemoradiotherapy Utilizing Intensity Modulated Radiation Therapy (IMRT) When Compared With 3D Conformal Radiotherapy (3DCRT) for Patients With Locally Advanced Rectal Cancer, Prospective Phase II Study.

Conditions
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Rectal Cancer, Radiotherapy, Toxicity Due to Radiotherapy

Intervention / Treatment
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* Radiation: Intensive Modulated Radiation Therapy
* Radiation: 3-Dimension Conformal Radiation Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with locally advanced rectal adenocarcinoma Performance status of 0-2 Adequate hematologic, renal, and hepatic function Exclusion Criteria: Prior radiotherapy to pelvis Metastatic disease at diagnosis

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: IMRT<br>Intensive Modulated Radiation Therapy | Radiation: Intensive Modulated Radiation Therapy<br>* Radiotherapy technique: IMRT<br>|
| Active Comparator: 3DCRT<br>3-Dimension Conformal Radiation Therapy | Radiation: 3-Dimension Conformal Radiation Therapy<br>* Radiotherapy technique: 3DCRT<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with treatment-related gastrointestinal and urinary adverse events as assessed by CTCAE v5.0 | Acute gastrointestinal and urinary toxicity | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pathological response to chemoradiotherapy | Pathological response to neoadjuvant chemoradiotherapy was assessed on the surgical specimen. | 3 months |