Colorectal Cancer Radiotherapy

Introduction

High-energy radiation attacks and eliminates cancerous cells in the rectum and colon through colorectal cancer radiotherapy, an effective treatment approach. Although chemotherapy and surgery are foundational treatments, radiation therapy has an important role to play—particularly in rectal cancer. This article delves into the application of radiotherapy, its utilization, its efficacy, the cost disparities across countries, and the ongoing clinical trials in China.

About the Disease

Colorectal cancer is the third most prevalent cancer worldwide, occurring in the colon and rectum. The majority of cases start out as polyps that have the potential to develop into cancer. Risk factors may include genetics, lifestyle, diet, and underlying conditions such as ulcerative colitis. Depending on the location and stage of the cancer, a multi-modal treatment plan may involve surgery, chemotherapy, and radiotherapy.

Indications

Radiotherapy is more commonly used in rectal cancer than colon cancer due to anatomical differences.

When Radiotherapy is Recommended:

• Neoadjuvant (before surgery): To shrink rectal tumors for easier and more successful surgical removal.

• Adjuvant (after surgery): To eliminate microscopic residual cancer cells.

• Definitive therapy: For patients who are not surgical candidates.

• Palliative care: To relieve symptoms such as bleeding, pain, or obstruction in advanced cases.

• Recurrent cancer: To treat localized recurrence.

Treatment Details

Radiotherapy for colorectal cancer typically uses external beam radiation therapy (EBRT), where targeted rays are directed at the tumor site from outside the body. Usually, the treatment consists of several sessions (fractions) spread over a few weeks.

Types of Radiation Therapy:

• 3D Conformal Radiation Therapy (3D-CRT): Shapes radiation beams to match the tumor.

• Intensity-Modulated Radiation Therapy (IMRT): Adjusts the intensity of beams to minimize damage to nearby tissues.

• Image-Guided Radiation Therapy (IGRT): Uses imaging during treatment to enhance accuracy.

• Stereotactic Body Radiation Therapy (SBRT): High precision, high dose in fewer sessions, used in some metastatic settings.

Treatment Duration:

• Typically, 5–6 weeks for rectal cancer, administered 5 days a week.

• Short-course radiotherapy (5 days) is also used in some early-stage cases.

Medicines Used

Concurrent administration of certain radiosensitizing chemotherapy drugs enhances the effectiveness of radiation, despite radiation being a local treatment. These drugs make cancer cells more vulnerable to the effects of radiation.

Common Drugs Used with Radiotherapy:

• 5-Fluorouracil (5-FU)

• Capecitabine (Xeloda) – oral form of 5-FU

• Oxaliplatin – in select clinical trials

These are not radiation treatments by themselves but work synergistically with it, especially in rectal cancer.

Effectiveness

Radiotherapy is highly effective in reducing local recurrence of rectal cancer and improving the chance of sphincter preservation (avoiding a permanent colostomy).

Key Benefits:

• Neoadjuvant radiotherapy combined with chemotherapy reduces local recurrence by up to 60%.

• Adjuvant radiotherapy improves overall survival and disease-free survival in selected patients.

• In palliative settings, radiation helps control symptoms like pain and bleeding in up to 80% of patients.

Risks and Side Effects

Radiotherapy is generally well-tolerated, but it can have both acute and chronic side effects depending on the dose, area treated, and patient health.

Common Short-term Side Effects:

• Skin redness and irritation around the radiation site

• Diarrhea or constipation

• Fatigue

• Nausea

• Urinary urgency or discomfort

Long-term Risks:

• Bowel obstruction or scarring

• Rectal bleeding

• Bladder problems

• Sexual dysfunction

• Secondary cancers (rare)

Supportive care and precise radiation planning significantly reduce these risks.

Recovery and Aftercare

Post-radiation recovery is an essential part of colorectal cancer treatment, especially when combined with surgery or chemotherapy.

Recovery Tips:

• Stay hydrated and maintain a gentle, nutritious diet.

• Use prescribed creams for skin care at the radiation site.

• Manage bowel habits with medications and fiber-rich diets.

• Attend follow-up appointments every 3–6 months initially.

• Monitor for delayed side effects with imaging and blood tests.

Psychological support and lifestyle counseling are crucial for holistic healing.

Cost and Availability

Radiotherapy for colorectal cancer varies in cost depending on technology, hospital type, country, and combination with chemotherapy.

Availability in India:

India offers advanced radiation technologies like IMRT, IGRT, and SBRT in premier institutions such as Tata Memorial Hospital, Apollo Hospitals, and AIIMS. Costs are significantly lower than in the West.

Availability in China:

China’s top cancer centers—like Fudan University Cancer Hospital, Sun Yat-sen University Cancer Center, and Beijing Cancer Hospital—offer state-of-the-art radiation therapy and participate in global clinical trials.

Patient Experiences

Patients undergoing radiotherapy for colorectal cancer often report a mix of manageable discomfort and strong outcomes. Many share stories of preserved bowel function, successful tumor downstaging, and regained quality of life.

Themes in Testimonials:

• Anxiety before starting radiation

• Relief from shrinking tumors

• Sphincter-sparing surgeries after neoadjuvant therapy

• Challenges with fatigue and bowel changes

• Emotional growth and resilience

Support groups and oncology counselors help manage both physical and emotional impacts of treatment.

Cost in Countries Like China, India, Israel, Malaysia, Korea, Thailand, Turkey, and USA

Note: Prices can vary based on hospital, machine type (linear accelerator), and city.

List of Ongoing Clinical Trials in China

China is advancing research in colorectal cancer radiotherapy, especially in integrating it with immunotherapy and precision medicine.

Notable Clinical Trials (as of 2025):

• NCT05859061: SBRT combined with PD-1 inhibitors for metastatic rectal cancer.

• NCT05849233: Short-course radiotherapy followed by immunotherapy for rectal adenocarcinoma.

• NCT05780379: Comparison of IMRT vs SBRT in recurrent rectal cancer.

• NCT05882941: Role of MR-guided adaptive radiotherapy in locally advanced rectal cancer.

• NCT05823100: Use of high-dose radiotherapy in oligometastatic colorectal cancer.

Interested patients can search more trials via the Chinese Clinical Trial Registry (ChiCTR) or consult tertiary hospitals in Beijing or Shanghai.

FAQ

Is radiotherapy used in all colorectal cancer cases?
No. It’s mainly used in rectal cancer or metastatic cases involving specific organs.

How is radiation therapy different from chemotherapy?
Radiotherapy targets local tumors using high-energy rays, while chemotherapy works systemically through drugs.

Does radiation hurt during treatment?
The process is painless, but skin irritation and fatigue may develop over time.

Can radiotherapy cure colorectal cancer?
In early-stage rectal cancer, neoadjuvant radiotherapy followed by surgery can be curative.

How long does each session take?
Each daily session typically takes 15–30 minutes, including setup and imaging.

Are there natural remedies to counter radiation side effects?
Yes—aloe vera, probiotics, hydration, and a low-fiber diet help reduce bowel and skin issues.

Can I work during radiotherapy?
Yes, but some may need rest days depending on fatigue or side effects.

Is it safe to have repeated radiotherapy?
Re-irradiation is possible in specific cases but needs expert evaluation to prevent tissue damage.