How Radiotherapy Works: A Step-by-Step Explanation

Radiotherapy Basics: What It Is & How It Helps

Radiation therapy uses high-energy waves, such as X-rays, electron beams, gamma rays, or protons, to damage cancer cells' DNA. This targeted approach stops cancer cells from growing and dividing, ultimately causing them to die.

The treatment works gradually, with cancer cells continuing to die for weeks or months after radiotherapy ends. For many common cancers, such as breast, bowel, uterine, skin, and prostate cancer, radiation therapy proves highly effective in reducing the risk of malignancy recurrence when delivered either before or after surgery.

Medical teams can use radiation therapy in nearly every type of cancer. The treatment serves multiple purposes:

• Destroying cancer cells completely

• Shrinking tumours before surgery

• Eliminating remaining cancer cells after surgery

• Managing cancer symptoms & improving quality of life

The versatility of radiation therapy makes it particularly valuable in cancer treatment. Doctors might use it as a standalone treatment or combine it with other therapies like chemotherapy or surgery. Furthermore, radiation therapy helps relieve symptoms in advanced cancer cases, particularly managing pain from bone metastases.

Radiation oncologists carefully plan treatments to target cancer cells while protecting healthy tissue. Treatment sessions typically last 15-30 minutes, with most patients receiving five treatments per week. The complete treatment course usually spans between four to nine weeks. This schedule allows optimal effectiveness while giving healthy cells time to recover between sessions.

Types of Radiotherapy: External vs. Internal Treatment

Doctors deliver radiation therapy through two primary methods: 

External Beam Radiation Therapy (EBRT):

EBRT is the most common radiation therapy treatment method. This technique employs specialised machines called linear accelerators that direct high-energy beams towards tumours without touching the patient's body. 

Several sophisticated forms of EBRT exist:

• 3D conformal radiation therapy creates detailed three-dimensional models of tumours using CT scans

• Intensity-modulated radiation therapy (IMRT) allows doctors to adjust radiation doses for different areas

• Image-guided radiotherapy (IGRT) uses X-rays or CT scans before each treatment

• Stereotactic radiosurgery focuses high doses of radiation on small brain tumours

• Stereotactic body radiation therapy (SBRT) targets tumours outside the brain

Internal Radiation Therapy:

Internal radiation therapy places radioactive materials directly inside or near the cancer site. This method treats smaller tumours in specific body parts: the head, neck, breast, cervix, uterus, and prostate. Two main types of internal radiation exist:

• Brachytherapy involves placing solid radioactive sources, called 'seeds', inside or beside tumours. 

• Systemic radiation therapy uses liquid radioactive materials that travel through the bloodstream to find and destroy cancer cells. 

The choice between external and internal radiation depends on various factors, including cancer type, tumour location, and size.

The Treatment Process: What to Expect Step-by-Step

The journey through radiation therapy follows five essential steps, beginning with an initial consultation where patients meet their radiation oncologist. The specialist reviews medical records, pathology reports, and imaging results to determine the most effective treatment approach.

Subsequently, patients undergo a simulation process to map the treatment area precisely. During this hour-long session, radiation therapists create a detailed treatment plan using CT scans or MRIs. Patients might receive small, permanent tattoo marks or wear specially crafted masks to ensure consistent positioning throughout their treatment journey.

Following simulation, a dedicated team of medical dosimetrists and physicists meticulously designs the treatment blueprint. Their primary goal is to deliver maximum radiation to cancer cells while protecting healthy tissue. This intricate planning phase typically spans several days to a week.

Once the planning phase concludes, treatment sessions commence. Each session typically lasts between 10 to 40 minutes, although the actual radiation delivery takes minutes. Patients lie still on a treatment table while a linear accelerator moves around them, delivering precise radiation beams from various angles.

Throughout the treatment course, patients generally receive:

• Five treatments weekly (Monday through Friday)

• Daily positioning checks using advanced imaging

• Weekly progress reviews with their radiation oncologist

• Regular monitoring of potential side effects

The treatment room maintains specific conditions, operating in semi-darkness to help therapists align light beams with the marked treatment areas. Although patients remain alone in the room during radiation delivery, they stay connected with their treatment team through an intercom system.

After completing the prescribed treatment course, patients enter the follow-up phase. The radiation oncology team schedules regular check-ups at 4 and 12 weeks post-treatment to monitor recovery and address any concerns. These appointments prove vital for managing potential side effects and ensuring optimal treatment outcomes.

How Radiation Targets Cancer Cells

At its core, radiation therapy destroys cancer cells through a precise mechanism that targets cellular DNA. The treatment operates through two distinct pathways: direct DNA damage and indirect damage through free radical formation.

The primary goal focuses on damaging the genetic material that controls cell growth and division. Cancer cells experience various forms of DNA damage upon exposure to radiation, specifically double-strand breaks (DSBs) and single-strand breaks (SSBs). Among these, DSBs prove most lethal to cancer cells.

Cancer cells respond to radiation-induced damage through complex biological processes. After detecting DNA damage, cells activate specific proteins like Rad24p, phosphorylated H2AX, and the NBS1/hMRE11/hRAD50 complex. These proteins are molecular sensors that trigger repair mechanisms or cell death pathways.

The effectiveness of radiation therapy stems from a fundamental biological difference between healthy and cancerous cells. Cancer cells typically multiply more rapidly than normal cells, making them more susceptible to radiation damage. Moreover, healthy cells possess stronger DNA repair capabilities, allowing them to recover more effectively from radiation exposure.

Radiation therapy does not eliminate cancer cells immediately. Instead, the process unfolds gradually over days or weeks as DNA damage accumulates. Even after treatment ends, cancer cells continue dying for weeks or months, steadily reducing tumour size.

The treatment's success depends on precise targeting. Modern radiation techniques aim to deliver optimal doses to tumour volumes whilst protecting surrounding healthy tissues. This accuracy comes from advanced imaging technologies and treatment planning systems that create detailed 3D models of tumours.

Understanding these cellular mechanisms helps medical teams optimise treatment plans. By monitoring specific proteins like γH2AX and 53BP1, doctors can predict how well patients might respond to radiation therapy. These molecular markers are valuable tools for personalising treatment approaches and improving patient outcomes.

Side Effects of Radiotherapy & How to Manage Them

Side effects from radiation therapy occur because the treatment affects both cancer cells and nearby healthy cells. Most patients experience some discomfort, yet the severity varies based on the treatment area and individual response.

Common Side Effects and Management Strategies

Fatigue: This exhaustion might appear suddenly or develop gradually. To combat fatigue, patients should:

• Plan activities for high-energy periods

• Take short breaks between tasks

• Maintain a balanced sleep schedule

• Eat 5-6 small frequent meals daily rather than three large ones

Skin changes: The treated area might become red, dry, or itchy, similar to a mild sunburn. Proper skin care involves:

• Using mild, fragrance-free soaps

• Patting the skin dry with soft towels

• Avoiding extreme temperatures

• Protecting the treated area from sun exposure

Hair loss: Hair loss occurs exclusively in the treatment area, unlike chemotherapy, which affects all body hair. After treatment, the hair might regrow differently, appearing thinner or with a changed texture.

Appetite changes: Medical teams often recommend:

• Eating slowly and in smaller portions

• Choosing foods high in protein and calories

• Staying well-hydrated

• Having easy-to-prepare meals readily available

Mouth and throat changes: These commonly occur with head and neck radiation. Patients might experience dry mouth, altered taste, or difficulty swallowing. Regular dental check-ups & proper oral hygiene help manage these effects.

Urinary and bladder changes: These changes typically start 3-5 weeks after beginning pelvic area radiation. Most issues are resolved within 2-8 weeks post-treatment. Management strategies include:

• Drinking adequate fluids

• Avoiding caffeine and alcohol

• Performing recommended exercises

• Seeking medical attention for severe symptoms

Most side effects gradually improve within 1-2 months after completing treatment. However, certain effects might persist longer or appear months later. Regular communication with the medical team ensures proper management and support throughout the treatment journey.

Life After Radiotherapy: Recovery & Long-Term Care

The completion of radiation therapy marks the beginning of a crucial recovery phase. Research shows that 5-10% of patients develop side effects after treatment, making proper follow-up care essential for optimal healing.

Medical teams create personalised follow-up programs tailored to each patient's needs. These typically include regular clinical check-ups and imaging appointments to monitor treatment effectiveness. The frequency of these visits gradually decreases as patients show steady improvement. Quality of life often improves significantly three months after treatment completion. 

Head and neck cancer patients might require additional support as they often experience more challenging recoveries. Their care plans typically focus on managing nutrition and swallowing difficulties that persist after treatment.

Physical recovery varies amongst patients. Most side effects peak within two weeks post-treatment, with complete healing taking several months. Throughout this period, patients should:

• Continue prescribed skincare routines

• Maintain proper nutrition

• Stay well-hydrated

• Balance rest with gentle activity

Mental wellness plays a key role in recovery. Many patients experience mixed feelings upon completing treatment, alongside concerns about cancer recurrence. Support services, including counselling and support groups, help patients navigate these emotional challenges effectively.

Patients should maintain open communication with their doctor & promptly report any unusual symptoms or concerns. This proactive approach ensures timely intervention and better long-term outcomes.

Conclusion

Radiation therapy stands as a powerful and proven weapon against cancer, offering hope to millions of patients worldwide. The treatment's ability to precisely target cancer cells while protecting healthy tissue makes it an essential part of modern cancer care.

The journey through radiation therapy presents challenges, from managing side effects to adapting to treatment schedules. However, medical teams provide comprehensive support throughout the process, helping patients navigate the physical & emotional aspects of their treatment.

Radiation therapy technology advances, offering more targeted and effective treatment options. Though the recovery journey varies for each patient, most people experience significant improvements in their quality of life within months after completing treatment. Regular follow-up appointments and proper self-care remain essential for achieving the best possible outcomes & maintaining long-term health.

FAQs

Does radiation therapy hurt? 

The treatment itself causes no pain or discomfort. Patients cannot see, smell, or feel the radiation whilst it is being administered. Some patients might experience mild discomfort from lying still on the treatment table, especially those with existing back problems.

How long does each treatment session take? 

Most radiation therapy sessions last between 15 to 20 minutes. Complex treatments like stereotactic radiosurgery require additional time. Patients should plan to spend approximately one hour at the treatment facility, accounting for preparation and positioning.

Can I work during treatment?

 Most patients continue working throughout their radiation therapy. The ability to work depends on:

• The type of radiation therapy received

• Whether chemotherapy occurs simultaneously

• Individual energy levels

• Job requirements and flexibility

How will I know if the treatment works? 

Treatment effectiveness might not be immediately apparent. Cancer cells continue dying for weeks or months after therapy ends. Symptom relief indicates success for palliative treatment, typically occurring within days or weeks.

Will I lose my hair? 

Hair loss occurs only in areas directly receiving radiation. Unlike chemotherapy, radiation therapy does not cause general hair loss throughout the body.