Radiation therapy remains a fundamental approach in cancer treatment, providing benefits to approximately 60% of all patients. Continuous advancements in treatment methodologies and refinements in radiation dosing have significantly enhanced the precision and efficacy of radiation therapy for cancer, making it an essential component of oncologists’ therapeutic strategies.
What is radiation therapy for cancer?
Radiation therapy for cancer is a sophisticated medical approach that utilizes high doses of radiation, typically X-rays, to destroy cancer cells and reduce tumor size. In contrast, lower doses of X-rays are employed in medical imaging, such as dental scans or bone fracture assessments, to visualize internal structures.
At elevated doses, radiation therapy for cancer disrupts the DNA of malignant cells, preventing their replication and ultimately causing cell death. The impact of the treatment is not instantaneous, often taking days or weeks to fully take effect. Even after the therapy concludes, cancer cells continue to perish for weeks or even months, contributing to the overall success of the treatment.
Uses of radiation therapy for cancer
Radiation therapy for cancer is a widely used treatment method, helping to manage nearly all cancer types. More than half of cancer patients receive radiation therapy as part of their care plans, and it can also be utilized to address certain non-cancerous conditions, including benign tumors.
For some individuals, radiation therapy for cancer is the sole treatment option. However, it is often combined with other approaches such as surgery, chemotherapy, or immunotherapy. Radiation therapy is administered before, during, or after these treatments to boost effectiveness and improve the chances of success. The timing of radiation therapy depends on the type of cancer being treated and whether the goal is to eradicate the disease or alleviate symptoms.
Radiation therapy for cancer may be applied in various scenarios, including:
- As a primary treatment: Known as monotherapy.
- Before surgery: Used to shrink the tumor size, referred to as neoadjuvant therapy.
- After surgery: Helps eliminate any remaining cancer cells, known as adjuvant therapy.
- In combination with other treatments: Such as chemotherapy, for improved cancer cell destruction.
- For symptom relief: Provides palliative care for advanced cancer cases.
Benefits of Radiation Therapy for Cancer
The advantages of radiation therapy for cancer include:
- Highly effective in eliminating most cancer cells within the tumor: Radiation therapy for cancer may serve as the sole treatment for small tumors and early-stage cancers.
- Targeting isolated cancer cells that cannot be removed through surgery.
- Reducing tumor size to enhance the effectiveness of surgical removal.
- Ensuring a high level of patient safety throughout the treatment process.
- Providing a painless treatment experience.
- Boosting treatment outcomes: When radiation therapy for cancer is combined with chemotherapy, it enhances the success rate and improves the overall effectiveness of chemotherapy compared to using either method alone.
- Alleviating cancer-related symptoms to improve patient comfort.
- Potentially stimulating the body’s immune system to recognize and respond to the tumor.
Types of radiation therapy for cancer
Radiation therapy for cancer is classified into two primary types: external and internal radiation therapy. The selection of the appropriate radiation therapy approach is determined by multiple factors, including:
- Age of the patient
- Type of cancer being treated
- Tumor location within the body
- Proximity of the tumor to healthy, radiation-sensitive tissues
- Patient’s overall health and medical history
- Requirement for additional cancer treatments
- Presence of other underlying medical conditions
External radiation therapy
Radiation therapy for cancer utilizes a sophisticated device called a linear accelerator, which precisely targets high-energy rays at the tumor while safeguarding the surrounding healthy tissues. This device does not come into physical contact with the body but instead moves around it, delivering radiation from multiple angles to ensure effective treatment.
Internal radiation therapy
Radiation therapy for cancer includes brachytherapy, a treatment in which the radiation source is positioned inside the body. The radiation source may be either solid or liquid.
- Solid source internal radiation therapy: In this type of treatment, seeds, strips, or capsules containing a radiation source are placed in the body near the tumor. Solid source internal radiation therapy is considered a localized treatment, similar to external radiation therapy.
- Internal radiation therapy for cancer utilizing a liquid source is referred to as systemic therapy, meaning the radiation circulates through the bloodstream to reach tissues across the body and attack cancer cells. Systemic radiation therapy is administered orally, intravenously via an IV line, or through injection. During systemic radiation therapy, bodily fluids such as urine, sweat, and saliva may contain radiation for a period following treatment.
The process of radiation therapy for cancer
Before radiation therapy for cancer
For cancer therapies that involve internal treatment, patients may need to undergo a physical examination and imaging procedures. Your doctor will provide guidance on how to prepare for the procedure, tailored to the specific method of radiation delivery.
Radiation therapy for cancer includes a planning session known as a treatment simulation, which consists of the following steps:
- Positioning: The patient is placed on a treatment table in the same position they will assume during radiation therapy sessions for cancer. The radiation therapy team may use a mold or mask to stabilize the patient’s body and ensure proper alignment. Temporary or permanent markings (small dots) may be applied to indicate areas requiring radiation.
- Getting the scan: A CT or MRI scan is performed to visualize the tumor’s location. This information allows the doctor to tailor X-rays precisely to target the tumor while safeguarding surrounding healthy tissue. The simulation process helps define the appropriate radiation dose and delivery method.
What happens during radiation therapy for cancer?
Radiation therapy for cancer using brachytherapy is typically conducted in a specialized outpatient treatment room or within a hospital setting. The doctor may place the radiation implant using a small, flexible tube called a catheter. In systemic internal radiation therapy for cancer, the patient receives a radioactive liquid through a vein. To ensure comfort, anesthesia is administered so that the patient experiences no pain or discomfort during radiation therapy for cancer.
For external radiation therapy for cancer, the patient is positioned on a treatment table in the same way as during the simulation process. The radiation machine moves around the patient but never makes physical contact. The radiation therapist controls the machine from a separate room and can communicate at any time via an intercom system. As the machine shifts positions, it delivers precise doses of radiation to the tumor. The patient experiences no discomfort throughout the treatment process.
What happens after treatment?
With radiation therapy for cancer involving internal treatment, patients can typically return home the same day after a brief recovery period. However, in some cases, a hospital stay may be necessary while the body eliminates small amounts of radiation. Following systemic (IV) radiation therapy for cancer, traces of radiation may be excreted through bodily fluids such as sweat, urine, and blood.
For patients receiving intravenous or permanent internal radiation therapy for cancer, there is a minimal risk of exposing others to radiation. It is essential to follow the guidance provided by the radiation therapy team regarding safe levels of contact after treatment.
Before and after external radiation therapy for cancer, patients can generally continue their normal daily activities without concern, as there is no risk of radiation exposure to others.
Side effects of radiation therapy for cancer
Radiation therapy for cancer may lead to specific side effects, including:
- Skin irritation: The skin may become sensitive, painful, and change in color, turning red or appearing lighter or darker than usual.
- Fatigue: Patients may experience a persistent feeling of tiredness.
- Hair loss: Occurs in the area receiving treatment.
- Nausea: Some patients may experience nausea or feel queasy.
- Loss of appetite: Reduced desire to eat may be observed.
- Mouth pain: Discomfort or soreness in the mouth can occur.
- Diarrhea: Digestive disturbances may arise.
Many of these side effects can be managed or prevented, and most will gradually fade after the completion of radiation therapy for cancer.
When does the patient return to daily activities?
Some individuals undergoing radiation therapy for cancer can maintain their daily activities without difficulty, while others may experience severe side effects that require them to take time off. Many patients do not notice the side effects until several weeks into treatment, as more cancer cells are destroyed.
Discuss both best- and worst-case scenarios with your doctor while planning your treatment schedule to ensure proper preparation and management.
When should I call a doctor?
Inform your doctor of any side effects you experience, particularly those that affect your quality of life. Based on your response to treatment, your doctor may need to modify your dosage, adjust your treatment schedule, or explore alternative treatment options.
Radiation therapy for cancer is a powerful tool in cancer treatment and can be combined with other therapies to improve outcomes. However, patients must be well-informed about potential side effects and maintain ongoing communication with their doctor to make necessary adjustments to their treatment plan. A solid understanding of radiation therapy for cancer can help enhance patients’ quality of life and improve the likelihood of successful treatment.
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