Radiotherapy
- Goals of Radiotherapy
- Curative: To completely eradicate cancer (e.g., early-stage prostate or lung cancer).
- Adjuvant: After surgery to eliminate residual microscopic disease (e.g., gynaecological cancer).
- Neoadjuvant: Before surgery to shrink tumors (e.g., rectal cancer).
- Palliative: To relieve symptoms such as pain or bleeding in advanced disease.
- Types of Radiotherapy
- External Beam Radiotherapy (EBRT): The most common form, where radiation is delivered from outside the body using a machine (e.g., linear accelerator).
- 3D Conformal Radiation Therapy (3D-CRT)
- Intensity-Modulated Radiation Therapy (IMRT)
- Stereotactic Body Radiotherapy (SBRT)
- Image-Guided Radiotherapy (IGRT)
- Stereotactic Radiotherapy (SRS/SABR).
- Mechanism of Action
Radiation damages DNA in cancer cells directly or indirectly (via free radicals), leading to cell death. Cancer cells are generally more susceptible than normal cells due to impaired DNA repair mechanisms.
- Emerging Trends
- Adaptive radiotherapy: Adjusts treatment in real-time based on anatomical changes.
- Radiogenomics: Studies genetic predictors of response and toxicity.
- Combination with immunotherapy/chemotherapy: For synergistic effects