Radiation Therapy
Radiation therapy is a medical treatment that uses ionizing radiation to control or kill Cancer cells. It works by damaging the DNA within tumor cells, preventing them from dividing and growing. It is commonly used in combination with Surgery, Chemotherapy, or Immunotherapy.
Mechanisms of Action
- Direct Damage: Ionizing radiation directly breaks DNA strands.
- Indirect Damage: Radiation generates free radicals (e.g., hydroxyl radicals) from water molecules, which then damage DNA and other critical cellular components.
- Cell Cycle Specificity: Most effective during mitosis; cells are most sensitive in the M and G2 phases.
Types of Radiation Therapy
- External Beam Radiation Therapy (EBRT): High-energy radiation directed at the tumor from a machine outside the body.
- Includes IMRT, IGRT, Proton Beam Therapy.
- Internal Radiation Therapy (Brachytherapy): Radioactive material placed inside the body, near or within the tumor.
Clinical Applications
- Primary treatment for various cancers (e.g., prostate, cervical).
- Adjuvant therapy post-surgery to reduce recurrence.
- Palliative care to relieve symptoms such as pain or obstruction.
Recent Advances & Alternative Paradigms
- Proton Therapy: Offers superior dose distribution, sparing healthy tissue.
- Cell Reprogramming in Glioblastoma: Emerging research suggests an alternative to cytotoxic ablation for aggressive brain tumors like Glioblastoma. Instead of killing cells, strategies aim to reprogram malignant glial cells into functional neurons or benign astrocytes, effectively stopping proliferation and restoring normal function. See detailed analysis in Glioblastoma Reprogramming: Transforming Brain Cancer Cells into Functional Neurons.
Side Effects
- Acute: Fatigue, skin irritation, localized tissue inflammation.
- Chronic: Secondary malignancies, fibrosis, neurological deficits (depending on site).