Radiotherapy — Procedure Guide, Recovery & Risks | MyMedicPlus

Radiotherapy delivers precisely targeted ionizing radiation to tumors, causing DNA double-strand breaks that inhibit cancer cell division and trigger apoptosis. It is given as external beam radiation therapy (EBRT) via a linear accelerator or internally as brachytherapy.

Used alone or combined with surgery and chemotherapy for breast, prostate, lung, cervical, head and neck, and brain cancers. Also used for benign conditions including keloids, arteriovenous malformations, and trigeminal neuralgia (stereotactic radiosurgery).

A planning CT scan defines target volumes and organs at risk. A dosimetrist creates a plan delivering the prescribed dose (60-70 Gy for radical intent) in daily fractions over 5-7 weeks via a LINAC. IMRT and VMAT techniques conform dose to the tumor while sparing healthy tissue.

Acute side effects peak 2-3 weeks into treatment. Fatigue, skin erythema, and site-specific reactions (mucositis, diarrhea) are common. Symptoms resolve 2-6 weeks after treatment completion. Annual imaging follow-up assesses response and detects recurrence.

Acute effects include fatigue, skin changes, mucositis, and diarrhea. Late effects depend on the treated site and include fibrosis, xerostomia, bowel dysfunction, lymphedema, and a secondary malignancy risk below 1% at 10 years.

Curative-intent radiotherapy achieves 5-year local control of 70-90% in many cancers. Palliative radiotherapy relieves bone pain in 80% of patients within 4 weeks. Prostate cancer treated with EBRT alone achieves 10-year biochemical control exceeding 80% for low-risk disease.