Radiation Therapy

1. Types: External Beam Radiation Therapy
   1. Three-Dimensional Conformal Radiation Therapy
   2. Four-Dimensional Radiation Therapy
   3. Intensity-Modulated Radiation Therapy
   4. Stereotactic Radiosurgery (Gamma Knife)
   5. Stereotactic Body Radiation Therapy (Cyberknife)
2. Types: Internal Radiation Therapy
   1. Brachytherapy
   2. Systemic Radiation Therapy (e.g. Iodine-131 for Thyroid Cancer)
3. Adverse Effects: General
   1. See Cancer Symptom
   2. See Radiation Dermatitis
4. Adverse Effects: Cardiopulmonary
   1. Cardiovascular Disease Risk
      1. Hodgkin's Lymphoma
      2. Breast Cancer
      3. Lung Cancer
      4. Adams (2003) Crit Rev Oncol Hematol 45(1):55-75
   2. Pneumonitis
      1. Associated cancers
         1. Breast Cancer
         2. Lung Cancer
         3. Mediastinal radiation
      2. Risk factors
         1. Increased radiation dose and Lung Volume radiated
         2. Comorbid lung disease or baseline PFT abnormalities
      3. Management
         1. Corticosteroids
         2. Pentoxifylline (Trental)
5. Adverse Effects: Gastrointestinal
   1. See Radiation Colitis
   2. Xerostomia
      1. Saliva substitute
      2. Pilocarpine
      3. Consider amifostine (Ethylol)
   3. Mucositis or Esophagitis
      1. Viscous Lidocaine
      2. Responds to typical GERD precautions and Proton Pump Inhibitors
   4. Diarrhea
      1. Modify diet: Low residue, decrease dairy products
      2. Consider Imodium
   5. Proctitis
      1. Consider Sulfasalazine (Azulfidine) orally for prevention
      2. Consider sucralfate enema for chronic symptoms
   6. Vomiting
      1. See Vomiting in Cancer
      2. Zofran and other 5-HT3 Receptor Antagonists
      3. Metoclopramide (Reglan)
      4. Prochlorperazine (Compazine)
      5. Corticosteroids
6. Adverse Effects: Genitourinary
   1. Cystitis
      1. Maximize hydration
      2. Uroprotective agents
   2. Erectile Dysfunction
      1. Consider Sildenafil (Viagra) and other phosphodiesterase type 5 inhibitors
   3. Vaginal dryness
      1. Vaginal lubrication
      2. Consider vaginal dilation if stenosis (especially over age 50 years)
   4. Infertility and Teratogenicity
      1. Consider egg and sperm preservation prior to radiation and Chemotherapy
7. References
   1. Berkey (2010) Am Fam Physician 82(4): 381-8