Intro to Radiation Oncology

Question 1

pros of radiation for cancer therapy

Answer 1

*local therapy
*non-invasive
*effective for both gross and microscopic disease
*minimal mortality risk acutely

Question 2

cons of radiation for cancer therapy

Answer 2

*adjacent/intervening tissues at risk
*slightly less effective than surgery for gross disease (for some cancers)

Question 3

limitations of radiation for cancer therapy

Answer 3

*radiation dosimetry (get the dose where it needs to go)
*normal tissue (organ at risk, OAR) tolerances and dose-limiting toxicities

Question 4

ionizing radiation therapy

Answer 4

*energy in the form of electromagnetic waves/particles
*high energy to ionize (remove electrons from) atoms
*controllable energy that can be directed at tumors or regions at risk
*works by DNA damage; radiation sensitivity indirectly related to DNA repair capacity
*goal net effect: kill cancer without irreparably damaging normal tissues

Question 5

types of radiation therapy

Answer 5

1. external beam radiation therapy
   -photons: produced in a linear accelarator
   -electrons: high-energy electron beam for superficial treatment
2. particle therapy
   -protons, neutrons, heavy ions (C, Pb), generated in specialized particle accelerators
3. brachytherapy: inherently radioactive material placed immediately adjacent to or inside the tumor (can be temporary or permanent)