The course will focus on fundamental concepts of the interaction of various types of radiation with living cells, tissues and organs. Radiation types include photons, electrons, protons and neutrons. All of these particles are used for cancer therapy and will be discussed in this context. Methods for calculating dose in the patient and dose calibrations for therapy accelerators will be presented.
This is a multi-disciplinary course drawing from instructors in physics, biology and chemistry. The course will be an introduction to many of the subjects covered in graduate medical physics programs.
One of the goals of this course is to give students an introduction to this field in order to allow considering medical physics as a career path. The biology and chemistry portion of the course will cover cell and organ responses to radiation as well as the clinical importance of fractionation and oxygenation for treating tumors. The physics portion of the class will include methods of dose delivery and dose calculations to the tumor volumes. Imaging techniques such as PET, CT and MRI will also be discussed.
This course will be offered as a 3 credit hour 400 level special topics course each Tuesday and Thursday in DeKalb in the Spring semester of 2008. Four instructors, L. Lurio (Physics), L. Yasui (Biology), E. Gaillard (Chemistry), G. Coutrakon (Loma Linda), will rotate through the course one week per month for the semester. Grades will be based on weekly homework assignments, a midterm and final exam.
Electron accelerators (6 to 25 MeV) and beam delivery systems for electron and X-ray treatments. X-ray generators for diagnostic imaging (0 – 70 keV). Getting good contrast for bone and calcium due to Z dependence of photoelectric effect. . Interactions of therapeutic X-rays in tissue or water ( 0 -25 MeV). Exponential law of attenuation of intensity for diagnostic and therapy X-rays. Include photoelectric, Compton and pair production and absorption coefficients for each. Discuss electron interactions in matter from Bethe Block equation and energy loss from 25 MeV to 0.
Instructor: Larry Lurio
Definition of dose for charged particles ( electrons and nuclei) and X-ray beams. Discuss dose vs. depth for these beams. Definition of Linear Energy Transfer (LET). Dose measurement techniques using ion chambers in water equivalent phantom. Definition and calibration of monitor units from the treatment head of electron linacs. How to deliver a prescribed dose at a point in the patient.
Instructor: George Coutrakon
Radiation chemistry, pre-chemical track events, initial chemical events, G values, absorbed dose and LET.
Instructor: Beth Gaillard
Radiation effects on cells (review cell structure and function, cell proliferation, DNA replication, chromosomes, DNA damage and repair). Cell cycles and sensitivity to radiation. Cell survival curves, dependence on LET and cell type. RBE and OER concepts. This will continue in Week 7.
Instructor: Linda Yasui
The physics of CT , MRI and PET imaging.
Instructor: Larry Lurio
Introduction to treatment planning (photons and electrons) using CT imaging, Dose Volume Histograms and normal tissue tolerances.
Instructor: George Coutrakon
Chemical processes in PET and BNCT. Radio-pharmaceuticals for imaging. Chemistry of attachment of radioactive elements to the tumor cells after injection into the body. Why PET shows hypoxic tumor cells better than CT.
Instructor: Beth Gaillard
Continuation of Week 4. Radiation effects on cells (review cell structure and function, cell proliferation, DNA replication, chromosomes, DNA damage and repair). Cell cycles and sensitivity to radiation. Cell survival curves, dependence on LET and cell type. RBE and OER concepts. Mid term Exam March 6.
Instructor: Linda Yasui
X-ray dose calibrations for standard field sizes and standard SAD and SSD setups. Using TPR’s for SAD setups and depth dose tables for SSD setups to calculate tumor doses at different depths for different field sizes in terms of monitor units. Calculating dose per monitor unit for irregular ( non-square) fields. Use of Pb wedges and how they affect the dose distribution in the patient.
Instructor: George Coutrakon
Medical Physics.
Instructor: Larry Lurio
Week 12 – Mar. 31- April 4:
Kinetics and mechanisms of chemical events leading to biological damage including nucleic acids, proteins and lipids. The oxygen effect; scavenging, molecular radiation sensitization and protection. Instructor: Beth Gaillard
Effects of radiation on normal tissues. Cell repair and the effects of fractionation. Predicting time –dose fractionation schedules using linear- quadratic model. How do á and â parameters ( in cell survival curves) predict sensitivity and repair from radiation exposure? What do high and low á/â ratios say about radiation sensitivity? Discuss sigmoid response curves for dose vs. tumor control.
Instructor: Linda Yasui
Radiation protection—Definition of Sievert, REM and Quality factors. QF dependence on LET. Radiation exposure to general public and radiation workers. Annual, quarterly, and weekly dose limits to the general public, radiation workers, and fetuses. Dose exposure rates from diagnostic imaging, cosmic rays, and radon gas.
Instructor: Larry Lurio
Medical Physics.
Instructor: George Coutrakon
1st lecture Medical Physics review with Larry Lurio. 2nd lecture Radiation Biology review with Linda Yasui.