 Multidisciplinary Effort › Surgery › Radiation › Systemic Rx (chemo, “drugs”)

 Assess patient  Review need for diagnostic studies  Consult with other physicians caring for the patient

 Goal › Deliver precisely measured dose of irradiation to a defined tumor volume with minimal damage to surrounding healthy tissue

 Curative › Probability of long-term survival  Palliative › Little or no hope for long-term survival › Alleviate symptoms › Improve quality of life

 Evaluate diagnostic studies  Knowledge of pathology  Define goal  Select appropriate treatment modalities  Determine optimal dose  Determine volumes to be treated  Monitor patient during and after treatment  Work closely with physics staff  Work closely with support staff

 Different doses required based on tumor type  Gross tumor volume (GTV) › All known gross disease  Clinical target volume (CTV) › GTV + regions possibly harboring microscopic disease  Planning target volume (PTV) › Margin added around CTV

 Simulation › “set-up” patient position and obtain CT images for planning and calculating  Treatment aids › Masks  Vac locks  Bolus  Shape Radiation Beams › MLC

 CT simulation  Display tumor volumes and normal tissue volumes 3-D  Dose volume histograms (DVHs)  Software advances

 Optimizes delivery of XRT to irregularly shaped volumes  Inverse RX planning  Dynamic delivery of XRT

 Begin with ideal dose distribution  Process with multiple iterations  Produces “Best Approximation” plan

 Dose response curves  Some general rules › Subclinical Disease = Gy › Gross Disease = Gy  Standard fractionation › 1.8 – 2.0 Gy per Fraction

 Potential for Sequela › Dose › Volume  TD 5/5  Acute side effects  Subacute side effects  Chronic side effects

 Optimal dose › Maximal probability tumor control with minimal frequency of complications

 Pre-op XRT › Eradicate subclinical disease › Decrease primary tumor volume › May affect healing from surgery  Post-op XRT › Eliminate residual tumor cells › Surgery may impair XRT effect

 Sequential treatment  Concurrent treatment  Goal › Increase tumor control  Disadvantage › May increase side-effects

 Surgery, XRT, Systemic Rx  Clinical Trials to define optimal treatment plan