Chapter 5 of 6
Plan Evaluation
In most cases, treatment planners will generate multiple trial plans for comparison. During the review process, physicians may adjust field borders or multileaf collimators (MLCs) to optimize the plan.
Evaluate Dose Distribution (Eclipse)
Breast Treatment Plan Evaluation
As we scroll through the CT images and assess the dose distribution, we note the presence of hotspots and cold spots, the maximum dose and its location, and the position of the prescription isodose line relative to the target.
Clinical Goals and Metrics
The Dose Volume Histogram (DVH) offers a concise overview of clinical goals and metrics.
Sample goals for the Planning Target Volume (PTV) may include:
Coverage: The 95-100% isodose line should closely conform to the chest wall.
Plan maximum dose: Less than 110% for standard fractionation and less than 107% for hypofractionation.
Ipsilateral lung V20: Less than 20% (this depends on the lung bite of the fields; if this value is too high, review the field setup).
Heart mean dose: Less than 2 Gy (Deep Inspiration Breath Hold [DIBH] can help reduce doses to the heart and lungs).
Next: Summary