Directions for planning on the Lung Phantom CT Set:
a. Create a simple AP/PA parallel-opposed isocentric homogeneous plan to treat the PTV. The PTV equals the GTV. The center of the PTV and isocenter are located on Slice 67, Z = 103.2. Position the isocenter at the center of the PTV on this slice and use symmetric unblocked 6 cm x 6 cm fields (Note: There will be a 1.5 cm margin laterally and 0.5 cm margins superiorly and inferiorly). Prescribe 6 Gy to isocenter using 6 MV photons under homogenous conditions with the AP and PA beams each delivering 3 Gy to isocenter (i.e. equal dose weighting). Calculate the monitor units using the grid spacing you would customarily use to treat a lung patient. Please contour the PTV as well as the skin.
b. Using the monitor units from the homogeneous plan, re-calculate the plan using heterogeneity corrections.
2. Send both plans electronically to the ATC and hard copy to the IROC Houston (Attn: RTOG lung benchmark, 8060 EL RIO St. Houston, TX 77054). Please include a cover page with institution name, contact information and the number of the RTOG protocol for which the institution wishes to be credentialed.
