Skip to main content

Table 2 Mean V45Gy Coverage of Target and Normal Structures among Different Plans

From: Assessment of nodal target definition and dosimetry using three different techniques: implications for re-defining the optimal pelvic field in endometrial cancer

  2D RTOG 0418-3DCRT NEW-3DCRT NEW-IMRT
NEW-PTV 50% 69% 98% 97%
  (p < 0.0009) (p < 0.0009) (p = NS)  
Small Bowel 24% 20% 32% 14%
  (p = 0.019) (p < 0.0009) (p < 0.0009)  
Rectum 26% 35% 52% 26%
  (p = NS) (p = 0.002) (p = 0.016)  
Bladder 83% 51% 73% 30%
  (p = NS) (p = NS) (p < 0.0009)  
  1. Definitions: 2D -four fields with borders extending from the L5-S1 interspace to the bottom of the obturator foramen, and the front of the pubic symphysis to the S2-S3 interspace with standard blocking. RTOG 0418-3DCRT - the nodes at risk and upper 3 cm of vagina contoured as per RTOG 0418 guidelines, with 7 mm added to the vessels and 10 mm to the vagina to create the CTV. Four fields were used with the block edges 5 mm beyond the CTV to account for the penumbra. Superior extent of the CTV was 7 mm below L5-S1. Inferior extent of CTV was limited so that the CTV ended at the top of the femoral heads. NEW-3DCRT - Four field 3D plan with the CTV based on our newly defined nodal volumes. NEW-IMRT - Seven field IMRT plan with the CTV based our newly defined nodal volumes.
  2. All of the V45Gy reported were mean values from the 10 patients analyzed. P values reported were from comparison against the NEW-IMRT plan.