Click here to


Are you sure ?

Yes, do it No, cancel

The Effect of Segment Number On Plan Quality of Intensity-Modulated Radiation Therapy for Upper Thoracic Esophageal Carcinoma

WZ Zhang, JY Lu, BT Huang*, Cancer Hospital of Shantou University Medical college, Shantou, Guangdong


(Sunday, 7/29/2018) 3:00 PM - 6:00 PM

Room: Exhibit Hall

Purpose: To investigate the effect of segment number (SN) on plan quality of intensity-modulated radiation therapy (IMRT) for upper thoracic esophageal carcinoma (UTEC) patients.

Methods: CT datasets of 15 UTEC patients were enrolled. Three groups of IMRT plans in which the SN were set to 64 (G1 group), 115 (G2 group) and 166 (G3 group) were designed. The dose was prescribed at 64 Gy in 32 fractions for the target volume. Three groups of plans were compared in terms of conformity index (CI), homogeneity index (HI), organ-at-risk (OARs) sparing, monitor units (MUs) and treatment time (TT).

Results: We found that the G1 Group plans obtained significantly higher mean dose (Dmean), D2 and HI but lower CI for the target than the other two groups (p<0.05). The G1 group plans showed slight reduction of V30 for the lungs than the G3 group plans, but V10 and V20 for the G1 group were slightly increased than the G2 group plans (p<0.05). The maximum dose (Dmax) to the spinal cord and heart among the three groups were comparable (p>0.05). The G1 Group plans resulted in up to 3.4% MUs and 7.6% TT reduction.

Conclusion: The dosimetric study demonstrates that reduction in SN to 64 was feasible for achieving comparable OARs sparing while remarkably reducing the MUs and shortening the TT.

Funding Support, Disclosures, and Conflict of Interest: This work was sponsored by National Natural Science Foundation of China (No. 81602667).


Not Applicable / None Entered.


Not Applicable / None Entered.

Contact Email