Program Information
A Novel Evaluation Model for the Plan Quality and Consistency for Cervical Cancer
C Tao1*, c li1 , T Liu1 , J Lu1 , (1) Shandong Cancer Hospital Affiliated to Shandong University, Jinan, Shandong,
Presentations
MO-L-GePD-T-1 (Monday, July 31, 2017) 1:15 PM - 1:45 PM Room: Therapy ePoster Lounge
Purpose: An evaluation model for cervical cancer, correlation analysis between equivalent uniform dose (EUD) – equivalent uniform distance (EUL), was established. And the application of this model aimed to assess the intensity-modulated radiotherapy (IMRT) plan consistency and quality.
Methods: 15 clinical approved plans, which optimized by EUD constraints, were reviewed in this study to establish evaluation model. Based on the computed tomography(CT), EULs (with different “a” values), were extracted for representing geometric relationship between bladder/rectum and PTV. And EUDs (with different “a” values: a = 0.5, 1 and 2) were also calculated on basis of corresponding clinical IMRT plans. Then linear regression was applied to test the correlation between EUDs and EULs with different “a” values, respectively. Furthermore, 29 clinical patients with cervical cancer, created by 3 dosimetrists in our institute, were enrolled to evaluate plan quality and consistency by EUD-EUL model.
Results: According to the linear regression analysis results of 15 patients, there was significant correlation between EUD and EUL. Especially, as all these 15 treatment plans were optimized by a = 1, the highest R2 was occurred in EUL-EUD with a = 1 both for bladder and rectum. As the evaluation of 29 IMRT plans created by three dosimetrists showed, dosimetrist B’s plans spared more bladder with better consistency (R2 = 0.8387) compared with the others (dosimetrist A: R2 = 0.6669, dosimetrist C: R2 = 0.6072). And for rectum, there was no significant difference of plan consistency observed (dosimetrist A: R2 = 0.5451, dosimetrist B: R2 = 0.5437, dosimetrist C: R2 = 0.5702).
Conclusion: Significant correlation between EUD and EUL can be used as evaluation model to access plan quality and consistency in cervical cancer.
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