An integrated strategy of biological and physical constraints in biological optimization for cervical carcinoma

Abstract

BackgroundFor cervical carcinoma cases, this study aimed to evaluate the quality of intensity-modulated radiation therapy (IMRT) plans optimized by biological constraints. Furthermore, a new integrated strategy in biological planning module was proposed and verified.MethodsTwenty patients of advanced stage cervical carcinoma were enrolled in this study. For each patient, dose volume optimization (DVO), biological model optimization (BMO) and integrated strategy optimization (ISO) plans were created using same treatment parameters. Different biological models were also used for organ at risk (OAR) in BMO plans, which include the LKB and Poisson models. Next, BMO plans were compared with their corresponding DVO plans, in order to evaluate BMO plan quality. ISO plans were also compared with DVO and BMO plans, in order to verify the performance of the integrated strategy.ResultsBMO plans produced slightly inhomogeneity and less coverage of planning target volume (PTV) (V95=96.79, HI = 0.10: p < 0.01). However, the tumor control probability (TCP) value, both from DVO and BMO plans, were comparable. For the OARs, BMO plans produced lower normal tissue complication probability (NTCP) of rectum (NTCP = 0.11) and bladder (NTCP = 0.14) than in the corresponding DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder; p < 0.01 for rectum and p = 0.03 for bladder). V95, D98, CI and HI values that were produced by ISO plans (V95 = 98.31, D98 = 54.18Gy, CI = 0.76, HI = 0.09) were greatly better than BMO plans (V95 = 96.79, D98 = 53.42Gy, CI = 0.71, HI = 0.10) with significant differences. Furthermore, ISO plans produced lower NTCP values of rectum (NTCP = 0.14) and bladder (NTCP = 0.16) than DVO plans (NTCP = 0.19 and 0.18 for rectum and bladder, respectively) with significant differences.ConclusionsBMO plans produced lower NTCP values of OARs compared to DVO plans for cervical carcinoma cases, and resulted in slightly less target coverage and homogeneity. The integrated strategy, proposed in this study, could improve the coverage, conformity and homogeneity of PTV greater than the BMO plans, as well as reduce the NTCP values of OARs greater than the DVO plans.

On the gEUD biological optimization objective for organs at risk in Photon Optimizer of Eclipse treatment planning system

“…On Eclipse, but using the specific biological optimization module based in TCP and NTCP (both Lyman and serial models), Kan reported that for nasopharyngeal cancer IMRT planning, the biological optimization yielded comparable TCP, relative to physical optimization, while presenting more hot spots in the target, better NTCP for parotids, no significant difference for serial organs. Similar conclusions were outlined by Feng for cervical cancer planning using IMRT and the same biological optimization module in Eclipse.…”

Stereotactic body radiation therapy in primary hepatocellular carcinoma: current status and future directions

“…Recurrence of HCC was observed in 3 patients. In the subset of 73 patients with primary liver tumors, toxicities included grade 2 ascites (1 patient), grade 3 ascites (1 patient), and grade 3 duodenal bleeding (1 patient) 7 months after completing treatment (22).…”

Dosimetric Comparison, Treatment Efficiency Estimation, and Biological Evaluation of Popular Stereotactic Radiosurgery Options in Treating Single Small Brain Metastasis

“…In addition, adding biological factors into the optimization stage of treatment plans can allow doctors to understand the prognostic effect of patients intuitively. There have been some studies (41)(42)(43)(44)(45) involving the concept of biological optimization. However, research in this area is still in the initial stage, and it will take a long way to replace physical optimization with biological optimization.…”