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Improving target coverage and organ-at-risk sparing in intensity-modulated radiotherapy for cervical oesophageal cancer using a simple optimisation method.

Lu JY, Cheung ML, Huang BT, Wu LL, Xie WJ, Chen ZJ, Li DR, Xie LX - PLoS ONE (2015)

Bottom Line: The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans.The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%.All verification tests were passed and no significant differences were found.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, China.

ABSTRACT

Purpose: To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer.

Methods: For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans.

Results: The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found.

Conclusion: The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs.

No MeSH data available.


Related in: MedlinePlus

Dose distributions of the BDF-based, DCS-based and Original plans for one case.
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pone.0121679.g002: Dose distributions of the BDF-based, DCS-based and Original plans for one case.

Mentions: Table 1 summarises the target dose-volume parameters for the 3 plans. The BDF-based plans provided the best target dose distributions with respect to most parameters, whereas the DCS-based plans were inferior to the BDF-based plans but superior to the Original plans. Compared with the Original plans, the BDF-based plans demonstrated significantly improved D2%, D98%, HI and CI values for the PTV64 and an improved CI for the PTV54 by approximately 4.4%, 0.3%, 50.3%, 11.4% and 3.7%, respectively. Compared with the DCS-based plans, the BDF-based plans demonstrated better D2%, HI and CI values for the PTV64 and a better CI for the PTV54 by approximately 1.9%, 25.7%, 8.3%, 3.3%, respectively, as well as a comparable D98% value for the PTV64. The DCS-based plans showed improvements over the Original plans in all respects except for the comparable CI for the PTV54. In the isodose distributions, significantly fewer hot spots of ≥ 105% (67.2 Gy) of the prescribed dose for the PTV64 were observed for the BDF-based plans, and the isodose lines appeared more conformal to the PTVs (Fig. 2). Besides, the dose-volume histogram (DVH) curves of the PTVs seemed far steeper for the BDF-based plans (Fig. 3).


Improving target coverage and organ-at-risk sparing in intensity-modulated radiotherapy for cervical oesophageal cancer using a simple optimisation method.

Lu JY, Cheung ML, Huang BT, Wu LL, Xie WJ, Chen ZJ, Li DR, Xie LX - PLoS ONE (2015)

Dose distributions of the BDF-based, DCS-based and Original plans for one case.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358965&req=5

pone.0121679.g002: Dose distributions of the BDF-based, DCS-based and Original plans for one case.
Mentions: Table 1 summarises the target dose-volume parameters for the 3 plans. The BDF-based plans provided the best target dose distributions with respect to most parameters, whereas the DCS-based plans were inferior to the BDF-based plans but superior to the Original plans. Compared with the Original plans, the BDF-based plans demonstrated significantly improved D2%, D98%, HI and CI values for the PTV64 and an improved CI for the PTV54 by approximately 4.4%, 0.3%, 50.3%, 11.4% and 3.7%, respectively. Compared with the DCS-based plans, the BDF-based plans demonstrated better D2%, HI and CI values for the PTV64 and a better CI for the PTV54 by approximately 1.9%, 25.7%, 8.3%, 3.3%, respectively, as well as a comparable D98% value for the PTV64. The DCS-based plans showed improvements over the Original plans in all respects except for the comparable CI for the PTV54. In the isodose distributions, significantly fewer hot spots of ≥ 105% (67.2 Gy) of the prescribed dose for the PTV64 were observed for the BDF-based plans, and the isodose lines appeared more conformal to the PTVs (Fig. 2). Besides, the dose-volume histogram (DVH) curves of the PTVs seemed far steeper for the BDF-based plans (Fig. 3).

Bottom Line: The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans.The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%.All verification tests were passed and no significant differences were found.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, China.

ABSTRACT

Purpose: To assess the performance of a simple optimisation method for improving target coverage and organ-at-risk (OAR) sparing in intensity-modulated radiotherapy (IMRT) for cervical oesophageal cancer.

Methods: For 20 selected patients, clinically acceptable original IMRT plans (Original plans) were created, and two optimisation methods were adopted to improve the plans: 1) a base dose function (BDF)-based method, in which the treatment plans were re-optimised based on the original plans, and 2) a dose-controlling structure (DCS)-based method, in which the original plans were re-optimised by assigning additional constraints for hot and cold spots. The Original, BDF-based and DCS-based plans were compared with regard to target dose homogeneity, conformity, OAR sparing, planning time and monitor units (MUs). Dosimetric verifications were performed and delivery times were recorded for the BDF-based and DCS-based plans.

Results: The BDF-based plans provided significantly superior dose homogeneity and conformity compared with both the DCS-based and Original plans. The BDF-based method further reduced the doses delivered to the OARs by approximately 1-3%. The re-optimisation time was reduced by approximately 28%, but the MUs and delivery time were slightly increased. All verification tests were passed and no significant differences were found.

Conclusion: The BDF-based method for the optimisation of IMRT for cervical oesophageal cancer can achieve significantly better dose distributions with better planning efficiency at the expense of slightly more MUs.

No MeSH data available.


Related in: MedlinePlus