| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1882920 | Radiation Physics and Chemistry | 2016 | 12 Pages |
•We compare IMRT plans using different leaf-width MLC for prostate cancer patients.•Two kinds of MLC leaf widths are 10 mm and 4 mm.•The narrower leaf-width MLC could only improve the target's dose conformity.
PurposeTo evaluate the impacts of different leaf-width of multileaf collimator (MLC) on the fixed-beam intensity-modulated radiotherapy (IMRT) planning for prostate cancer patients with intermediate risk factors.Materials and methodsSixteen prostate cancer patients with intermediate risk factors were retrospectively recruited. For each patient, the two IMRT plans using MLC leaf width of 10 mm and 4 mm (sIMRT and mIMRT) were compared. All of plans were generated with the same setup and optimized parameters and methods. Homogeneity index (HI), conformity index (CI), dose distribution for planning tumor volume (PTV) and organs at risk (OARs) were analyzed to evaluate the quality of the plans. Delivery time (DT), monitor units (MUs) and control points (CPs) were used to assess the efficiency of treatment.ResultsFor the target dose distribution, the mean HI values of the two plans for 16 patients are similar (sIMRT vs. mIMRT: 1.120±0.13 vs. 1.103±0.099, p>0.05). The mean CI of the mIMRT plans was significantly better than that of the sIMRT plans (sIMRT vs. mIMRT: 0.648±0.11 vs. 0.688±0.10, p<0.05). For the OARs sparing, the mIMRT plans failed to reduce the dose to OARs compared to the sIMRT plans, except for the rectum, in which the mIMRT plans gained significantly lower V40, V50 and V70 (percentage of countered volume receiving ≥40, 50 and 70 Gy). For the efficiency of treatment, the mean DTs and CPs of the mIMRT plans were obviously higher than that of the sIMRT plans.ConclusionsFor the IMRT of the prostate cancer patients with intermediate risk factors, the plans with the narrower leaf-width MLC failed to promote the quality of plans, OARs dose sparing and the efficiency of treatment, and could only improve the conformity of the plans.
