Volumetric Modulated Arc Therapy for Delivery of Prostate Radiotherapy: Comparison With Intensity-Modulated Radiotherapy and Three-Dimensional Conformal Radiotherapy

Volumetric‐modulated arc therapy and intensity‐modulated radiation therapy treatment planning for prostate cancer with flattened beam and flattening filter free linear accelerators

“…Earlier investigations using similar equipment (TPS and linac manufacturer)18, 43 confirm this result for prostate carcinoma treatment. Other studies found reverse results,39, 44, 45, 46 but referred to RapidArc ® compared to sliding window IMRT, which needs more MU than our step‐and‐shoot technique. For the re‐irradiation of spinal column metastasis with the same equipment as the present study,16 there was no difference in the number of MU between IMRT and VMAT which can be taken as an example that different targets must be investigated individually.…”

A RapidArc planning strategy for prostate with simultaneous integrated boost

“…The combined analysis of PTV3 is in line with the majority of previously published data. ( 3 , 4 , 18 , 19 ) RA and IMRT are comparable in most facets with the conformity of RA better than IMRT but the maximum dose within the PTV is larger. Detailed analysis of PTV1 and PTV2 is not considered here, but all 20 plans (RA and IMRT) comply with the CHHiP protocol requirements.…”

“…The study compares RA and IMRT plans produced for 10 randomly‐selected high and intermediate risk (as defined by the CHHiP protocol; clinical stages: T1b/c, T2a/b/c or T3a, and with $\text{PSA}+((\text{Gleason}\hspace{0.17em}\text{score}-6)*>15)$, previously treated patients with prostate carcinoma at the Wellington Blood and Cancer Centre. The comparison with 3DCRT has been omitted due to the results of previously published studies ( 3 , 4 , 18 , 19 ) and the difficulty of comparing SIB and sequential boost plans.…”

“…The EUD is defined as the uniform dose that will produce the equivalent radiobiological effect as the organ specific nonuniform dose distribution. This value is mathematically defined as: ( 26 ) $EUD={\left(\frac{1}{N}\underset{i}{false\sum }{D}_i^a\right)}^{\frac{1}{a}}$ where N is the number of voxels within the investigated structure, $D_i$ represents the dose to each individual voxel within the structure, and a is an organ specific dose volume parameter ($\mathrm{a}=8.3$ for rectum and $\mathrm{a}=2$ for bladder ( 19 ) . Volumes of normal tissue receiving more that 2 and 5 Gy have been calculated.…”

“…These treatments are delivered over one or several continuous arcs whilst the multileaf collimator (MLC) positions, dose rate and gantry angular velocity may be dynamically varied. A variety of planning related studies ( 2 – 19 ) comparing three‐dimensional conformal radiotherapy (3DCRT), static gantry IMRT, rotational IMRT and sometimes TomoTherapy or proton therapy, ( 4 , 9 , 14 , 18 ) for various clinical sites (including prostate ( 3 , 4 , 18 , 19 ) have been previously published. In general, these studies have shown rotational IMRT to be at least comparable with static gantry IMRT (both IMRT techniques make improvements over standard 3DCRT), while many show an improved level of conformity, sparing of critical structures, and a slightly reduced level of homogeneity in the target volume.…”