A comparison of a moderately hypofractionated IMRT planning technique used in a randomised UK external beam radiotherapy trial with an in-house technique for localised prostate cancer.
Rep Pract Oncol Radiother
; 25(3): 360-366, 2020.
Article
em En
| MEDLINE
| ID: mdl-32256220
ABSTRACT
AIM:
To compare the radiotherapy technique used in a randomised trial with VMAT and an in-house technique for prostate cancer.BACKGROUND:
Techniques are evolving with volumetric modulated arc therapy (VMAT) commonly used. The CHHiP trial used a 3 PTV forward planned IMRT technique (FP_CH). Our centre has adopted a simpler two PTV technique with locally calculated margins. MATERIALS ANDMETHODS:
25 patients treated with FP_CH to 60 Gy in 20 fractions were re-planned with VMAT (VMAT_CH) and a two PTV protocol (VMAT_60/52 and VMAT_60/48). Target coverage, conformity index (CI), homogeneity index (HI), monitor units (MU) and dose to the rectum, bladder, hips and penile bulb were compared.RESULTS:
PTV coverage was high for all techniques. VMAT_CH plans had better CI than FP_CH (p ≤ 0.05). VMAT_60/52/48 plans had better CI than VMAT_CH. FP_CH had better HI and fewer MU than VMAT (p ≤ 0.05). More favourable rectum doses were found for VMAT _CH than FP_CH (V48.6, V52.8, V57, p ≤ 0.05) with less difference for bladder (p ≥ 0.05). Comparing VMAT_CH to VMAT_60/52/48 showed little differences for the bladder and rectum but VMAT_CH had larger penile bulb doses (V40.8, V48.6, mean, D2, p ≤ 0.05). Femoral head doses (V40.8) were similarly low for all techniques (p = ≥ 0.05).CONCLUSION:
VMAT produced more conformal plans with smaller rectum doses compared to FP_CH albeit worse HI and more MU. VMAT_60/52 and VMAT_60/48 plans had similar rectal and bladder doses to VMAT_CH but better CI and penile bulb doses which may reduce toxicity.
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Base de dados:
MEDLINE
Tipo de estudo:
Clinical_trials
/
Guideline
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article