Radiotherapy of malignant gliomas: comparison of volumetric single arc technique (RapidArc), dynamic intensity-modulated technique and 3D conformal technique

Abstract

Purpose: The analysis was designed to identify the optimal radiation technique for patients with malignant glioma.

Methods: A volumetric-modulated radiation treatment technique (RapidArc), an IMRT technique and a 3D conformal technique were calculated on computed tomograms of 14 consecutive patients with malignant glioma. The treatment plans were compared with each other using dose-volume histograms.

Results: The 3D conformal technique showed a good PTV coverage, if PTV was distant to organs at risk (OAR). If PTV was nearby OAR, the 3D technique revealed a poor PTV coverage in contrast to both intensity-modulated techniques. The conventional IMRT technique showed a slightly better PTV coverage than RapidArc. The advantages of RapidArc were a shorter treatment time, less monitor units and a small V(107%).

Conclusions: If PTV is distant to OAR, the use of 3D conformal technique is sufficient. Otherwise an intensity-modulated technique should be used. RapidArc was faster than conventional IMRT and should be preferred if PTV coverage is adequate.