Brain tumor radiotherapyRadiotherapy of malignant gliomas: Comparison of volumetric single arc technique (RapidArc), dynamic intensity-modulated technique and 3D conformal technique
Section snippets
Methods and materials
Fourteen consecutive patients with malignant glioma WHO stages III–IV were included in our analysis. All patients underwent radiochemotherapy with temozolomide [12] and received a total dose of 60.0 Gy to the tumor or preoperative tumor region. All patients were positioned with a mask system (Sinmed, Reeuwijk, Denmark). Continuous 5 mm CT scans of the head were obtained with a single-slice spiral CT scanner in supine position (Somatom Balance, Siemens Medical Systems, Forchheim, Germany).
The
Results
The CI95% was slightly higher for RapidArc (0.89) relative to IMRT (0.86) but much higher than 3D conformal technique (0.63) (Table 1). Nevertheless PTV coverage was higher for IMRT (94.7%) than for RapidArc (90.5%) and 3D conformal technique (81.2%). If considering patients with PTV located distant to OAR (in this case optical nerves, chiasm and brainstem) PTV coverage for 3D conformal technique was 94.3% (50% of the analyzed patients). This decreased PTV coverage to 68.2% for patients with
Discussion
This study analyzed RapidArc, sliding window IMRT and 3D conformal technique for patients with malignant glioma.
If PTV was distant to OAR (in this case optical nerves, chiasm and brainstem), the PTV coverage was acceptable by use of 3D conformal technique (94.3% of the volume is covered by 95% of the prescribed dose). This was comparable to PTV coverage achieved by the intensity-modulated treatment technique (Table 1). The advantages of 3D conformal technique were small low-dose areas, less
Conclusions
If PTV is distant to optical nerves, chiasm and brainstem 3D conformal technique can be applied in order to have small low-dose areas, few monitor units and short delivery time accompanied with good PTV coverage. If PTV is nearby OAR intensity-modulated treatment technique should be used. If PTV coverage is acceptable, RapidArc should be favored because of the short treatment time. Otherwise conventional IMRT should be applied.
References (21)
- et al.
Volumetric-modulated arc radiotherapy for carcinomas of the anal canal: A treatment planning comparison with fixed field IMRT
Radiother Oncol
(2009) - et al.
A treatment planning study comparing volumetric arc modulation with RapidArc and fixed field IMRT for cervix uteri radiotherapy
Radiother Oncol
(2008) - et al.
A triple Gaussian pencil beam model for photon beam treatment planning
Med Phys
(1995) - et al.
Commissioning and quality assurance of RapidArc radiotherapy delivery system
Int J Radiat Oncol Biol Phys
(2008) - et al.
Radiochemotherapy in patients with primary glioblastoma comparing two temozolomide dose regimens
Int J Radiat Oncol Biol Phys
(2008) - et al.
Intensity modulation with photons for benign intracranial tumours: a planning comparison of volumetric single arc, helical arc and fixed gantry techniques
Radiother Oncol
(2008) - et al.
Volumetric modulated arc radiotherapy for carcinomas of the oro-pharynx, hypo-pharynx and larynx: a treatment planning comparison with fixed field IMRT
Radiother Oncol
(2009) - et al.
Tolerance of normal tissue to therapeutic irradiation
Int J Radiat Oncol Biol Phys
(1991) - et al.
Risk of secondary malignant neoplasms from proton therapy and intensity-modulated x-ray therapy for early-stage prostate cancer
Int J Radiat Oncol Biol Phys
(2009) - et al.
Effect of intensity-modulated pelvic radiotherapy on second cancer risk in the postoperative treatment of endometrial and cervical cancer
Int J Radiat Oncol Biol Phys
(2009)
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2019, Radiotherapy and OncologyCitation Excerpt :Given unchanged PFS and OS, we consider this unsupported by our data. While multiple linear regression revealed that IG-VMAT produced statistically significant lower mean dose to the brain than CRT (similar to other authors [29–31]), the difference was numerically too small to impact PFS or OS outcomes, which is contrary to [29] where, however, the dissimilar histology of the VMAT and CRT cohorts may obscure the sole impact of technology. Given the correlation of FET-PET uptake with tumor cell density [16,17], the use of FET-PET in the target delineation for RT should, at least in theory, improve the radiation dose coverage of infiltrative disease.