Use of FDG-PET to guide dose prescription heterogeneity in stereotactic body radiation therapy for lung cancers with volumetric modulated arc therapy: a feasibility study.
Radiat Oncol. 2014-12-01; 9(1):
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1. Radiat Oncol. 2014 Dec 23;9:300. doi: 10.1186/s13014-014-0300-9.
Use of FDG-PET to guide dose prescription heterogeneity in stereotactic body
radiation therapy for lung cancers with volumetric modulated arc therapy: a
de Figueiredo BH, Antoine M, Trouette R, Lagarde P, Petit A, Lamare F, Hatt M,
BACKGROUND: The aim of this study was to assess if FDG-PET could guide dose
prescription heterogeneity and decrease arbitrary location of hotspots in SBRT.
METHODS: For three patients with stage I lung cancer, a CT-simulation and a
FDG-PET were registered to define respectively the PTVCT and the biological
target volume (BTV). Two plans involving volumetric modulated arc therapy (VMAT)
and simultaneous integrated boost (SIB) were calculated. The first plan delivered
4 × 12 Gy within the PTV(CT) and the second plan, with SIB, 4 × 12 Gy and 13.8 Gy
(115% of the prescribed dose) within the PTV(CT) and the BTV respectively. The
Dmax-PTV(CT) had to be inferior to 60 Gy (125% of the prescribed dose). Plans
were evaluated through the D95%, D99% and Dmax-PTV(CT), the D2 cm, the R50% and
R100% and the dice similarity coefficient (DSC) between the isodose 115% and BTV.
DSC allows verifying the location of the 115% isodose (ideal value = 1).
RESULTS: The mean PTV(CT) and BTV were 36.7 (±12.5) and 6.5 (±2.2) cm3
respectively. Both plans led to similar target coverage, same doses to the OARs
and equivalent fall-off of the dose outside the PTV(CT). On the other hand, the
location of hotspots, evaluated through the DSC, was improved for the SIB plans
with a mean DSC of 0.31 and 0.45 for the first and the second plans respectively.
CONCLUSIONS: Use of PET to decrease arbitrary location of hotspots is feasible
with VMAT and SIB for lung cancer.
PMID: 25534014 [Indexed for MEDLINE]