Use of VMAT in breast cancer with regional lymph node involvement and simultaneous integrated boost (SIB) comparing to 3D conformal radiotherapy

JOINT EVENT: 4^th International Conference and Exhibition on Medical Physics and Biophysics & 2^nd International Conference on Nuclear Medicine & Radiation Therapy

July 27-28, 2017 Rome, Italy

Alvaro Seguro, Laura Diaz and M Amparo Iborra

Hospital de Jerez, Cadiz, Spain
HU Puerta del Mar, C�¡diz, Spain

Posters & Accepted Abstracts: J Nucl Med Radiat Ther

Abstract :

Boost of the surgical tumor bed has shown benefit in reducing the risk of local relapse in lumpectomy and new techniques of radiotherapy allow their incorporation simultaneously to the treatment of the breast. Furthermore, if we must treat regional lymph node chains, OAR toxicity can make us lose coverage of our volume of treatment so these techniques become more important. The aim of this study is to evaluate the potential advantage of Volumetric Modulated Arc Therapy (VMAT) over 3D conformal radiotherapy (3DCRT) in the treatment of breast cancer with regional node involvement and simultaneous integrated boost (SIB) of the tumor bed with respect to volume coverage and doses to Organs at Risk (OAR). Two techniques were compared in 15 patients. Treatment schedule consisted of 50Gy/2Gy daily to breast and regional nodes and SIB over tumor bed to 60Gy (BED 66Gy 2Gy/ daily fr.) all in 25 fractions. 3DCRT employed 6 to 8 coplanar hemifields with one isocenter and VMAT was developed with a restriction of the angulations for the arc to 200�º-220�º avoiding contralateral breast. Target coverage and dose to (OAR) were analyzed using mean dose, % of the prescribed dose to 9 % of the target volumes, heterogeneity and Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) constraints respectively. Although we did not have significant differences in the coverage of PTV, we got better homogeneity in planning target volume (PTV) with VMAT and the greatest benefit was obtained with the dose delivered to ipsilateral lung with a decrease of at least 10% in V20 that always was below 25% in VMAT technique. We consider VMAT as most appropriated technique for these treatments.

Biography :

Email: Seguro.alvaro@gmail.com