Journal of Radiation Research and Radiation Proces ›› 2014, Vol. 32 ›› Issue (4): 40203-040203.doi: 10.11889/j.1000-3436.2014.rrj.32.040203

• RADIOBIOLOGY AND RADIOMEDICINE • Previous Articles     Next Articles

The dosimetric difference in IMRT treatment planning based on different isocenter positions for the thoracic and abdominal large target volume

ZHU Xiaoyang1  WANG Ming2   

  1. 1(Department of Radiation Oncology, the Second Affiliated Hospital, School of Medicine,
    Zhejiang University, Hangzhou 310009, China)
    2(Department of Radiation Oncology, Changzhou Hospital, Changzhou 061001, China)
  • Received:2014-04-17 Revised:2014-05-19 Online:2014-08-20 Published:2014-07-23

Abstract:

Nine patients suffering with left breast cancer after radical mastectomy and thirteen patients suffering with esophagus cancer were selected. All plan target volumes (PTV) included supraclavicular areas. Two IMRT plans(IMRT-PTV and IMRT-lung) for 22 patients were developed according to different isocenter positions (PTV center and the center determined by the lung volume in PTV). The dosimetric differences of PTV and normal tissues were analyzed using dose-volume histogram (DVH) for the two IMRT plans. The results showed that left lung V20 and heart V30 of the left breast cancer after radical mastectomy IMRT-lung plans dropped significantly(t=−6.154, −5.084; p=0.038, 0.040), and left lung V20, V30, right lung V30 and heart V40 of the Esophagus cancer IMRT-Lung plans were also significantly lower(t=−7.493, −8.092, −6.332, −6.945; p=0.025, 0.019, 0.042, 0.032), but not for other normal tissues. These findings indicate that changing isocenter position based on the lung volume involved in PTV can obtain the fewer dose of some normal tissues around the target volume.

Key words: Isocenter position, Large target volume, Intensity modulated radiationtherapy, Dosimetry

CLC Number: 

  • R73.55,TL72