Application research of Carniospinal Irradiation Using Multi-ISO with Jaw Track or Jaw Fixed Technique. [J]. Journal of Southwest Medical University 45(3):227-231(2022)
DOI:
Application research of Carniospinal Irradiation Using Multi-ISO with Jaw Track or Jaw Fixed Technique. [J]. Journal of Southwest Medical University 45(3):227-231(2022) DOI: 10.3969/j.issn.2096-3351.2022.03.009.
Application research of Carniospinal Irradiation Using Multi-ISO with Jaw Track or Jaw Fixed Technique
Objective To investigate the dosimetric differences between IMRT and VMAT in CSI ( Carniospinal irradiation ) using multi-ISO with static jaw technique or jaw tracking technique,so as to provide guidance and reference for the selection of clinical radiotherapy techniques. Methods 14 CSI patients were selected and treated with Elekta's Monaco 5.11 treatment planning system. Four plans were designed for each patient,including IMRT-MISO-SJT,IMRT-MISO-JTT,VMAT-MISO-SJT and VMAT-MISO-JTT.. The differences of target area,organ at risk,normal tissue dose,500cGy low dose volume and monitor units were compared. Results All the four groups of plans could meet the clinical requirements,and there was no significant difference in Dmean and D98% of the target area among the four groups of plans (P > 0.05). VMAT-MISO-SJT had the best prescription dose volume covering target area (Vpre) and dose conformity index(CI) of target area,and had significant difference with IMRT-MISO-SJT and IMRT-MISO-JTT (P < 0.05),but had no significant difference with VMAT-MISO-JTT (P > 0.05). The target dose homogeneity index (HI) of VMAT-MISO- JTT was the best,which showed significant difference with IMRT-MISO-SJT (P < 0.05),but showed no significant difference with IMRT-MISO-JTT (P > 0.05). IMRT-MISO-JTT plan had the lowest maximum irradiation dose of lens and mean dose of heart,but showed no significant difference with other plans (P > 0.05). IMRT-MISO-SJT had the lowest average dose of kidney and monitor units (MU),and had significant difference with VMAT-MISO-SJT and VMAT-MISO-JTT (P < 0.05),but had no significant difference with IMRT-MISO-JTT (P > 0.05). Conclusion The HI,CI and Vpre of target dose of VMAT-MISO-SJT were better than that of IMRT-MISO-SJT and IMRT-MISO-JTT. However,IMRT-MISO-SJT plan could better reduce the mean dose of left and right kidneys,low-dose volume of 500cGy and monitor units. In craniospinal irradiation radiotherapy plans,static jaw technique and jaw tracking technique had no significant effect on the dose distribution and monitor units in IMRT and VMAT plans.