Comparison of volumetric-modulated arc therapy (VMAT) with nine-field dynamic intensity-modulated radiation therapy (IMRT) for Cervical cancer

Abstract

Objective To compare the planning quality and volume of organ at risk (OAR) between volumetric-modulated arc therapyv(VMAT) and nine-field dynamic intensity-modulated radiation therapy (IMRT) in radiotherapy for cervical cancer patients, explore the best way to cervical cancer radiotherapy. Methods Selected 20 patients with cervical cancer were divided into 2 groups, 10 cases for each group. Cervical cancer patients with no surgery was performed for A group (group A), received the radical radiotherapy, prescription dose gross tumor volume (GTV) 56 Gy, clinical target volume (CTV) 50 Gy. Another group of patients with cervical cancer radical surgery (group B), giving the whole basin lymph node auxiliary radiation therapy, prescription dose CTV 50 Gy. Each cervical cancer patient received VMAT and IMRT program designs, the differences in dose volume histogram (DVH), irradiated volume of organ at risk (OAR), heterogeneity index (HI), conformity index (CI), maximum dose (PTVmax), minimum dose (PTVmin) and mean dose (PTV mean) were compared between two plans in 2 groups. Results Two kinds of radiation technology in target area dosimetry were not statistical difference between two groups (P>0.05). In endanger organs on the protection of two groups of VMAT planning groups in the small intestine V20 and left femoral head V20 had obvious advantages with statistically significance (P<0.05). Conclusions Two groups of dosimetry between VMAT and IMRT program design are similar in cervical cancer. Two groups of VMAT planning groups to protect endanger organ slightly better than that of IMRT group, but VMAT planning group shortens treatment time and improves the accuracy and efficacy of treatment. Key words: Uterine cervical neoplasms/RT; Radiotherapy, intensity-modulated/MT; Radiotherapy dosage