Abstract:
Objective To compare the advantages and disadvantages of volumetric modulated arc therapy(VMAT)and fixed-field intensity-modulated radiotherapy(f-IMRT)in radical radiotherapy for cervical cancer.
Methods Clinical materials of 43 cervical cancer patients with VMAT and f-IMRT were analyzed retrospectively. Dosimetric parameters, the clinical complications and efficacy were compared between two groups.
Results The conformity index(CI)of VMAT plan group was higher than that of f-IMRT plans group, and no significant differences were found in other dosimetric parameters such as maximum dose(
Dmax), average dose(
Dmean), homogeneity index(HI)and machine tuning(MU). VMAT plan group resulted in reductions in
V30,
V40,
V50 of intestine,
V40 of rectum and
V50 of the bladder(
P<0.05). There were significant differences between the two groups in grade Ⅰ and Ⅱ gastrointestinal side effects.
Conclusion Compared with f-IMRT plan, VMAT plan has a better conformability, which can better protect normal tissues such as small intestine and bladder as well as significantly shorten treatment time, so it is a better option for external radiotherapy for cervical cancer.