Dosimetric comparison between the use of insertion needles and Fletcher applicator in brachytherapy for cervical cancer

To investigate the difference between CT-guided three‑dimensional brachytherapy using insertion needles and Fletcher applicator brachytherapy.

Ninety-three patients with cervical squamous cell carcinoma were included. Insertion needle or Fletcher applicators were used depending on tumor conditions. The target volume, target and organs at risk (OAR) dose, and treatment-related complications, in patients receiving the different brachytherapy techniques were compared.

The mean volume of the high-risk clinical target volume (HR-CTV) and intermediate-risk clinical target volume (IR-CTV) in the Fletcher applicator group were smaller compared with the insertion needle group (P<0.05). The mean values of D90 per fraction of the HR-CTV and IR-CTV in the Fletcher applicator group were 101 cGy and 60 cGy lower, respectively, compared with the insertion needle group (P<0.05). The mean bladder and rectum D0.1cm3 per fraction, the mean sigmoid and small intestine D2cm3 per fraction were statistically different between two groups( all P<0.05), the remaining dosimetric parameters were no significant differences (P>0.05). Following dose normalization, with the exception of the mean normalized sigmoid D0.1cm3 per fraction for the received by the OAR in the Fletcher applicator group and the insertion needle group were significantly different (P<0.05). There was no serious complication in the brachytherapy of two types applicators.

Brachytherapy using insertion needles enables the treatment of larger target volumes with higher target doses when compared with conventional Fletcher applicator brachytherapy. In addition, the doses received by the OAR are lower, indicating that it is a safe and effective technique that warrants wide adoption.