@article {YuanA284, author = {X Yuan and Y Zhang and J Miao and L Gao and J Hu}, title = {EP437 Dosimetric analysis of 3D-printed minimally invasive-guided template in the combined intracavitary/interstitial brachytherapy treatment of locally advanced cervical cancer}, volume = {29}, number = {Suppl 4}, pages = {A284--A284}, year = {2019}, doi = {10.1136/ijgc-2019-ESGO.496}, publisher = {BMJ Specialist Journals}, abstract = {Introduction/Background To compare the dosimetric difference of whether 3D printing minimally invasive guiding template was used in local advanced cervical cancer intracavitary combined with interstitial radiotherapy.Methodology A total of 56 patients with locally advanced cervical cancer were performed radical radiation therapy. Intensity-modulated radiation therapy prescription dose of 46.8{\textendash}50.4 Gy/26{\textendash}28 f, 1.8 Gy/times, joint intracavitary was inserted between the radiation dose graft 6Gy/times, once per week, a total of 5 times. Fifty-six patients were randomly divided into two groups, among which 25 patients in the template group were assisted with 3d-printed minimally invasive guiding template for intrauterine canal implantation and implant needle, and 31 patients in the free implant group were assisted with intrauterine canal implantation and implant needle implantation by hand. All patients were guided by CT to adjust the position and depth of the insertion needle, and the final CT image was transferred to Oncentra Brachy TPS system to formulate the treatment plan and implement the treatment.Results A total of 280 post-radiotherapy plans were made, including 125 in the template group and 155 in the free implant group. Compared with the free implant group, the D90 of high-risk clinical target area (CTV) and medium-risk CTV increased (P\<0.05) in the template group, and the D2cm3 of bladder, rectum and sigmoid colon decreased significantly (P\<0.05).Number of CT scans, time of insertion, and number of needles: there were statistically significant differences in CT scan times, implant time and number of needles between the template group and the free implant group (P\<0.05).Conclusion The application of 3D printing minimally invasive guiding template in the treatment of local advanced cervical cancer has obvious advantages in terms of dosimetry, short operation time and less pain for patients.Disclosure Nothing to disclose.}, issn = {1048-891X}, URL = {https://ijgc.bmj.com/content/29/Suppl_4/A284.1}, eprint = {https://ijgc.bmj.com/content/29/Suppl_4/A284.1.full.pdf}, journal = {International Journal of Gynecologic Cancer} }