Comparison of dosimetry and short?term outcome between 3D printing multi?channel applicator interstitial brachytherapy and conventional intracavitary brachytherapy for locally advanced cervical cancer

YANG Wencui; SONG Lijuan; ZHANG Qianwen; ZHAO Lin; ZHANG Chunlin; GAO Liying.

Abstract：explore the dosimetry, short?term efficacy and toxicity of vaginal multi?channel individualized model made by 3D printing technology in radical radiotherapy of cervical cancer. Methods Retrospective analysis from Nov 2013 to Oct 2016 was done on 26 locally advanced cervical cancer patients with bullky tumors(tumor size＞5cm) after external beam radiotherapy received 3D printing multi?channel applicator interstitial brachytherapy ( 3DP?ISBT group). Dosimetry index including the total dose ( external beam radiotherapy+brachytherapy)D90 of HR?CTV and D2cc for bladder, rectum and sigmoid were compared between 3DP?ISBT group and 30 patients who received conventional intracavatary brachytherapy (ICBT group). The recent efficacy and toxicity were observed. Results The mean D90 value for HR?CTV in 3DP?ISBT group and ICBT group were(88. 5±3. 6)Gy and (77. 9±5. 8)Gy, respectively.The HR?CTV D90 of the two groups were 92. 5% and 86. 5%, respectively.The D2cc for rectum and sigmoid in 3DP?ISBT group were (65. 2±5. 2) Gy and (68. 7±4. 1)Gy, lower than (69. 8±6. 0)Gy and (70. 4±4. 8)Gy of ICBT group with statistic significance(P＜0. 05), and while the D2ccfor bladder in the two groups were (81. 7±6. 6) Gy and (86. 7±6. 3) Gy without significance( P＞0. 05).The 1?year tumor local control rate in 3DP?ISBT group and ICBT group were 86. 2% and 58. 3% with statistic significance(P＝0. 03). There were 4 patients oc?curred intestinal perforation during the treatment in 3DP?ISBT group, and no other serious adverse reaction occurred. Conclusion 3D?printing multi?channel applicator interstitial brachytherapy shows a significant dosimetry advantage compared with conventional intracavitary brachytherapy with better short?term efficacy. However, the long term efficacy and toxicity need to be further investigated.