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Abstract
Introduction To analyzed the clinical outcomes and dose changes imperfect uterine tandem implantation in HDR-brachytherapy for cervical cancer.
Methods We reviewed the imperfect intrauterine insertion images during November 2020 and July 2021. The physicist designed 2D and 3D plans on prescription (6Gy) for perfect and imperfect images. Evaluates the clinical outcome and predicts NTCP of perfect and imperfect placement. The CTVref, Vref, COIN, EQD2 of OARs and NTCP were extracted using corresponding formulas. The differences two plans were compared using paired t-test.
Results 41 of 1742 brachytherapy images showed 24 of 319 patients(7.52%). According to imperfect position of uterine tandem, we divided it into four types: inadequate implantation, anterior, posterior wall and fundus perforation. CTVref and Vref in PER-3D group is superior to PER-2D. COIN only met the requirements in the PER-3D group (>0.64). EQD2 of OARs and NTCP were the lowest in PER-3D group. In inadequate implantation, IM-group improves EQD2 and NTCP of rectum,sigmoid colon and small intestine(P<0.05) in 3D; NTCP of bladder is added to IM-group(P<0.05) in 2D. In anterior wall perforation, IM-group increases EQD2 of OARs and NTCP of rectum and small intestine in 3D, and IM-group increases EQD2 and NTCP of OARs (sigmoid and small intestine) (P<0.05) in 2D. In posterior wall perforation,IM-group increased EQD2 and NTCP of rectum and sigmoid in both plans. In fundus perforation, IM-group increased EQD2 of sigmoid.
Conclusion/Implications PER-3D is the optimal planning to meet the brachytherapy of cervical cancer. It is recommended to correct the imperfect insertion of the uterine canal before clinical treatment.
Diverse anatomical situations during brachytherapy of cervix (sagittal view). A)Normal sized and anteverted, B)retroverted uterus, C)acutely anteflexed uterus, D)short uterus, E)presence of obstructing cervical mass
Comparison of dose distribution between patients with and without satisfaction with intrauterine tube placement brachytherapy plan