Intensity-modulated radiation therapy versus three-dimensional conformal radiation therapy with concurrent nedaplatin-based chemotherapy after radical hysterectomy for uterine cervical cancer: comparison of outcomes, complications, and dose-volume histogram parameters.

Background: The purpose of this study is to report our clinical outcomes using intensity-modulated radiation therapy (IMRT) for adjuvant treatment of cervical cancer, compared with three-dimensional conformal radiation therapy (3DCRT), in terms of tumor control, complications and dose-volume histogram (DVH) parameters.
Methods: Between March 2008 and February 2014, 62 patients were treated with concurrent nedaplatin-based chemotherapy and whole-pelvic external beam radiation therapy (RT). Of these patients, 32 (52%) received 3DCRT and 30 (48%) received IMRT.
Results: The median follow-up periods were 40 months (range 2-74 months). The 3-year overall survival rate (OS), locoregional control rate (LRC) and progression-free survival rate (PFS) were 92, 95 and 92% in the IMRT group, and 85, 82 and 70% in the 3DCRT group, respectively. A comparison of OS, LRC and PFS showed no significant differences between IMRT and 3DCRT. The 3-year cumulative incidences of grade 2 or higher chronic gastrointestinal (GI) complications were significantly lower with IMRT compared to 3DCRT (3% vs. 45%, p < .02) and in patients with V40 of the small bowel loops of ≤340 mL compared to those with >340 mL (3% vs. 45%, p < .001). Patients treated with IMRT had a higher incidence of grade 3 acute hematologic complications (p < .05). V40 and V45 of the small bowel loops or bowel bag were predictive for development of both acute and chronic GI complications.
Conclusions: Our results suggest that IMRT for adjuvant treatment of cervical cancer is useful for decreasing GI complications without worsening outcomes.