The effect of dose-painted intensity-modulated radiotherapy combined with chemotherapy for stage IIIB cervical cancer

Objective: To investigate the effect of dose-painted intensity-modulated radiotherapy (DP-IMRT) combined with chemotherapy on stage IIIB cervical cancer. Methods: A total of 107 stage IIIB cervical cancer patients were treated with DP-IMRT combined with chemotherapy. The planning target volume (PTV) was divided into regions with different prescribed absorbed doses (so-called PTV-subvolume [PTVsv]): PTVsv(1) (the part of the PTV that overlaps with the organ at risk (OAR)) received 39.6-45 Gy, 1.8 Gy/fraction (fx); and PTVsv(2) (the part of the PTV that does not overlap with the OAR) received 44-50 Gy, 2.0 Gy/fx. The lymph nodes were simultaneously boosted; lymph nodes with a short axis dimension <1 cm received 50-55 Gy, 2.0-2.4 Gy/fx, while nodes with a short axis dimension >1 cm received 55-66 Gy, 2.2-2.6 Gy/fx. External radiotherapy was followed by intracavitary brachytherapy. Patients were followed up regularly to collect the survival information. Results: Five years after therapy, the overall survival rate and progression-free survival rate were 61.0% and 55.0%, respectively. The cumulative rates for total grade 3 or higher chronic gastrointestinal or genitourinary toxicity were 4.67% and 1.9% respectively. Conclusion: Without compromising the primary PTV, DP-IMRT achieved good outcomes for stage IIIB cervical cancer patients with a favorable gastrointestinal toxicity profile.