Intensity Modulated Radiation Therapy and Image-Guided Adapted Brachytherapy for Cervix Cancer

Abstract

Purpose: This study reported long-term outcomes of patients with cervical cancer who were treated with intensity modulated radiation therapy and 3-dimensional (3D) image-guided adapted brachytherapy (IMRT/3D-IGABT) compared with those treated with 2-dimensional (2D) external irradiation and 2D brachytherapy (2D EBRT/BT).

Methods and materials: This study included patients with newly diagnosed cervical cancer and pretreatment fluorodeoxyglucose positron emission tomography scans who were treated with curative-intent irradiation from 1997 to 2013. The treatment policy changed from using 2D EBRT/BT to IMRT/3D-IGABT in 2005. Patterns of recurrence, cancer-specific survival (CSS), and overall survival (OS) were evaluated. Late gastrointestinal and genitourinary toxicity were scored with National Cancer Institute Common Terminology Criteria for Adverse Events.

Results: The median follow-up for patients alive at the time of last follow-up in the 2D EBRT/BT group (n = 300) was 15.3 years (range, 10.8-20.5 years). In the IMRT/3D-IGABT group (n = 300), it was 7 years (range, 5-12.4 years). According to the International Federation of Gynecology and Obstetrics, 33% of tumors were stage IB1 to IB2, 41% were stage IIA to IIB, and 26% were stage IIIA to IVA. The results after 5 years for patients treated with 2D EBRT/BT showed that freedom from relapse (FFR) was 57%, CSS was 62%, and OS was 57%. For the IMRT/3D-IGABT group, the 5-year results showed that FFR was 65% (P = .04), CSS was 69% (P = .01), and OS was 61% (P = .04). When stratified by lymph node status according to positron emission tomography scan results, disease control was most improved with IMRT/3D-IGABT versus 2D EBRT/BT in patients with positive pelvic lymph nodes only (P = .02). Cumulatively, 88 of 600 patients (15%) had grade ≥3 late bowel/bladder toxicity. The 2D EBRT/BT group had 55 patients (18%), and the IMRT/3D-IGABT group had 33 patients (11%; P = .02).

Conclusions: IMRT/3D-IGABT was associated with improved survival and decreased gastrointestinal and genitourinary toxicity in patients with cervical cancer compared with those who received 2D EBRT/BT.

Fig. 1.

Kaplan-Meier plots comparing IMRT/3D-IGABT versus 2D EBRT/BT outcomes for (A) regional control, (B) distant control, (C) freedom from relapse, (D) cancer-specific survival, and (E) overall survival. Abbreviations: IMRT = intensity modulated radiation therapy; 2D EBRT/BT = 2-dimensional external beam radiation therapy/brachytherapy; 3D-IGABT = 3-dimensional image-guided adapted brachytherapy.

Fig. 2.

Kaplan-Meier plots of freedom from relapse comparing IMRT/3D-IGABT versus 2D EBRT/BT for patients with (A) no FDG-avid nodes, (B) FDG-avid pelvic lymph nodes only, and (C) FDG-avid pelvic and paraortic nodes. Kaplan-Meier plots of CSS comparing IMRT/3D-IGABT versus 2D EBRT/BT for patients with (D) no FDG-avid nodes, (E) FDG-avid pelvic lymph nodes only, and (F) FDG-avid pelvic and paraortic nodes. Abbreviations: CSS = cancer-specific survival; FDG = fluorodeoxyglucose; IMRT = intensity modulated radiation therapy; 2D EBRT/BT = 2-dimensional external beam radiation therapy/brachytherapy; 3D-IGABT = 3-dimensional image-guided adapted brachytherapy.

Fig. 3.

Cumulative hazard plot of grade 3 or higher bowel or bladder late toxicities in the IMRT/3D-IGABT and 2D EBRT/BT groups. Abbreviations: B/B = bowel or bladder; IMRT = intensity modulated radiation therapy; 2D EBRT/BT = 2-dimensional external beam radiation therapy/brachytherapy; 3D-IGABT = 3-dimensional image-guided adapted brachytherapy.