Toward four-dimensional image-guided adaptive brachytherapy in locally recurrent endometrial cancer

Brachytherapy. Nov-Dec 2014;13(6):554-61. doi: 10.1016/j.brachy.2014.06.004. Epub 2014 Jul 20.

Abstract

Purpose: To evaluate clinical outcome and feasibility of a four-dimensional image-guided adaptive brachytherapy concept in patients with locally recurrent endometrial cancer.

Methods and materials: Forty-three patients with locally recurrent endometrial cancer were included. Treatment consisted of conformal external beam radiotherapy followed by a boost using pulsed-dose-rate brachytherapy (BT). Large tumors were treated with MRI-guided interstitial BT. Small tumors were treated with CT-guided intracavitary BT. The planning aim (total external beam radiotherapy and BT) for high-risk clinical target volume was D90 > 80 Gy, whereas constraints for organs at risk were D2cc ≤ 90 Gy for bladder and D2cc ≤ 70 Gy for rectum, sigmoid, and bowel in terms of equivalent dose in 2 Gy fractions.

Results: Median high-risk clinical target volume was 18 cm(3) (range, 0-91). D90 was 82 Gy (range, 77-88). D2cc to bladder, rectum, and sigmoid were 67 Gy (range, 50-81), 67 Gy (range, 51-77), and 55 Gy (range, 44-68), respectively. Median followup was 30 months (6-88). Two-year local control rate was 92% (standard error [SE], 5). Disease-free survival rate and overall survival rate was 59% (SE, 8) and 78% (SE, 7), respectively. Patients with low- to intermediate-risk for recurrence had a 2-year disease-free survival rate of 72% (SE, 9) compared with 42% (SE, 12) in patients with high risk for recurrence (p = 0.04). Late morbidity Grade 3 was recorded in 5 (12%) patients.

Conclusions: Four-dimensional image-guided adaptive brachytherapy is feasible in locally recurrent endometrial cancer. Local control rate is good. Systemic control remains a problem in patients with high risk for recurrence.

Keywords: Image-guided adaptive brachytherapy; Recurrent endometrial cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brachytherapy / methods*
  • Disease-Free Survival
  • Endometrial Neoplasms / mortality
  • Endometrial Neoplasms / radiotherapy*
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods
  • Middle Aged
  • Neoplasm Recurrence, Local / mortality
  • Neoplasm Recurrence, Local / radiotherapy*
  • Organs at Risk
  • Radiotherapy Dosage
  • Radiotherapy, Conformal
  • Survival Rate
  • Treatment Outcome