21st century oncology.
Top Line: Nearly half a century after 3D-imaging has been widely available to patients, large-scale data is here to support image-guided brachytherapy for locally-advanced cervical cancer.
The Study: EMBRACE-I was a huge collaborative international effort to prospectively record cancer outcomes among over 1300 women receiving definitive chemoradiation for stage IB-IVA cervical cancer across Asia, Europe and North America. Over half were stage IIB with a pretty even distribution otherwise. Everyone received 40-50 Gy conventionally fractionated whole pelvis external beam radiation with concurrent cisplatin 40 mg/m2 weekly followed by—and here’s where the 21st century comes in—consolidative MR-guided brachytherapy. In other words, MRI-based treatment planning with the brachy applicator in place was mandatory. The median EQD2 dose delivered to 90% (d90%) of the high-risk target volume (gross tumor at time of brachy application plus entire cervix) across all these women at diverse institutions was 90 Gy (IQR 85–94). Now remember, the whole concept of image guided brachytherapy is to tailor the consolidative dose distribution to the actual tumor volume remaining after external beam. This resulted in 1 of 5 women receiving significantly larger high-dose distributions than with 2D-planning and 2 of 5 women significantly smaller—the latter being the biggest fear of the old guard. Well, at a median follow-up of over 4 years, estimated 5-year local control was excellent at 92% (95% CI 90-93%). Grade 3+ GI toxicity occurred in 9%, GU in 7%, vaginal in 6%, and fistula in 3%.
TBL: Consolidative MRI-guided brachytherapy for locally-advanced cervical cancer results in unprecedented local control with acceptable toxicity. | Pötter, Lancet Oncol 2021