Results from a recent pioneering international research examining the late adverse events of two forms of combined brachytherapy targeting cervical cancer revealed that the strategy is successful in delivering high doses of radiation to the tumors without increasing late side-effects related to treatment.
Brachytherapy is an internal radiotherapy treatment strategy that involves placing a radioactive source nearby the tumor. The procedure is usually performed after an MRI or CT scanning identification of the precise tumor position, also termed image-guided brachytherapy (IGBT). There are two forms of brachytherapy, intracavitary (IC) and interstitial brachytherapy (IS). In IC, the radioactive source is placed in the vagina and the uterus, while in IS needles are inserted into the tumor to deliver the radiation.
In a recent presentation during the 3rd ESTRO Forum, which took place in Barcelona, Spain, Dr. Lars Fokdal (MD, PhD), a consultant at the Aarhus University Hospital in Denmark stated, “Image-guided brachytherapy has transformed treatment for cervical cancer considerably, and dose adaptation and a combination of intracavitary and interstitial brachytherapy enable us to deliver radiation that is targeted at the tumour while avoiding other organs. However, although some centres are using IC/IS brachytherapy, there are concerns that the technique might increase the likelihood of adverse side-effects occurring three months or more after the end of radiation treatment.”
For the study, Dr. Fokdal and co-workers from France, Slovenia, The United Kingdom, Ireland, The Netherlands and Austria examined a total of 731 women with a diagnosis of locally advanced cervical cancer. Patients were enrolled into the “retroEMBRACE” study, which is collecting retrospective data on the use of IGBT for cervical cancer in about 800 patients from 12 different countries.
Data was analyzed from a subgroup of 300 women receiving treatment at different institutions with a combination of IC and IS brachytherapy on more than 20% of women. The researchers also analysed data on the subgroup of 310 women receiving treatment from institutions with IC brachytherapy alone.
“We found that combined IC/IS brachytherapy enabled us to deliver higher doses to the tumour without delivering more radiation to the bladder and the bowel. This meant that there was no increased risk in severe adverse side-effects three or more months later, but there is a better chance of a cure,” Dr. Fokdal explained. “These results show that combined IC/IS brachytherapy is a good treatment and should serve as a benchmark for future brachytherapy in cervical cancer,” he added.
Potential late side effects of radiotherapy for cervical cancer involve bowel and bladder dysfunction as well as loss of flexibility, narrowing, or drying of the vagina, the bowel or the bladder. These potential complications of radiation treatment are graded from 0 to 5 (0 for no problems to 5 for death).
Results from the study revealed that there were no differences between the two groups of patients after an average of 40 months follow-up regarding late complications in the bladder, gastro-intestinal or vaginal graded 2-5.
In comparison with patients who were less likely to receive treatment of combined IC/IS brachytherapy, the results revealed that the dose of radiation in the IC/IS patient group was more targeted to the tumor area, with about 90% of the tumors receiving a dose that was 9Gy higher in comparison to the dose given to non-IC-IS patients. Nevertheless, these high target radiation doses in the group of patients that received the IC/IS treatment did not cause higher doses of radiation to the bowel, which were in average 4Gy lower.
Professor Philip Poortmans, President of ESTRO, commented in the news release: “Dr Fokdal and colleagues show again that intensive close collaboration between high-level departments from several countries can help to extend our knowledge of how to further improve the outcome of our patients. This specific study of the EMBRACE network shows how the best results may be obtained by properly using the newest technical developments in the field of brachytherapy. Now, the next step is to teach these optimised techniques to all our other colleagues who treat locally advanced cervical cancer but do not yet use interstitial techniques as an addition to intracavitary ones.”