Barcelona, Spain: A rare but potentially serious complication following radiation treatment for cervical cancer is a narrowing of the tube (the ureter) that takes urine from the kidneys to the bladder, which can lead to kidney damage and sometimes life-threatening infections. This is called ureteral stricture and, until now, there have been concerns that brachytherapy might increase the risk, although the treatment itself is associated with better survival.

However, new research presented at the ESTRO 37 conference today (Saturday) from two large international trials, shows that intracavitary and interstitial (IC/IS) brachytherapy is safe and does not increase the risk of ureteral stricture. Intracavitary (IC) brachytherapy involves placing an applicator in the uterus, while interstitial (IS) brachytherapy involves inserting needles directly into the tumour. Then the appropriate radiation dose is delivered to the cancer via one or both of these approaches. The procedure is performed after a CT or MRI scan has pinpointed the exact position of the cancer, so that the radiation treatment can be targeted precisely, and this is called image-guided brachytherapy (IGBT).

Dr Lars Fokdal (MD, PhD), a consultant at the Aarhus University Hospital, Denmark, who led the study, said: "These results show that image-guided brachytherapy using intracavitary combined with interstitial techniques is safe and is not associated with more cases of ureteral stricture afterwards compared to using intracavitary techniques alone."
Dr Fokdal and his colleagues looked at data from 1772 patients with cervical cancer that had started to spread to nearby tissues (locally advanced) who were enrolled in two trials of the treatment - EMBRACE and retro-EMBRACE - that were being carried out in 12 countries. IC/IS IGBT was delivered to 36% of the patients.

After following the patients for between one and 163 months (the middle or 'median' number of months was 29), 36 patients were diagnosed with the more severe form of ureteral stricture (grade 3-4). The overall risk of developing grade 3-4 ureteral stricture was 2% after three years and 3.2% after five years. The risk was lowest (1.3%) among the 1370 patients with small tumours, and highest among the 130 patients with more advanced cancer and who had ureters swollen due to a build-up of urine (hydronephrosis) at the time of diagnosis. In these patients the risk of ureteral stricture was 13.6% after three years and 23.4% after five years.

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