Patients in PACE-A study report fewer urinary and sexual side effects after SBRT for prostate cancer

Men with prostate cancer are less likely to experience urinary and sexual side effects two years after treatment with an advanced type of radiotherapy than with surgery, according to researchers from The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research (ICR), London.

The PACE-A study compares the long-term side effects of stereotactic body radiotherapy (SBRT) versus surgery in patients with early stage prostate cancer. Results from the trial were presented at the 2023 ASCO Genitourinary Cancers Symposium in February.

Across 10 UK centres, 59 men were treated with SBRT and 50 with surgery. After two years, significantly fewer patients (4.5 per cent) treated with SBRT reported needing to use urinary pads when compared with surgery (47 per cent). Patients treated with SBRT also reported better sexual function after two years than those treated with surgery.

However, although moderate or serious bowel problems were not reported by many men in the study, those treated with SBRT were more likely than surgical patients to report minor problems.

SBRT, which can be carried out on an Accuray CyberKnife or a modern linear accelerator, allows clinicians to target tumours to sub-millimetre precision. It delivers five high doses of radiation over one to two weeks compared with standard radiotherapy, which delivers more moderate doses through approximately 20 sessions over four weeks. The Royal Marsden has two CyberKnife machines, funded by The Royal Marsden Cancer Charity.

Alexander Szczerbiuk from Morden was diagnosed with prostate cancer in November 2017 and recruited to the PACE-A trial for treatment with SBRT via CyberKnife. He said: “It was only two months from my diagnosis to the last of my five CyberKnife sessions, and I was as pleased as punch everything happened so quickly.

“Before the treatment, my biggest concern was incontinence, as I really couldn’t bear the thought of having to use urinary pads. This meant I was delighted to be selected for CyberKnife which, as a minimally invasive option, was a no-brainer. Fortunately, the side effects have been minimal and, while I experience rectal bleeding very occasionally, I urinate normally and have never needed to use a pad.”

Chief investigator Professor Nicholas van As, medical director and consultant clinical oncologist at The Royal Marsden NHS Foundation Trust and ICR professor in precision prostate radiotherapy said: “This world-first study reveals that SBRT is often kinder and can mean less long-term side effects than surgery for prostate cancer patients.

“One of the biggest concerns for men I see in clinic ahead of treatment for prostate cancer is whether it will make them incontinent, and many worry about the impact on their sexual function too. While there is a risk both SBRT and surgery will cause problems, these results suggest SBRT is less likely to.

“Going forwards, these results should support clinicians in facilitating important discussions with prostate cancer patients about whether to opt for SBRT or surgery, helping them make an informed decision based on their individual needs and concerns.”

After being diagnosed with prostate cancer in October 2017, Colin Maskell from Sutton was enrolled onto the PACE-A trial. He commented: “My treatment started in January 2018 and there was nothing to it really. With CyberKnife, you just lie down and look up – at The Royal Marsden you can see a nice image of the sky and cherry blossoms – while a robotic arm swings around you.

“I don’t recall having to miss much work as the treatment was over so quickly, and, besides a bit of fatigue, I didn’t have any side effects.

“Five years on, I’ve never experienced incontinence and, while my orgasms are different, the change isn’t a big deal and my sexual function is good.”

Lead picture: Patient Alexander Szczerbiuk took part in the PACE-A study and reported good results.

Published on page 2 of the March 2023 issue of RAD Magazine.