In England, thousands of men diagnosed with prostate cancer will soon have access to a more precise type of radiotherapy that could reduce treatment time by as much as 75 percent. This change is based on findings from a trial conducted by The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust.
The trial, known as the PACE-B trial, indicated that stereotactic body radiotherapy (SBRT), which is also referred to as stereotactic ablative radiotherapy (SABR), is a more effective and targeted option compared to standard external radiotherapy. It allows for the treatment of many small, low-risk prostate cancers in just five hospital visits instead of the usual 20.
All 48 NHS radiotherapy centers in England are expected to begin offering this five-session SBRT treatment to qualified men within the next three months.
Who is SABR for?
NHS England has approved SBRT for men with early-stage prostate cancer that hasn’t extended beyond the prostate and carries a low or medium risk of growth or spread. It is estimated that around 3,500 men with this type of cancer will opt for the new treatment annually over conventional radiotherapy.
Power and precision
SBRT utilizes multiple small, intense energy beams directed at a tumor from various angles. This method allows for a very high radiation dose to cancer cells while sparing healthy tissues, thanks to its precise targeting. However, standard radiotherapy may still be a better choice for larger tumors that have the potential to grow or spread, as it can reach cancer cells beyond the tumor’s boundaries.
The PACE-B trial, managed by the Clinical Trials and Statistics Unit at ICR, aimed to compare the effectiveness of five SBRT sessions over two weeks against 20 sessions of standard intensity-modulated radiotherapy (IMRT) administered five times a week for four weeks. The phase III international randomized trial found that both options proved equally effective in managing cancer.
Keeping cancer under control
After five years, 96 percent of patients who received SBRT maintained cancer control with no recurrence, compared to 95 percent of those who underwent conventional radiation. Side effects were relatively low in both groups, with 5.5 percent of SBRT patients experiencing grade 2 or higher side effects affecting genital or urinary organs, as opposed to 3.2 percent in the conventional group. Only one patient from each treatment faced serious gastrointestinal side effects. While these grade 2 effects could be bothersome, they generally required minimal medical intervention.
Given that SBRT involves only a quarter of the sessions of standard radiotherapy, it places significantly less demand on patients as well as the healthcare system. NHS England estimates that if one in five eligible men choose this treatment, around 50,000 additional prostate cancer treatment appointments could become available each year.
‘A game-changer’
Professor Emma Hall, Director of the Clinical Trials and Statistics Unit at The Institute of Cancer Research, expressed her enthusiasm for SBRT’s implementation. She mentioned that patients can now receive treatment in just five doses, a major relief that minimizes hospital time and travel while ensuring effective care.
Professor Nicholas van As, a Consultant Clinical Oncologist at The Royal Marsden, emphasized the importance of this advancement for prostate cancer patients in England. He highlighted that the PACE-B trial sought to establish whether it’s safe to deliver prostate radiotherapy in significantly fewer sessions without affecting outcomes, and the results confirmed it.
Professor Peter Johnson, NHS National Clinical Director for Cancer, noted that this technology allows radiotherapy to be concentrated precisely where it’s needed, minimizing harm to healthy cells. He added that this reduction in treatment sessions will help men return to their lives much quicker.
