Using MRI – rather than CT – for post-surgical monitoring can effectively detect cancer relapse without exposing men to unnecessary radiation.
Men who are being followed after treatment for early-stage testicular cancer could benefit from switching from CT to MRI for long-term monitoring.
Stage one testicular seminoma accounts for between 40 percent and 50 percent of testicular cancer cases. Currently, men are treated with removal of the affected testicle and five years of monitoring with regular CT scans. But, while these scans can pick up signs of cancer recurrence, they also expose these men – who are typically young and unlikely to die from their disease – to additional radiation that can increase the risk of other cancers later in life.
MRI, however, performs just as well in pinpointing relapse without the extra radiation, according to research from The Institute of Cancer Research (TICR) in London. Investigators presented their findings during the GU ASCO conference this month.
“We found that the benefit of having continued CT scan beyond three years was outweighed by the potentially harmful exposure to radiation, given the small number of men who relapse and our success at treating those patients,” said Robert Huddart, TICR urological cancer professor and urological oncology consultant at The Royal Marsden NHS Foundation Trust. “Our study also found that MRI could have real benefits for men with testicular cancer in achieving similar outcomes to CT but with lower doses of radiation.”
In addition, he said, putting patients through fewer scans not only lowers patient anxiety, but it also alleviates pressure placed on an institution’s resources.
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To determine the role MRI could play in monitoring these patients, TICR experts partnered with investigators from Leeds/Huddersfield and University College London to conduct the TRISST clinical trial, the largest study to date to examine this issue. They enrolled 669 men with stage one testicular cancer who had their affected testicle surgically removed. These patients were monitored with either the standard follow-up of seven CT scans, 3 CT scans, or the same regimes with MRI scans.
Based on their analysis, a small number of men – 12 percent (82 men) – saw their cancer return, and only 10 had advanced disease at detection. And, most cases – all but five – were identified within three years post-surgery. Specifically, among the cases of advanced cancer, nine detected cases were in the three-scan group, and only one was in the seven-scan group. This finding, the team said, indicates that additional CT monitoring after three years could be unnecessary, and, because all of these men in the study were treated successfully, it also shows that the risks from the additional scans did not outweigh the benefits men experienced from having fewer studies.
Of the advanced cancers detected, CT caught eight, and MRI detected two. The difference, however, was not significant, the team noted.
“Survival for early-stage testicular cancer is almost 100 percent, which is great news,” said Michelle Mitchell, chief executive at Cancer Research UK. “With almost all men being treated successfully it means optimizing monitoring after surgery could have huge impact, not just in terms of detecting relapse at a point where treatment is most likely to be successful, but minimizing potential harms what may come from scans.”
The team is now going further, collecting health economic data to determine if implementing a three-scan MRI regimen could be recommended as a standard surveillance plan. The ultimate hope, they said, is that these study results will play a role in the care men receive for testicular cancer in the future, potentially reducing radiation exposure while providing appropriate monitoring.
“These are relatively young men and, for most, their cancer won’t return,” said Dr. Fay Cafferty, project lead at University College London. “So, striking the right balance with monitoring is crucial to avoid unnecessary radiation exposure and stress associated with hospital visits. TRISST has shown that relapses can still be detected at an early stage, and successfully treated, with fewer scans, and when using MRI rater than CT.”