Combining MR- and ultrasound-guided biopsies for prostate cancer diagnosis may enable detection of over 30 percent more tumors, says a study in California.
Researchers at UCLA have found that while not often used together, combining the traditional method of ultrasound imaging with MR imaging can allow clinicians to detect up to 33 percent more cancers.
“Our research suggests that the different biopsy methods identify different tumors,” senior author Dr. Leonard Marks, the Jean B. deKernion chair in the department of urology at the David Geffen School of Medicine at UCLA, said in a statement. “To maximize our ability to identify prostate cancer, we need to take advantage of all the information we can. Our cancer detection rate, while using different methods in tandem, surpasses that from using either method alone. In this case, one plus one equals three.”
One million men in the U.S. undergo biopsies annually to determine if they have prostate cancer, many of which use ultrasound-guided imaging to visualize the prostate and allow clinicians to take a representative sampling of tissue. Ultrasound, however, is unable to clearly display the location of tumors in the prostate gland.
MR-guided biopsies, in contrast, are more targeted and enable clinicians to locate specific lesions and take tissue samples only from those spots. As a result, such procedures have become more commonplace in the last decade. But while research has demonstrated the advantages of MR-guided biopsy, how to apply it has been unclear. Some tumors also do not appear as lesions on MR scans, preventing them from being detected.
The team carried out a 300-person study over a three-year period. In that time, MR located a prostate lesion in 248 men. Using available biopsy information and both methods together, researchers detected cancer in 70 percent of them. While MR did not detect lesions in the other 52 men, 15 percent were found to have cancer after undergoing ultrasound-guided biopsies, proving that MR cannot detect all lesions. The authors say the trial is the first to directly compare the different biopsy sampling methods in the same group of men.
“Men being assessed for prostate cancer should first receive an MR before biopsy,” said Marks, who is also the co-founder of Avenda Health, a biomedical device company aiming to treat prostate tumors with a laser device. “When there’s a lesion on MR, physicians should take systematic and targeted biopsies together for the best chance at finding cancer. Even if the MR is negative for lesions, men at risk — including those with elevated levels of prostate-specific antigen, a prostate nodule, or family history — should still receive a traditional, systematic biopsy.”
The ability to identify precise locations of tumors in the prostate is becoming more significant, as treatments become more targeted. Focal therapy, for instance, could eliminate cancerous tissue in the gland without destroying healthy tissue, making it an alternative to prostatectomy, a common and invasive treatment in which the entire gland is surgically removed.
Funding for the study was provided through a grant from the National Cancer Institute, as well as by the Jean Perkins Foundation, the Kent Kresa Family Foundation, and the Steven C. Gordon Family Foundation.
The findings were published in JAMA Surgery