Editor’s note: People who have been treated for breast cancer may experience a recurrence; that is, their cancer may come back. Scientists recently tested and compared different ways to detect recurrence. Out of 1,000 women, the scientists found, about 18 will have recurrent cancer that is missed by mammography and ultrasonography, but is successfully detected with MRI. The results suggest that women who have undergone breast conservation therapy might do well to be screened for recurrence using MRI.
“Single-screening breast magnetic resonance imaging (MRI) detects 18.1 additional cancers after negative findings with mammography and ultrasonography (US) per 1,000 women with a history of breast cancer, according to a study published in the August issue of Radiology.
“Hye Mi Gweon, M.D., from the Seoul National University College of Medicine in South Korea, and colleagues evaluated cancer detection rates, cancer characteristics and MRI performance characteristics in 607 consecutive women (median age, 48 years) with breast cancer who underwent breast conservation therapy (BCT). These women had negative mammography and US findings, and most underwent preoperative MRI examinations (91.8 percent).
“The researchers found that MRI detected 11 additional cancers (18.1 cancers per 1,000 women). The positive predictive value (PPV) for recall was 9.4 percent (11 of 117 examinations), PPV for biopsy was 43.5 percent (10 of 23), and the sensitivity and specificity were 91.7 percent (11 of 12) and 82.2 percent (489 of 595), respectively.”
“Oncologists at UC San Diego Moores Cancer Center are the first in San Diego to meld magnetic resonance imaging (MRI) technology with a traditional ultrasound prostate exam to create a three-dimensional map of the prostate that allows physicians to view growths that were previously undetectable.
“An ultrasound machine provides an imperfect view of the prostate, resulting in an under-diagnosis of cancer, said J. Kellogg Parsons, MD, MHS, the UC San Diego Health System urologic oncologist who, along with Christopher Kane, MD, chair of the Department of Urology and Karim Kader, MD, PhD, urologic oncologist, is pioneering the new technology at Moores Cancer Center.
“ ‘With an ultrasound exam, we are typically unable to see the most suspicious areas of the prostate so we end up sampling different parts of the prostate that statistically speaking are more likely to have cancer,’ said Parsons, who is also an associate professor in the Department of Urology at UC San Diego School of Medicine. ‘The MRI is a game-changer. It allows us to target the biopsy needles exactly where we think the cancer is located. It’s more precise.’ ”
“In a world first, an Australian clinical trial has shown that biopsy guided by MRI can significantly improve the diagnosis of life-threatening prostate cancer and reduce the over-diagnosis of non-life-threatening cases, thus avoiding the side effects of unnecessary treatment.
“At present, to find out if he has prostate cancer – following a test that shows he has raised prostate-specific antigen (PSA) levels – a man has to undergo a painful procedure called transrectal ultrasound guided biopsy (TRUSGB) that involves taking up to 30 random needle biopsies of his prostate through the rectum.”
“In men with recurrent prostate cancer following radiation therapy, magnetic resonance imaging (MRI)-guided focal cryoablation is feasible and seems safe, according to a study published in the August issue of Radiology. Joyce G.R. Bomers, from Radboud University Nijmegen Medical Centre in the Netherlands, and colleagues, studied 10 consecutive patients with histopathologically proved recurrent prostate cancer after radiation therapy, without evidence of distant metastases. While patients were under general anesthesia, a urethral warmer was inserted, followed by transperineal insertion of cryoneedles during real-time MRI (magnetic resonance imaging) and insertion of a rectal warmer. MRI guidance was used to continuously monitor ice ball growth. Two cycles of freezing and thawing were conducted. Follow-up included a urologist visit, prostate-specific antigen level measurement, and multiparametric MRI at 3, 6, and 12 months.”
The standard imaging practice for detecting prostate cancer that returns after treatment, called recurrent prostate cancer, combines positron emission tomography (PET) with computed tomography (CT), known as PET/CT. In a recent clinical study researchers from the Technical University Munich in Germany, compared PET/CT to PET combined with magnetic resonance (MR), known as PET/MR. The study involved 31 patients with recurrent prostate cancer and found that PET/MR detected more areas of metastatic tumors, and allowed for more precise mapping of tumors, than PET/CT. The researchers say PET/MR can be considered an alternative to PET/CT, particularly when small tumors are involved. The US FDA approved the first PET/MR device in 2011.