Ultrasound, CT, MRI and bone scanning are essential in prostate cancer management, and with accurate reporting crucial for effective treatment, experts offered a primer to help radiologists understand what surgeons, radiation oncologists and medical oncologists want to know about prostate cancer imaging results in the June issue of the American Journal of Roentgenology. The authors also issued a call for standardized reporting, outlining its value.
“Prostate cancer is the second leading cause of cancer death among men,” wrote Shahin Tabatabaei, MD, of the division of urology at Massachusetts General Hospital in Boston. “In 2010, an estimated 217,730 men [were] diagnosed with prostate cancer, and 32,000 will die of it.”
Imaging and imaging interpretation are vital for staging, treatment decision-making and prognosis. Although the ideal scenario may be collaborative image review with both the referring physician and radiologist discussing key images and findings, the writers acknowledged this protocol is impossible in some situations. Thus, they explained imaging reports “must be precise enough to guide clinical decision-making.”
Tabatabaei and colleagues explained applications for various modalities and highlighted key points for radiologists to include in reports.
Transrectal ultrasound is commonly used to guide biopsy procedures and interventions such as cryotherapy, brachytherapy and high-intensity focused ultrasound. Reports should contain the following data: prostate dimensions and volume, presence (and length if applicable) of intravesical prostatic protusion, presence and location of hypoechoic lesions, presence of asymmetry or protusion into the prostatic capsule and presence of asymmetry between the seminal vesicles.
Although neither CT nor MRI is routinely employed in prostate cancer imaging, both modalities are occasionally used.
Specifically, CT or MRI may be used to image high-risk patients with T3 or T4 primary tumors or probable lymph node involvement. In such cases, the CT report should include prostate dimensions, presence (and length if applicable) of intravesical prostatic protusion, any asymmetry in prostate contour and presence of pelvic or periaortic lymphadenopathy, with measurements.
Although MRI offers better soft tissue resolution than CT, its accuracy does not suffice for primary tumor evaluation, explained the authors. It may be used for pelvic lymph node assessment in high-risk patients or to evaluate patients at high risk for bone involvement.
MRI reports should include: prostate dimensions, presence (and length if applicable) of intravesical prostatic protusion, any asymmetry in prostate contour, any abnormal signal intensity in the peripheral or transitional zones, loss of periprostatic fat plane, seminal vessel signal intensity and any lack of symmetry, presence of pelvic or periaortic lymphadenopathy, with measurements and comments regarding imaged pelvic and vertebral bones.
Finally, bone scanning may be used to evaluate for bone metastasis and for primary staging in patients considered high risk for bone metastasis. These reports need to include a precise description of the size and location of lesions as well as a comment, if indicated, on the likelihood that the lesion is a malignant metastasis versus a benign process.
Tabatabaei et al concluded with a call for standardized reporting using nationally accepted templates, which could ensure higher quality reports, better patient care and improve reimbursement. They suggested that task force committees direct the effort on the basis of evidence-based data, before pointing out that templates enable more accurate and efficient data mining, which may be used to inform future clinical studies.