How Accurate Are Cancer Scans?

Uterine cancer patients were given scans to see how accurate they could be at diagnosis

(RxWiki News) Body scans may just be the wave of the future. They’re far less invasive than biopsy or exploratory surgery. But can they really find cancer in the deep layers of the uterus?

A recent study tested the accuracy of scans in 94 uterine cancer patients.

The study’s findings showed that one type of scan found existing cancer best, while another found spreading cancer best.

"Talk to your doctor about diagnostic options."

Jin Zheng-Yu, MD, professor in the Department of Radiology at Peking Union Medical College in Beijing, China, worked with a team of researchers for the investigation.

For the study, 94 women that had already tested positive for endometrial cancer through tissue samples were given magnetic resonance imaging (MRI) scans.

Researchers were trying to see if MRI scans were accurate enough to detect the presence of endometrial cancer. Special specs were added to these uterine MRIs to better see the layers of the uterine wall: T2 weighted imaging (T2WI) was either combined with a contrast enhancer or diffusion weighted imaging (DWI).

DWI is a scanning method that uses the body’s own water content to create an image. Contrast enhancers are oral or injected chemicals that cause the body’s atoms to work with the scan to create the best possible image.

In 62 of the patients, the MRI scans did show cancer in the middle uterine layer. In the remaining 32 patients, cancer in the deeper, inner uterine layer was found. A total of 24 groups of cancer spreading lymph nodes and 164 non-cancer spreading lymph nodes were found in the scans as well.

When T2WI was combined with a contrast enhancer the scans showed these percentages when telling the difference between cancer in the middle uterine layer and the inner uterine layer:

  • 88 percent accuracy
  • 90 percent specific area of cancer presence
  • 84 percent sensitivity to the accurate presence of cancer
  • 92 percent accurate prediction of no cancer
  • 82 percent accurate prediction of cancer

When T2WI was combined with a DWI, the scans showed these percentages when telling the difference between cancer in the middle uterine layer and the inner uterine layer:

  • 82 percent accuracy
  • 87 percent specific area of cancer presence
  • 72 percent sensitivity to the accurate presence of cancer
  • 86 percent accurate prediction of no cancer
  • 74 percent accurate prediction of cancer

Both T2WI with contrast enhancer and DWI were also tested for the same percentages for cancer-spreading lymph nodes.

The research authors concluded that the MRIs of T2WI combined with contrast enhancement was far better than T2WI combined with DWI in assessing the depth of middle uterine layer cancer invasion.

But when it came to finding cancer spreading to the lymph nodes, DWI was more sensitive than T2WI combined with a contrast enhancer.

Further studies on larger groups will be necessary to replicate these findings.

No financial information was given and no conflicts of interest were reported. This study was published in October in Zhongguo yi xue ke xue yuan xue bao by the Chinese Academy of Medical Sciences.

Review Date: 
November 19, 2012