Description of Treatment/Procedure:

Computer aided detection (CAD) programs are designed to recognize abnormal patterns in mammography images. The abnormal findings (typically both masses and microcalcifications) are marked, alerting the radiologist to take a closer look at the identified areas. The goal is to increase the cancer detection rate, reduce interobserver variability, and, ultimately, reduce breast cancer deaths by increasing early detection. CAD systems are intended to be used by radiologists after they have completed the evaluation of the images without the CAD prompts.

Committee Summary

With regard to computer aided detection (CAD) of breast cancer, the ICSI Technology Assessment Committee finds:

1. CAD causes no direct harm to patients. Misdiagnoses (false-positive or false-negative results) can lead to unnecessary follow-up testing, unnecessary patient anxiety, or delays in obtaining treatment. Lower numbers of false positive marks per image are typically observed for microcalcifications (0.20-0.30 marks/image) compared with masses (0.75-1.0 marks/image).
   
2. In two studies involving screening populations, between 10% and 16% of malignancies were detected by CAD alone and not detected by a radiologist. In one of these studies involving over 12,800 women, the detection rate for cancer increased 19% (from 3.2 to 3.8 cases per 1,000) with the addition of CAD. The evidence supports the use of CAD or a second reading by an independent radiologist to assure quality results.
   
3. For microcalcifications, the reported sensitivity of CAD is 98% to 100%. For masses, architectural distortions, and densities, the reported sensitivity is 67% to 90%. (Conclusion Grade II)
   
4. The radiologist remains the reader and interpreter of the mammogram. CAD assists the radiologist by identifying areas warranting further review.
   
5. In one study with 208 lesions, masses of 10 to 30 mm in diameter were more likely to be detected by a CAD system compared with either smaller or larger lesions.
   
6. The recall rate increased only slightly with the addition of CAD. Reported values ranged from 6.5% to 14.4% without CAD and 7.6% to 15.8% with CAD. The positive predictive value for predicting malignant histopathology on the biopsy was unchanged. Reported values ranged from 28% to 38%.
   
7. Data from one study suggest that CAD applied to digital mammography approximates the results achieved when CAD is applied to film-screen images.