Less-Invasive Biopsies More Common

By Michael Smith, North American Correspondent, MedPage Today
Published: August 13, 2010
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine,
Harvard Medical School, Boston and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner Earn CME/CE credit for reading medical news.

The number of biopsies using less-invasive percutaneous methods nearly doubled over a decade, according to researchers.

And, because of the shift to image-guided procedures, radiologists are now performing half of all procedures, and 70% of lymph node biopsies, according to Sharon Kwan, MD, of the University of California San Francisco, and colleagues.

But practice patterns are still evolving and in some areas, nonradiologists are increasing their share of biopsies, Kwan and colleagues reported online in Radiology.

The first percutaneous needle biopsy of the liver was reported in 1932, but the advent of new imaging techniques in recent years suggests that image-guided percutaneous procedures -- performed by radiologists -- would have largely replaced more invasive procedures.

To investigate the issue, Kwan and colleagues analyzed Medicare claims data from 1997 through 2008, which showed that biopsies using all procedures rose from 1,380 to 1,945 procedures per 100,000 Medicare enrollees between 1997 and 2008.

That change represents a compound annual growth rate of 3%, the researchers reported.

During the study period, they found, percutaneous needle biopsies did increase -- from 59% to 67% of all biopsies (with the exception of breast biopsies, where a coding change in 2001 affected the reported distribution of open versus percutaneous procedures).

The use of percutaneous needle biopsies rose from 295,836 in 1997 to 573,397 in 2008 -- equivalent to an increase from 953 to 1,645 biopsies per 100,000 Medicare enrollees, for a compound annual growth rate of 5%.

On the other hand, the researchers reported, biopsies performed with nonpercutaneous approaches had a compound annual growth rate of minus 3% over the same time period.

But the choice of method varied widely with anatomic site, they found. On one hand, percutaneous needle biopsies were the dominant choice for kidney and liver, representing 96% and 90%, respectively, of all biopsies in these sites in 2008.

On the other hand, percutaneous needle biopsies were the minority in the superficial lymph nodes and musculoskeletal soft tissues, at 46% and 30%, respectively, they reported.

Most Current Procedural Terminology codes don't distinguish between percutaneous procedures performed with and without image guidance, the researchers noted, but for two areas that do -- percutaneous core biopsies of the breast and fine needle aspirations -- there was an increase in the use of imaging.

For breast biopsies, image guidance rose from 85% in 2002 to 95% in 2008, while for fine needle aspirations, the increase was even greater -- from 54% in 2004 to 77% in 2008, they found.

Over the study period, the top three specialties performing biopsies were radiology, general surgery, and pulmonology. Members of those specialties together performed 75% of all biopsies during the period.

Radiologists' share, however, increased steadily, from 35% in 1997 to 56% in 2008, while general surgeons and pulmonologists saw their shares decrease from 21% to 15% and 10% to 5%, respectively, Kwan and colleagues reported.

The most rapid growth, according to anatomic region, occurred in lymph node biopsies, where radiologists' share increased from 12% to 70%, for a compound annual growth rate of 22%.

Radiologists' share of fine needle aspirations also increased -- from 4% to 44%, for a compound annual growth rate of 37%.

The researchers noted that one limitation of Medicare data is that they mainly involve an elderly population, so the findings may not apply to a younger population.

Also, they reported, the precision of the analysis was limited by the "idiosyncrasies" of Current Procedural Terminology coding, which was used to calculate numbers and types of procedures.

The study was supported by the National Institute of Biomedical Imaging and Bioengineering.

The authors declared they had no financial relationships to disclose.

Primary source: Radiology

Source reference:
Kwan SW, et al "Effect of advanced imaging technology on how biopsies are done and who does them" Radiology 2010; DOI: 10.1148/radiol.10092130.

Source