Virtual Colonoscopy Can Screen for Bone Loss

CHICAGO — CT colonography can screen as reliably for osteoporosis as dual-energy x-ray absorptiometry and can be used to screen simultaneously for bone loss and colorectal cancer, a study of 35 patients suggests.

Of the currently accepted tests for colorectal cancer—CT colonography (CTC), flexible sigmoidoscopy or barium enema every 5 years, and colonoscopy every 10 years—”virtual colonoscopy stands out as the only one that can look outside the colon,” study investigator Dr. Aslam Rizwan said at the annual meeting of the Radiological Society of North America.

The investigation showed that there was excellent agreement between retrospectively derived bone mineral density (BMD) and T scores from CTC data sets and BMD and T scores from dual-energy x-ray absorptiometry (DXA) in the same patients, reported Dr. Rizwan of the University of California, San Francisco.

The dual-purpose screening with CTC would provide information on osteoporosis risk with no additional radiation, Dr. Rizwan said.

However, he emphasized that he is not suggesting that CTC replace DXA; rather, in patients who already are being screened for colorectal cancer, “the data [on BMD] is there; it's available, and we should use it.”

He added that “both techniques have been proven individually. We're showing that it's feasible to do both tests on the same patient at the same time. These patients are going to be screened for polyps … so for no extra cost we can also screen for [bone loss].”

Use of CTC to screen simultaneously for osteoporosis and colorectal cancer offers “added value to a test you're going to give anyway. … The added value is that it can give you information on BMD,” said study coauthor Dr. Judy Yee, who is also of the university.

A total of 30 men and 5 women with a mean age of 66 years (age range 54-79) underwent both CTC and DXA. Two experienced readers independently calculated BMD and T scores from CTC data sets. CT bone density measurements were obtained with a bone mineral analysis software package at three vertebral bodies from T12 to L1.

In addition, density measurements alwere obtained from fat and muscle to provide an internal reference for calculating BMD, T scores, and z scores, Dr. Yee explained.

For both readers, significant correlations were found between the CT and DXA BMD measurements for each vertebral body, and between the CT and DXA T scores for each vertebral body.

Significant correlations also were found between the CT and DXA BMD averages for all vertebrae for both readers.

The results revealed good agreement between the two readers as well, Dr. Rizwan said.

The Centers for Medicare and Medicaid Services (CMS) do not currently offer coverage for CTC, other than for diagnosis in symptomatic patients, said Dr. Yee, but “we hope there will be [screening] coverage in 2009.”

Dr. Rizwan said that prospective studies are planned. He and Dr. Yee reported no financial conflicts of interest related to this study.

Value is added to CT colonography by being able to detect osteoporosis. Radiological Society of North America

CHICAGO — CT colonography can screen as reliably for osteoporosis as dual-energy x-ray absorptiometry and can be used to screen simultaneously for bone loss and colorectal cancer, a study of 35 patients suggests.

Of the currently accepted tests for colorectal cancer—CT colonography (CTC), flexible sigmoidoscopy or barium enema every 5 years, and colonoscopy every 10 years—”virtual colonoscopy stands out as the only one that can look outside the colon,” study investigator Dr. Aslam Rizwan said at the annual meeting of the Radiological Society of North America.

The investigation showed that there was excellent agreement between retrospectively derived bone mineral density (BMD) and T scores from CTC data sets and BMD and T scores from dual-energy x-ray absorptiometry (DXA) in the same patients, reported Dr. Rizwan of the University of California, San Francisco.

The dual-purpose screening with CTC would provide information on osteoporosis risk with no additional radiation, Dr. Rizwan said.

However, he emphasized that he is not suggesting that CTC replace DXA; rather, in patients who already are being screened for colorectal cancer, “the data [on BMD] is there; it's available, and we should use it.”

He added that “both techniques have been proven individually. We're showing that it's feasible to do both tests on the same patient at the same time. These patients are going to be screened for polyps … so for no extra cost we can also screen for [bone loss].”

Use of CTC to screen simultaneously for osteoporosis and colorectal cancer offers “added value to a test you're going to give anyway. … The added value is that it can give you information on BMD,” said study coauthor Dr. Judy Yee, who is also of the university.

A total of 30 men and 5 women with a mean age of 66 years (age range 54-79) underwent both CTC and DXA. Two experienced readers independently calculated BMD and T scores from CTC data sets. CT bone density measurements were obtained with a bone mineral analysis software package at three vertebral bodies from T12 to L1.

In addition, density measurements alwere obtained from fat and muscle to provide an internal reference for calculating BMD, T scores, and z scores, Dr. Yee explained.

For both readers, significant correlations were found between the CT and DXA BMD measurements for each vertebral body, and between the CT and DXA T scores for each vertebral body.

Significant correlations also were found between the CT and DXA BMD averages for all vertebrae for both readers.

The results revealed good agreement between the two readers as well, Dr. Rizwan said.

The Centers for Medicare and Medicaid Services (CMS) do not currently offer coverage for CTC, other than for diagnosis in symptomatic patients, said Dr. Yee, but “we hope there will be [screening] coverage in 2009.”

Dr. Rizwan said that prospective studies are planned. He and Dr. Yee reported no financial conflicts of interest related to this study.

Value is added to CT colonography by being able to detect osteoporosis. Radiological Society of North America

CHICAGO — CT colonography can screen as reliably for osteoporosis as dual-energy x-ray absorptiometry and can be used to screen simultaneously for bone loss and colorectal cancer, a study of 35 patients suggests.

Of the currently accepted tests for colorectal cancer—CT colonography (CTC), flexible sigmoidoscopy or barium enema every 5 years, and colonoscopy every 10 years—”virtual colonoscopy stands out as the only one that can look outside the colon,” study investigator Dr. Aslam Rizwan said at the annual meeting of the Radiological Society of North America.

The investigation showed that there was excellent agreement between retrospectively derived bone mineral density (BMD) and T scores from CTC data sets and BMD and T scores from dual-energy x-ray absorptiometry (DXA) in the same patients, reported Dr. Rizwan of the University of California, San Francisco.

The dual-purpose screening with CTC would provide information on osteoporosis risk with no additional radiation, Dr. Rizwan said.

However, he emphasized that he is not suggesting that CTC replace DXA; rather, in patients who already are being screened for colorectal cancer, “the data [on BMD] is there; it's available, and we should use it.”

He added that “both techniques have been proven individually. We're showing that it's feasible to do both tests on the same patient at the same time. These patients are going to be screened for polyps … so for no extra cost we can also screen for [bone loss].”

Use of CTC to screen simultaneously for osteoporosis and colorectal cancer offers “added value to a test you're going to give anyway. … The added value is that it can give you information on BMD,” said study coauthor Dr. Judy Yee, who is also of the university.

A total of 30 men and 5 women with a mean age of 66 years (age range 54-79) underwent both CTC and DXA. Two experienced readers independently calculated BMD and T scores from CTC data sets. CT bone density measurements were obtained with a bone mineral analysis software package at three vertebral bodies from T12 to L1.

In addition, density measurements alwere obtained from fat and muscle to provide an internal reference for calculating BMD, T scores, and z scores, Dr. Yee explained.

For both readers, significant correlations were found between the CT and DXA BMD measurements for each vertebral body, and between the CT and DXA T scores for each vertebral body.

Significant correlations also were found between the CT and DXA BMD averages for all vertebrae for both readers.

The results revealed good agreement between the two readers as well, Dr. Rizwan said.

The Centers for Medicare and Medicaid Services (CMS) do not currently offer coverage for CTC, other than for diagnosis in symptomatic patients, said Dr. Yee, but “we hope there will be [screening] coverage in 2009.”

Dr. Rizwan said that prospective studies are planned. He and Dr. Yee reported no financial conflicts of interest related to this study.

Value is added to CT colonography by being able to detect osteoporosis. Radiological Society of North America