Early Leader in CT Scans As in Krull’s case, low-dose CT scans play an important role in the Medical Center’s screening program. It was the mysterious shadow on Krull’s CT scan that prompted Hogarth to initiate the virtual bronchoscopy. CT scans recently have garnered more attention; a National Cancer Institute (NCI) study released in November showed that CT scans reduce deaths from lung cancer by 20 percent (compared to traditional chest X-rays) by detecting cancers at relatively early stages. The study is significant because it is one of the first times that a clear benefit has been shown for any form of lung cancer screening, Hogarth said. Results were based on the premise that finding tumors early allows patients to be treated before the cancer becomes deadly. “Because of the smoking stigma, there has generally been less funding, action and awareness of lung cancer,” Hogarth said. The newest CT machines are able to obtain detailed crosssectional images of entire organs and not just partial views, as with the older scanners. Organs can be viewed from any angle, and the speed of the new scanners means radiation exposure is significantly reduced. The Medical Center’s 256-slice CT machine produces scans within seconds, four times the capacity of previous generations of scanners. A scan, head to toe, can be acquired in 10 seconds. Because the data is processed more quickly, it translates into higher-quality scans. Previously, when a CT scan depicted a suspicious lesion, there were fewer options for diagnosis and treatment. In many cases, it required sticking a needle through the chest for a biopsy or surgery to remove the suspicious growth. For patients with enlarged lymph nodes or nodules, like Krull, surgery was often required to sample the abnormalities. But now physicians can use less invasive scopes. Since Krull’s treatment, Hogarth has added a new instrument to his high-tech arsenal called Endobronchial Ultrasound (EBUS), which allows him to sample tissues from beyond the confi nes of the endobronchial tree, such as enlarged lymph nodes. The EBUS scope has an ultrasound on its end, which allows Hogarth to see through the bronchial walls into the enlarged lymph nodes and take samples. All of this is done as an outpatient with no scars — and no scalpels.
to conventional bronchoscopy doubled the number of lesions identified, compared to standard bronchoscopy. Another way to boost the dynamics of bronchoscopy is through a technology called narrow-band imaging. Pre-cancers and cancers usually have abnormal growths of blood vessels leading to them. Narrow-band imaging identifies lesions not seen in a regular bronchoscope using two wavelengths of light to highlight the blood vessels and make them easier for the physician to see. These new technologies are useful not just episodically, when a CT scan finds something suspicious, but in tracking the health of a lung cancer survivor, like Krull. In December 2010, six years after his cancer treatment, Krull had his routine CT scan. This time, the results were clear. But because of his former smoking and medical history, Hogarth followed up with the autofluorescence scope and the narrow-band imaging. “There were no abnormalities seen at all,” Hogarth said. “These technologies allow us to identify someone who has a definitive risk for lung cancer and to say, ‘Let’s go in and destroy it.’ Quite literally, we’re nipping cancer in the bud.” ■ Ruth Carol contributed to this report. For more information about the lung cancer screening program, please call 773-702-9660.
Finding Pre-Cancers, Moving to Prevention Borrowing from the lexicon of video gaming, bronchoscopy also has the ability to “power up” by adding fluorescent light to detect lesions at the pre-cancerous phase — when the lesion is just a few cells in thickness. This “autofluorescence capability” allows pre-cancerous tissues to appear in a different color than the healthy tissue. Despite the success of most CT scans in finding abnormalities, they can still miss small pre-cancers starting within the airways of the lungs, but an autofluorescence scope allows physicians to detect and remove these lesions before they have any opportunity to grow or invade lung tissue. “We can sometimes find lesions invisible to the naked eye,” Hogarth said. “The analogy is a colonoscopy that allows you to remove a polyp which, if left alone, could become a cancer. We’re eliminating the pre-cancers.” Initial results from a study of more than 3,000 patients at multiple medical centers found that adding autofluorescence
Kyle Hogarth, MD, using the lung mapping software to help locate the lesions that need to be sampled in a patient. Photo by Bruce Powell
“We can sometimes find lesions invisible to the naked eye. The analogy is a colonoscopy that allows you to remove a polyp which, if left alone, could become a cancer. We’re eliminating the pre-cancers.” — Kyle Hogarth, MD
Medicine on the Midway Spring 2011
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