A new, large-scale study of more than 10,000 adults found that more than one in every 200 asymptomatic people screened with CT colonography, or virtual colonoscopy, had clinically unsuspected malignant cancer and more than half of the cancers were located outside the colon. The findings were published in the April issue of the journal Radiology.

“We are finding that virtual colonoscopy screening actually identifies more unsuspected cancers outside of the colon than within it,” said lead author Perry J. Pickhardt, M.D., professor of radiology and chief of GI Imaging, at the University of Wisconsin School of Medicine & Public Health. “As with asymptomatic colorectal cancers identified by virtual colonoscopy screening, these cancers are often detected at an early, curable stage.”

Colorectal cancer remains the second leading cause of cancer death in the U.S., and the National Cancer Institute estimated that there would be 146,970 new cases diagnosed in 2009 and 49,920 deaths. The disease is largely preventable through screening for colon polyps, which are benign growths that may develop into cancer if not removed. The American Cancer Society recommends that people at average risk for colorectal cancer begin regular colorectal cancer screening at age 50, but current compliance with this recommendation is below 50 percent. Many people resist screening because of the discomfort and inconvenience caused by the conventional optical colonoscopy test.

Virtual colonoscopy is less invasive than optical colonoscopy and produces precise and detailed “fly-through” images of the entire colon’s interior without having to insert a scope. With virtual colonoscopy screening, there is essentially no risk of bleeding or of perforating the colon. There is no need for intravenous sedation, and the procedure is less costly than conventional optical colonoscopy. It also is more convenient, typically taking 10 minutes or less.

Virtual colonoscopy also allows for limited assessment of structures outside the colon (extracolonic), including the abdomen, pelvis and portions of the lungs. Additional diagnostic tests for unsuspected extracolonic findings are performed in about 6 percent of cases, nearly half of which ultimately prove to be clinically relevant.

“Optical colonoscopy cannot provide for any assessment beyond the colon itself, whereas virtual colonoscopy can detect a wide array of unsuspected extracolonic diseases, most notably cancers and aortic aneurysms,” Dr. Pickhardt said.

For the study, Dr. Pickhardt and colleagues set out to determine the detection rate and clinical outcome of unsuspected malignancies detected with virtual colonoscopy in an asymptomatic screening population. The researchers retrospectively reviewed the medical records of 10,286 adults (5,388 men and 4,898 women) with a mean age of 59.8 years who were evaluated at either the University of Wisconsin or National Naval Medical Center. All of the adults had undergone colorectal cancer screening with virtual colonoscopy at the two centers between April 2004 and March 2008. The mean time for follow-up was 30.2 months.

Unsuspected cancer was confirmed in 58 patients, including 33 women and 25 men. Invasive colorectal cancer was found in 22 patients, and extracolonic cancer was found in 36 patients. Cancers in 31 patients (53.4 percent) were stage 1 or localized cancers.

“To our knowledge, none of the patients who presented with stage 1, stage 2 or localized disease at diagnosis has progressed to a higher stage,” Dr. Pickhardt said. “The fact that so many of the cancers in our study were localized or detected at an early stage appears to have positively affected survival.”

Extracolonic malignancies, which outnumbered cases of invasive colorectal cancer, included renal cell carcinoma, lung cancer and non-Hodgkin lymphoma, among others.

“Although extracolonic evaluation at screening CT colonography does carry some disadvantages, such as patient anxiety, inconvenience, or the potential for benign biopsy, our results suggest that early detection of asymptomatic extracolonic cancer represents an additional benefit of screening CT colonography that is not available with optical colonoscopy,” Dr. Pickhardt said.

“Virtual colonoscopy is an accurate, safe and convenient screening test that could potentially be a life-saving examination,” he added.

Current evidence suggests that using Doppler ultrasound in high-risk pregnancies to monitor a fetus’ health may reduce caesarean sections and the number of babies who die, according to a new Cochrane Systematic Review.

Doppler ultrasound is a well established technique used to diagnose problems during pregnancy. In the same way that a speed radar measures how fast cars are travelling, Doppler ultrasound can monitor how fast blood is moving in the umbilical blood flow. Professionals can then look to see whether the blood flow is normal, indicating that the fetus is healthy, or abnormal, indicating that the fetus is under stress. The health professionals can then decide which high-risk pregnancies need assistance in delivering the baby, and which women can be left to deliver without assistance.

The aim of using Doppler is to reduce risk to the baby. However, some experts argue that it may prompt some unnecessary early interventions.

The review included 18 studies which together included 10,000 women in “high risk” groups. High risk women included those who had previously lost babies during pregnancy, those carrying growth restricted babies and women with hypertension or diabetes. Women who were examined with Doppler ultrasound were compared with those who had no Doppler or with those who had cardiotocography (CTG), which monitors the baby’s heartbeat. According to the results, Doppler reduced infant deaths, possibly through better timing of caesarean sections, as well as reducing the number of caesarean sections themselves, and inductions of labour. However, the researchers say the studies included were of questionable quality.

“A case could certainly be made for a higher quality, multi-centre trial of Doppler ultrasound than we have so far seen,” said lead researcher Zarko Alfirevic, who is based at the Division of Perinatal and Reproductive Medicine at the University of Liverpool. “It is quite possible that for some so-called high risk groups fetal Doppler offers little or no benefit. Women with diabetes are one such group where fetal Doppler may, in fact, give false reassurance.

“It is important to point out, of course, that it is the clinical decision that follows a Doppler ultrasound examination that changes the outcome for the baby, and currently there is little agreement on what intervention should follow an abnormal Doppler finding.”

Combining drugs and radiotherapy improves the survival chances of women receiving treatment for cervical cancer. These are the conclusions of Cochrane Researchers who carried out the most comprehensive study of the effects of combined drug and radiotherapy in cervical cancer treatment to date.

Cervical cancer is the second most common cancer in women worldwide. Treatments for the disease have changed markedly over the last decade as a result of guidelines issued by the National Cancer Institute (NCI) in 1999, which stated that chemoradiotherapy should be considered as an alternative to radiotherapy. Chemoradiotherapy combines chemotherapy (drug treatment) and x-ray treatment, whereas radiotherapy is just x-ray treatment.

“We saw clear evidence that adding chemotherapy to radiotherapy improves survival, as well as disease free survival,” said Claire Vale, of the Medical Research Council Clinical Trials Unit in London in the UK. “These are effective, affordable treatments that provide a benchmark for other potential treatment approaches.”

The researchers analysed data from 15 trials involving a total of 3,452 women. They found that compared to women who had radiotherapy alone, women receiving chemoradiotherapy were more likely to live for longer after treatment. Five years after receiving treatment, 66 out of every 100 women survived with chemoradiotherapy compared to 60 out of 100 with radiotherapy. In addition, treatment with chemoradiotherapy reduced the chance of the cancer coming back or spreading to other areas. Crucially, their analysis showed that the benefits of chemoradiotherapy were not just restricted to the platinum-based drugs recommended by the NCI.

Based on a small subset of the data, there was also an indication that continuing drug therapy after chemoradiotherapy could improve survival rates even further, although the researchers say more studies are required to confirm this. “We suggest that new trials are needed to find out whether giving extra chemotherapy is better for women with cervical cancer or not,” said Vale.

The world’s smallest flexible microscope is diagnosing some big diseases and allowing physicians to treat patients on the spot. Dr. Michel Kahaleh, associate professor of medicine in the Division of Gastroenterology and Hepatology at the University of Virginia Health System, is the only physician in Virginia currently using probe-based confocal laser endomicroscopy (pCLE). pCLE is a technique that lets him view live tissue in real time at the cellular level. This allows the identification of cancer with pinpoint precision and permits precise removal of the diseased tissue.

“Until now, if we found suspicious tissue during one of these diagnostic procedures, we often had to randomly sample it and send it to the laboratory for analysis, which can take up to a week,” says Kahaleh. “With pCLE, we can pinpoint the dangerous tissue during the initial diagnostic procedure and remove or treat it the same day.”

Kahaleh and his team are using pCLE to more accurately differentiate cancerous and pre-cancerous tissue during colonoscopies, upper endoscopies, and the standard pancreatic and bile duct cancer detection procedure. They also use pCLE to catch and treat gastrointestinal cancers and other GI diseases, including those of the colon, bile duct, pancreas, and esophagus.

“This new imaging tool gives us the opportunity to immediately see changes up to the cell level and potentially gain insights of what may be wrong, thus optimizing patient treatment,” Dr. Kahaleh explains.

A growing body of research continues to warn of the potential long-term effects of radiation exposure for patients and medical providers during such imaging procedures as x-rays and computed tomography (CT) scans, both of which are traditionally used with certain heart procedures.

Now researchers at the University of Virginia Health System have developed a promising x-ray free technique to treat a common heart disorder called atrial fibrillation – a breakthrough that could all but eliminate radiation exposure to patients and their medical providers.

“One of the most exciting things about our research is the direct impact on patient care and safety,” says John D. Ferguson, MD, associate professor of cardiology in the UVA School of Medicine. The study, led by Ferguson, appears in the December 2009 issue of Circulation. “Cardiac interventions continue to evolve toward lower risk procedures, and this study is another huge step in that direction.”

More than two million Americans suffer from atrial fibrillation (AF), a condition characterized by an irregular heart rate that can lead to weakness, blood clotting and even stroke.

In order to regulate the heart’s rhythm, physicians commonly perform a catheter ablation – a procedure in which doctors use x-ray fluoroscopy to guide a catheter, or flexible tube, to the affected area of the heart. The procedure typically lasts three to four hours, leaving patients and medical providers exposed to significant radiation.

But Ferguson’s research team has developed and successfully tested a new technique to perform catheter ablation of AF using an ultrasound catheter (intracardiac echocardiography) and electroanatomic mapping without the use of x-ray fluoroscopy for the entire procedure.

Using an ultrasound catheter within the heart, physicians can obtain high resolution images of the heart and other key anatomic structures. This provides complete visualization at all times of the catheter’s location, allowing physicians to steer the tube to affected target areas while avoiding injury to key cardiac structures.

The novel technique also uses a computer mapping system, which displays in 3D the image of the heart and the catheter’s location and allows physicians to record precise location points along the catheter’s path.

And to further eliminate radiation exposure in AF patients, the new technique uses cardiac MRI instead of CT scans for all required imaging prior to the procedure. Researchers performed the novel technique in a pilot study on 21 consecutive patients referred to the UVA Atrial Fibrillation Center.

“Larger studies are needed to confirm the safety of the procedure, but the concept that you can perform complex electrophysiology procedures without any use of x-ray is outstanding,” says Brian Annex, MD, chief of the UVA Division of Cardiology.

“This research is a ground-breaking step in our efforts to minimize radiation exposure to all patients. This is a major goal that is especially critical to those most vulnerable — patients who would otherwise require excessive radiation due to weight, women of child bearing potential, and of course children and younger adults,” Annex says.

“This procedure is currently being used in selected patients at UVA Medical Center while ongoing investigations are underway to establish the full spectrum of patients who we hope can receive this type of approach in the near future.”

“T-rays” may make X-rays obsolete as a means of detecting bombs on terrorists or illegal drugs on traffickers, among other uses, contends a Texas A&M physicist who is helping lay the theoretic groundwork to make the concept a reality. In addition to being more revealing than X-rays in some situations, T-rays do not have the cumulative possible harmful effects.

Alexey Belyanin focuses his research on terahertz, otherwise known as THz or T-rays, which he says is the most under-developed and under-used part of the electromagnetic spectrum. It lies between microwave radiation and infrared (heat) radiation.

Belyanin, associate professor in the Texas A&M Physics and Astronomy Department, has collaborated with colleagues at Rice University and the National High Magnetic Field Laboratory to publish findings about their T-ray research in the renowned journal Nature Physics.

“THz radiation can penetrate through opaque dry materials. It is harmless and can be used to scan humans,” Belyanin says. “Unfortunately, until recently the progress in THz technology has been hampered by a lack of suitable sources and detectors.”

Belyanin and his team have offered hope: The researchers are able to control the T-rays by varying external parameters like temperature or magnetic field, making it possible to build THz sensors, cameras and other devices.

Traditionally, powerful photons from visible or near-infrared laser pulses are used to probe semiconductors, knocking electrons out of the atoms. Belyanin and collaborators use the less powerful T-rays instead, which only excite the waves in the electron gas because T-rays do not have enough energy to knock out electrons.

“This is as if instead of throwing a stone into a tank of water, which would create a lot of splashes, we gently vibrate one wall of the tank, sending a sound wave through the body of water and ripples over its surface,” he explains.

By varying temperature and the magnetic field, scientists can tune the pulses and observe the behavior of the waves.

“This provides extremely valuable and unique information about the properties of the material, just like seismic waves tell you what is in the Earth’s interior,” the Texas A&M physicist points out.

“The highlight of our results is observations of interference of magnetoplasmons. By tiny changes in the applied magnetic field or temperature, we can make plasma waves amplify or cancel each other. This makes the whole sample either completely opaque or transparent to the incident THz radiation.”

Belyanin believes the technology has important practical implications, such as in security work.

“Using THz cameras, we could detect weapons or drugs concealed on a human body, or look inside envelopes and boxes,” he says. There are many other applications for THz radiation, including material studies, chemistry, biology, medicine.”

Members of a Syracuse University research team have shown that an obscure phenomenon called stochastic resonance (SR) can improve the clarity of signals in systems such as radar, sonar and even radiography, used in medical clinics to detect signs of breast cancer. It does this by adding carefully selected noise to the system.

The result has been a distinct improvement in the system’s ability to correctly identify precancerous lesions, plus a 36 percent reduction in false positives. The inventors have developed a novel method of calculating precisely the correct type and level of noise to add to existing noise in radiography or a similar system.

“We see a broad spectrum of applications for this technology,” says research assistant professor Hao Chen. “If a system’s performance is unsatisfactory, we add noise to the system based on a specific algorithm that can significantly improve system performance.”

A patent covering the technology has been issued to Chen, Distinguished Professor Pramod K. Varshney and research professor James Michels. All are associated with SU’s L.C. Smith College of Engineering and Computer Science.

In mammography studies carried out by doctoral candidate Renbin Peng, the challenge was to identify clusters of micro-calcifications in breast tissue. These early signs of precancerous conditions average only 0.3 mm in size and offer only subtle contrast with surrounding tissue. In addition to improving detection of these lesions, the group has reduced false positives by more than a third.

While the current focus of the research group is on medical uses of stochastic resonance, other applications are expected in enhancing audio, video, geophysical, environmental, radar and other signals. The group has been receiving support from the U.S. Air Force Office of Scientific Research. Ongoing investigations by the Syracuse group are expected to produce further improvements in the efficiency and robustness of the SR-based detection techniques.

This is a wonderfully comprehensive article on urolithiasis in pregnancy and is filled with pearls based on the authors’ experiences with 300 such patients. Valuable clinical take home points include:

a.) One can improve the accuracy of an ultrasound diagnosis of a stone from 56% to 72% by looking for additional indications of obstruction such as the absence of ureteral jets and/or elevated resistive indices.

b.) Colic on the left is more commonly associated with stones (65% vs. 47%) likely due to the cushioning effects of the left colon.

c.) Ureteroscopy is safe and resolved the stone problem in 88% of patients. There was one ureteral perforation; holmium laser lithotripsy is preferred.

d.) As with other smaller studies, fortunately only 3% of the cases occurred during the first trimester.

e.) Ultrasonography is the first line study. If it proves inconclusive, a limited 3 shot IVP was performed and provided an accurate diagnosis in 89%.

f.) Overall 64% of the patients passed their stones spontaneously. Stents were placed in 15%, ureteroscopy was performed in 9%, and only 2% came to placement of a nephrostomy tube. Of note, nearly 2/3rds of the stents were placed during the third trimester; among these patients, almost half poorly tolerated the stent. Given the high success of ureteroscopy and the need to rarely place a post ureteroscopy stent, it would appear that ureteroscopy may be a better alternative than stent placement when intervention is required, especially in the third trimester.

g.) Among patients with an indwelling stent, periodic ultrasonography was performed every 6-8 weeks in order to detect encrustation requiring stent exchange. As such, stent changes were required in only 22% of their patients.

UroToday.com – The development of scarless Laparo-Endoscopic Single Site surgery (LESS) appears to be the next evolutionary step of laparoscopy. In this article we described the technique of LESS radical nephrectomy and we reviewed our experience in a cohort of 10 patients.

The results indicated that LESS nephrectomy is feasible with the use of specially designed instruments. The equipment used was efficient for the safe accomplishment of all cases without the need to conversion to open surgery or to conventional laparoscopy. Nevertheless, in two cases of right nephrectomy, an additional port was deemed necessary in order to offer lateral retraction of the liver. The only part of the procedure not facilitated well by current instrumentation was kidney retrieval at the end of the precedure, since the standard 15-mm Endo-catch bag couldn’t be inserted through the TriPort used and, a cumbersome approach was performed for organ retrieval. New specially designed ports or endo-catch bags are expected in order to overcome the above issue. An intraoperative bleeding was the only complication encountered and was successfully managed endoscopically.

Currently, the advantages of LESS over conventional laparoscopy are not yet well documented. The superiority of LESS approach in matters of scar formation and postoperative pain is questionable. Despite the sophisticated flexible/ articulating instruments used, the technical performance of the approach is still considered challenging and time consuming. Significant laparoscopic experience is necessary for the performance of LESS radical nephrectomy. However, LESS should be considered as a further step in minimally invasive surgery. In addition, the use of more advanced instrument designs as well as robotics may improve intraoperative ergonomics to further enhance the benefit of the LESS approach.

Duke University Medical Center researchers have figured out how stem cells in the malignant brain cancer glioma may be better able to resist radiation therapy. And using a drug to block a particular signaling pathway in these cancer stem cells, they were able to kill many more glioma cells with radiation in a laboratory experiment.

The work builds off earlier research which showed that cancer stem cells resist the effects of radiation much better than other cancer cells.

The Duke team identified a known signaling pathway called Notch as the probable reason for the improved resistance. Notch also operates in normal stem cells, where it is important for cell-cell communication that controls cell growth and differentiation processes. The study was published in late November by Stem Cells journal.

“This is the first report that Notch signaling in tumor tissue is related to the failure of radiation treatments,” said lead author Jialiang Wang, Ph.D., a research associate in the Duke Division of Surgery Sciences and the Duke Translational Research Institute. “This makes the Notch pathway an attractive drug target. The right drug may be able to stop the real bad guys, the glioma stem cells.”

Stem cells in a cancer are the source of cancer cell proliferation, Wang said. Hundreds of cancer stem cells can quickly become a million tumor cells.

The Duke researchers, in collaboration with a team led by Dr. Jeremy Rich at Cleveland Clinic, used drugs called gamma-secretase inhibitors that target a key enzyme involved in Notch signaling pathway on gliomas in a lab dish. These inhibitors are being studied by other researchers for their ability to fight tumors in which Notch is abnormally activated, such as leukemia, breast and brain tumors.

“In our study, gamma-secretase inhibitors alone only moderately slowed down tumor cell growth,” said senior author Dr. Bruce Sullenger, Duke Vice Chair for Research and Joseph W. and Dorothy W. Beard Professor of Surgery. “But when we looked at these molecules combined with radiation at clinically relevant doses, the combination caused massive cell death in the tumors and significantly reduced survival of glioma stem cells. These findings often correlate with better tumor control.”

Wang said ongoing clinical trials are testing gamma-secretase inhibitors as stand-alone therapy for breast and brain tumors. “Our study suggests that Notch inhibition using these drugs would provide significant therapeutic benefits if combined with radiotherapy, and I hope that future research will study this combination therapy in this vulnerable patient population,” Wang said. “More effective radiation may be attainable if we can stop Notch signaling in the tumor stem cells.”