June 11, 2010

Headlines in the News:

High-Intensity Ultrasound Ablation Possible Treatment for Bone Tumor

Study Finds Groundbreaking Technology in TechniScan's Warm Bath Ultrasound Promising

Ultrasound Can Help Tissue Grafts Survive

Cervical Length Equivalent to Fetal Fibronectin for Predicting Preterm Birth

High-Intensity Ultrasound Ablation Possible Treatment for Bone Tumor

High-intensity focused ultrasound appears to be effective for ablating primary bone tumors, and could contribute to existing chemotherapy and limb-salvaging surgical regimens, according to Chinese researchers.

They found that long-term survival rates for patients with stage IIb disease were substantially better in patients who underwent the complete regimen of high-intensity focused ultrasound and chemotherapy than in those who did not finish the chemotherapy cycles or who underwent partial ablation only.

The study appears in the June issue of Radiology. As a local treatment, the authors note, high-intensity focused ultrasound can be used to treat malignant tumors, and a high rate of complete tumor ablation can be achieved.

This looks like a promising way to treat bone tumors, said Levon N. Nazarian, MD, a professor of radiology and vice chair of education at Thomas Jefferson University in Philadelphia, Pennsylvania.

"The technology has existed in the United States for quite a few years, and is similar to that used to treat uterine fibroids and, more recently, tumors in the liver," said Dr. Nazarian, who was not involved in the study.

However, there will be some hurdles in the United States before it is approved for use in bone tumors, he added. In an interview, Dr. Nazarian pointed out that bone tumors are often treated in referral centers. "There is potential for these centers to see this technique as a less invasive way of treating bone tumors," he said, "and to possibly adopt this technique."

Because the technology is already available, it could be used off-label to treat bone tumors, but the idea would be to get approval from the US Food and Drug Administration for this indication, Dr. Nazarian explained. "Unfortunately, it often takes a long time to go from the literature to clinical use, as it has to go through clinical trials, which can be lengthy and expensive."

Possible Limb-Saving Technique?

Globally, limb-salvaging treatment has become a routine method of treating bone cancer in carefully selected patients, write the authors. However, amputation remains the treatment of choice for primary bone malignancies in China, because of a shortage of well-trained orthopedic oncologists and late diagnoses. Therefore, new techniques are needed.

"There has been a general consensus that ultrasound energy cannot enter bone at an intensity sufficient for therapeutic ablation," wrote lead author Wenzhi Chen, MD, and colleagues from the Clinical Center for Tumor Therapy, Second Affiliated Hospital of Chongqing Medical University in China. "Thus, we questioned whether high-intensity focused ultrasound ablation therapy could be effectively applied to bone tumors.

The authors sought to address that question by evaluating the effectiveness of ultrasonography-guided high-intensity focused ultrasound ablation in the treatment of patients with primary bone malignancies. The cohort consisted of 80 patients — 60 with stage IIb disease and 20 with stage III disease (Enneking staging system). Treatment options consisted of either chemotherapy plus ultrasound ablation or ablation alone. The choice of treatment depended on the type of cancer.

High-intensity focused ultrasound ablation (60 to 20 W of ultrasound energy) plus chemotherapy was performed in 62 patients with osteosarcoma, 1 patient with periosteal osteosarcoma, and 3 patients with Ewing's sarcoma.

The chemotherapeutic regimen used included cisplatin, adriamycin, methotrexate, and ifosfamide. Chemotherapy was administered in 3 to 5 cycles before ultrasound ablation was performed; another 4 to 6 cycles were given after the ablation.

The remaining patients were diagnosed with chondrosarcoma, giant cell bone cancer, periosteal sarcoma, or an unknown malignancy, and were treated with high-intensity focused ultrasound ablation only because these malignancies are insensitive to chemotherapy.

Follow-up imaging showed that in 69 patients, the tumors had been completely ablated; greater than 50% tumor ablation was observed in the remaining 11 patients.

Best Survival in Patients Who Completed Full Regimen

Overall survival rates for the entire cohort was 89.8% for 1-year, 72.3% for 2-year, 60.5% for 3-year, 50.5% for 4-year, and 50.5% for 5-year survival. The authors also then calculated disease-free survival for 54 patients with stage IIb disease who completed the full regimen of high-intensity focused ultrasound ablation treatment; it was 100% for 1-year, 84.0% for 2-year, 73.5% for 3-years, 62.8% for 4-year, and 62.8% for 5-year survival.

Survival Rates Categorized by Disease Stage

The survival rates at different intervals were significantly different between the 2 disease stages (P < .001), and survival was significantly higher among patients who completed the full treatment protocol than among those who did not (P < .001). For example, patients with stage IIb disease who achieved complete tumor ablation and the full 9 cycles of chemotherapy had a 5-year survival rate of 86.4%. But patients who did not complete the full chemotherapy protocol had a 5-year survival rate of 35.9%.

Of the 69 patients who had completely ablated tumors, only 5 (7%) experienced local tumor progression after a mean follow-up of 36.8 months. Upon multivariate analysis, the authors found that tumor stage (P = .00) and completed treatment (P = .01) were associated with survival, whereas age, sex, and tumor histology were not independent factors for survival.

The most common adverse event, other than mild local pain, was skin toxicity (21%), followed by peripheral nerve damage (12%). Overall, 40 adverse events were recorded, and 14 patients experienced complications that required surgical intervention.

"The results of this study demonstrate that [ultrasonography]-guided focused ultrasound can render complete bone tumor responses," the authors conclude, adding that further studies are needed to ascertain which patient subgroup(s) would be best suited for this noninvasive treatment.

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Article written by staff at medscape.com and adapted for the purposes of this newsletter.

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Study Finds Groundbreaking Technology in TechniScan's Warm Bath Ultrasound Promising

TechniScan, Inc.'s  unique whole breast ultrasound technology, which provides a comfortable, radiation-free method for assessment of breast lesions was part of a scientific presentation at the National Consortium of Breast Centers (NCBC) conference in Las Vegas last week.

Yuri Parisky, radiologist, vice president and trustee of the NCBC organization and consultant to TechniScan, Inc. participated in the Orange County, CA research study that was presented at the conference.  The objective of the study was to determine the usability of the new Warm Bath Ultrasound (TM) technology in a standard breast diagnostic practice.  The study found that the groundbreaking technology used in TechniScan's Warm Bath Ultrasound (WBU) produced promising results and indicated that it may have a future role in the evaluation of breast lesions.

"Ultrasound technology is playing a larger role in breast diagnostics because it images cysts, fibroadenomas and cancers differently than mammography. Ultrasound is much better at seeing through dense breasts and finding cancers when they are smaller," said Parisky. "The emergence of whole breast ultrasound technology and specifically the WBU system is providing us with 3-D images of the entire breast, and will hopefully become a standard imaging modality in the next few years."

TechniScan's Warm Bath Ultrasound system is designed to capture three-dimensional images of the breast as a woman lies prone on a table and state-of-the art ultrasound technology is used in a warm water tank to capture images of the breast anatomy.

The company's science is revolutionary since it is the first high-resolution, 3-D system to deliver quantitative data. The WBU system uses traditional reflection imaging, but uniquely, it also measures the speed of sound and attenuation as sound waves travel through the breast.

At the breast center conference in Las Vegas on March 21, Parisky presented the clinical experience using TechniScan's whole breast ultrasound system.  He explained that of the 34 patients participating in the study at the Breast Care and Imaging Center of Orange County, there were 14 cases with cysts, one case of silicone granulomas from a breast implant, 14 benign masses and eight biopsy-confirmed malignancies. The Warm Bath Ultrasound images were able to provide 3-D visualization of lesion location within the breast.

The study also found that the WBU scanning system was easy to use and required minimal training. A sonographer is not necessary to administer the scan since the system is automated. Additionally the scans were quick (approximately 12 minutes per breast) and required no breast compression.

"The WBU system was clearly able to distinguish between fibroglandular and other complex structures within the breast. Combined, the speed of sound, reflection and attenuation images are expected to improve 3-D visualization and improve specificity of breast lesions," said Parisky.

The future for whole breast ultrasound is encouraging. The radiologist panel at the Emerging Technologies Lecture at NCBC acknowledged that ultrasound paired with mammography is finding more cancers than mammography alone and 3-D imaging provides greater insight into the breast anatomy.

"We expect whole breast ultrasound will become a widely adopted modality for 3-D breast imaging in the coming years as radiologists begin to recognize the ease of use and imaging capabilities of automated breast ultrasound systems. We believe that our whole breast ultrasound will be competitive with technologies like breast MRI, and study after study is validating that ultrasound is finding cancers that mammography alone can't image," said Dave Robinson, chief executive officer at TechniScan.

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Article written by staff at news-medical.net and adapted for the purposes of this newsletter.

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Ultrasound Can Help Tissue Grafts Survive

According to a new study, ultrasound could help tissue grafts to survive and thrive following surgery. As per recent evidence, ultrasound at lower frequency can also be used to help certain body tissues to cure and redevelop.

Low-intensity ultrasound can regenerate cartilage and bone. It can also be used in tissue engineering to stimulate cells. A patient's own fatty tissue is used by surgeons in procedures like facial plastic surgery, breast reconstruction and surgery on the vocal cords.

But, it varies from person to person that how well these tissue grafts survive. If the graft fails to get sufficient oxygen and glucose, the grafted tissue will fade and die.

A research team looked conducted a test to know whether ultrasound could improve the feasibility of grafted tissue during the post-op period. Adipose cells were used by the researchers for their experiments, which is taken from tissue left over from tummy-tuck operations and mouse muscle cells.

The test cells were treated with LIUS at 30mW/cm2 for short bursts of three or ten minutes, for a six-day period. The researchers examined for the number of cells, metabolism, viability and for signs of damage to the cells. LIUS can influence the viability of the cultured adipose cells, as per the results of the research conducted.

Lead author Dr. Hyoungshin Park, from MIT said, “In the context of using LIUS to enhance autograft survival, the possibility that the LIUS can directly activate signaling pathways in implanted cells needs to be taken into account”.

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Article written by staff at topnews.co.uk and adapted for the purposes of this newsletter.

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Cervical Length Equivalent to Fetal Fibronectin for Predicting Preterm Birth

A new disposable measuring probe called CerviLenz, designed to measure vaginal cervical length, is as effective as fetal fibronectin in assessing risk for preterm delivery, according to researchers here at the American Congress of Obstetricians and Gynecologists 58th Annual Clinical Meeting. But whether the tool has any advantages over physical examination by an experienced clinician and/or screening by ultrasound remains unclear.

Researchers at Harbor-UCLA Medical Center in Los Angeles, California, found CerviLenz to have negative and positive predictive values similar to fetal fibronectin in screening women for risk for preterm birth.

"Fetal fibronectin is a good predictor of preterm birth, but it's limited by cost, turnaround time of an hour or more, and inability to [use it] after intercourse or with bleeding," said lead researcher Richard Burwick, MD. Cervical length in asymptomatic patients and cervical length and effacement in symptomatic patients are also good predictors of preterm birth; a cervical length shorter than 25 mm is associated with a 6-fold increased risk, he added. However, cervical length is often measured by digital exam, which "can be variable and often very subjective," Dr. Burwick said.

In a study published in the Journal of Reproductive Medicine (2007;52:385-389), researchers found that CerviLenz had 88% sensitivity, 92% specificity, and 99% negative predictive value for identifying patients with a short cervix (less than 30 mm), compared with transvaginal ultrasound. Those researchers concluded that the CerviLenz tool could be used to screen for patients with short cervixes who might benefit from transvaginal ultrasound.

Although preterm birth is a complication in more than 12% of pregnancies and results in significant neonatal morbidity and mortality, only 21% to 27% of women with symptoms of preterm labor will deliver preterm. Therefore, clinicians have long sought an accurate way to assess risk for preterm birth and interventions for the morbidities associated with preterm delivery, Dr. Burwick noted.

In the UCLA study, 52 patients between 24 and 34 weeks of gestation and at risk for preterm labor underwent a speculum exam, fetal fibronectin collection, CerviLenz measurements, and cervical cultures. All had uterine contractions, less than 3 cm dilation, and intact membranes with singleton gestation. None had had recent intercourse or vaginal bleeding.

The mean gestational age among all participants was 30.4 weeks, 28.9% had experienced a previous preterm birth, and 72.6% were Hispanic (the remaining were white, black, or other ethnicities).

Patients with a negative fetal fibronectin test and no cervical changes were discharged home with the standard management of hydration, terbutaline, and bed rest. Those with a positive fetal fibronectin test or cervical changes received corticosteroids and were evaluated for potential admission and tocolysis.

Forty-three women underwent the CerviLenz test and 49 had their fetal fibronectin levels measured. Of the women who underwent CerviLenz measurements, 20.9% had a cervical length of less than 30 mm. Of those who underwent fetal fibronectin measurement, 24.5% were positive.

Positive predictive values and negative predictive values for preterm birth with the fetal fibronectin test and CerviLenz were similar, Dr. Burwick reported.

Prior to 37 weeks of gestation, fetal fibronectin had a positive predictive value of 33.3%, whereas the positive predictive value of CerviLenz was 22.2%. When the researchers analyzed both tests for positive and negative predictive values in assessing risk for preterm delivery within 7 days of evaluation, they found that the positive predictive value of fetal fibronectin was 16.7% and of CerviLenz was 22.2%. The negative predictive value in assessing risk for preterm labor and preterm delivery within 7 days of evaluation was also similar for both tests — 97.3% for fetal fibronectin and 97.1% for CerviLenz.

"CerviLenz is advantageous because it provides immediately quantifiable results and can be measured even in the presence of bleeding and after recent vaginal intercourse," Dr. Burwick said.

However, larger studies need to be done to assess how useful CerviLenz is likely to be, said John T. Repke, MD, FACOG, professor and chair of the Department of Obstetrics and Gynecology at Penn State University College of Medicine in Hershey, Pennsylvania.

"The problem with comparing CerviLenz to fetal fibronectin is that a positive test result with fetal fibronectin is usually not too helpful, although a negative result does give you a high degree of assurance that a person is not going to [give birth] within the next 1 to 2 weeks. So if one were to say fetal fibronectin is not a useful tool, then one could conclude from this study that CerviLenz is not particularly useful either," he said.

Most clinicians agree that cervical length plus fetal fibronectin are often the best methods, when used together, for screening women at risk for preterm birth, added Katherine Wenstrom, MD, director of the Division of Maternal Fetal Medicine at Women's and Infants Hospital of Rhode Island in Providence. "The study confirms that cervical length does help predict preterm birth. But the question is: Does the CerviLenz device add anything? Experienced obstetrician examiners get pretty good at measuring cervical length with their hands," she said.

Dr. Wenstrom noted that CerviLenz is unlikely to replace ultrasound or be proven better than this imaging test at assessing risk for preterm delivery. "With ultrasound you can not only determine the length of the cervix, you can also look at the upper part of the cervix to see the dilation of the internal os — whether the membranes are prolapsing — a process we call funneling. I can't believe that CerviLenz could add anything to what we would learn with ultrasound," she said.

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Article written by staff at medscape.com and adapted for the purposes of this newsletter.

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