Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Vaginal cancer detected more often with PET than CT scans

24.06.2005


In patients with vaginal cancer, PET scans detected twice as many primary tumors and cancerous lymph nodes as did CT scans, according to researchers at Washington University School of Medicine in St. Louis. At this time, however, Medicaid, Medicare and many private insurers specify CT (computed tomography) for diagnosing and monitoring this cancer.



The researchers hoping to encourage a change in that standard report their comparison of the two methods in the July 1 issue of the International Journal of Radiation Oncology, Biology, Physics.

Like cervical cancer, vaginal cancer advances predictably, spreading to lymph nodes increasingly higher up in the body as the disease progresses. Doctors use information about the size of the tumor and the involvement of lymph nodes to determine treatment, such as where to target radiation and whether to use surgery or chemotherapy.


The results of this study suggest that the use of PET, or positron emission tomography, would make diagnosis of vaginal cancer much more accurate and allow better selection of treatment, according to study author Perry W. Grigsby, M.D., professor of radiation oncology and radiology.

However, until the procedure is reviewed and approved by the Centers for Medicaid and Medicare Services (CMS), vaginal cancer patients will most likely not be evaluated using PET scans.

CMS policies set standards often followed by private health insurance companies and therefore strongly determine what procedures physicians use. Studies such as this one play an essential role in CMS acceptance of new procedures.

"In 1999, we began publishing papers showing that PET scans picked up more cancerous lymph nodes in patients with cervical cancer," Grigsby says. "Armed with data from these kinds of studies, I went to Washington in 2003 to petition CMS to approve the use of PET scans for diagnosis of cervical cancer. In January of 2005, the procedure was approved for cervical cancer."

Several other cancers, in addition to cervical cancer, can be diagnosed and monitored using PET scans as the result of CMS acceptance. Grigsby is now working to persuade CMS that PET scans will improve the diagnosis and treatment of vaginal cancer.

"CT scans are useful in many cases, but they have a limit to their resolution," says Grigsby, who sees patients at the Siteman Cancer Center and is affiliated with Barnes-Jewish and St. Louis Children’s Hospitals. "When you’re evaluating lymph nodes for cancer using CT, the node has to be at least a centimeter for it to be considered abnormal. But PET scans can detect much smaller nodes that have cancerous cells."

PET scans are effective for this purpose because they use a different detection method than CT scans. CT scans obtain cross-sectional views of the body by detecting the amount of X-rays that pass through the body’s tissues. Small tumors can easily escape detection.

On the other hand, PET scans detect radioactivity that emanates directly from a tumor after a patient has received a dose of radioactive glucose, which accumulates in tumors. Even tiny tumors will collect enough "hot" glucose to show up on the PET scan.

Vaginal cancer is very similar to cervical cancer; both are linked to the presence of human papillomavirus. About 1 percent of gynecological malignancies are vaginal. The rates of survival with vaginal cancer are considered to be similar to those of cervical cancer.

According to Grigsby, if cervical cancer has not spread beyond its primary site, about 90 percent of patients will survive. The rate of survival drops to 70 percent if the cancer has spread to lymph nodes in the pelvis. The next stage of progression, in which the cancer has spread to nodes near the heart, has a survival rate of 30 to 40 percent. After that, untreated cervical cancer will move to nodes near the collar bone and will not be survivable.

"It is very important to know at the time of diagnosis, for both cervical and vaginal cancer, not only what the patient has in the pelvis, but where the tumor has spread," Grigsby says. "That will absolutely determine the kind of treatment."

Gwen Ericson | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>