Posts Tagged ‘procedure’

Prostate cancer: Pioneering new imaging method

Severely ill prostate cancer patients are helping researchers test a diagnostic tool that involves injecting a radioactive substance into their bodies. Norway has the fifth highest mortality rate for prostate cancer in Europe.

Four doses of a radioactive tracer called 18F- FACBC are on their way from Oslo to Trondheim in a private jet. Three NTNU researchers, one doctor, two radiographers and a bioengineer fidget nervously as they wait. They check the time.

The plane cannot be delayed. Today is a bad day for fog to descend around Oslo’s main airport, Gardermoen, or for there to be a traffic jam between the Trondheim airport and the city hospital, St. Olavs. Everything has to be on time.

Radioactive decay

From the second that 18F- FACBC is injected into its container, it begins to degrade. In 110 minutes, half of the radioactive substance is gone. If the plane is delayed too much, there won’t be any radioactivity left for the last patient. Then more doses have to be flown up from Oslo.

Now the plane is 20 minutes late. Time really is money when it comes to this radioactive substance. One dose costs NOK 30 000 (3700 Euros). The first patient is already on the table, ready for the procedure. He has an aggressive form of prostate cancer. Doctors fear that it has spread to his lymph nodes.

Now he is waiting to be examined with the most advanced imaging technology that can be found in Norway, a combined PET MRI scan with a price tag of NOK 50 million. He will have to lie still in what boils down to a tiny cave for over an hour while the machine scans and makes images of his blood, bones, and cancer cells.

Finding its way through the body

But this kind of advanced imaging requires a radioactive tracer. With its short half-life, 18F- FACBC (which is an abbreviation for 1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid) has just the right characteristics for the job.

The medical team works quickly when the doses finally arrive at the hospital.

Fortunately, the timing is perfect. First the patient is given an injection of the tracer in his arm, and then placed into the machine, where the tracer finds its way into his veins.

For the radioactive substance to find its way into cancer cells, it needs to have a carrier, a kind of pilot that is able to lead the way to the tumours. In this case, an amino acid acts as the carrier. This is because of cancer cells’ appetite for certain amino acids. A cancer cell is much more active than other cells. It needs more building blocks than other cells, more food. As a result, it attracts and absorbs the amino acid that has been injected into the body.

The radioactive tracer is picked up by detectors that are placed in a ring around the patient in the scanner, and the machine makes images of the cancer cells that light up from the tracer. At the same time, MRI photos of the area are taken, so that doctors get a unique package of information to help them determine which type of treatment is appropriate.

Eight private jets

After an hour, the scan is over and the patient is backed out of the PET MRI. A day later, all of the radioactivity will have left his body. In a few days, he will be in surgery. Hopefully, he has a number of healthy years left to live.

It will take a few years, however, before researchers will be able to conclude how PET MRI scans can be used to improve the diagnosis and treatment of prostate cancer. First, they need to conduct their study with 32 patients. Eight private jets of radioactive tracer will need to be flown to Trondheim, at a cost of NOK 960 000 for this substance.

Shorter, less surgery

This is the first research study in the world where amino acids and PET MRI are being used to try to improve the diagnosis of prostate cancer.[faktaboks=”1″ stillopp=”hoyre” storrelse=”liten”/]

Currently, doctors remove the lymph nodes found in the pelvis of patients with aggressive prostate cancer, without really knowing if it is necessary. Only by cutting into the lymph nodes after they have been removed can doctors determine if the cancer had actually spread.

The NTNU researchers’ goal is for PET MRI to be able to do this detective work before the patient has to undergo surgery, so that surgeons know whether or not removing a patient’s lymph nodes is actually necessary. As a result, some patients should be able to have shorter, less involved surgery, which means less side effects and potential complications.

Diagnoses and the answer key

Researcher will go through the images of all 32 study participants, and then compare these images to their “answer key,” which in this case are the lymph nodes that were removed and biopsied from the patients. Comparing the nodes with the PET MRI images will show whether or not the scans can be used to help in the diagnosis of prostate cancer.

source : http://www.sciencedaily.com/releases/2014/09/140904084500.htm

Increase seen in use of double mastectomy, although not associated with reduced death

Randomized trials have demonstrated similar survival for patients with early-stage breast cancer treated with breast-conserving surgery and radiation or with mastectomy. However, previous data show increasing use of mastectomy, and particularly bilateral mastectomy (removal of both breasts) among U.S. patients with breast cancer. Evidence for a survival benefit with this procedure appears limited to rare patient subgroups. “Because bilateral mastectomy is an elective procedure for unilateral breast cancer [in one breast] and may have detrimental effects in terms of complications and associated costs as well as body image and sexual function, a better understanding of its use and outcomes is crucial to improving cancer care,” according to background information in the article.

Allison W. Kurian, M.D., M.Sc., of the Stanford University School of Medicine, Stanford, Calif., and colleagues used data from the California Cancer Registry from 1998 through 2011 to compare the use of and rate of death after bilateral mastectomy, breast-conserving therapy with radiation, and unilateral mastectomy (removal of one breast).

The analyses included 189,734 patients. The researchers found that the rate of bilateral mastectomy increased from 2.0 percent in 1998 to 12.3 percent in 2011, an annual increase of 14.3 percent. The increase in bilateral mastectomy rate was greatest among women younger than 40 years: the rate increased from 3.6 percent in 1998 to 33.0 percent in 2011, increasing by 17.6 percent annually. Use of unilateral mastectomy declined in all age groups

Bilateral mastectomy was more often used by non-Hispanic white women, those with private insurance, and those who received care at a National Cancer Institute-designated cancer center; in contrast, unilateral mastectomy was more often used by racial/ethnic minorities and those with public/Medicaid insurance.

Compared with breast-conserving surgery with radiation, bilateral mastectomy was not associated with a mortality difference, whereas unilateral mastectomy was associated with higher mortality.

“In a time of increasing concern about overtreatment, the risk-benefit ratio of bilateral mastectomy warrants careful consideration and raises the larger question of how physicians and society should respond to a patient’s preference for a morbid, costly intervention of dubious effectiveness,” the authors write.

“These results may inform decision-making about the surgical treatment of breast cancer.”

Editorial: Contralateral Prophylactic Mastectomy: Is It a Reasonable Option?

In an accompanying editorial, Lisa A. Newman, M.D., M.P.H., of the University of Michigan, Ann Arbor, discusses the issues involved with the use of contralateral prophylactic mastectomy (risk-reducing mastectomy for the unaffected breast).

“The need for patients to be accurately informed regarding safe and oncologically acceptable treatment options is indisputable. The dense fog of complex emotions that accompanies a new cancer diagnosis can impair the ability to process this information. Patients should be encouraged to allow the intensity of these immediate reactions to subside before committing to mastectomy prematurely. Physicians should not permit excessive treatment delays to compromise outcomes, but the initial few weeks surrounding the diagnosis are more effectively utilized by time invested in patient education and procedures that contribute to comprehensive treatment planning as opposed to hastily coordinating impulsive, irreversible surgical plans.”

source : http://www.sciencedaily.com/releases/2014/09/140902171150.htm

Keyhold surgery for cancer spread to liver

Each year, 3500 Norwegian develop colorectal cancer. Most of them undergo surgery. In half of them, the cancer spreads. Thirty per cent of those in whom the cancer has spread can now be operated on with a new surgical method.

“With our new surgical method we can transform an acute, terminal disease into a chronic disease,” says one of the world’s leading surgeons in the field of laparoscopy (keyhole surgery), Professor Bjørn Edwin at the Intervention Centre of UiO and Oslo University Hospital, Norway.

His solution is to preserve as much of the liver as possible.

“We try to take as little as possible. This is a completely new way of thinking.”

The most common surgical method is still to remove half of the liver if the cancer has spread to parts of it.

“By removing only a small piece at a time, we increase the chances that the patient can have repeat surgery. In other words, we try to preserve the liver to have some of it left if the cancer should return. Most of the patients have a recurrence within ten years. The idea is this: If we leave parts of the right side, we can later remove the left side of the liver. This is what we refer to as good liver housekeeping,” Bjørn Edwin explains. He notes that the method only works for patients in whom the cancer has spread from the intestine to the liver. For patients with a primary tumour in the liver, other treatment methods are used.

For the last twenty years, Edwin has remained one of the country’s leading pioneers in the field of laparoscopy.

“With laparoscopy, we can intervene and operate many times, since the method does not produce the same adhesions as open surgery does. The results are equally good, and there are fewer complications. In addition, laparoscopy has taught the surgeons to operate more neatly,” Bjørn Edwin states to the researchmagazine Apollon.

Four small holes

This way to perform surgery is far better for the patient than a classic operation. Instead of cutting open the abdomen, the surgeon makes four small holes. He can then use trocars, which are stiff tubes, to insert his instruments and a camera. One hole is for the video camera. Through the other holes, the surgeon can introduce a forceps, an instrument, a scalpel or other implements needed to cut the liver loose. Before starting the procedure, however, they must first inflate the abdomen to provide a large cavity where they can work.

A large amount of blood flows through the liver. To avoid haemorrhages, the blood flow to the part which is to be operated on must be halted by ligating the arteries. This can be done by tying a suture around the blood vessels.

“If the patient nevertheless should start haemorrhaging we must switch to a regular operation. This happens in only one of a hundred cases. Previously, we also opened the abdomen occasionally to be on the safe side.”

Many different techniques can be used to cut the liver. The surgeons can use a scalpel, ultrasound or electrosurgical forceps. To incise the large blood vessels they use a sewing machine. Before the blood vessel is cut, they block it by sewing three rows of clips on each side of the cut.

The excised section of liver must be withdrawn from the body intact.

If the excised section of liver were ground up, it could be brought out of the body in liquid form, but then the pathologists would be unable to analyse the tumours. The liver section must therefore be removed whole.

This is done by inserting a plastic bag through one of the stiff tubes. The bag has the shape of an angler’s hand net.

“We catch the liver, close the bag, pull it towards the skin and out through a small incision.”

A gentle procedure

Laparoscopy is not only less painful than classic surgery, but the patients recover more quickly and spend fewer days in hospital.

“The average hospitalization period after a laparoscopic intervention is three days, while patients spend five to seven days in hospital after open surgery.”

Edwin is currently investigating the correlation between surgical methods and survival rates.

“Based on the illness histories of patients who have been operated on for cancer that has spread to the liver, expected survival is higher with laparoscopy, but the responses are not statistically significant. We don’t know exactly why the survival rates increase, but it might be related to the immune response.”

The story behind

Gastric surgeons started to use keyhole surgery in the late eighties, initially on gall-bladder patients. This surgical method was described one hundred years ago, and was first used by gynaecologists during the forties.

“In those days, the surgeon looked through a telescope, but having video on a screen enabled us to perform laparoscopy in a far more sophisticated way.”

Bjørn Edwin is a pioneer in the field of keyhole surgery and was among the very first to use this method for liver surgery. Now, Bjørn Edwin has taught his method to surgeons in Norway as well as abroad.

“Laparoscopy will increasingly replace open surgery. Ten years after we started, other countries have followed. American hospitals are still opposed to the surgical method for preserving liver tissue. France is now using it, and Russia is following suit.”

When he attended a world conference on cancer of the liver and pancreas in 2008, hardly anyone used laparoscopy on these organs. Two years later, there were some. At this year’s conference in Seoul it became evident that many have now started to use this new surgical technique.

Interdisciplinary team

To perform modern laparoscopy, collaboration with the engineers is absolutely essential. Using a three-dimensional map of the liver, the surgical team can see where the blood vessels are located and plan where to make their incisions accordingly.

“We are now undertaking research to enable us to see the movements of the instruments interactively on the map of the liver during surgery,” Bjørn Edwin says. He emphasizes that the trials with modern laparoscopy would have been impossible without the strong interdisciplinary team at the Intervention Centre.

“There, we have close proximity to physicists, radiologists and other specialists. It’s a superb setting for undertaking a development stage,” Edwin points out.

source : http://www.sciencedaily.com/releases/2014/08/140825084628.htm