All posts by Daniel Davies

Implantable device delivers drugs directly to the cancer site

Researchers from Massachusetts Institute of Technology (MIT) and Massachusetts General Hospital (MGH) have now developed a small, implantable device that delivers chemotherapy drugs directly to pancreatic tumours.

In a study of mice, they found that this approach was up to 12 times more effective than giving chemotherapy drugs by intravenous injection, which is how most pancreatic cancer patients are currently treated.

“It’s clear there is huge potential for a device that can localize treatment at the disease site,” said Laura Indolfi, a postdoc in MIT’s Institute for Medical Engineering and Science (IMES) and the MGH Cancer Center, who is one of the study’s lead authors.

“You can implant our device to achieve a localized drug release to control tumor progression and potentially shrink [the tumor] to a size where a surgeon can remove it.”

Image courtesy of the researchers. Featured image courtesy of Bryce Vickmark

Image courtesy of the researchers. Featured image courtesy of Bryce Vickmark

During the tests, the researchers compared two groups of mice carrying transplanted human pancreatic tumors.

One group received the drug-delivery implant loaded with the chemotherapy drug paclitaxel, and the other received systemic injections of the same drug for four weeks, which mimics the treatment human patients usually receive.

In mice with the drug-delivery implant, tumour growth slowed, and in some cases tumours shrank. The researchers also found that after four weeks, the concentration of paclitaxel in the tumors of mice with the implanted device was five times greater than in mice that received injections.

“This combination of local, timed, and controlled release, coupled with the judicious use of critical compounds, could address the vital problems that pancreatic cancer has provided as obstacles to pharmacological therapy,” said a member of MIT’s Institute for Medical Engineering and Science and senior author, Elazer Edelman.

Image courtesy of Bryce Vickmark

Image courtesy of Bryce Vickmark

The researchers are now preparing to design a clinical trial for human patients.

While they began this project with a focus on pancreatic cancer, they expect that this approach could also be useful in treating other tumors that are difficult to reach, such as tumors of the gastrointestinal tract.

The researchers hope that by getting drugs directly to the tumor site treatment for difficult to reach cancers will improve, and they are already plotting ways to reach other types of cancer using the same process.

“The greatest benefit of this device is the ability to implant it with minimally invasive procedures so we can give a tool to oncologists and surgeons to reach tumors that otherwise would be difficult to reach,” said Indolfi.

We may never know how safe driverless cars are until the public are let loose with them

Current methods being used to test driverless cars wont definitively prove their safety, according to a report by US think tank RAND.

The RAND report states that autonomous vehicles would have to be driven hundreds of millions of miles and, under some scenarios, hundreds of billions of miles to create enough data to clearly demonstrate their safety.

“Our results show that developers of this technology and third-party testers cannot drive their way to safety,” said co-author of the study and a senior scientist at RAND, Nidhi Kalra. “It’s going to be nearly impossible for autonomous vehicles to log enough test-driving miles on the road to statistically demonstrate their safety, when compared to the rate at which injuries and fatalities occur in human-controlled cars and trucks.”

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Image courtesy of Mercedes Benz. Featured image courtesy of Tesla.

RAND believes alternative testing methods must be developed to supplement on-road testing, but even then it may not be possible to fully establish the reliability of autonomous vehicles prior to making them available for public use.

Under even the most-aggressive test driving assumptions, it would take existing fleets of autonomous vehicles tens and even hundreds of years to log sufficient miles to adequately assess the safety of the vehicles when compared to human-driven vehicles.

Alternative methods of testing might include accelerated testing, virtual testing and simulators, mathematical modelling, scenario testing and pilot studies.

“Even if autonomous vehicle fleets are driven 10 million miles, one still would not be able to draw statistical conclusions about safety and reliability,” said  co-author of the study and senior statistician at RAND, Susan M. Paddock.

driverless-cars

According to the National Highway Traffic Safety Administration, more than 90% of automobile crashes are caused by human errors such as driving too fast, being drunk at the wheel, as well as distraction and fatigue.

But despite the high number of crashes, injuries and fatalities from human drivers the rate of human errors is low in comparison with the number of miles that people drive.

Americans drive nearly 3 trillion miles every year, according to the Bureau of Transportation Statistics. In 2013, there were 2.3 million injuries reported, which is a failure rate of 77 injuries per 100 million miles driven.

The 32,719 fatalities recorded in 2013 amount to a failure rate of about 1 fatality per 100 million miles driven.

“The most autonomous miles any developer has logged are about 1.3 million, and that took several years. This is important data, but it does not come close to the level of driving that is needed to calculate safety rates,” said Paddock.

The report, “Driving to Safety: How Many Miles of Driving Would It Take to Demonstrate Autonomous Vehicle Reliability?” is available from RAND.