One of the main issues with delivering radiation doses to tumors is that the location of these cancers is purely guess work. Now bio-engineers from the US are promising a tiny device that can not only predict the exact dosage delivered inside the tumor, but can also locate it accurately.
This "wireless implantable passive micro-dosimeter," enclosed in a glass capillary small enough to inject into a tumor with a syringe, is being developed by engineers at Purdue University and would help to kill tumors more effectively.
The team developing this device is headed by Babak Ziaie, an associate professor in the School of Electrical and Computer Engineering and a researcher at Purdue's Birck Nanotechnology Center.
Ziaie said that the device could be in clinical trials in 2010.
"Because organs and tumors shift inside the body during treatment, a new technology is needed to tell doctors the exact dosage of radiation received by a tumor," said Ziaie.
While conventional imaging systems are difficult to use during radiation therapy, are costly and sometimes require X-rays, which can damage tissue when used repeatedly, the new device uses radio frequency identification, or RFID, technology, which does not emit damaging X-rays.
This device is not run on batteries but will be activated with electrical coils placed next to the patient. It contains a miniature version of dosimeters worn by workers in occupations involving radioactivity and this tiny dosimeter could provide up-to-date information about the cumulative dose a tumour is receiving over time.
"It's a radiation dosimeter and a tracking device in the same capsule and will be hermetically sealed so that it will not have to be removed from the body," said Ziaie.
The prototype of this sensitive dosimeter was tested with radioactive cobalt. One of the most striking features of this device is that it would not require intricate circuitry, which could make the device easier and less expensive to manufacture than more complex designs. The system consists of simple electronic devices called capacitors and coils.
With a diameter of about 2.5 millimeters, or thousandths of a meter, and length of 2 centimeters, this miniature device is small enough to fit inside a large-diameter needle for injection with a syringe. However, the researchers are working towards reducing its size further, shrinking it to about half a millimeter in diameter and half its current length, roughly the size of a rice grain.
The findings of this research are detailed in a paper appearing in an upcoming issue of IEEE Transactions On Biomedical Engineering.