Extra-Cranial Stereotactic Radiotherapy Lessens Side Effects for Lung Cancer Patients

Using advanced equipment from Varian Medical Systems (Palo Alto, CA, USA), a team of clinicians at Lindenhofspital (Bern, Switzerland) has effectively delivered three highly focused, powerful radiotherapy doses aimed at destroying a small tumor on the patient's lung.

Dr. Leon Andre, a medical physicist at the private Lindenhofspital, reported the tumor has shrunk as a result of the treatment and the patient is now recovering well. The treatment took place using a Varian Clinac 23EX linear accelerator with a 120-leaf MLC (multileaf collimator) to enable clinicians to narrow down the beam to millimeter accuracy, thereby reducing the risk of side effects.

"Surgery was not an option for this patient because her other lung had been removed a year ago,” explained Dr. Andre. "A new tumor appeared on her remaining lung and we decided that the best option would be to deliver three high-dose stereotactic treatments over a 10-day period. We are very pleased with the way the patient has responded to this new stereotactic treatment.”

Stereotactic radiation therapy treatment is frequently used for cranial tumors but recent advances in real-time imaging equipment and beam-shaping devices have broadened its use to the rest of the body. These advances include the On-Board Imager, an imaging device that extends from the linear accelerator and enables highly accurate image-guided radiotherapy (IGRT) treatments, and the 120-leaf Millennium multileaf collimator, which allows the beam to be shaped to extreme levels of precision. Without such developments, clinicians would have been forced to expose a margin of between 5 and 10 mm of healthy tissue around the target tumor to account for possible movement.

"The purpose of extra-cranial stereotactic radiotherapy is to increase the dose to achieve the best possible tumor control rates while minimizing the risk of side effects,” added Dr. Andre. "This can only be achieved by decreasing the amount of normal healthy tissue that is exposed.


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