Doctors at the University Hospitals of Geneva (HUG) have begun to utilize the Calypso® GPS for the body® technology to enhance the accuracy of radiotherapy in the treatment of lung cancer.
A recent article in Le Temps, a magazine serving French-speaking residents of Switzerland, offered details of the first Calypso-guided treatment at HUG, which took place in July of this year. The patient, a fifty-year-old woman, received treatment for early-stage lung cancer.
According to the article, radiation oncologists are faced with the challenge of delivering as much ionizing radiation to the tumor as possible while finding ways to minimize the exposure of surrounding healthy tissues.
“This is all the more important when the tumor is located near vital organs, such as the heart or spinal cord," Francesca Caparrotti, a radiation oncologist who is responsible for the treatment of lung cancer at HUG, is quoted as saying.
Calypso provides the clinical team with a continuous stream of information about the position of the tumor throughout a course of treatment, the article explains. The medical linear accelerator—the machine that generates the radiation beam—is stopped automatically any time the tumor shifts out of position.
To accomplish this, HUG physicians inserted three tiny electromagnetic transponders into the patient’s lung* tumor by bronchoscopy. Each of the three implants emits its own electromagnetic signal, which is picked up by the Calypso system detector. In this way, the system detects the precise position of each transponder and therefore of the tumor, continuously and in real time.
"For patients, pulmonary stereotactic radiotherapy is a new option for local treatment in addition to surgery," says Benjamin Besse, of the thoracic cancer unit at the Gustave-Roussy Institute in Villejuif, France, where this type of treatment has been offered for two years. Although effective, surgical removal of a lung lobe or lung cannot always be offered to all patients, especially if their respiratory condition is compromised, the article asserts. Under these conditions, an alternative approach is welcome. As to whether outcomes from the two approaches are equivalent, Dr. Besse says: "The side effects of stereotactic radiotherapy are usually modest. But we still do not have any randomized studies comparing the two."
"Compared to conventional stereotactic radiotherapy, this GPS-guided technique is more accurate and less risky, which is always a plus for the quality of life of the patient," adds Dr. Caparrotti.
* The Anchored Beacon® transponder for lung is pending FDA 510(k) clearance and is not available for sale in all markets.
Original French-language article in Le Temps