New monitoring system enhances precision in radiotherapy

At the Clinic for Radiotherapy and Special Oncology of Hannover Medical School (MHH), a new linear accelerator is now in use. Equipped with an advanced positioning and monitoring system that includes a surface scanner, this device is designed to ensure precise targeting of tumors during radiotherapy while minimizing unnecessary exposure to surrounding healthy tissue. 

"The new technology offers a range of advantages," explains clinic director Prof. Hans Christiansen. "The smallest movements within the treatment region are detected in real time, and radiation, for example, is only released when the target is in exactly the right place." 

The surface scanner features multiple cameras that provide continuous, non-invasive monitoring of the patient’s position. This allows for constant observation throughout the entire irradiation process without the need for repeated X-ray control images. "During the ongoing irradiation, fewer control images with X-rays are required to check the exact positioning, thus reducing the additional radiation load in healthy tissue," says Prof. Bremer, senior physician at the clinic. 

This real-time surface tracking enhances patient safety and contributes to more effective radiotherapy sessions. 

One of the key benefits of the new system is its ability to track respiratory phases. This is particularly important for young patients with left-sided breast cancer, where the heart lies close to the chest wall. With respiratory gating, radiation can be delivered during deep inhalation, when the heart moves further away from the chest wall, thereby reducing the risk of long-term radiation-related heart damage.  

"We were already able to observe breathing phases with the previous linear accelerator. The patients received verbal instructions on how to breathe. This is no longer necessary because the patients can control the duration of the individual radiation sessions themselves. With the new technology, breath-controlled radiation (breath gating) is optimised and thus better guarantees that the heart is maximally distant from the chest wall during radiation," explains Dr. Anne Caroline Knöchelmann, senior physician at the clinic. 

• The patient uses a breath-hold technique to navigate a ball into a virtual basket on the screen. 

• When the ideal breathing depth is achieved (Deep Inspiration Breath Hold, DIBH), radiation is delivered. 

• If the patient exhales, the radiation automatically pauses until the optimal position is reached again. 

MEDICA-tradefair.com; Source: Hannover Medical School (MHH)