{"id":575,"date":"2026-10-05T15:18:33","date_gmt":"2026-10-05T15:18:33","guid":{"rendered":"https:\/\/www.valentiscancerhospital.in\/blogs\/?p=575"},"modified":"2026-10-17T15:18:42","modified_gmt":"2026-10-17T15:18:42","slug":"how-does-cyberknife-s7-track-moving-tumours-during-radiation-treatment","status":"publish","type":"post","link":"https:\/\/www.valentiscancerhospital.in\/blogs\/how-does-cyberknife-s7-track-moving-tumours-during-radiation-treatment\/","title":{"rendered":"How Does CyberKnife S7 Track Moving Tumours During Radiation Treatment?"},"content":{"rendered":"\n

\u201cWill radiation still reach my tumour when I breathe?\u201d This is an understandable question, especially for patients with lung, liver or pancreatic tumours.<\/p>\n\n\n\n

CyberKnife S7<\/a><\/strong> addresses this challenge by combining X-ray imaging, external breathing sensors, motion-modelling software and a robotic treatment arm. Its Synchrony technology estimates where a moving tumour is between imaging checks and adjusts radiation delivery accordingly. This helps the treatment beam follow the target while the patient breathes naturally.link.<\/p>\n\n\n\n

At Valentis Cancer Hospital in Meerut, CyberKnife S7 forms part of the hospital\u2019s advanced radiation treatment services. Understanding its tracking process can help patients approach treatment with greater clarity.<\/p>\n\n\n\n

Why Do Tumours Move During Radiation Treatment?<\/h3>\n\n\n\n

When you breathe, your diaphragm moves and your chest expands. These movements can shift organs inside the chest and abdomen, including the lungs, liver and pancreas. A tumour within these organs may therefore change position throughout the breathing cycle.<\/p>\n\n\n\n

Radiation treatment<\/strong><\/a> for moving tumors must account for this movement. Without appropriate motion management, a plan may need a larger treatment margin around the tumour to accommodate its changing position.<\/p>\n\n\n\n

CyberKnife\u2019s respiratory tracking aims to follow this motion, helping clinicians target the tumour while limiting unnecessary radiation exposure to nearby healthy tissue. Safety margins remain necessary; tracking does not eliminate uncertainty entirely.<\/p>\n\n\n\n

How CyberKnife S7 Tracks a Moving Tumour<\/h2>\n\n\n\n

The process involves several connected technologies rather than a single camera watching the tumour continuously.<\/p>\n\n\n\n

1. X-Ray Images Locate the Internal Target<\/h4>\n\n\n\n

During treatment setup, paired X-ray images help establish the target\u2019s position. Depending on the treatment approach, the system may identify the tumour directly or locate implanted markers called fiducials that serve as reference points.<\/p>\n\n\n\n

Some suitable lung tumours can be tracked without implanted markers. Whether marker-free tracking is possible depends on how clearly the target appears on the imaging system.<\/p>\n\n\n\n

2. External Sensors Monitor Breathing<\/h4>\n\n\n\n

Small light-emitting markers placed on the patient\u2019s chest or abdomen allow an optical camera system to monitor external breathing movement.<\/p>\n\n\n\n

These markers do not directly detect cancer. Instead, they provide a continuous signal showing how the body\u2019s surface moves during breathing. The system links this signal with internal target positions obtained from X-ray images.<\/p>\n\n\n\n

3. Synchrony Builds a Motion Model<\/h4>\n\n\n\n

The software creates a mathematical relationship, called a correlation model, between external breathing movement and internal tumour movement.<\/p>\n\n\n\n

For example, it learns where the target tends to be as the patient breathes in and out. This relationship allows the system to estimate the tumour\u2019s position between X-ray checks.<\/p>\n\n\n\n

Importantly, the model can account for differences between inhalation and exhalation rather than assuming that internal movement always follows a simple, identical path.<\/p>\n\n\n\n

4. The Robotic Arm Adjusts Beam Direction<\/h4>\n\n\n\n

Using the estimated target position, the robotic arm adjusts radiation delivery to follow the moving target.<\/p>\n\n\n\n

Think of it as carefully aiming at a moving object rather than repeatedly treating a fixed point and hoping the object returns there. However, this analogy simplifies a tightly controlled medical process: tracking accuracy depends on imaging, modelling, planning and clinical checks working together.<\/p>\n\n\n\n

5. Fresh Images Check the Model<\/h4>\n\n\n\n

Breathing patterns can change during a session. The system therefore acquires additional X-ray images periodically to check and update the relationship between external movement and internal target position.<\/p>\n\n\n\n

This distinction matters: continuous external monitoring is combined with intermittent internal imaging, not continuous X-ray filming of the tumour.<\/p>\n\n\n\n

What Are the Benefits for Patients?<\/h3>\n\n\n\n

For appropriately selected patients, motion-synchronised robotic radiation treatment offers several potential advantages:<\/p>\n\n\n\n