Any movement during respiration can affect the quality of preliminary imaging and can put neighboring organs at risk to exposure from tangential beams
Thoracic radiotherapy can be complicated for the patient and the operator alike.
The SpiroDyn'rX (SDX), developed by the company Dyn'R, is a spirometer-plus-software system that helps more accurately position the organs around the respiratory system, adding value to existing imaging apparatuses and radiotherapy devices.
By monitoring the respiratory movements of the patient and designating a visual representation "optimal inspiration zone" for the patient to achieve, the SDX aids in a more precise, and thus more effective, imaging or radiotherapy session.
It is intended in particular for the treatment of the lung, breast, and liver.
The normal breathing of a patient generates significant movements in certain organs in the thoracic and abdominal area.
Any tumor mass attached to these organs will thus move when a patient breathes.
A successful radiotherapy treatment can only be achieved when these organs are still, namely, while the patient holds their breath.
Thus, doctors turn to controlled respiration to achieve three things: quality images, restrict movement of target organs during radiation, and protect adjacent organs.
Unfortunately, the breathing of human is never perfectly reproducible, greatly varying according to the patient's position, stress or fatigue, injections of contrast media, etc.
Strict control of reproducible respiratory movements has become indispensible to effectively treat all organs that move during respiration.
The deep-inspiration breath hold method (DIBH) can reduce post-radiotherapy problems by accurately positioning and repositioning the tumor mass from the imaging step until the end of treatment.
The SDX uses the patient's own breathing capacity to designate a customized time when radiotherapy, or imaging, would be best performed.
The SDX is composed of two parts: a spirometer and video glasses combination located in the imaging or treatment room, and software installed on a PC computer located in the control room.
The patient breathes into the spirometer wearing a pair of video glasses.
The operator monitors the process from a computer in the control room.
By sending data from the spirometer to the central computer, the software illustrates the levels of inhalation and exhalation by curves.
A preparation phase is performed to determine the maximum and minimum breathing levels of the patient, and how long their breath-hold will be so the doctor can deduce the best pulmonary expansion from it.
This is the optimal time to perform radiotherapy or imaging.
That ideal position of pulmonary expansion, the "optimal inspiration zone" is displayed in the patient's video glasses as a colored bar, much like an animated progress bar in computer software, that the patient must achieve with each phase of the treatment.
Once that level is reached, a green light appears in the video glasses to signal to the patient to inhale and hold his breath once he reaches the inspiration zone, and that the imaging or treatment is beginning.
If the patient hesitates more than one second when entering or leaving the optimal inhalation zone, the zone disappears, and the patient will need to start over.
The imaging or treatment can either be started manually or automatically, via software available with the optional command unit.
With manual operation, the operator watches the patient's inspiration zone.
Once the optimum level is reached, the operator starts the device.
A ringing noise signals the end of breath-hold and the end of treatment, so the operator can turn the device off.
With the optional connection box, the software detects the optimum inspiration level and automatically starts the respective device.
The data is transmitted from the spirometer via USB cable to the control room's computer.
According to the patient's maximum breath hold, the software knows when to stop the device so the patient can exhale.
With either method, this operation can be performed several times is succession, depending on the patient's abilities.
