The modern oncological practices are cognizant of the late cardiac effects of treatment. The risk of cardiac events due to thoracic radiation and cardiotoxic drugs is well established in long term survivors of breast cancer and other thoracic malignancies.
In a landmark study by Darby el al it was determined that rates of major coronary events increased linearly with the mean dose to the heart by 7.4% per Gray.
The current radiation techniques have evolved to deliver radiation precisely and protect the adjacent organs & also account for thoracic motion in order to decrease the cardiac doses. One such technique to minimize the radiation dose to the heart is deep inspiratory breath hold(DIBH)technique.
Deep Inspiratory Breath Hold (DIBH)
DIBH is a technique where patients take a deep breath and holds the breath while the radiation is delivered. By taking a deep breath the lung is inflated which increases the distance between the chest wall and the heart, expanding the lung volume. In addition to reduction of cardiac dose the dose to the lungs is also reduced leading to decreased inflammation.(
The process of DIBH involves the training of the patient in a specific breathing pattern and treating the patient in a specific timing of breath hold as identified by the breathing waveform.
The process of DIBH requires the patient to be on couch for approximately 40 -50 minutes so many patients cannot comply with this protocol.
DIBH at DNSH-the first of its kind
The HALCYON LINAC in known to reduce the treatment time but inherently the motion management (DIBH)is not feasible on the machine.
We at DNSH innovated the DIBH implementation on HALCYON for the first time in the world by utilising the ABC(Automated Breathing Control) machine of the other LINAC.
A mock drill was conducted on a dummy patient for assessing the feasibility and a protocol was subsequently formulated. Once all quality assurance tests were satisfactory then clinical implementation was done on a patient with mediastinal lymphoma.
The overall treatment time of DIBH on HALCYON was reduced to 8-10minutes which improved patient comfort as well as further reduced the risk of motion.
It was a welcome surprise to the machine application experts ,they applauded our innovation and acknowledged it as the first of its kind DIBH on HALCYON across the globe. So far we have successfully treated 50 patients with DIBH in last 2 years.
Better is possible. It does not take genius. It takes diligence. It takes ingenuity. And above all, it takes a team willing to try