IMRT (intensity-modulated radiotherapy) transformed radiotherapy dose calculation and therapy methods in the 1990s by allowing the use of higher doses. The IMRT technique makes it possible to optimise the distribution of the radiation dose so that an increasingly high dose can be delivered to the cancer tissue while minimising the dose entering healthy issue.
Several treatment fields were initially used in IMRT. A computer optimises or a medical physicist sets the beam directions in the radiotherapy fields and decides the number of fields. The purpose is to administer a maximum dose of radiation into the tumour. Determining the shape of the radiotherapy field makes it possible to minimise the radiation dose to normal tissues. During radiation, the radiotherapy field is cropped with metal shielding or the thin metal leaves of the treatment device. This allows optimum radiation dose distribution and protects areas such as the spinal cord and the salivary glands from unnecessary radiation. This way, tumours can be destroyed more effectively and safely.
It is safe to say that the VMAT Rapid Arc technique combined with stereotactic radiotherapy is the most advanced form of intensity‑modulated radiotherapy. We use this treatment at Docrates to benefit our patients.