Left-Side Breast 3DCRT Field-in-Field Technique Planning Radiotherapy

The field-in-field technique is a method improving dose homogeneity by decreasing regions of high dose by utilizing field-in-fields. The MLC leaves of the field-in-field can be moved to block regions of high dose, and by transferring monitor units (MU) from the primary field onto the field-in-field via field weighting, dose deposition in these blocked regions will reduce. As long as all the field sizes remain identical and the MLC leaves of the field-in-field do not extend beyond their physical limitation, both can eventually merge to form a sliding window. Doing so will allow a radiation therapist to treat the primary field and its respective field-in-fields in one go allowing for a reduction in treatment time