What situations do you use IMRT vs 4-field box technique (or visa versa) for patients with an intact cervix with no pelvic or para-aortic nodal involvement?  

The main argument is sparing of small bowel and marrow dose. Comparing the dosimetry of the two plans would give the answer as to whether there is any advantage in a particular patient as it varies based on anatomy, BMI, size of uterus and disease 

When using IMRT for intact cervix, it is important to be aware of organ motion and take into consideration the possible motion of the cervix and uterus. It is often necessary to use fairly large CTV and PTV margins around these target organs. A locally advanced cervix cancer with parametrial or sid...

I have been utilising IMRT for all intact cervix patients, but carefully plan wide PTV's for the cervix, uterus and parametria. The advantages are bowel sparing -and possibly bone marrow sparing. However some patients may obtain very little benefit from IMRT depending upon tumor size and body habi...

When IMRT is not covered by insurance for Gyn tumors.