Research progress on predictive factors and time points of adaptive re-planning in intensity-modulated radiation therapy for head and neck cancer

Adaptive re-planning contributes to improve the dosimetric uncertainties induced by anatomical changes during intensity-modulated radiation therapy (IMRT) for head and neck cancer patients and can enhance the local control rate and quality of life of patients. Previous research has demonstrated that presence of relatively large lymph nodes before treatment and significant loss of body weight during treatment are pivotal predictive factors of re-planning during IMRT. At 4 weeks after IMRT, the volume of the target and peripheral organ at risk (OAR) tends to steadily decrease. One to two cycles of adaptive re-planning are recommended at 3 or 4 weeks after IMRT. (authors)