New volumes.

Nasopharyngeal carcinoma may respond well during the course of radiation. In addition, there can often be significant patient anatomic changes as a result of toxicity in the head and neck. In this single-center retrospective retrospective study, patients were offered planned re-simulations at 15 and 25 fractions prior to starting treatment. Half (49%) elected to participate while the rest received standard treatment based on the original CT. At the 15 fraction sim, 10.5% of patients were replanned and 66% were replanned at the 25 fraction sim. Nearly a quart (23%) were replanned at both 15 and 25 fractions. Among those who participated in planned re-simulation,8-year locoregional recurrence-free survival was significantly higher at 87.4% v 75.6%. That difference was particularly notable for those with more advanced, T3-4N2-3 (87.9% v 59.5%). However, there was no difference in overall or distant metastasis free survival. The rate of grade 3-4 xerostomia, but no other toxicities, was lower with replanning (3.5% v 9.5%). | Zhou, Radiother Oncol 2022