Dosimetric effect of set-up errors on nasal NK/T cell lymphoma based on dose reconstruction

• DOI: 10.3760/cma.j.issn.1004-4221.2019.11.011
• Publication Date: 2019-11-15
• Authors: Zhanyu Wang; Junwen Tan; Yusong Long; Xiantao He; Gang Li; Yongfu Feng; Weixue Liang

Objective To evaluate the dosimetric effects of set-up errors on nasal NK/T cell lymphoma by introducing into radiotherapy planning system for dose reconstruction.

Methods Ten patients with were recruited. A non-coplanar volumetric modulated arc therapy plan was designed CT image and clinical target area each patient. After completion plan, introduced changing ISO treatment, calculation performed to reconstruct distribution.

Results With increase errors, decreased order affected in different directions was: left-right direction> head-foot front-rear direction. When translational direction -3 mm 3 rotating -3° 3°, range change all targets less than ±3%. ≤ mm, organ at risk or similar prescribed dose. were> doses lens, spinal cord, parotid gland optic nerve gradually exceeded Only when ≥ lens Special attention should be paid influence greater left right cord gland, as well due larger front rear actual from our department, it exerted slight effect irradiation GTV CTV, which ±2%. In a few cases, potentially limit, special diverted overdose nerve.

Conclusions The will result deficiency lymphoma, especially upon The 3° is limited. Therefore, recommended maintain single within 3°. department exert little dose, but small number organs are exceeding limit. It necessary evaluation extension region risk.

Key words: Nasal natural killer/T-cell lymphoma; Set-up error; Dosimetry