Department of E.N.T, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Taizhou, 317000 Zhejiang, China.
Department of Pharmacy, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Taizhou, 317000 Zhejiang, China.
Comput Math Methods Med. 2022 Jul 11;2022:4651364. doi: 10.1155/2022/4651364. eCollection 2022.
To study the feasibility of intensity modulated radiation therapy (IMRT) for stage N nasopharyngeal carcinoma (NPC) and its parotid gland (PG) function preservation from physical and dosimetric aspects.
All the clinical data of 77 patients with pathologically confirmed TNM NPC who received radiotherapy between July 2017 and October 2019 in the Radiotherapy Center of Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University were analyzed retrospectively. Three-dimensional conformal radiotherapy (3D-CRT) and IMRT were used in 35 and 42 cases, respectively. The treatment efficiency and the dosimetry differences of the PG in the intensity modulation plan were compared between groups. Quantitative monitoring of 99mTc radionuclide imaging of PG was performed before, at the end of, and 3, 6, and 12 months after radiotherapy. The degree of PG function injury and xerostomia was compared between groups at the end of radiotherapy and 12 months later.
Higher minimal, maximal, and average irradiation doses of PG were determined in 3D-CRT-treated patients compared with IMRT-treated cases ( < 0.05). Compared with before radiotherapy, the PG uptake index (UI) and excretion index (EI) of both cohorts of patients decreased to varying degrees at the end of radiotherapy, with PG function injury and xerostomia symptoms observed in all cases but with no obvious difference between groups ( > 0.05). To a certain extent, the PG function recovered and the xerostomia symptoms relieved in both groups 12 months after radiotherapy, with better improvements in IMRT group versus 3D-CRT group.
IMRT has similar short-term efficacy to 3D-CRT in treating patients with stage N NPC, but it can effectively reduce the dose of PG radiotherapy and protect the PG function on the premise of ensuring sufficient tumor coverage and dose, showing certain dosimetry advantages.
从物理和剂量学方面研究调强放疗（IMRT）治疗局部区域 N 期鼻咽癌（NPC）及其腮腺（PG）功能保护的可行性。
回顾性分析 2017 年 7 月至 2019 年 10 月在温州医科大学附属台州医院放射治疗中心接受放疗的 77 例经病理证实的局部区域 N 期 NPC 患者的所有临床资料。35 例患者接受三维适形放疗（3D-CRT），42 例患者接受调强放疗（IMRT）。比较两组患者的治疗效果和 PG 调强计划的剂量学差异。在放疗前、放疗结束时以及放疗后 3、6 和 12 个月，对 99mTc 放射性核素成像 PG 进行定量监测。比较两组患者在放疗结束时和 12 个月后 PG 功能损伤和口干的程度。
与 IMRT 组相比，3D-CRT 组患者 PG 的最小、最大和平均照射剂量更高（<0.05）。与放疗前相比，两组患者的 PG 摄取指数（UI）和排泄指数（EI）在放疗结束时均有不同程度的下降，所有患者均出现 PG 功能损伤和口干症状，但组间无明显差异（>0.05）。在放疗结束后 12 个月，两组患者的 PG 功能在一定程度上得到恢复，口干症状得到缓解，IMRT 组的改善优于 3D-CRT 组。
IMRT 治疗局部区域 N 期 NPC 的短期疗效与 3D-CRT 相似，但在保证肿瘤充分覆盖和剂量的前提下，能有效降低 PG 放疗剂量，保护 PG 功能，具有一定的剂量学优势。
