中国癌症杂志 ›› 2023, Vol. 33 ›› Issue (1): 54-60.doi: 10.19401/j.cnki.1007-3639.2023.01.006

• 论著 • 上一篇    下一篇

局部晚期胰腺癌75 Gy同步加量放射治疗的剂量可行性研究

庄晗(), 凌池芳, 王佳舟, 韩序, 姜睿, 胡伟刚()   

  1. 复旦大学附属肿瘤医院放射治疗中心,复旦大学上海医学院肿瘤学系,上海市放射肿瘤学重点实验室,上海市放射治疗临床医学研究中心,上海 200032
  • 收稿日期:2022-08-31 修回日期:2022-10-25 出版日期:2023-01-30 发布日期:2023-02-13
  • 通信作者: 胡伟刚(ORCID: 0000-0002-4409-6804),博士,研究员,复旦大学附属肿瘤医院放射治疗中心副主任。
  • 作者简介:庄晗(ORCID: 0000-0002-8599-5195),硕士,研究实习员。

Radiation therapy in locally advanced pancreatic cancer with 75 Gy simultaneous integrated boost: a dosimetric feasibility study

ZHUANG Han(), LING Chifang, WANG Jiazhou, HAN Xu, JIANG Rui, HU Weigang()   

  1. Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai Key Laboratory of Radiation Oncology, Shanghai Clinical Research Center for Radiation Oncology, Shanghai 200032, China
  • Received:2022-08-31 Revised:2022-10-25 Published:2023-01-30 Online:2023-02-13
  • Contact: HU Weigang

摘要:

背景与目的:近年来,胰腺癌的发病率逐年上升,调强放射治疗(intensity-modulated radiotherapy,IMRT)已被广泛应用于胰腺癌的治疗,但多数胰腺癌IMRT的剂量学研究的处方剂量都小于60 Gy。本研究旨在探究局部晚期胰腺癌(locally advanced pancreatic cancer,LAPC)患者75 Gy同步加量放射治疗的剂量可行性并比较共面IMRT(coplanar IMRT,CO-IMRT)与非共面IMRT(non-coplanar IMRT,NC-IMRT)技术的剂量学差异。方法:纳入复旦大学附属肿瘤医院2018年1月—2021年12月收治的符合入组标准的10例接受同步加量放射治疗的LAPC患者,处方剂量为50 Gy的计划靶区(planning target volume,PTV),记为PTV50 Gy,处方剂量为75 Gy同步加量的PTV,记为PTV75 Gy,靶区照射分次均为25次。为每例患者分别设计CO-IMRT和NC-IMRT计划。同1例患者两种计划的射野数、处方剂量和危及器官(organs at risk,OAR)的优化条件完全相同。统计CO-IMRT和NC-IMRT计划的靶区剂量分布、适形性指数(conformity index,CI)、均匀性指数(homogeneity index,HI)、OAR剂量学结果、出束时间和机器跳数(monitor units,MU)。评估靶区是否满足临床要求以及OAR剂量限值是否符合临床正常组织效应定量分析(quantitative analysis of normal tissue effects in the clinic,QUANTEC)要求,并比较CO-IMRT计划与NC-IMRT计划之间的剂量学差异。结果:CO-IMRT和NC-IMRT均可达到靶区剂量覆盖要求并满足QUANTEC的剂量限值要求。两种PTV的CI、HI、出束时间和MU之间的差异无统计学意义(P>0.05)。在左侧肾Dmean[(10.15±1.53)Gy vs(9.29±1.78)Gy,P<0.05]、左侧肾V12[(32.74±7.45)% vs(26.03±8.97)%,P<0.05]、右侧肾Dmean[(7.37±2.41)Gy vs(6.62±2.37)Gy,P<0.05]、右侧肾V12[(22.27±10.30)% vs(14.94±8.62)%,P<0.05]、肝V30[(6.37±4.05)% vs(5.47±3.70)%,P<0.05]、小肠V30[(9.96±6.66)% vs(8.73±6.19)%,P<0.05]、小肠V45[(1.15±0.71)% vs(0.96±0.61)%,P<0.05]、胃V45[(5.37±3.96)% vs(4.52±3.32)%,P<0.05]、大肠V30[(13.18±4.95)% vs(9.19±4.94)%,P<0.05]指标上,NC-IMRT显著优于CO-IMRT,差异有统计学意义(P<0.05)。在脊髓Dmax、肝Dmean、双侧肾V20、双侧肾V28、小肠Dmax、胃Dmax和十二指肠V55(mL)指标上,CO-IMRT与NC-IMRT之间差异无统计学意义(P>0.05)。结论:基于75 Gy同步加量放射治疗治疗LAPC时,CO-IMRT和NC-IMRT均能达到靶区剂量覆盖要求并满足OAR剂量限值。在不影响靶区剂量覆盖质量的前提下,NC-IMRT在双肾、肝和胃肠道的剂量分布上更有优势,能够更好地保护OAR,降低放射治疗对胃肠道、肝和肾的毒性。

关键词: 局部晚期胰腺癌, 调强放射治疗, 剂量学

Abstract:

Background and purpose: The incidence of pancreatic cancer has increased annually. Intensity-modulated radiotherapy (IMRT) has been widely used in the treatment of pancreatic cancer, however most dosimetric studies for pancreatic cancer have prescribed doses less than 60 Gy. The purpose of this study was to investigate the feasibility and dosimetric differences between coplanar IMRT (CO-IMRT) and non-coplanar IMRT (NC-IMRT) when using 75 Gy simultaneous integrated boost for patients with locally advanced pancreatic cancer (LAPC). Methods: Ten patients with LAPC treated with simultaneous integrated boost at Fudan University Shanghai Cancer Center from January 2018 to December 2021 were included. The prescribed dose for the planning target volume (PTV)50 Gy was 50 Gy in 25 fractions, and 75 Gy in 25 fractions for the simultaneous integrated boost PTV75 Gy. CO-IMRT and NC-IMRT plans were designed for each patient separately, with identical number of fields, prescription doses and OAR constrains for the same patient. The PTV dose distribution, conformability index (CI), homogeneity index (HI), indices to organs at risk (OAR) for multiple end points, beam-on time and monitor units (MU) were analyzed. We evaluated whether the PTV met clinical requirements and quantitative analysis of normal tissue effects in the clinic (QUANTEC) limits, and compared dosimetric differences between the two plans. Results: Both CO-IMRT and NC-IMRT could achieve the required dose coverage of PTV and meet the QUANTEC dose limits for OAR. The differences in CI, HI, beam-on time and MU between the two plans were not statistically significant (P>0.05). NC-IMRT was significantly decreased left kidney Dmean[(10.15±1.53) Gy vs (9.29±1.78) Gy, P<0.05], left kidney V12[(32.74±7.45)% vs (26.03±8.97)%, P<0.05], right kidney Dmean[(7.37±2.41) Gy vs (6.62±2.37)Gy, P<0.05], right kidney V12[(22.27±10.30)% vs (14.94±8.62)%, P<0.05], liver V30[(6.37±4.05)% vs (5.47±3.70)%, P<0.05], small intestine V30[(9.96±6.66)% vs (8.73±6.19)%, P<0.05], small intestine V45[(1.15±0.71)% vs (0.96±0.61)%, P<0.05], stomach V45[(5.37±3.96)% vs (4.52±3.32)%, P<0.05] and large bowel V30[(13.18±4.95)% vs (9.19±4.94)%, P<0.05]. There was no significant difference between CO-IMRT and NC-IMRT in spinal cord Dmax, liver Dmean, bilateral renal V20, bilateral renal V28, small intestinal Dmax, gastric Dmax and duodenal V55(mL) (P >0.05). Conclusion: In the treatment of LAPC using 75 Gy simultaneous integrated boost, both CO-IMRT and NC-IMRT can achieve excellent PTV coverage and meet the OAR constraints in all patients. Without affecting the quality of PTV coverage, NC-IMRT has more advantages in the dose distribution of OAR, which can better protect the OAR and reduce the toxicity to the gastrointestinal tract, liver and kidneys.

Key words: Locally advanced pancreatic cancer, Intensity-modulated radiotherapy, Dosimetry

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