Ramos-Prudencio Rubi, Pérez-Álvarez Sandra Ileana, Flores-Balcazar Christian Haydée, de León-Alfaro Mayra Angélica, Herrera-González José Alfredo, Elizalde-Cabrera Jonathan, Rubalcava-Ortega Johnatan, Espinoza-Alvarado Lissett, Balderrama-Ibarra Ricardo Iván
Department of Radiotherapy, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez, Sección XVI, Tlalpan, México City 14080, Mexico.
Division of Radiotherapy, Instituto Nacional de Cancerología, 22 San Fernando Ave, Sección XVI, Tlalpan, México City 14080, Mexico.
Rep Pract Oncol Radiother. 2020 Jul-Aug;25(4):586-593. doi: 10.1016/j.rpor.2020.04.020. Epub 2020 May 19.
Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas.
RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR).
We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI).
Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (p < 0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; p < 0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF.
Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.
我们的目标是比较适形3D（C3D）放射治疗（RT）、调强放疗（IMRT）和容积调强弧光治疗（VMAT）在治疗垂体腺瘤中的计划技术。
放射治疗对于垂体腺瘤的管理很重要。治疗计划的进步使得能够给予更高的放射剂量，同时降低影响危及器官（OAR）的风险。
我们对接受外照射放疗（使用带有均整器的C3D、无均整器[FFF]的C3D、IMRT和VMAT）的垂体腺瘤患者进行了为期5年的回顾性研究。我们比较了剂量体积直方图数据。对于危及器官，我们记录了D2%、最大剂量和平均剂量。对于计划靶体积（PTV），我们记录了V95%、V107%、D95%、D98%、D50%、D2%、最小剂量、适形指数（CI）和均匀性指数（HI）。
纳入了58例垂体腺瘤患者。所有技术的靶体积覆盖均可接受。HI值分别为：IMRT为0.06；VMAT为0.07；C3D为0.08；C3D FFF为0.09（p<0.0001）。VMAT和IMRT提供了最佳的靶体积适形性（CI分别为0.64和0.74；p<0.0001）。VMAT对视神经通路、晶状体和耳蜗的剂量最低。颈部极度屈曲的体位显示，它有助于主要针对VMAT进行计划，通过仅使用一条弧并实现所需的适形性，减少治疗时间，同时使用C3D、C3D FFF能更好地保护危及器官。
我们的结果证实，使用IMRT、VMAT、C3D、C3D FFF对垂体腺瘤进行外照射放疗能为靶区提供充分覆盖。单弧或不完全弧的VMAT在符合所需的剂量学目标方面表现更好，如靶区覆盖和正常结构的剂量限制，并且治疗时间更短。颈部极度屈曲在治疗计划中可能有助于更好地保护危及器官。当无法采用其他治疗技术时，颈部极度屈曲的C3D是一种合适的治疗选择。
