The Potential of Helical Tomotherapy in the Treatment of Head and Neck Cancer

• Published in: The oncologist (Dayton, Ohio) Vol. 18; no. 6; pp. 697 - 706
• Main Authors: Van Gestel, Dirk, Verellen, Dirk, Van De Voorde, Lien, Ost, Bie, De Kerf, Geert, Vanderveken, Olivier, Van Laer, Carl, Van den Weyngaert, Danielle, Vermorken, Jan B., Gregoire, Vincent
• Format: Journal Article
• Language: English
• Published: Durham, NC, USA AlphaMed Press 01-06-2013
• Subjects: Head and neck cancer; Head and Neck Cancers; Head and Neck Neoplasms - pathology; Head and Neck Neoplasms - radiotherapy; Helical tomotherapy; Humans; Radiotherapy Dosage; Radiotherapy, Image-Guided - methods; Radiotherapy, Intensity-Modulated - methods; Randomized Controlled Trials as Topic; Tomography, X-Ray Computed; Helical tomotherapy; Head and neck cancer
• ISSN: 1083-7159; 1549-490X
• DOI: 10.1634/theoncologist.2012-0424

A decade after its first introduction into the clinic, little is known about the clinical impact of helical tomotherapy (HT) on head and neck cancer (HNC) treatment. Therefore, we analyzed the basics of this technique and reviewed the literature regarding HT's potential benefit in HNC. The past two decades have been characterized by a huge technological evolution in photon beam radiotherapy (RT). In HNC, static beam intensity‐modulated radiotherapy (IMRT) has shown superiority over three‐dimensional conformal RT in terms of xerostomia and is considered the standard of care. However, the next‐generation IMRT, the rotational IMRT, has been introduced into the clinic without any evidence of superiority over static beam IMRT other than being substantially faster. Of these rotational techniques, HT is the first system especially developed for IMRT in combination with image‐guided RT. HT is particularly promising for the treatment of HNC because its sharp dose gradients maximally spare the many radiosensitive organs at risk nearby. In addition, HT's integrated computed tomography scan assures a very precise dose administration and allows for some adaptive RT. Because HT is specifically developed for IMRT in combination with (integrated) image‐guidance, it allows for precise dose distribution (“dose painting”), patient setup, and dose delivery. As such, it is an excellent tool for difficult HNC irradiation. The literature on the clinical results of HT in HNC all show excellent short‐term (≤2 years) results with acceptable toxicity profiles. However, properly designed trials are still warranted to further substantiate these results.
摘要
自螺旋断层放射治疗（ HT ）首次应用到临床实践中以来，已经过去了 10 年，但 HT 对头颈部癌（ HNC ）的临床影响依然知之甚少。因此，我们分析了这项技术的基本原理并回顾了关于HT对 HNC 潜在获益的文献。过去的20年内光子束放射治疗（ RT ）出现了重大技术革新。在 HNC 患者中，静态束调强放射治疗（ IMRT ）已显示在口腔干燥方面优于三维适形RT，被考虑作为标准治疗。然而，下一代 IMRT 即旋转 IMRT 已引进临床实践，而旋转 IMRT 除了速度大幅度加快之外，尚无任何证据显示其具有超越静态束 IMRT 的优势。 就旋转技术而言， HT 为首个专门系统性研发用于 IMRT 联合图像引导RT的技术。 HT 特别有望用于治疗 HNC ，因为该技术明显的剂量梯度在最大程度上保护了照射野附近很多对放射敏感的器官。另外， HT 融合了计算机断层扫描，因而确保给予的剂量非常精准并为适应性 RT 留出了可能性空间。由于 HT 特别为 IMRT 联合（融合）图像引导而研发，该技术考虑到了精准的剂量分布（“剂量描画分布”）、患者放疗时摆位以及剂量传送。所以，对于高难度的 HNC 照射来说这是一个极佳的工具。关于 HT 用于 HNC 的临床结果的文献均显示短期（≤ 2年）疗效很好且毒性反应可接受。然而，仍需要设计良好的试验来进一步验证上述结果。The Oncologist 2013;18:697‐706
This article discusses the basics of helical tomotherapy (HT) for head and neck cancer (HNC) treatment. HT allows for precise dose distribution, patient setup, and dose delivery, making it a valuable tool for difficult HNC irradiation. The literature regarding HT's potential benefit in HNC is also reviewed.