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Head and Neck Cancer Section Heading Section sub Technologic Advances in External Beam Radiotherapy for Head and Neck Cancer Dirk Van Gestel, MD, 1 Vincent Gregoire, MD, PhD 2 and Jan B Vermorken, MD, PhD 3 1. Radiation Oncologist, University Radiotherapy Department Antwerp, Belgium; 2. Professor in Radiation Oncology, Radiation Oncology Department and Centre for Molecular Imaging and Experimental Radiotherapy, St-Luc University Hospital, Brussels, Belgium; 3. Emeritus Professor of Oncology, Department of Medical Oncology, Antwerp University Hospital, Edegem, Belgium Abstract Purpose: Radiotherapy (RT) has evolved substantially since its first clinical use in 1896. Most recently, the introduction of the computed tomography (CT) scan in the 1980s launched 2 decades of technologic (r)evolution. In this article we will give an overview of the recent technical advances in external beam RT for head and neck cancer (HNC). Discussion: In HNC, intensity-modulated RT (IMRT) has become standard of care as it has shown superiority over 3D conformal RT in terms of prevention of xerostomia. Other treatment options are fractionated stereotactic RT as a boost and the use of particle therapy with its interesting ballistic capacities. Carbon ions will be mainly used for radio-resistant cancers because of the supplementary higher biologic effect. Adaptive RT is promising but needs much more evolution before it can be optimally used. All these new techniques require a high level of image guidance in order to reach their maximal capacities. Rigorous quality assurance of all the different steps in the irradiation process is essential to deliver the right dose exactly at the right place. Conclusion: The recent rapid technologic evolution in RT is particularly interesting for HNC as it permits better sparing of the many radiosensitive organs in close vicinity to these aggressive tumors. Keywords Technologic advances, radiotherapy, head and neck cancer Disclosure: The authors have no conflicts of interest to declare. Acknowledgements: The authors wish to thank Hans Langendijk for his critical review of this article. Received: June 26, 2013 Accepted: August 12, 2013 Citation: Oncology & Hematology Review (US), 2013;9(2):109–114 Correspondence: Dirk Van Gestel, MD, Department of Radiotherapy, University Radiotherapy Department Antwerp, Lindendreef 1, 2020 Antwerp, Belgium. E: dirk.van.gestel@uza.be and dirk.vangestel@zna.be Radiotherapy (RT) was used clinically for the first time in 1896, and, since then, has evolved impressively, in particular, more recently. Initially, RT was referred to as ‘Röntgen therapy,’ after the discovery of the X-rays by Wilhelm Röntgen in 1895. 1 In those early days of RT, external beam RT (EBRT) with superficial kilovolt (kV) X-rays, in addition to treating some malignant diseases, was mainly used to treat various skin diseases through its anti-inflammatory capacities and infectious diseases, such as tuberculosis, due to the supposed antibacterial activity of X-rays. 2 As such, RT was widely used in this era before the introduction of antibiotics, chemotherapeutic agents, and steroids. However, for the treatment of cancer, these early EBRT treatments with rather unreliable treatment units often resulted in severe side effects and/or poor local control. The development of reliable therapeutic X-rays equipment would ultimately take 40 years, until the mid-1930s, however, still using EBRT treatment with low energy (and thus less penetration) X-rays. 3 Nevertheless, it was the introduction of the prolonged fractionated scheme by Coutard in those days that allowed such EBRT to provide cancer cure with acceptable toxicity. 4 This approach continued until the 1950s, when units with cobalt-60, a synthetic radioactive isotope of cobalt, were able to treat patients with © To u ch MEdical MEd ia 2013 gamma-rays of 1.2 MV (high energy and thus high penetration). The first million volt (super voltage) units, the linear accelerators (linacs), were produced in the US in the 1940s, but it would take until 1953 before the first patient was treated with a linac at the London Hammersmith Hospital. 5 In order to avoid losing time with treatment planning in the actual treatment room, ‘simulator’ rooms devoted to treatment planning were built. On a treatment-like machine, treatments could be simulated with the aid of fluoroscopy and 2D radiographs. The recent history of EBRT techniques in head and neck cancer (HNC) (see Figure 1) is characterized by the search for the best possible equilibrium between treatment intensification in order to further improve loco-regional control and toxicity reduction (see Figure 2). This is not only true for locally advanced disease but also, or perhaps even in particular, for early stages treated with RT. The recent history of RT in general and of RT in HNC in particular, starts with the introduction of the computed tomography (CT) scan (Godfrey Houndsfield, 1971) in RT planning in the 1980s. Conventional fluoroscopy-based 2D RT makes room for 3D conformal RT (3D-CRT) (see 109