Introduction

Cancer is one of the top causes of death around the world. It causes a serious impact on society, health, and the economy. Asia plays a major role in the global cancer issue, with an estimated 9.8 million new cases and 5.4 million deaths each year, representing nearly half of all cases and deaths worldwide [1].

Head and neck cancer (HNC) includes a diverse group of tumors, arising from the mucosal surfaces of the Upper Aerodigestive Tract (UADT), such as the oral cavity, pharynx, and larynx [2, 3]. Together, these cancers make up a significant part of the global cancer burden and are a leading cause of morbidity and mortality around the world [4]. The incidence and distribution of HNC vary widely across regions, which reflects differences in exposure to known risk factors such as tobacco use (both smoking and chewing), alcohol consumption, Betel Quid (BQ) chewing, viral infections including HPV, and other environmental factors [4, 5]. In India, HNC is especially common, with lip and Oral Cavity Cancers (OCC) accounting for 10.17% of all cases according to GLOBOCAN, 2022, making them the most prevalent cancer type in the region and highlighting the disease as a serious public health concern [6].

In the past, the management of HNC has continued to improve with advancements in surgical, systemic, and radiation therapy modalities. Early treatment approaches were often associated with limited disease control and significant treatment-related toxicities [7, 8]. However, with advancements in diagnostic imaging and staging systems, management of HNC has continued to improve. Despite these advancements, achieving optimal tumor control while preserving organ function and quality of life remains a central challenge in HNC treatment [9].

Radiation therapy (RT) plays a pivotal role in the HNC, either as an adjuvant or as the primary mode of treatment, in combination with chemotherapy and surgery [7]. The complex anatomy of the head and neck region, along with the close proximity of critical organs at risk (OAR), demands high levels of precision in radiation delivery [10]. Technological advancements in RT have driven a transition from conventional two-dimensional radiotherapy (2DRT) to Three- Dimensional Conformal Radiation Therapy (3DCRT), and subsequently the advent of Intensity- Modulated Radiation Therapy (IMRT), and Image Guided Radiation Therapy (IGRT) [11, 12]. Recently, advanced techniques such as Stereotactic Radiosurgery (SRS), Stereotactic Radiotherapy (SRT), Volumetric Modulated Arc Therapy (VMAT), and Stereotactic Body Radiation Therapy (SBRT) in RT treatment plans, Tomotherapy, Proton Therapy (PT) and Adaptive Radiotherapy (ART), have further enhanced dose conformity and reduced exposure to surrounding normal tissues [13].

Alongside these technological advances, patient positioning and immobilization have received more attention as crucial elements of accurate radiotherapy delivery [14]. Reproducible positioning and image guidance are crucial because setup uncertainties and patient motion can compromise target coverage and increase the risk of toxicity [15]. To address these challenges, innovations like multi-axis treatment couches and sophisticated immobilization devices have been introduced.

The purpose of this review is to present a historical background and comprehensive review of the literature on the subject of HNC, focusing on the epidemiology, global disease burden, treatment approaches, and latest advancements in the HNC treatment by the radiotherapy technique. By integrating historical background and the latest literature, this review seeks to highlight progress achieved so far in the management of patients with HNC.