Head and neck cancers comprise of cancers of arising from the epithelial lining of the lip, oral cavity, pharynx and larynx. The overall incidence of Head and Neck cancers continues to increase, despite decrease in the incidence of smoking suggestive of potential change in etiology. Presently Head and Neck cancer form the seventh most common cancer globally The primary treatment of oral cavity cancer comprises of surgery with adjuvant radiation with or without chemotherapy for locally advanced cancers or early-stage cancer in presence of high-risk factor. Cancers of the oropharynx are treated primarily with radiotherapy for early stage and chemoradiation for locally advanced disease. Laryngeal cancers are treated with either radiotherapy alone or chemoradiation, with surgery reserved for patients with laryngeal cartilage involvement or non-functional larynx.
Radiotherapy for head and neck cancer is delivered with conventional fractionation at 2- 2.2Gy per fraction to a total of 70 Gy dose equivalent. There are certain other altered fractionation types which has been tested like hyperfractionation with an intention to reduce late toxicities as well as accelerated and hypofractionation to counteract the effects of accelerated repopulation. Altered fractionation trials with hyperfractionation show increase in overall survival benefit when compared to radiotherapy alone but worse OS outcomes when compared to chemoradiation with lower toxicities. The advent of the COVID 19 pandemic popularised hypofractionated regimens with the ASTRO-ESTRO consensus statement which achieved a strong consensus about hypofractionated RT.
The addition of concurrent chemotherapy has been found to be superior compared to radiation alone in terms of locoregional control as well as overall survival. The MACH-NC meta analysis showed a 6.5% difference at 5 years and 3.6% at 10 years in favour of concurrent chemotherapy. The optimal dose of chemotherapy remains an important question. Although several studies have shown a significant improvement in overall survival with increasing cumulative cisplatin doses there might not be additional benefit of increasing dose of chemotherapy beyond a cumulative dose of 200mg/m2.
Through this study, the investigators aim to assess and compare the disease related outcomes, acute and late toxicities as well as the quality of life parameters of patients treated with hypofractionated radiotherapy along with two cycles 3 weekly concurrent chemotherapy versus those following the conventional chemotherapy regimen.
Rationale of study
1. Reduction in overall treatment time Squamous cell cancer of the Head and Neck region are rapidly proliferating cancers. Earlier studies have estimated a median value of labeling S-phase fraction (LI), duration, and estimated potential doubling time (Tpot) as 9%, 9 hours, and 5 days respectively. Although some studies failed to show any predictive value of pretreatment potential doubling time and labeling index in patients treated with conventional fractionation the effect of accelerated repopulation which is estimated to be triggered around about 4 +/- 1 weeks cannot be undermined. Several studies have shown a strong negative relation between overall treatment time and locoregional control and overall survival with an average loss of LRC from 1-1.2% per day to 12-14% per week. The dose time factor, also known as the K factor (or λ/α factor as used in some publications) ranges between 0.5 and 0.99 Gy/day with a recent meta-analysis on laryngeal cancers estimating it as 0.6 - 0.8.
2. Resource and financial benefits for patients, caregivers and hospitals. Reduction in total number of fractions will lead to an overall shorter duration of treatment and lesser number of hospital visits. For patients, an earlier end to treatment and lesser number of hospital visits will be a source of physical and financial relief. For caregivers, this will allow an earlier return to work or other responsibilities. For the healthcare system, it allows more patients to be offered treatment using the same resources.
3. Better patient compliance Reduced treatment time will increase patient compliance especially for patients who are taking treatment away from home.
