Head and neck cancers form a majority of the cancers of developing world accounting for 23% of all cancer in males and 6% in females in India.¹ Aggressive locoregional treatment is offered for these patients. Despite this the survivors remain at risk of developing recurrences which are common within first 2 years and the cumulative estimated five year incidence of loco regional relapse is 29-31% in high risk patients.^2-4 Main site of failure of Head neck cancers is locoregional.⁵ Also the risk of second cancers which is about 5% per year, the incidence being between 16-30%.^6-8 Various factors affect the risk of recurrence and second cancers.

The toxicity and quality of life factors due to initial treatment may limit the ability to offer further radical treatment without increasing morbidity or affecting further the quality of life of these patients. These factors have to be considered while considering treatment decisions for treatment of these patients with a result that one or more modality may not be offered which otherwise would have been offered for patients with similar stage primary tumors.

The treatment of choice in a case of a recurrence or second neoplasm is salvage surgery. In case of inoperable and/or unresectable cases, other modalities could be considered including chemotherapy and radiation. Chemotherapy alone is essentially palliative and the results are quite dismal⁹ with response rates between 10% and 40% and median survivals of six to eight months and no long term survivors even with the best multidrug regimens^10-13.

Radiotherapy is an important modality for primary treatment of head neck cancers and has been successfully used at various subsites with success comparable to the surgery and with an added advantage of organ preservation. Head and neck radiotherapy even for the primary tumor is challenging because of the anatomy and the number of critical organs that are present very close to the target area. Another factor is the late tissue toxicity. All these reduce the therapeutic ratio.

Concept of reirradiation with curative intent has been used with judicious case selection of recurrence / second primary by several institutions with varied success.^14-21 Complication rates after reirradiation vary from 7%to 50% but are higher for reirradiation of sites like the nasopharynxor PNS due to their proximity to critical structures like brain, cranial nerves, and the orbits.^15,22 The aspects that are evaluated prior to reirradiation and determining the dose constraints must be standardized. Due to the ability and availability to deliver precise and accurate radiotherapy using advanced delivery techniques like IMRT & IGRT, relatively better normal tissue sparing can be achieved. The study of these conformal techniques has been evaluated and found to give comparable outcomes although the acute toxicity was high.²³

Various factors affect the decision for treatment. Factors related to the prior treatment as to the dose, fractionation, late effects and time interval since prior radiation, factors related to the patient like performance status, age, comorbidities and factors of the present tumor site, volume in previously irradiated region, ability to offer surgery and / or radiotherapy need to be assessed and correlated with the outcomes. Besides documentation of those who take treatment, their follow up to get an outcome would be reasonable. Besides documentation and reporting of the Quality of life is needed to assess the impact of benefit with reirradiation.

Swallowing dysfunction has been reported in 30-50% of patients of head and neck cancers treated with intensive nonsurgical therapies.^22-24 About one third of dysphagic patients develop aspiration pneumonia requiring treatment, with mortality rates ranging between 20% and 65%.²⁵ Although dysphagia improves over time in 32% of HNCPs, 48% of patients fail to report improvement in dysphagia -associated symptoms and in 20% of patients symptoms worsen overtime.²⁶ Dysphagia may pre-exist therapy (14% ^[27] to 18% ^[28] of HNCPs) due to the obstruction by the tumour volume or infiltration of structures involved with swallowing. In the operative population, surgical extirpation of structures necessary for normal deglutition results in swallowing abnormalities. In the patients treated with radiotherapy (RT), dysphagia is secondary to damage of neural and soft tissues ^[29].

RT-induced swallowing dysfunction may occur both acutely during treatment and as a late effect of therapy. Radiation dose delivery to dysphagia–aspiration-related structures (DARSs), those anatomical structures that are critical to the swallowing function ^[30] has been shown to predict swallow outcome in a number of studies. DARS comprise of the superior, middle and inferior pharyngeal constrictor muscles, cricopharyngeus muscle, esophagus inlet muscles, cervical esophagus, base of tongue, supraglottic larynx and glottic larynx . Severity of dysphagia increase with the dose received by the pharyngeal constrictors ⁽³¹⁾ but it also increases with the volume of the pharyngeal constrictors irradiated ^(31,32,33). The volume of the middle pharyngeal constrictor muscle receiving 50 Gy (p = 0.04), the mean dose to this structure (p = 0.02) and to the supraglottic larynx (p = 0.04) were significantly associated with late swallowing problems. It has been seen that while treating orophryngeal cancer with IMRT technique, dose to superior pharyngeal constrictors and myo/geniohyoid complex should be monitored and constrained whenever possible ^.34 The volume of the larynx receiving >or=50Gy (p = 0.04 and p = 0.03, respectively) and volume of the inferior constrictor receiving >or=50Gy (p = 0.05 and p = 0.02, respectively) were significantly associated with both aspiration and stricture.³³