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Role of radiotherapy as an adjuvant treatment of oral cavity cancers is well established. Standard indications for adjuvant radiation include T3-T4 tumor, node positive disease, margin positivity and extranodal extension. Concurrent chemotherapy is considered in presence of margin positivity and extra-nodal extension. External beam radiation therapy (EBRT) to a dose of 56-64Gy in conventional fractionation is the standard of care as an adjuvant therapy. There are certain indications such as margin positivity and extra-nodal extension where dose  escalation has shown to be beneficial in terms of locoregional control. Apart from EBRT, possible options for dose escalation are brachytherapy (BT) and stereotactic body radiation therapy (SBRT).

Both BT and SBRT can possibly be considered either alone or in combination with EBRT. In situations where neck irradiation is not warranted these 2 modalities may be considered as a radical treatment. In patients with margin positive status these 2 modalities are useful as local dose escalation strategies without increase in the toxicity. BT although an invasive  modality can improve local control by local dose escalation. Due to the rapid fall off of the dose there is reduction in late toxicity such as xerostomia. BT can be considered either after surgical wound healing or can be considered as a peri-operative approach. While peri-operative BT is more advantageous for the patient due to convenience and no need for repeat anaesthesia, it may not be feasible in some centres and requires close collaboration with surgical team. BT can also be considered as a boost after EBRT where addressing the neck nodes is necessary.

SBRT on the other hand is a non invasive technique which may be considered for similar indications of BT. The dose fall off in SBRT however may not be as rapid as in BT. SBRT can also be considered either alone or in combination with EBRT. One of the potential utility of SBRT could be in local dose escalation for the nodes which have extra-nodal extension. However more work is needed to establish its efficacy for this indication.
While use of both BT and SBRT still remains controversial in the management of adjuvant treatment of oral cavity cancers, both may have a role in certain scenarios which needs to be evaluated in prospective studies.