Radiation Therapy and Systemic Therapy
Radiation fundamentals
Know that radiation is delivered in fractions, that total dose and fractionation matter, and that altered fractionation (hyperfractionation, accelerated) can improve outcomes in some settings at the cost of toxicity. Understand the concept of the planning target volume and organs at risk, and why sparing the parotids, spinal cord, and mandible matters. Know that concurrent chemotherapy with radiation acts as a radiosensitizer and improves local control in high-risk disease.
Systemic therapy
Understand the roles of chemotherapy (platinum-based regimens are central), targeted therapy (cetuximab against EGFR), and immunotherapy (checkpoint inhibitors) in recurrent/metastatic or selected definitive settings. Know that induction chemotherapy is used selectively and is not standard for all patients. Recognize that HPV-positive disease may have different systemic therapy considerations.
Toxicity you must recognize
Mucositis, xerostomia, dysphagia, dermatitis, and osteoradionecrosis are core. Know that dental evaluation before radiation reduces osteoradionecrosis risk, and that xerostomia is dose-dependent to parotid sparing.
Traps
Questions test whether you know chemotherapy is a radiosensitizer in the adjuvant/definitive setting versus palliative intent in metastatic disease. A frequent trap is assuming adding chemotherapy always improves survival regardless of setting. Another is confusing acute versus late toxicity.
Rule of thumb
Ask: what is the intent (definitive, adjuvant, palliative), and what is the mechanism (radiosensitization vs systemic control)? Example: concurrent cisplatin with adjuvant radiation after high-risk resection is given for radiosensitization and local control, not as systemic disease control-framing the intent correctly resolves many items.