Systemic Therapy Integration, Supportive Care, and Toxicity Management
What to know
Radiosensitizers (cisplatin, 5-FU, temozolomide), radioprotectors (amifostine), immunotherapy timing, and toxicity management (mucositis, xerostomia, pneumonitis, cystitis, proctitis, dermatitis, fatigue).
Concepts to master
- Concurrent chemoradiation improves local control/OS in many sites but increases toxicity.
- Immunotherapy + RT: watch for radiation recall and enhanced toxicity; sequencing matters.
- Supportive care: oral care, fluoride, amifostine for parotid sparing, growth factors per guidelines.
- Late toxicity: xerostomia, fibrosis, second malignancy, neurocognitive effects.
Traps
- Assuming adding chemo always helps - it can increase toxicity without survival benefit in some settings.
- Missing radiation recall with certain agents (e.g., doxorubicin, gemcitabine).
- Overlooking organ-at-risk constraints when combining agents (e.g., nephrotoxicity with cisplatin).
Rule of thumb
Concurrent = sensitization (more local control, more acute toxicity); sequential = less interaction. Choose concurrent when the trial evidence supports survival benefit for that site/stage.
Worked example
A patient on gemcitabine develops erythema in a previously irradiated field after starting the drug. This is radiation recall - manage supportively and coordinate with medical oncology regarding the offending agent.