Radiation Recall Phenomenon Following Vaccination in a Patient With Prior Radiation to Lower Extremity Liposarcoma

Area of Science:

• Oncology
• Dermatology
• Immunology

Background:

• Radiation recall phenomenon (RRP) involves inflammatory reactions in prior radiation fields.
• Triggers include chemotherapy, medications, and infections.
• Vaccination is an emerging potential trigger for RRP.

Observation:

• A 67-year-old female patient with a history of radiation to the right thigh for liposarcoma presented with a blister.
• The blister appeared in the previously irradiated right thigh three days after receiving COVID-19, RSV, and influenza vaccines.
• The reaction progressed to an ulcer over two months, while the active breast radiation site remained unaffected.

Findings:

• This case suggests that vaccines, including COVID-19, RSV, and influenza vaccines, can act as triggers for RRP.
• The reaction selectively occurred in the prior radiation field (right thigh), not the current radiation site (breast).

Implications:

• Highlights vaccination as a potential RRP trigger.
• Emphasizes the importance of considering RRP in patients with prior radiation history who develop skin reactions post-vaccination.
• Suggests further research into the mechanisms of vaccine-induced RRP and selective radiation field involvement.