Unusual Presentation of Postradiation Sarcoma With Subsequent Intestinal Metastasis Revealed by 18F-FDG PET/CT

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Radiation-related sarcoma is a known, albeit rare, complication following radiation therapy for primary cancers.
• Typically, radiation-induced sarcomas manifest several years after treatment and require a significant in-field radiation dose.
• The consensus definition for radiation-related sarcoma involves a specific latency period and dose threshold.

Observation:

• A 60-year-old male patient presented with a right axillary sarcoma.
• The sarcoma was detected via whole-body F-FDG PET/CT scan.
• This occurred only 1 year after the patient completed chemoradiotherapy for an initial malignancy.

Findings:

• The patient exhibited an ultrashort latency period for sarcoma development, deviating from the established definition of radiation-related sarcoma.
• Whole-body F-FDG PET/CT also incidentally revealed metastatic sarcoma to the small intestine.
• The findings suggest a potential for atypical presentations of radiation-induced sarcomas.

Implications:

• This case underscores the need to consider atypical presentations of radiation-related sarcomas, even with shorter latency periods.
• Advanced imaging like F-FDG PET/CT plays a crucial role in detecting unexpected malignancies and metastases.
• Further research may be warranted to understand the mechanisms behind rapid sarcoma development post-radiation.