Even Small Pleural Effusion Could Be Potential Pitfall on Posttherapeutic 131I Scintigraphy

Area of Science:

• Nuclear Medicine
• Radiology
• Oncology

Background:

• Post-therapeutic 131I whole-body scintigraphy is essential for detecting residual thyroid cancer.
• Pleural and pericardiac effusions are known to potentially accumulate radioiodine, mimicking metastatic disease.
• Previous reports focused on massive effusions with significant radioiodine uptake.

Observation:

• A 37-year-old male patient presented with a very small volume of pleural effusion.
• The effusion demonstrated unexpected radioiodine uptake on post-therapeutic scintigraphy.

Findings:

• This case demonstrates that even minimal pleural effusions can exhibit radioiodine accumulation.
• The observed uptake in a small effusion represents a potential pitfall in interpreting whole-body scans.

Implications:

• Accurate interpretation of post-therapeutic 131I scans requires careful consideration of small effusions.
• Clinicians should be aware of this potential pitfall to avoid misdiagnosis of metastatic disease.
• Further investigation may be warranted to understand the mechanisms of radioiodine uptake in small effusions.