Prostatic bed calcification with [99mTc]Tc-MDP uptake: Easy to miss on planar images

Area of Science:

• Nuclear Medicine
• Radiology
• Oncology

Background:

• Bone scintigraphy using 99mTc-MDP is a common imaging technique for detecting bone metastases in prostate cancer.
• Extra-osseous uptake on bone scintigraphy can sometimes be challenging to interpret, potentially mimicking metastatic disease.

Purpose of the Study:

• To evaluate the utility of SPECT/CT in differentiating prostatic bed calcification from bone metastases in a patient with high-risk prostate adenocarcinoma.
• To highlight the potential for misinterpretation of planar bone scintigraphy findings.

Main Methods:

• A 65-year-old male patient with high-risk prostate adenocarcinoma underwent bone scintigraphy with 99mTc-MDP.
• SPECT/CT imaging was performed to further characterize an area of suspicious radiotracer uptake.

Main Results:

• Planar bone scintigraphy showed increased radiotracer uptake in the left pubic region, suspicious for metastatic involvement.
• SPECT/CT imaging localized the uptake to an extra-osseous calcified zone within the prostate bed, not representing bone metastasis.

Conclusions:

• Prostatic bed calcification can mimic bone metastases on planar 99mTc-MDP bone scintigraphy.
• SPECT/CT is crucial for accurate characterization of equivocal findings and avoiding misdiagnosis of metastatic prostate adenocarcinoma.