[Paracoccidioidomycosis assessed with 4 isotopic studies]

Area of Science:

• Nuclear Medicine
• Infectious Diseases
• Radiology

Background:

• Paracoccidioidomycosis (South American blastomycosis) is a prevalent granulomatous disease in Latin America caused by Paracoccidiosis brasiliensis.
• Disease transmission mechanisms remain unclear, with frequent involvement of lungs, liver, spleen, ganglia, oropharynx, and brain.
• While treatment with Amphotericin or Ketoconazole shows good response, high recurrence rates necessitate effective monitoring.

Purpose of the Study:

• To evaluate the utility of gallium-67, bone scintigraphy, bone marrow scintigraphy, and lymph-scintigraphy in staging and follow-up of Paracoccidioidomycosis.
• To compare the sensitivity of these radioisotopic studies with conventional radiological methods.

Main Methods:

• Study included 12 patients with Paracoccidioidomycosis, utilizing gallium-67, bone, bone marrow, and lymph-scintigraphy.
• Six patients underwent repeat studies after therapy to assess treatment response.
• Analysis focused on radio-pharmaceutical uptake patterns and changes over time.

Main Results:

• Gallium-67 showed lung accumulation in all patients; abnormal uptake was also noted in ganglia, liver, spleen, and bone.
• Bone scintigraphy abnormalities correlated with gallium findings; bone marrow scintigraphy revealed peripheral expansion in 6/12 patients.
• Post-therapy scans demonstrated decreased radio-pharmaceutical uptake, regression of bone marrow expansion, and normalization of lymph node appearance.

Conclusions:

• The combination of gallium-67, bone, bone marrow, and lymph-scintigraphy is valuable for staging Paracoccidioidomycosis.
• These radioisotopic methods provide effective follow-up for therapy response, surpassing conventional radiological study sensitivity.