Altered [^99mTc]Tc-MDP biodistribution from neutron activation sourced ⁹⁹Mo

Area of Science:

• Nuclear Medicine
• Radiochemistry
• Oncology

Background:

• Concerns exist regarding global shortages of fission-produced molybdenum-99/technetium-99m (99Mo/99mTc) medical isotopes.
• Alternative production methods for 99Mo/99mTc are being explored to ensure supply.

Purpose of the Study:

• To compare 99mTc Methylene Diphosphonate ([99mTc]Tc-MDP) derived from neutron-activated 99Mo against reactor-produced 99Mo in oncology patients.
• To evaluate the safety and efficacy of investigational [99mTc]Tc-MDP in bone scans.

Main Methods:

• A single-center, phase III, open-label study was conducted.
• Neutron activation produced 99Mo was used for solvent generator separation of 99mTc.
• The investigational [99mTc]Tc-MDP was administered to oncology patients undergoing bone scans.

Main Results:

• The investigational [99mTc]Tc-MDP passed all quality assurance tests, meeting standards for human administration.
• Altered biodistribution of the investigational [99mTc]Tc-MDP was observed in patients.
• The altered biodistribution poses a risk of erroneous clinical interpretation.

Conclusions:

• While meeting quality standards, [99mTc]Tc-MDP from neutron-activated 99Mo exhibited unexpected biodistribution changes.
• The underlying cause for the altered biodistribution is currently unknown.
• Further research is essential to elucidate the cause and implications of these findings for clinical use.