Patient specific treatment planning for systemically administered radiopharmaceuticals using PET/CT and Monte Carlo...

Area of Science:

• Nuclear Medicine
• Medical Physics
• Radiopharmaceutical Therapy

Background:

• Radiopharmaceutical efficacy relies on molecular targeting and radionuclide properties.
• NM404 shows promise for personalized dosimetry in combined diagnostic and therapeutic applications.
• Concurrent use of iodine-124 ([(124)I]) for PET imaging and iodine-131 ([(131)I]) for radiotherapy is feasible with NM404.

Purpose of the Study:

• To establish patient-specific dosimetry for NM404 using diagnostic PET/CT data and Monte Carlo simulations.
• To determine radiation dose distribution in tumors and organs at risk for treatment planning.
• To assess the feasibility of NM404 for simultaneous diagnosis and therapy.

Main Methods:

• Radiolabeling NM404 with [(124)I] for PET imaging and [(131)I] for radiotherapy.
• Acquiring serial PET/CT data for liver metastasis.
• Employing a software interface (SCMS) to convert PET/CT data into a Monte Carlo environment for radiation transport analysis.

Main Results:

• [(124)I]NM404 PET imaging identified organs at risk, guiding maximum injected activity for [(131)I]NM404 therapy.
• Monte Carlo simulations quantified dosimetry within the liver and tumor.
• Tumor absorbed doses were 1.2 mGy/MBq for [(124)I] and 1.5 mGy/MBq for [(131)I].
• Liver absorbed doses were 0.031 mGy/MBq for [(124)I] and 0.022 mGy/MBq for [(131)I].

Conclusions:

• Patient-specific dosimetry for NM404 is achievable using [(124)I] PET/CT and Monte Carlo methods.
• This approach enables precise radiation dose calculation for personalized radiotherapy planning.
• NM404 offers a viable dual diagnostic and therapeutic radiopharmaceutical for targeted cancer treatment.