Optimizing the diagnostic value of postsurgical I-123 SPECT thyroid imaging and applying patient-specific dosimetry for radioiodine ablation of thyroid remnants




General Objective of the Project

The goal of the project is to accurately determine the volume of thyroid remnants after a postsurgical diagnostic imaging procedure with I-123, and then to accurately calculate the therapeutic I-131 dose for ablation, according to the recent management guidelines of the American Thyroid Association, and not the administered activities to be empirically determined by institutions. 

Specific Scientific and Technological Objectives of the Project

(a) Design, develop and validate a human-sized neck-thyroid phantom with capabilities of inserting variable sizes of thyroid remnants and that can simulate various thyroid-to-background activity ratios.

(b) Optimize the diagnostic postsurgical thyroid SPECT imaging protocols using I-123, and acquire/process images with variable sizes of thyroid remnants using the elaborated neck-thyroid phantom at the three consortium Nuclear Medicine Departments.

(c) Develop and validate a scatter correction algorithm, using the triple-energy window method, to correct diagnostic thyroid AC-SPECT images using I-123.

(d) Develop and validate a partial volume correction algorithm using automatic and semi-automatic techniques to segment the thyroid remnant(s) and correct them for the partial volume effect using diagnostic I-123 SPECT images.

(e) Calculate the volume of the thyroid remnants and visualize their 3D morphology for observing possible abnormalities.

(f) Calculate I-131 doses for thyroid remnants ablation using diagnostic I-123 SPECT images and provide possible radiobiological models to estimate the potential impact of particular therapies to the possible detected thyroid cancer remnants.

(g) Develop, and validate the performance and practicality, of a user-friendly open-access software package consisting of the proposed algorithms for (i) scatter correction, (ii) partial volume correction, (iii) volume calculation, and (iv) calculation of radioiodine dose for thyroid remnants ablation.