The goal of the project was 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. The general objectives were to:
(a) Optimize the diagnostic value of postsurgical thyroid I-123 SPECT imaging, using an elaborated human-sized thyroid phantom with variable sizes of thyroid remnants and the three imaging modalities of the collaborating Hospitals, so as to accurately determine the volume of thyroid remnants and then accurately calculate the I-131 dose for thyroid remnants ablation.
(b) Develop, validate and provide for application, an educational and training open-access automated and friendly-user software to (i) correct the images for scattering, (ii) segment thyroid remnants and correct for the partial volume effect, (iii) calculate their volume, (iv) calculate the I-131 dose for ablation and provide radiobiological models to estimate the potential impact of particular therapies to the possible detected thyroid cancer remnants.
(c) Disseminate the results to interested scientific and health professional societies to encourage educational and (pre)clinical application.
Specific Scientific and Technological Objectives
(a) Design, develop and validate a human-sized neck-thyroid phantom with capabilities of inserting variable sizes of thyroid remnants to simulate various remnant-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 consortium Hospitals.
(c) Develop and validate a scatter correction algorithm, using the triple-energy window method, to correct diagnostic thyroid I-123 / I-131 AC-SPECT images.
(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 / I-131 SPECT images.
(e) Calculate the volume of the thyroid remnants.
(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.