Percutaneous microwave ablation of thyroid nodules: efficacy evaluation with 99m Tc - pertechnetate and 99mTc-MIBI functional imaging

Background: Local abla ve treatments play an important role for pa ents who cannot be treated surgically.Radiofrequency abla on is a well-established alterna ve to surgical treatment of thyroid nodules, however it also has disadvantages.Microwave abla on (MWA) is a new minimally invasive treatment promising several improvements.The aim of this retrospec ve study was to evaluate the effects of microwave abla on on thyroid nodules by 99m Tc-pertechnetate and 99m Tc-MIBI scin graphy.Materials and Methods: 30 pa ents with overall 40 nodules were treated.For the abla on of thyroid nodules, a microwave generator working with frequencies from 902 to 928 MHz was used.The abla on me ranged between 120 and 300 seconds per abla on zone.The target temperatures ranged between 60-80 °C.Pre-and post-interven onal, the radionuclide uptake was determined using a thyroid specific scin lla on camera.For 27 cold nodules 99m Tc-MIBI was used for evalua on; 13 indifferent nodules were measured with 99m Tc-pertechnetate.Results: The rela ve change of uptake was detected as a quo ent of pre-and post-therapeu c uptake.The sta s cal analysis of scin graphy data proved the efficacy of microwave abla on.99m Tc-pertechnetate scin graphy showed an uptake reduc on of 39% (range 9 to 85%).99m Tc-MIBI imaging showed a median reduc on of 40% (p<0.01)(range 7 to 100%).Conclusion: The determined results show the effec veness of MWA as a treatment op on for benign thyroid nodules.With func onal scin graphy a significant ac vity decrease could be detected in the abla on zone; hence a verifica on of affec vity was possible a=er a short period of me.