Maximal safe dose of I-131 after failure of standard fixed dose therapy in patients with differentiated thyroid carcinoma

Abstract

The maximal safe dose provides an effective means of treatment in patients who failed to respond adequately to conventional fixed dose therapy. I-131 MSD therapy can be considered in patients who fail fixed dose therapy.

The conflict between treatment optimization and registration of radiopharmaceuticals with fixed activity posology in oncological nuclear medicine therapy

“…This approach was implemented more than 50 years ago by Benua et al [1], and was successfully applied in the following decades by Leeper [2]. Unfortunately, the method has now been abandoned by many institutions, but it has continued in use in other centres [3][4][5][6][7][8]. The method provides solid indications of best outcome, in contrast to the fixed activity approach [3,4], although a clinical study with the highest level of evidence (phase III randomized) has never been pursued.…”

“…Unfortunately, the method has now been abandoned by many institutions, but it has continued in use in other centres [3][4][5][6][7][8]. The method provides solid indications of best outcome, in contrast to the fixed activity approach [3,4], although a clinical study with the highest level of evidence (phase III randomized) has never been pursued. This approach was recently re-proposed [9], with the introduction of the acronym AHASA (as high as safely attainable) instead of ALARA.…”

“…Even in patients in whom the intended purpose is purely palliative, there are indications that the patient benefit (response rate [3,4] and overall survival [4,19]) could be improved if the optimization (when possible) or maximization principles are adopted.…”

Dosimetry and thyroid cancer: the individual dosage of radioiodine

“…The authors also note that such treatment almost always produced a partial biochemical tumor response. Lee et al (2008) likewise determined the maximal safe activity calculated according to the original Benua approach for 47 patients. Their mean calculated safe activity was 12.5 GBq.…”

The “reset button” revisited: why high activity 131I therapy of advanced differentiated thyroid cancer after dosimetry is advantageous for patients

“…While we consider that the study by Klubo-Gwiezdzinska provides an initial indication in favour of AHASA, Lee et al found that 45% of patients who failed to respond to pretreatment with a fixed activity approach, achieved a partial or complete radiological response after ASAHA therapy [22]. Though at a low level of evidence, it nonetheless seems that there are at least two papers supporting the advantages of AHASA.…”