Title:Radiotheragnostics Paradigm for Radioactive Iodine (Iodide) Management of Differentiated Thyroid Cancer
VOLUME: 26 ISSUE: 31
Author(s):Einat Slonimsky and Mark Tulchinsky*
Affiliation:Department of Radiology, Section of Nuclear Medicine, Penn State Health, the Milton S. Hershey Medical Center, Penn State University Hospital, Hershey, Pennsylvania 17033, Department of Radiology, Section of Nuclear Medicine, Penn State Health, the Milton S. Hershey Medical Center, Penn State University Hospital, Hershey, Pennsylvania 17033
Keywords:Radioactive Iodide Treatment (RAIT), Differentiated Thyroid Cancer (DTC), radiotheragnostics, Post Total Thyroidectomy
(PTT), Treatment of Known Disease (TKD), thyroglobulin.
Abstract:
This review of radioactive iodide treatment (RAIT) extends from historical origins to its modern utilization
in differentiated thyroid cancer (DTC). The principles embedded in the radiotheragnostics (RTGs) paradigm
are detailed.
The diverse approaches in current practice are addressed, and this broad variability represents a major weakness
that erodes our specialty’s trust-based relationship with patients and referring physicians. The currently developing
inter-specialty collaboration should be hailed as a positive change. It promises to clarify the target-based
terminology for RAIT. It defines RAIT of post total thyroidectomy (PTT), presumably benign thyroid as ‘remnant
ablation’ (RA). ‘Adjuvant treatment’ (AT) referrers to RAIT of suspected microscopic DTC that is inherently
occult on diagnostic imaging. RAIT directed at DTC lesion(s) overtly seen on diagnostic imaging is termed
‘treatment of known disease’ (TKD).
It was recently recognized that a ‘recurrent’ DTC is actually occult residual DTC in the majority of cases. Thyroglobulin
with remnant uptake concord (TRUC) method (aka Tulchinsky method) was developed to validate that
a benign remnant in the post-thyroidectomy neck bed, as quantified by the RAI uptake, is concordant with a
measured thyroglobulin (Tg) level at the time of the initial post-thyroidectomy evaluation. It allows recognition of
occult residual DTC contribution to post-thyroidectomy Tg. Case examples demonstrate the application of the
TRUC method for a logical selection of a specific RAIT category, using imaging-guided identification and management
of RAI-avid versus RAI-nonavid residual DTC, i.e. the radiotheragnostics paradigm.
