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SPECT/CT localization of oral radioiodine activity: a retrospective study and in-vitro assessment.

Burlison JS, Hartshorne MF, Voda AM, Cocks FH, Fair JR - Nucl Med Commun (2013)

Bottom Line: Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals.Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of I from Argenco HP 77.Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals.

View Article: PubMed Central - PubMed

Affiliation: aDepartment of Radiology, University of New Mexico bPrivate Practice, Albuquerque, New Mexico cDepartment of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA.

ABSTRACT

Purpose: We sought to further localize radioiodine activity in the mouth on post-thyroid cancer therapy imaging using single-photon emission computed tomography/computed tomography (SPECT/CT).

Materials and methods: We retrospectively reviewed all patients (58) who underwent thyroid cancer therapy with iodine-131 (131I) at our institution from August 2009 to March 2011 whose post-therapy radioiodine imaging included neck SPECT/CT. A small group (six) of diagnostic 131I scans including SPECT/CT was also reviewed. Separately, we performed in-vitro 131I (sodium iodide) binding assays with amalgam and Argenco HP 77 (77% dental gold alloy) as proof of principle for these interactions.

Results: Of the 58 post-therapy patients, 45 (78%) had undergone metallic dental restorations, and of them 41 (91%) demonstrated oral 131I activity localizing preferentially to those restorations. It was observed that radioiodine also localized to other dental restorations and to orthodontic hardware. Gum-line activity in edentulous patients suggests radioiodine interaction with denture adhesive. In vitro, dental amalgam and Argenco HP 77 bound 131I in a time-dependent manner over 1-16 days of exposure. Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals. Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of I from Argenco HP 77.

Conclusion: SPECT/CT shows that radioiodine in the oral cavity localizes to metallic dental restorations. Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals.

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Related in: MedlinePlus

Diagnostic 123I SPECT/CT of the neck and upper chest to assess a mediastinal mass (confirmed to be a multinodular goiter) shows gum-line activity in this edentulous patient, presumably bound to denture adhesive. (a) The MIP (maximal intensity projection) shows multiple foci of activity associated with the multinodular goiter, along with physiologic submandibular gland activity and curvilinear activity in the mouth. (b) The CT image through the mouth shows that the patient is edentulous. Coronal (c) and axial (d) SPECT/CT fusion images demonstrate radioiodine activity localizing along the gum lines. SPECT/CT, single-photon emission computed tomography/computed tomography.
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Figure 2: Diagnostic 123I SPECT/CT of the neck and upper chest to assess a mediastinal mass (confirmed to be a multinodular goiter) shows gum-line activity in this edentulous patient, presumably bound to denture adhesive. (a) The MIP (maximal intensity projection) shows multiple foci of activity associated with the multinodular goiter, along with physiologic submandibular gland activity and curvilinear activity in the mouth. (b) The CT image through the mouth shows that the patient is edentulous. Coronal (c) and axial (d) SPECT/CT fusion images demonstrate radioiodine activity localizing along the gum lines. SPECT/CT, single-photon emission computed tomography/computed tomography.

Mentions: In total, 11 patients from the 131I group had localizing oral radioactivity not corresponding to metallic dental restorations. Of them, three edentulous patients had radioiodine activity concentrated along the gum lines (Fig. 2), suggesting that radioiodine adheres to or interacts with residual denture adhesive. Three near-edentulous patients had 131I activity localizing to the remaining teeth. Interestingly, one such near-edentulous patient with 131I activity localizing to the remaining teeth (Fig. 3, eight teeth, no hardware) also accumulated activity on his scalp and hands, suggesting that poor hygiene may have contributed to dental 131I activity. In the remaining five patients with localizing activity, 131I nonspecifically associated with unrestored teeth.


SPECT/CT localization of oral radioiodine activity: a retrospective study and in-vitro assessment.

Burlison JS, Hartshorne MF, Voda AM, Cocks FH, Fair JR - Nucl Med Commun (2013)

Diagnostic 123I SPECT/CT of the neck and upper chest to assess a mediastinal mass (confirmed to be a multinodular goiter) shows gum-line activity in this edentulous patient, presumably bound to denture adhesive. (a) The MIP (maximal intensity projection) shows multiple foci of activity associated with the multinodular goiter, along with physiologic submandibular gland activity and curvilinear activity in the mouth. (b) The CT image through the mouth shows that the patient is edentulous. Coronal (c) and axial (d) SPECT/CT fusion images demonstrate radioiodine activity localizing along the gum lines. SPECT/CT, single-photon emission computed tomography/computed tomography.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815121&req=5

Figure 2: Diagnostic 123I SPECT/CT of the neck and upper chest to assess a mediastinal mass (confirmed to be a multinodular goiter) shows gum-line activity in this edentulous patient, presumably bound to denture adhesive. (a) The MIP (maximal intensity projection) shows multiple foci of activity associated with the multinodular goiter, along with physiologic submandibular gland activity and curvilinear activity in the mouth. (b) The CT image through the mouth shows that the patient is edentulous. Coronal (c) and axial (d) SPECT/CT fusion images demonstrate radioiodine activity localizing along the gum lines. SPECT/CT, single-photon emission computed tomography/computed tomography.
Mentions: In total, 11 patients from the 131I group had localizing oral radioactivity not corresponding to metallic dental restorations. Of them, three edentulous patients had radioiodine activity concentrated along the gum lines (Fig. 2), suggesting that radioiodine adheres to or interacts with residual denture adhesive. Three near-edentulous patients had 131I activity localizing to the remaining teeth. Interestingly, one such near-edentulous patient with 131I activity localizing to the remaining teeth (Fig. 3, eight teeth, no hardware) also accumulated activity on his scalp and hands, suggesting that poor hygiene may have contributed to dental 131I activity. In the remaining five patients with localizing activity, 131I nonspecifically associated with unrestored teeth.

Bottom Line: Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals.Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of I from Argenco HP 77.Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals.

View Article: PubMed Central - PubMed

Affiliation: aDepartment of Radiology, University of New Mexico bPrivate Practice, Albuquerque, New Mexico cDepartment of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA.

ABSTRACT

Purpose: We sought to further localize radioiodine activity in the mouth on post-thyroid cancer therapy imaging using single-photon emission computed tomography/computed tomography (SPECT/CT).

Materials and methods: We retrospectively reviewed all patients (58) who underwent thyroid cancer therapy with iodine-131 (131I) at our institution from August 2009 to March 2011 whose post-therapy radioiodine imaging included neck SPECT/CT. A small group (six) of diagnostic 131I scans including SPECT/CT was also reviewed. Separately, we performed in-vitro 131I (sodium iodide) binding assays with amalgam and Argenco HP 77 (77% dental gold alloy) as proof of principle for these interactions.

Results: Of the 58 post-therapy patients, 45 (78%) had undergone metallic dental restorations, and of them 41 (91%) demonstrated oral 131I activity localizing preferentially to those restorations. It was observed that radioiodine also localized to other dental restorations and to orthodontic hardware. Gum-line activity in edentulous patients suggests radioiodine interaction with denture adhesive. In vitro, dental amalgam and Argenco HP 77 bound 131I in a time-dependent manner over 1-16 days of exposure. Despite subsequent washings with normal saline, significant 131I activity (maximally 12% for amalgam and 68% for Argenco HP 77) was retained by these metals. Subsequent soaking in a saturated solution of potassium iodide partially displaced 131I from amalgam, with near-total displacement of I from Argenco HP 77.

Conclusion: SPECT/CT shows that radioiodine in the oral cavity localizes to metallic dental restorations. Furthermore, in-vitro studies demonstrate partially reversible binding of 131I to common dental metals.

Show MeSH
Related in: MedlinePlus