ORIGINAL ARTICLES   

The Quarterly Journal of Nuclear Medicine 2003 June;47(2):129-38

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Importance of radio-guided minimally invasive parathyroidectomy using hand-held γ probe and low 99mTc-MIBI dose. Technical considerations and long-term clinical results

Rubello D. ¹, Casara D. ¹, Giannini S. ², Piotto A. ³, De Carlo E. ⁴, Muzzio P. C. ⁵, Pelizzo M. R. ²

¹ 2nd Nuclear Medicine Service, General Hospital of Padova, Padova, Italy 2 1st Clinical Medicine Institute, University of Padova, Padova, Italy 3 3rd Clinical Surgery Institute, University of Padova, Padova, Italy 4 3rd Clinical Medicine Institute, University of Padova, Padova, Italy 5 Oncological Radiology, University of Padova, Padova, Italy

Aim. 99mTc-­MIBI ­radio-­guided sur­gery ­results, ­obtained in a ­group of 141 ­patients ­with pri­mary hyper­pa­rath­yr­oi­dism (HPT), are ­reported.
­Methods. All ­patients ­were pre­op­er­a­tively eval­u­ated by a ­single day pro­tocol ­based on ­double-­tracer para­thy­roid scin­tig­raphy and ­neck ultra­sound, and ­then oper­ated by the ­same sur­gical ­team. In 102 ­patients (72.3%) ­with a ­high ­scan/ultra­sound prob­ability of sol­i­tary para­thy­roid ­adenoma and ­normal thy­roid ­gland, a min­i­mally inva­sive ­radio-­guided sur­gery was ­planned. In the ­other 39 ­patients (27.7%) ­with ­scan/ultra­sound evi­dence of ­multi-glan­dular dis­ease (n=8) or con­com­i­tant nod­ular ­goiter (n=31), the intra­op­er­a­tive γ ­probe was ­used ­during a stan­dard bilat­eral ­neck explo­ra­tion. Intra­op­er­a­tive ­quick para­thy­roid hor­mone (PTH) ­levels ­were rou­tinely meas­ured. The min­i­mally inva­sive ­radio-­guided sur­gery tech­nique we devel­oped, con­sisted of: a) injec­tion of a low 37 MBq 99mTc-­MIBI ­dose in the oper­a­tive ­theatre ­during ­anaesthesia induc­tion, b) ­patient’s ­neck ­scan ­with a ­hand-­held ­γ ­probe ­just ­before the sur­gical cut to ­localize the cuta­neous pro­jec­tion of the para­thy­roid ­adenoma, c) ­intraoper­a­tive ­probe detec­tion of the para­thy­roid ­adenoma and its ­removal ­through a ­small 2-2.5 cm ­skin inci­sion.
­Results. Min­i­mally inva­sive ­radio-­guided sur­gery was suc­cess­fully per­formed in 99/102 ­patients (97.0%). The ­γ ­probe was par­tic­u­larly ­useful in ­patients ­with an ­ectopic para­thy­roid ­adenoma in the ­upper med­i­as­tinum (n=11) or to the ­carotid bifur­ca­tion (n=1) or ­located ­deep in the ­neck (n=8). Min­i­mally inva­sive ­radio-­guided sur­gery was ­also ­obtained in 18/23 ­patients who had pre­vi­ously under­gone thy­roid/para­thy­roid sur­gery. The ­mean oper­a­tive ­time for min­i­mally inva­sive ­radio-­guided sur­gery was 38 min. No ­major sur­gical com­pli­ca­tion was ­recorded. Con­ver­sion to bilat­eral ­neck explo­ra­tion was ­required in ­only 3 ­cases ­because of ­intra-oper­a­tive diag­nosis of para­thy­roid car­ci­noma (n=2), and per­sis­tence of ele­vated ­quick PTH ­levels ­after ­removal of the pre­op­er­a­tively vis­u­al­ized para­thy­roid ­adenoma (n=1). ­Among ­patients ­treated by stan­dard bilat­eral ­neck explo­ra­tion, the ­γ probe was ­useful in local­izing a thym­ical ­enlarged para­thy­roid ­gland in 1 ­patient ­with ­multi-glan­dular dis­ease, a para­thy­roid ­adenoma ­located ­deep in the ­neck in 4 ­patients ­with con­com­i­tant nod­ular ­goiter and an ­ectopic para­thy­roid ­adenoma to the ­carotid bifur­ca­tion in ­another. How­ever, in ­some ­other ­patients ­with a para­thy­roid ­adenoma ­located ­near to the thy­roid, it was dif­fi­cult to ­intraoper­a­tively dis­tin­guish the para­thy­roid ­adenoma ­from a ­MIBI ­avid thy­roid ­nodule.
Con­clu­sion. It can be con­cluded ­that: (a) in pri­mary HPT ­patients ­with ­high ­scan/ultra­sound prob­ability of sol­i­tary para­thy­roid ­adenoma and ­normal thy­roid ­gland, the ­γ ­probe ­appears to be an effec­tive, ­rapid and ­safe tech­nique to per­form min­i­mally inva­sive ­radio-­guided sur­gery; b) a 99mTc-­MIBI ­dose as low as 37 MBq ­appears to be ade­quate to suc­cess­fully per­form ­radio-­guided sur­gery; c) the meas­ure­ment of ­quick PTH is rec­om­mended ­during min­i­mally inva­sive ­radio-­guided sur­gery; d) min­i­mally inva­sive ­radio-­guided sur­gery can be per­formed ­also in HPT ­patients ­with pre­vious para­thy­roid/thy­roid sur­gery ­thus lim­iting sur­gical ­trauma; e) ­with the pos­sible excep­tion of para­thy­roid ­adenoma ­located in ­ectopic ­sites or ­deep in the ­neck, the γ ­probe tech­nique ­does not ­seem rec­om­mend­able in HPT ­patients ­with con­com­i­tant nod­ular ­goiter.