Radioguided Thyroid Surgery in High Risk Cancer Patients

Dhave Setabutr, M.D.1, Mark Tulchinsky, M.D.2, Stephan J. Nogan, B.S.1,

Michael P. Ondik, M.D.1, David Goldenberg, M.D., F.A.C.S.1

1Division of Otolaryngology – Head and Neck Surgery, Department of Surgery, Penn State

University College of Medicine, Hershey, Pennsylvania 2Division of Nuclear Medicine, Department of Radiology, Penn State University College of

Medicine, Hershey, Pennsylvania

Introduction Postoperative whole body I-131 scanning (WBIS) and I-131

ablation is recommended for most patients with differentiated

thyroid carcinoma (DTC) following thyroidectomy. It is

advantageous to have minimal functioning residual thyroid in

post-operative patients with DTC. I-131 is less effective with a

large residual thyroid tissue burden and decreased TSH levels1,2.

It is accepted that in low-risk DTC patients recombinant human

TSH (rhTSH) injections can be substituted for intrinsic TSH

stimulation for remnant tissue ablation. Pre-treatment WBIS can

be omitted all together in those cases and post-treatment WBIS

obtained instead. Therefore, it is sometimes necessary to re-

operate on higher-risk DTC patients with a significant

functioning thyroid remnant. It may be challenging to find and

safely remove this remnant in the post-operative thyroid bed,

especially in those with multiple prior surgeries.

We report the successful use of Tc-99m pertechnetate and

intraoperative radio guidance to locate and remove thyroid

remnants in the reoperative setting.

Cases Three cases of differentiated thyroid cancer with excessive

remnant thyroid tissue were identified at Penn State Hershey

Medical Center since June 2009. These patients were deemed

high risk based on their histopathology variant. Tc-99m

pertechnetate was administered immediately prior to surgery

and images were acquired. The skin was marked after

identification of distinct areas of uptake. Intraoperatively, an

OMNI (Care Wise, Morgan Hill, California, USA) probe was

utilized to localize the tissue. Their preoperative presentations

and postoperative course are reviewed.

Case 1: 23 year old female who had previously underwent hemi-

thyroidectomy and completion thyroidectomy for follicular

carcinoma was referred for removal of remnant thyroid tissue

after a nuclear medicine whole body imaging revealed a 72-hour

uptake of 12.1%.

Case 2: 44 year old female with a diagnosis of papillary thyroid

carcinoma had a 24-hour iodine uptake of 35.2% post-

thyroidectomy and was referred for reoperative thyroid surgery

for removal of remaining thyroid tissue.

Case 3: 67 year old female who had underwent a

hemithyroidectomy for a Hurthle cell neoplasm underwent a

right completion thyroidectomy for an incidental papillary

carcinoma found at surgery. A thyroid uptake scan revealed a

24-hour uptake of 12.9% and reoperative thyroid surgery was

recommended.

Figure 2: Skin markings performed

preoperatively by Nuclear Medicine.

Note thyroidectomy scar from prior

surgery.

Figure 3: Intraoperative use of the gamma probe and Tc99mm

Pertechnetate to localize two foci of residual thyroid tissue.

Discussion

Following thyroidectomy for DTC, a large thyroid remnant may

interfere with postoperative radioablation therapy. Thyroid

reoperations are tedious and demanding procedures because of

fibrosis, inflammation, edema, friability of the tissues, and

obliteration of anatomical landmarks. Reoperation carries a

significantly higher complication rate than the initial surgery3,4.

Radioguided surgery is increasingly being used to facilitate the

detection and removal of residual or recurrent thyroid tissue in

patients with well-differentiated thyroid carcinoma3. We

support the notion that radioguidance can be an invaluable tool

for localization of smaller foci of DTC. Depending on the type of

differentiated thyroid cancer, up to 40% of recurrent cancer will

lose their avidity for iodine4. In our cases we utilized a probe

and Tc99m pertechnetate, which favorably compares to

alternatives (I-123 and I-131) as it is easier to obtain, less

expensive, and causes less radiation exposure. This technique

allowed us to readily locate small foci of thyroid tissue in the

postoperative field.

In each of our cases the intraoperative use of radioguidance with

the gamma probe allowed for the specific location of the

suspected thyroid tissue. In a neck that has undergone previous

operation, intraoperative radioguidance provides for efficient

targeting of persistent thyroid tissue.3,5

Conclusion Radioguided thyroid surgery is an effective method for localizing

remnant tissue in previously operated fields. The intraoperative

use of radioguidance with Tc-99m pertechnetate facilitated

removal of the remnant thyroid tissue in all cases presented

here, allowing for subsequent I-131 whole body scintigraphy and

ablation.

References 1. Cooper DS, Doherty GM, Haugen BR, et al. Management guidelines for

patients with thyroid nodules and differentiated thyroid cancer. Thyroid

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2. Muratet JP, Giraud P, Daver A, Minier JF, Gamelin E, Larra F. Predicting the

efficacy of first iodine-131 treatment in differentiated thyroid carcinoma. J

Nucl Med 1997;38(9):1362-8.

3. Tunca F, Giles Y, Terzioglu T, et al. Does intraoperative radioguided surgery

influence the complication rates and completeness of completion

thyroidectomy? Am J Surg 2008;196(1):40-6.

4. Cummings CW. Cummings Otolaryngology: Head & Neck Surgery: 4th ed.

Philadelphia: Elsevier Mosby; 2005. 4 v. (xxxviii, 4523, lix p.)

5. Travagli JP, Cailleux AF, Ricard M, et al. Combination of radioiodine (131I)

and probe-guided surgery for persistent or recurrent thyroid carcinoma. J Clin

Endocrinol Metab 1998;83(8):2675-80.

Figure 1: Preoperative imaging

with Tc99m pertechnetate

reveals residual thyroid tissue.

Figure 4: Gross specimen of remnant

thyroid tissue on Gamma probe.