Ultrasonography is the most sensitive test
for detection of recurrent thyroid cancer in the neck
(March 2003)
The background of
the study. The most common site of recurrence of papillary
and follicular cancer of the thyroid gland is in the thyroid bed
or in lymph nodes in the neck. In this study the efficacy of iodine-131
scanning, ultrasonography, and measurement of serum thyroglobulin
for the detection of recurrent tumor in the neck was compared.
How the study was done. The study
subjects were 494 patients with thyroid cancer, of whom 86 percent
had papillary cancer and 14 percent had follicular cancer. All the
patients had been treated by total thyroidectomy and then 50 to
100 mCi (1850 to 3700 MBq) of iodine-131. All patients were then
treated with thyroxine.
The patients were evaluated at 6- to 12-month intervals by ultrasonography
of the neck, measurements of serum thyroglobulin, and whole-body
iodine-131 scans after cessation of thyroxine therapy. Tumor recurrence
in the neck was defined as a tumor mass in the neck proven to be
cancer by ultrasound-guided fine-needle aspiration biopsy or surgical
excision.
The results of the study. During
an average follow-up period of 55 months, recurrent thyroid cancer
was detected in the neck in 51 of the 494 patients (10 percent).
The recurrence was detected by ultrasonography in 94 percent of
these 51 patients. Biopsy revealed tumor in 85 percent. All 38 patients
who underwent surgery had recurrent cancer. Tumor recurrence was
detected by the other tests in fewer patients.
The results of ultrasonography were suspicious for neck recurrence
in 45 patients (9 percent), but biopsies were negative, and none
had evidence of recurrence by the other tests and during follow-up.
The conclusions of the study. Ultrasonography
is more sensitive than iodine-131 scans or serum thyroglobulin measurements
for detecting the recurrence of thyroid cancer in the neck.
The original article. Frasoldati
A, Pesenti M, Gallo M, Caroggio A, Salvo D, Valcavi R. Diagnosis
of neck recurrences in patients with differentiated thyroid carcinoma.
Cancer 2003;97:90-6.
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