Patients with detectable Tg during the last ¹³¹I treatment and a negative post-therapeutic WBS have significant earlier and more recurrences than patients without detectable Tg. Survival in both groups is comparable. After initial therapy, the combination of a negative high dose post-therapeutic WBS with detectable Tg is a valuable predictor for earlier and more recurrences, but is not associated with survival.

Background: The role of postoperative external beam radiotherapy (EBRT) in patients with residual iodine refractory differentiated thyroid cancer (IR-DTC) is still inconclusive. The aim of this retrospective study was to evaluate locoregional control (LRC) and overall survival (OS), and potential side effects after postoperative EBRT for both microscopic and macroscopic non-radically resected locally advanced IR-DTC. Methods: Between 1990 and 2016, 49 patients with locally advanced IR-DTC received EBRT for microscopic (R1; n=28) or macroscopic (R2; n=21) locoregional residual disease. For more insight into the added effect of EBRT we performed an intra-patient sub-analysis in 32 patients who had undergone more than one surgical intervention, comparing LRC after primary, curative-intended surgery with LRC after repeated surgery plus EBRT. To estimate LRC and OS we used Kaplan Meier curves. From 2007 onwards, we prospectively recorded toxicity data in our head and neck cancer database (n=10). Results: LRC rates five years after EBRT were higher for R1 (84.3%) than for R2 (44.9%) residual disease (p=0.016). The five-year OS rate after EBRT was 72.1% for R1 and 33.1% for R2 disease (p=0.003). In the intra-patient analysis (n=32) LRC rates were 6.3% five years after only initial surgery, and 77.9% after repeated surgery with EBRT (p=<0.001). Acute toxicity was limited to grade I and II xerostomia, mucositis, and hoarseness; only one patient developed late grade III dysphagia. Conclusions: Postoperative EBRT is associated with long-lasting locoregional control and overall survival with acceptable toxicity in patients with locally advanced IR-DTC, especially in microscopic residual disease.

An (18)F-FDG-PET within three months after a negative WBS with detectable Tg-off showed additional tumor localization in 17% of the patients, leading to a change in clinical management in 13%. A clinically useful Tg-off cutoff value was not found, but 90% of positive (18)F-FDG-PET scans occurred in patients with a Tg-off >2.00 ng/mL.

Background. In the Netherlands, differentiated thyroid cancer (DTC) is treated surgically in three different hospital types, including university, teaching, and nonteaching peripheral hospitals. This study evaluates postoperative complications and referral patterns in patients with DTC in the northern region of the Netherlands to gain an understanding on how to improve management implementation. Methods. Data from 567 patients diagnosed between 1989 and 2009 were obtained from the Netherlands Cancer Registry and were supplemented with information from hospital digital information systems and patient records from 15 hospitals: 1 university, 3 teaching, and 11 peripheral hospitals. Surgically treated patients with a histologically proven DTC derived from the original pathology reports were included. Results. Surgical treatment could be performed in a single procedure in 234 patients (41.3%), but several surgeries were needed in the remaining 333 patients (58.7%). Recurrent laryngeal nerve (RLN) palsy occurred after all types of thyroid surgical procedures, but mostly after initial (hemi)thyroidectomy and reoperations. RLN was temporary in 3.2% of the nerves at risk and persistent in 1.8%. Temporary hypocalcemia developed in 13.7% of patients, and persistent hypocalcemia occurred in 4.8%. Patients were mainly referred to the university hospital from a nonteaching (40.7%, 48/118) or teaching hospital (11.1%, 16/144); however, 80% of patients were not referred. Conclusions. The complication rate and number of multiple surgeries support the efforts in optimizing clinical management in thyroid cancer. Careful considerations prior to initial surgical treatment by early discussion in telemedicine-based regional tumor boards could possibly prevent reoperations and potentially diminish complications.