Longer-term recurrence rate after low versus high dose radioiodine ablation for differentiated thyroid Cancer in low and intermediate risk patients: a meta-analysis.

BACKGROUND: Regarding the longer-term recurrence rate the optimal activity for the remnant thyroid ablation in patients with differentiated thyroid cancer (DTC) is discussed controversially. For the short-term ablation success rate up to 12 months there are already several meta-analyses. In this study we performed the first meta-analysis regarding the longer-term recurrence rate after radioactive 131-I administration. METHODS: We conducted an electronic search using PubMed/MEDLINE, EMBASE and the Cochrane Library. All randomized controlled trials (RCTs) assessed the recurrence rate after radioactive iodine ablation in patients with DTC, with a follow-up of at least two years were selected. Statistics were performed by using Review Manager version 5.3 and Stata software. RESULTS: Four RCTs were included in the study, involving 1501 patients. There was no indication for heterogeneity (I2 = 0%) and publication bias. The recurrence rate among patients who had a low dose 131-iodine ablation was not higher than for a high dose activity (odds ratio (OR) 0.93 [95% confidence interval (CI) 0.53-1.63]; P = 0.79). The mean follow-up time was between 4.25 and 10 years. The subgroup analysis regarding the TSH stimulated thyroglobulin values (< 10 ng/mL versus < 2 ng/mL versus ≤1 ng/mL) showed no influence on recurrence rate. CONCLUSIONS: For the first time we showed that the longer-term, at least 2-year follow-up, recurrence rate among patients who had 131-iodine ablation with 1.1 GBq was not higher than with 3.7 GBq.

Clinical impact of retinoids in redifferentiation therapy of advanced thyroid cancer: final results of a pilot study.

Differentiated thyroid cancer is a malignant tumour that has a fairly good prognosis, with patients surviving for many years. Multimodal therapy with surgery, radioiodine therapy and TSH suppressive medication is of proven efficacy. However, loss of differentiation is observed in up to one-third of patients with differentiated thyroid cancer, paralleled by an increase in tumour grading and loss of thyroid-specific functions (thyrotropin receptor, iodine accumulation). Such tumours may no longer be amenable to standard treatment protocols, including TSH suppression and radioiodide therapy. Retinoic acids have been shown to exert re-differentiating effects on thyrocytes in various experimental studies and case reports, and it was on this basis that this pilot study was initiated. Patients with advanced thyroid cancer and without the therapeutic options of operation or radioiodide therapy were treated with 13- cis-retinoic acid at a dosage of 1.5 mg/kg body weight daily over 5 weeks. Parameters for assessment of the therapeutic effect were serum thyroglobulin (TG) levels, radioiodine uptake, and tumour size prior to and after retinoid treatment. Fifty patients were evaluated for response, classified as reduction in tumour size and TG levels, stable disease or disease progression. Thirteen patients showed a clear increase in radioiodine uptake, and eight a mild increase. TG levels were unchanged or decreased in 20 patients. Tumour size was assessable in 37 patients; tumour regression was observed in six, and there was no change in 22. In total, a response was seen in 19 patients (38%). Response to retinoid therapy did not always correlate with increased radioiodine uptake, so other direct antiproliferative effects have to be assumed. The encouraging results of the study and the low rate of side-effects with good tolerability of retinoids warrant further studies with altered inclusion criteria and employment of other redifferentiating drugs or combinations of agents.

[Minimally invasive parathyroidectomy with local anesthesia in conjunction with ultrasonography, sestamibi scintigraphy and intraoperative parathyroid hormone measurement]. / Minimal-invasive Parathyreoidektomie in Lokalanaesthesie in Verbindung mit Ultrasonographie, Sestamibi-Szintigraphie und intraoperativer Parathormonmessung.

INTRODUCTION: The standard procedure in patients with primary hyperparathyroidism (pHPT) includes cervical exploration and identification of all four enlarged parathyroid glands. New localization techniques, i.e., ultrasonography associated with color duplex sonography, 99mTc-sestamibi scintigraphy and the possibility of intraoperative parathormone (iPTH) measurement permit minimally invasive parathyroidectomy (MIP). Three different methods have been established: minimally invasive open parathyroidectomy, endoscopic parathyroidectomy and video-assisted parathyroidectomy. We present our experience with open MIP with the patient under local anesthesia (LA). METHODS: In 25 patients with pHPT the operation was started under local anesthesia. Preoperatively, ultrasonography and sestamibi scintigraphy were performed in each patient. iPTH measurement was carried out intraoperatively. RESULTS: In 23 patients (92%) the operation was done successfully in LA. There were no postoperative complications. During follow-up none of the patients developed hypercalcemia again. CONCLUSION: MIP in connection with ultrasonography, sestamibi scintigraphy and intraoperative PTH measurement offers a promising treatment for patients with pHPT.

[111-indium DTPA octreotide scintigraphy in colorectal liver metastases]. / 111-Indium-DTPA-Octreotid-Szintigraphie bei kolorektalen Lebermetastasen.

The somatostatin analogue octreotide is effective in the treatment of neuroendocrine and other tumours. 111-In-labelled DTPA-octreotide scintigraphy is successful in localizing primary neuroendocrine tumours and metastases and other tumours containing somatostatin receptors. An antiproliferative effect of octreotide was also demonstrated for colorectal carcinoma. Since only about 40% of colorectal carcinomas express somatostatin receptors, we tried to establish whether 111-In-labelled DTPA-octreotide scintigraphy is able to reveal the receptor status of liver metastases in patients with colorectal liver metastases. This would be useful in selecting patients for adjuvant therapy studies with octreotide. We performed 111-In-labelled DTPA-octreotide scintigraphy in ten patients with nonresectable liver metasoffes of colorectal origin and curatively resected primary. In nine of ten patients the liver metastases were somatostatin receptor negative, in one patient somatostatin receptor positive. In the patient with somatostatin receptor-positive liver metastases after resection of a rectal carcinoma, the histological examination of the biopsies from the liver metastases showed a solid tumour of neuroendocrinal differentiation. In the repeated histological examination of the specimen of the rectal primary, a small solid tumour with neuroendocrinal differentiation was found between formations of adenocarcinoma (adenoendocrine carcinoma). In our study 111-In-labelled DTPA-octreotide scintigraphy did not indicate the receptor status of liver metastases from colorectal carcinoma and was not useful in the planning of therapeutic regimens. For the diagnosis of the receptor status of colorectal liver metastases autoradiographic investigation on tissue biopsies are still necessary. In patients with adenoendocrine carcinomas 111-In-labelled DTPA-octreotide scintigraphy may help to histologically differentiate the metastases.