The risk of toxicity attributable to radioiodine therapy (RIT) remains a subject of ongoing research, with a whole-body dose of 2 Gy proposed as a safe limit. This article evaluates the RIT-induced cytogenetic damage in two rare differentiated thyroid cancer (DTC) cases, including the first follow-up study of a pediatric DTC patient. Chromosome damage in the patient\'s peripheral blood lymphocytes (PBL) was examined using conventional metaphase assay, painting of chromosomes 2, 4, and 12 (FISH), and multiplex fluorescence in situ hybridization (mFISH). Patient 1 (female, 1.6 y.o.) received four RIT courses over 1.1 years. Patient 2 (female, 49 y.o.) received 12 courses over 6.4 years, the last two of which were examined. Blood samples were collected before and 3-4 days after the treatment. Chromosome aberrations (CA) analyzed by conventional and FISH methods were converted to a whole-body dose accounting for the dose rate effect. The mFISH method showed an increase in total aberrant cell frequency following each RIT course, while cells carrying unstable aberrations predominated in the yield. The proportion of cells containing stable CA associated with long-term cytogenetic risk remained mostly unchanged during follow-up for both patients. A one-time administration of RIT was safe, as the threshold of 2 Gy for the whole-body dose was not exceeded. The risk of side effects projected from RIT-attributable cytogenetic damage was low, suggesting a good long-term prognosis. In rare cases, such as the ones reviewed in this study, individual planning based on cytogenetic biodosimetry is strongly recommended.

Surgical resection followed by radioactive-iodine (131I) therapy constitutes a standard treatment for differentiated thyroid cancer (DTC). 131I is normally excreted through kidneys and treatment of patients with end stage renal disease (ESRD) on hemodialysis requires special attention for dosage of 131I, timing of dialysis and radiation safety. We present a case of a post-thyroidectomy patient with ESRD on haemodialysis who required radioactive iodine ablation with review of literature.

Objective: This single-center, observational case-control feasibility study sought to test key elements of a protocol for an eventual long-term international observational case-control study of a larger patient cohort, to evaluate the risk of breast cancer as a second primary malignancy in females with differentiated thyroid cancer (DTC) given radioiodine therapy (RAI) during childhood or adolescence. Patients: Females developing DTC after the Chernobyl accident in Belarus and ≤19 years old at the time of thyroid surgery were enrolled: patients given RAI (n = 111) and controls of similar age not given RAI (n = 90). Results: One case of breast cancer was newly diagnosed among the RAI patients, but none in controls. Patients given RAI significantly less frequently needed 2nd surgeries than did controls (23%, 26/111 vs. 39%, 35/90, P < 0.05); the main indication for such procedures usually is suspicion of local recurrence. RAI patients appeared to have had more frequent reproductive difficulties than did controls: 78% (87/111) of the former vs. 93% (84/90) of the latter had a history of pregnancy (P < 0.01), and the mean number of pregnancies was 1.5 ± 1.2 in RAI patients vs. 1.9±1.1 in controls (P < 0.05). Most notably, infertility was observed in 23% (26/111) of RAI patients vs. 4% (4/90) of controls (P < 0.01). In conclusion, a international observational case-control study on breast cancer after DTC in patients given RAI vs. not given RAI appears to be feasible. Additional research and everyday clinical attention should be devoted to reproductive function after RAI in young females.

Here, we report the findings of a 25-year cytogenetic follow-up study on a male patient who received 2 rounds of radioiodine treatment within a span of 26 months (1.78 GBq in 1992 and 14.5 GBq in 1994). The patient was 34 years old with a body mass index of 25 at the time of the first radioiodine treatment. Multicolor FISH and multicolor banding (mBAND) techniques performed on the patient detected inter- and intrachromosomal exchanges. Although the frequency of chromosome translocations remained essentially the same as reported in our earlier study (0.09/cell), the percentage of reciprocal (balanced) translocations increased from 54.38 to 80.30% in the current study. In addition to simple chromosome translocations, complex exchanges (0.29%) involving more than 2 chromosomes were detected for the first time in this patient. Strikingly, a clonal translocation involving chromosomes 14 and 15, t(14p;15q), was found in 7 of the 677 cells examined (1.03%). The presence of complex and clonal translocations indicates the onset of chromosomal instability induced by internal radioiodine exposure. mBAND analysis using probes specific for chromosomes 1, 2, 4, 5, and 10 revealed 5 inversions in a total of 717 cells (0.69%), and this inversion frequency is several-fold higher than the baseline frequency reported in healthy individuals using the classical G-banding technique. Collectively, our study suggests that stable chromosome aberrations such as translocations and inversions can be useful not only for retrospective biodosimetry but also for long-term monitoring of chromosomal instability caused by past radioiodine exposure.

Differentiated thyroid carcinoma is an uncommon malignancy of childhood and adolescence that is unique because it has an overall favorable prognosis despite its relatively high rate of nodal and distant metastases. Total thyroidectomy and positive 131I therapy are recommended for cases with pulmonary metastases. In contrast, anaplastic thyroid cancer is one of the most aggressive malignancies that have an unfavorable and miserable prognosis. We report a case with an impressively long history. The patient had multiple pulmonary metastases that had been diagnosed by 131I administration when he was 14 years old, about 45 years before he underwent thyroidectomy. He had been kept unaware of his disease by his family and received no treatment for most of his life. Pulmonary nodules were noted at several medical checkups and showed a remarkable decrease in size during the untreated 44-year period after the 131I administration. At age 58, his thyroid cancer was first detected and total thyroidectomy was performed, with subsequent radioiodine therapy for pulmonary metastases. Unfortunately, anaplastic carcinoma developed and he died of disseminated tumors later.

The aim of this analysis was to collect and analyse Germany-wide data on the status and development of in-patient Nuclear Medicine therapy. The official hospital quality reports were to be used as the data source.
METHODS: The reference reports from all hospitals in Germany with Nuclear Medicine therapy units, compiled by Gemeinsamer Bundesausschuss (G-BA) from the machine-usable XML data of the quality reports, were analysed for the years 2010 and 2012. Results from our own preceding investigations of structured quality reports for the years 2004, 2006 and 2008 were used to assess the longer-term development. To determine the Germany-wide incidence of thyroid surgery and radio-iodine therapy, public databases of Institut für das Entgeltsystem im Krankenhaus (InEK) were assessed for the years from 2004 to 2012.
RESULTS: The total number of in-patient Nuclear Medicine treatment cases decreased from 50 363 to 47 314 patients in the period from 2010 to 2012. There was a marked decline of 17.5% in case incidence over the longer period from 2004 to 2012. The decrease is primarily due to a decrease in cases with hyperthyroidism (ICD code E05). The number of thyroid surgeries has been declining since 2009. There was a moderate 23.7% increase in the number of cases with the diagnosis of thyroid carcinoma (ICD code C73) from 2004 to 2012.
CONCLUSIONS: Presumably, the improved iodine supply in Germany has led to a decline in inpatients with hyperthyroidism in nuclear medicine and consequently to a decrease in both the number of radio-iodine therapies and thyroid operations in surgery. In contrast, the number of patients in nuclear medicine therapy units diagnosed with thyroid cancer has increased moderately which correlates with the worldwide increasing incidence of this disease.

Tracheal chondrosarcoma is a rare malignant mesenchymal tumor and there are less than 15 reports in the literature. We report a rare case of laryngotracheal chondrosarcoma in a 74-year-old man. He gave a history of radioiodine therapy for thyroid papillary carcinoma about 24 years ago. Diagnostic steps, histological presentation, and therapy are described in detail.