High-dose Radioiodine Therapy Research Articles

High dose radioactive iodine therapy and its short term adverse effects

The disorders of the thyroid gland are on the rise. Radioactive iodine (RAI- I-131) is now used for the treatment of hyperthyroidism and thyroid carcinoma. This helps in the destruction of the follicular cells and radiation help in annulling the cancer cells. RAI has many adverse effects; the short-term effects include – gastrointestinal, salivary dysfunction, and thyroiditis, and long-term adverse effects - secondary carcinomas. The facilities for giving radioactive iodine therapy (RAIT) are less in the state of Kerala; also the adverse effects of RAIT are less studied in our population.To evaluate the pattern of short-term adverse effects following high doses of radioactive iodine therapy in patients with thyroid carcinomaThis study was designed as a prospective observational study conducted on patients attending the Department of Nuclear Medicine for high-dose radioiodine therapy in a tertiary care center. Patients were followed up for any occurrences of adverse effects for six months. Data were analyzed using SPSS software version 18 and an independent t-test was done to find the association between dose and adverse drug reactions (ADR).The study comprised 75 participants, of which, 59(79%) were females. The adverse reactions were reported by 59 participants (79%). Loss of taste and smell in 48 participants (64%), xerostomia in 30 patients (40%) were reported. After one month of RAIT, these subsided. The association of dose vs ADR was found to be significant (p=0.008). The complete blood counts (CBC) were done pre-and post- RAIT showed a statistically significant decrease in all parameters (p=0.00 each).Radioactive iodine produces short-term adverse effects which are self-limiting. However, there is a need to identify and manage it for better treatment and patient compliance.

High dose radioiodine therapy preceded by fertility preservation surgery in metastatic malignant struma ovarii: A tale of endurance and prudent management

Struma ovarii is a type of mature ovarian teratoma which accounts for roughly 0.5%–1% (1) of all ovarian tumours and approximately 3% of all ovarian teratomas (2). To be classified as struma ovarii, more than 50% of the tumour must be comprised of thyroid tissue (3). Malignant struma ovarii being rare, no proper guidelines exists regarding its surgical approach or postoperative management. Metastatic malignant struma ovarii, in addition to radical surgery for ovarian mass will require total thyroidectomy to facilitate high dose radioiodine therapy. Here we present the case of a newly married, nulliparous, young lady in her third decade who was diagnosed with malignant struma ovarii with metastatic deposits in fallopian tube and extensive deposits in mesentery and peritoneum., She underwent cryopreservation of embryos followed by bilateral salphingo-oopherectomy + omentectomy + stripping of peritoneum over bladder, abdominal side walls, pelvic peritoneum + appendectomy with preservation of uterus. Total thyroidectomy was done simultaneously. Subsequently she underwent high dose radioiodine therapy. Complete ablation of the residual metastatic deposits were achieved by one sitting of therapy.

Слезотечение у пациентов после высокодозной терапии радиоактивным йодом

Purpose. To estimate the frequency of tearing in patients after high-dose radioiodine therapy. Materials and Methods. The survey was conducted in 500 patients after radioiodine therapy (group 1) and 654 volunteers (group 2). We asked whether the respondent noticed epiphora last month, in case of a positive answer we specified how many times during the day it was necessary to wipe the tear, comparing the result with Munk scale. Results. The patients of group 1 noticed tearing in 232 cases, the respondents of group 2 noticed it in 186 cases. Epiphora was more frequent in patients of group 1 (46 % of cases), rather than in volunteers of group 2 (27 % of cases). Excessive tearing was noticed in 8.8 % of patients of group 1 and 3.5 % of respondents of group 2. The difference was statistically significant. Conclusion. 8.8 % of patients complain about excessive tearing after high-dose radioiodine therapy, which is more frequent than in the general population. This may be related to secondary acquired nasolacrimal duct obstruction. Key words: epiphora, nasolacrimal duct obstruction, radioiodine therapy.

Clinical outcome of patients with differentiated thyroid cancer and raised antithyroglobulin antibody levels: a retrospective study

BackgroundThyroglobulin (Tg) is a specific tumor marker for differentiated thyroid cancer (DTC). However, in the presence of an antithyroglobulin antibody (TgAb), it becomes unreliable. The purpose of the study was to assess the long-term outcome of DTC patients with raised TgAb.MethodIn a retrospective study, we included patients with DTC who had raised TgAb following total thyroidectomy. We excluded patients with persistently raised Tg (≥ 1 ng/ml) or radioiodine avid disease. Serial TgAb levels, excellent response (ER), incomplete response (IR), and anatomical recurrence were evaluated.ResultsA total of seventy-six patients were included in the study. Patients with IR had higher baseline TgAb (1071.27 ± 1216.17 vs. 99.61 ± 91.29 IU/ml, p < 0.001) and central compartment lymph node metastases (70.8% vs. 46.4%, p = 0.035) in comparison to those in the ER group. In the first follow-up, 64 (84.2%) patients had a stable or fall in the TgAb (0 to − 98.3%). Sixty-eight patients received high-dose radioiodine therapy (RIT). Out of these, 59 (86.5%) had transient, and 51 (75%) had a long-term fall in TgAb. After a follow-up period of 58.74 ± 26.26 months, 63.2% (48 out of 76) patients had IR. Nine (11.8%) patients had a rising TgAb level (3.7–170.9%) from baseline. Eleven patients underwent 18F-FDG PET/CT, and five of them demonstrated metabolically active recurrent disease. Three patients underwent cervical lymph nodes dissection. None of the patients died during the follow-up period.ConclusionHigh post-operative TgAb levels and central compartment lymph nodal metastases are risk factors for IR. RIT leads to a significant fall in the TgAb in these patients. The low level of raised TgAb is associated with an excellent outcome. Patients with recurrences had very high baseline TgAb > 1000 IU/ml. Raised TgAb was associated with good clinical outcomes and not associated with increased mortality.

Do Current Radiation Safety Guidelines allow the Safe Release of a Thyroid Cancer Patient after High-dose Radioiodine Therapy? An Indian Perspective.

Aim:Radionuclide therapy may produce a significant radiation exposure risk to the patient's caregivers. The study aims to assess the radiation exposure rate to caregivers after the patient's discharge from the isolation ward.Materials and Methods:Patients of the well-Differentiated thyroid cancer (DTC)were given high-dose radioiodine therapy as an inpatient. Their radiation exposure was measured daily, and they were discharged once the exposure rate falls as per standard guidelines. Detail counseling of the patient and caregiver about radiation safety was done before admission and at the time of discharge. Caregivers were given thermoluminescence dosimeter (TLD) to wear as a locket for 7 days. Radiation exposure received by the caregiver was measure after that.Results:A total of 22 patients (8 male and 14 female) of DTC were recruited in the study. The mean age was 39.0 ± 14.5 years. Patients were treated with 3.79 ± 1.07 (102.4 ± 28.9 mCi) (1.85–5.55 (50–150 mCi) GBq of radioiodine. They were discharged from the isolation ward at a radiation level of 0.028 ± 0.015 mSv/h (3.193 ± 1.71 mR). The mean effective dose received by the caregiver was 14.60 ± 3.43 mSv (1460 ± 343 mR) (9.73–24.25 (973–2765 mR) mSv.Conclusion:Our study denotes that the caregivers of DTC patients receive a significant radiation dose. It was well above the caregiver's annual dose-limit constraints regarding the rationales well as international guidelines of 5 mSv/yr. These could be related to the long travel in public transport and housing conditions. There is a need for patient-specific discharge criteria rather than following standard guidelines to minimize radiation exposure to caregivers.

Role of laser ablation in multimodal treatment of radioiodine- refractory bone metastases of thyroid cancer: a retrospective study.

To assess the efficacy, safety, and pain benefits of imaging-guided laser ablation (IGLA) in patients with radioiodine-refractory (RR) bone metastases from differentiated thyroid carcinoma (DTC). The institutional medical records of patients with bone metastases from DTC treated with laser ablation (LA) were reviewed retrospectively. Local response, complications, and effects on pain relief were investigated. Six osteolytic lesions in five patients (one male, four females; mean age 65.4 ± 5.1 years, range 58-72) were treated with IGLA. All lesions were osteolytic and all have had previous treatments with high-dose radioiodine therapy followed by external radiotherapy (EBRT). All patients assumed opioid analgesics for severe pain. Overall, the lesions (mean size 5.8 ± 3.2 cm; median 5.0 cm, range 3.0-12.0 cm) underwent nine IGLA sessions (mean 1.8 ± 0.4 sessions; median 2.0 sessions, range 1-2). In four (80%) out five lesions, cross-sectional imaging showed a nearly complete response (CR) while the largest lesion was ablated by 80%. Pain changes were assessed with the Brief Pain Inventory-Short Form, that was administered before IGLA and during a 6-month follow-up. Patients experienced significant reduction in worst pain, average pain, and pain interference. Following IGLA, the average daily opioid requirement rapidly and progressively decreased. Treatments were well-tolerated and no major complications occurred. IGLA is an effective and safe debulking procedure and provides significant pain relief in patients suffering from DTC bone metastases that are not responsive to standard treatments. So, IGLA could be considered as part of a multimodality management of advanced thyroid cancer with RR metastatic skeletal involvement.

Molecular Profile and Clinical Outcomes in Differentiated Thyroid Cancer Patients Presenting with Bone Metastasis

Objective: Differentiated thyroid cancer patients uncommonly present with bone metastasis as the initial manifestation. Their molecular profile is largely unknown. The aim of this study was to evaluate the histopathology, molecular profiles, and response to radioactive iodine therapy in these patients. Methods: Eight patients presented with symptomatic bone metastasis from an unknown primary tumor. We identified these patients by performing a retrospective chart review. Pathology slides were reviewed and the molecular analysis of 112 thyroid cancer-related genes was performed on bone metastasis specimens using targeted next-generation sequencing. Results: These patients presented with long bone fractures, spinal cord compression, or intractable bone pain. Histopathologic analysis of the bone and thyroid tumor specimens revealed follicular variant of papillary carcinoma in 7 patients and tall cell variant papillary carcinoma in 1 patient. Primary tumor size ranged from 0.4 to 7.5 cm. All patients received high dose radioiodine therapy following thyroidectomy. Molecular analysis revealed telomerase reverse transcriptase (TERT) mutations in 7 (88%) tumors, 4 (50%) contained co-occurring TERT and RAS GTPase gene (RAS) mutations, 2 had isolated TERT mutations, and 1 had TERT and proto-oncogene B-Raf (BRAF) V600E mutations, respectively. Tumors carrying RAS, TERT, or a combination of these mutations were radioiodine-avid, with predictable tumor response and reduction in serum thyroglobulin levels. One patient with radioiodine-refractory disease harbored BRAF and TERT mutations. Conclusion: These results demonstrate that differentiated thyroid cancers presenting with bone metastasis independent of the primary tumor size have a high prevalence of TERT mutations, frequently coexisting with RAS mutations. This molecular signature may predict a favorable response to radioiodine therapy. Abbreviations: BRAF = proto-oncogene B-Raf; DNA = deoxyribonucleic acid; DTC = differentiated thyroid cancer; FV = follicular variant; PTC = papillary thyroid carcinoma; RAI = radioactive iodine; RAS = Ras GTPase gene; TERT = telomerase reverse transcriptase; TG = thyroglobulin.

Voice Outcome of Total Thyroidectomy in Comparison With Administration of Recombinant Human TSH

The larynx is an end-organ target for hormones, and thyroid hormone may act on the larynx. We objectively compared and analyzed the phonetic characteristics of patients who underwent total thyroidectomy before and after radioiodine therapy (RIT) according to administration of recombinant human TSH (rh-TSH). Ninety-one patients who had undergone a total thyroidectomy participated (50 patients without rh-TSH, 41 patients with rh-TSH). Voice samples were obtained postoperatively (Post-OP), before high-dose RIT (Pre-RIT), and after high-dose RIT (Post-RIT). Frequency-, perturbation-, and noise-related parameters were evaluated for acoustic analysis, and the voice handicap index (VHI) was used for the subjective evaluation. Frequency-related parameters decreased significantly in patients without rh-TSH administration, but not changed at three periods in patients with rh-TSH administration. Pitch perturbation parameters were not changed at each period in two groups, but amplitude perturbation parameters were changed significantly in two groups. The functional scores of the VHI increased significantly at Pre-RIT in two groups and physical scores increased in patients without rh-TSH at Pre-RIT. The hypothyroidism after total thyroidectomy affects phonation significantly. Our results suggest that rh-TSH administration during RIT resulted in improving voice results during RIT in the patients with total thyroidectomy.

Radioiodine ablation in thyroid cancer patients: renal function and external radiation dose rate at discharge according to patient preparation.

An elevated thyroid stimulating hormone (TSH) level is essential for the uptake of radioiodine into thyroid remnants and residual thyroid cancer in patients undergoing high-dose radioiodine therapy (HD-RIT). Recently, the use of recombinant human thyroid stimulating hormone (rh-TSH) has increased in preference over the conventional method of thyroid hormone withdrawal (THW). However, the clinical influences of the two methods, aside from the therapeutic effects, have not been widely evaluated. The aim of this work was to investigate the influences of the two methods, particularly on the renal function and external radiation dose rate (EDR) from patients undergoing HD-RIT. From February 2012 to November 2016, 667 patients (M:F=138:529, mean age: 47.7±11.8 years), who underwent first HD-RIT (120, 150, or 180 mCi, 1 mCi=37 MBq) for ablation of remnant thyroid tissue or residual thyroid cancer, were enrolled. Patients who were proven to have distant metastasis to lung or bone were excluded. Low- to high-risk patients based on 2015 American thyroid association management guidelines who underwent first HD-RIT in our department were included. The period from total thyroidectomy to HD-RIT was limited within 12 months. The following parameters were collected and evaluated: age, gender, histology type and TNM stage of thyroid cancer, glomerular filtration rate on the admission day for total thyroidectomy (baseline GFR), GFR on the day of HD-RIT (follow-up GFR), thyroglobulin (Tg) and TSH levels on the day of HD-RIT, and EDR on the discharge day after HD-RIT. There were 386 patients using the THW method and 281 patients choosing the rh-TSH method. The baseline GFR of the THW group (106±16 mL/min/1.73 m2) and that of the rh-TSH group (104±17 mL/min/1.73 m2) were within normal limits and there was no significant difference. However, follow-up GFR of the THW group (84±17 mL/min/1.73 m2) was much lower than that of the rh-TSH group (104±16 mL/min/1.73 m2) (P=0.000). In the THW group, the follow-up GFR decreased significantly (P=0.000), yet the follow-up GFR of the rh-TSH group was not statistically different when compared with its baseline GFR (P=0.142). EDRs were lower in all rh-TSH subgroups compared to those of THW subgroups with statistical significance. Tg and TSH levels were not different between the two groups, excluding a few small-sized subgroups analyses. In this retrospective analysis of renal function and EDR, the use of rh-TSH appears to help maintain renal function and finally decrease EDR in contrast to the THW method when undergoing HD-RIT.

Low- and high-dose radioiodine therapy for low-/intermediate-risk differentiated thyroid cancer: a preliminary clinical trial.

To compare the ablation results, therapeutic responses and adverse reactions between a low dose (1.1GBq) or high dose (3.7GBq) of 131I in low-/intermediate-risk differentiated thyroid cancer (DTC) patients. The factors influencing the ablation result and therapeutic response were also analyzed. The researchers used a random number table to randomly assign the enrolled patients to the low-dose group or high-dose group at a 1:1 ratio, and assessment of ablation result, therapeutic response, and adverse reactionsevaluated6±3months after therapy. A total of 140 patients were enrolled in the study through October 2014-June 2015. Until February 2016, 132 patients completed the trial. 99 patients were re-examined under thyroid-stimulating hormone (TSH) stimulation 3-9months after 131I therapy. For the low-dose and high-dose groups, the success rates of ablation were 52.7% (29/55) and 59.1% (26/44), respectively. The ablation results did not differ significantly between the two groups (P=0.548). One hundred and thirty two patients were re-examined 2-9months after 131I therapy. The low-dose group had an excellent response rate of~80% (53/66), an indeterminate response rate of~20% (13/66), and no cases with a biochemical incomplete response. The high-dose group had an excellent response rate of~85% (56/66), an indeterminate response rate of~11% (7/66), and a biochemical incomplete response rate of~4% (3/66). No significant differences in the therapeutic response were observed between the two groups (P=0.087). Patients in stage N1b had a significantly lower success rate of ablation than those in stage N0 (P=0.000). The success rate of ablation increased significantly with lower thyroglobulin (Tg) levels (P=0.000). A pre-treatment Tg level was significantly associated with a higher excellent response rate (P=0.002). Pre-treatment-stimulated Tg of 0.47 and 3.09μg/L were identified as cut-off values for predicting the ablation result and therapeutic response, respectively. The incidences of adverse reactions were 18% (12/66) and 39% (26/66) in the low-dose and high-dose groups, respectively, and this difference between the two groups was significant (P=0.007). The result of thyroid remnant ablation and the response to therapy did not differ significantly between the two groups. The low-dose group had a lower incidence of adverse reactions than the high-dose group. N1b and pre-treatment-stimulated Tg were factors influencing the ablation result, whereas pre-treatment-stimulated Tg was a factor influencing the therapeutic response. Pre-treatment-stimulated Tg of 0.47 and 3.09μg/L were identified as cut-off values for predicting the ablation result and therapeutic response, respectively. The study protocol was approved by the Clinical Trials and Biomedical Ethics Committee of our hospital and registered on the Chinese Clinical Trial Registry under the registration number ChiCTR-IOR-15006139.

High dose radioiodine therapy affects ovarian reserve

Women undergoing radioiodine (RAI) therapy are advised to refrain from conceiving for 6-12 months following treatment as ovaries are exposed to radiation. It is unclear if this exposure carries a risk for reduced fertility, however earlier menopause has been reported in women undergoing RAI treatment. Given the finite number of primordial follicles women are endowed with at birth, radiation injury to germinal cells is not expected to be reversible. We sought to assess the effect of RAI on ovarian reserve of women undergoing treatment for differentiated thyroid cancer (DTC) by prospectively examining blood levels of anti-Müllerian hormone (AMH), and accepted index of the size of this reserve.

Radiation safety in the management of patients undergoing radioactive iodine ablation therapy.

High-dose radioiodine therapy for thyroid cancer poses risks to healthcare workers, family members, and the public. Oncology nurses can effectively manage these risks by employing the three key principles of time, distance, and shielding.

Unusual case of hepatic metastasis in follicular thyroid carcinoma detected using I-131 whole body scintigraphy and single-photon emission computerized tomography/computerized tomography.

Papillary and follicular thyroid carcinomas, together known as differentiated thyroid carcinomas (DTC), are among the most curable of cancers. Distant metastases are rare events at the onset of DTC. Among these presentations, metastasis to the liver is even more unusual. Only 11 cases of DTC with liver metastasis were previously reported in the literature. We present a 55-year-old male on Iodine-131 whole body scintigraphy showed intense uptake in thyroid bed, metastasis in both lungs and right lobe of the liver. Radioiodine concentration in liver metastases made him amenable to high-dose radioiodine therapy patient.

The effect of high dose radioiodine therapy on formation of radiation retinopathy during thyroid cancer treatment.

Objective: Non-thyroidal complication of high-dose radioiodine therapy for thyroid carcinoma might cause salivary and lacrimal gland dysfunction, which may be transient or permanent in a dose-dependent manner. However, radiation retinopathy complicating 131I therapy, has not been previously well characterized. The aim of this study was to evaluate the extent of retinal damage among patients who had received high doses of radioiodine treatment.Methods: Forty eyes of 20 patients (3 male, 17 female) who received 250-1000 mCi during 131I therapy and on ophthalmological follow up for a year after the last treatment were included in the study. Mean age of the study group was 50 years (range 25-70 years). In ophthalmologic examination, visual acuity was measured in order to determine visual loss. Intraocular pressure was measured in all the patients. Then lens examination was carried out with slit lamp biomicroscopy in order to investigate cataract or partial lens opacities. Fundus observation was carried out through the dilated pupil with slit lamp biomicroscopy using 90 D noncontact lens.Result: The best corrected visual aquity with Snellen chart was found as 1.0 in 36 eyes (90%) and between 0.6 and 0.9 (10%) in 4 eyes (10%). At the biomicroscopic fundus examination, retinal hemorrhage consistent with radiation retinopathy, microaneurysm, microinfarction, edema or exudation, vitreus hemorrhage, partial or total optical disc pallor indicating papillopathy in the optic disc were not observed in any of the eyes.Conclusion: This result indicates that there is not any significant correlation between repeated high-dose radioiodine therapy and radiation retinopathy in differentiated thyroid carcinomas. Even though there is not a significant restriction in use of higher doses of radioiodine therapy in differentiated thyroid carcinoma, more extensive studies are needed in order to obtain more accurate data on possible occurrence of retinopathy.

Significance of Salivary Gland Radioiodine Retention on Post-ablation (131)I Scintigraphy as a Predictor of Salivary Gland Dysfunction in Patients with Differentiated Thyroid Carcinoma.

We investigated whether (131)I whole-body scintigraphy could predict functional changes in salivary glands after radioiodine therapy. We evaluated 90 patients who received initial high-dose (≥3.7GBq) radioiodine therapy after total thyroidectomy. All patients underwent diagnostic (DWS) and post-ablation (TWS) (131)I whole-body scintigraphy. Visual assessment of salivary radioiodine retention on DWS and TWS was used to divide the patients into two types of groups: a DWS+ or DWS- group and a TWS+ or TWS- group. Salivary gland scintigraphy was also performed before DWS and at the first follow-up visit. Peak uptake and %washout were calculated in ROIs of each gland. Functional changes (Δuptake or Δwashout) of salivary glands after radioiodine therapy were compared between the two groups. Both peak uptake and the %washout of the parotid glands were significantly lower after radioiodine therapy (all p values <0.001), whereas only the %washout were significantly reduced in the submandibular glands (all p values <0.05). For the parotid glands, the TWS+ group showed larger Δuptake and Δwashout after radioiodine therapy than did the TWS- group (all p values <0.01). In contrast, the Δuptake and Δwashout of the submandibular glands did not significantly differ between the TWS+ and TWS- groups (all p values >0.05). Likewise, no differences in Δuptake or Δwashout were apparent between the DWS+ and DWS- groups in either the parotid or submandibular glands (all p values >0.05). Salivary gland radioiodine retention on post-ablation (131)I scintigraphy is a good predictor of functional impairment of the parotid glands after high-dose radioiodine therapy.

Nasolacrimal duct obstruction as a complication of iodine-131 therapy in patients with thyroid cancer

There are few studies evaluating the effect of radioioine therapy on the lacrimal drainage system. This study reports on symptomatic and asymptomatic nasolacrimal duct obstruction (NLDO) as complications of high-dose radioiodine therapy in these patients. Eighty-one cases were randomly selected from a population of radioiodine-treated differentiated thyroid carcinoma patients and were enrolled in a historical cohort study. The patients were categorized into four subgroups on the basis of the received cumulative dose of iodine-131 (I-131). In addition, 17 age-matched and sex-matched individuals were selected as the control group. Using dacryoscintigraphy and a clinical datasheet, the patients and controls were evaluated for partial or complete and symptomatic or asymptomatic NLDO. The data on different subgroups of patients were compared with the data of the control group. Twenty-nine out of 162 exposed eyes (18%) and three out of 34 control eyes (9%) had evidence of NLDO on scintigraphic images. Among patients treated with less than 11.1 GBq of I-131 (subgroup A), six out of 78 eyes (7.7%) had partial or complete NLDO. This was evident in 23 out of 84 eyes (27.4%) among patients treated with 11.1 GBq or more (subgroup B). The frequency of complete NLDO increases significantly when the cumulative dose of radioiodine exceeds 11.1 GBq (2.9% in the control group, 3.8% in subgroup A, and 23.8% in subgroup B; P=0.006). NLDO may be considered as a side effect of I-131 therapy, especially with a cumulative dose of 11.1 GBq or more.

Prognostic implication of thyroglobulin and quantified whole body scan after initial radioiodine therapy on early prediction of ablation and clinical response for the patients with differentiated thyroid cancer

To investigate predictors for successful ablation and disease-free status after high-dose radioiodine therapy in patients with differentiated thyroid cancer. We enrolled 173 consecutive patients with differentiated thyroid cancer between November 2001 and December 2004 retrospectively (female 145, 46 ± 12 years). All patients underwent total thyroidectomy and I-131 ablative therapy (IAT) (3.7-5.4 GBq). The success or failure of ablation was assessed 6-9 months after the IAT with reference to undetectable thyroglobulin (Tg) and negative I-131 whole body scan (WBS). Afterward, the decision for disease-free status was evaluated using Tg and WBS (follow-up period after 1st IAT 7-81 months, median 43 months, criteria of disease-free: less than 10 ng/ml TSH-stimulated Tg or less than 2 ng/ml TSH-unstimulated Tg and/or negative WBS). Clinical and tumoral factors such as sex, age, pathologic type, the size of tumor, quantified cervical uptake in WBS1, pattern in WBS1, ablative therapy dose, AJCC stage, lymph node (LN) stage, Tg just before IAT (Tg1), and ablation status were assessed using logistic regression analyses. There were 93 successful ablations (54 %). Significant predictors for the ablation failure were Tg1 (OR = 8.42; 95 % CI = 2.76-25.69; p < 0.0001), LN metastasis (OR = 3.05; 95 % CI = 1.11-8.37; p = 0.031), and quantified cervical uptake in WBS1 (OR = 4.95; 95 % CI = 1.07-22.88; p = 0.041). One hundred fifty-five patients were determined as disease-free after follow-up. All the eighteen patients with persistent disease were identified as ablation failure after first IAT. Significant predictors for the disease-free status were Tg1 (OR = 0.98; 95 % CI = 0.97-0.99; p = 0.028), tumor size (OR = 0.53; 95 % CI = 0.28-0.96; p = 0.044), and quantified cervical uptake in WBS1 (OR = 0.87; 95 % CI = 0.76-0.98; p = 0.024). The thyroglobulin and quantified cervical uptake in whole body scan are significant predictors for the successful ablation and disease-free status after follow-up.

Pre-therapeutic blood dosimetry in patients with differentiated thyroid carcinoma using 124-iodine: predicted blood doses correlate with changes in blood cell counts after radioiodine therapy and depend on modes of TSH stimulation and number of preceding radioiodine therapies

Pre-therapeutic blood dosimetry prior to a high-dose radioiodine therapy (RAIT) is recommended and a blood dose of 2 Gy is considered to be safe. In this study, changes in the blood cell count after radioiodine therapy of high risk differentiated thyroid carcinoma (DTC) were analyzed and compared with the results of the pre-therapeutic blood dosimetry using 124I. Moreover, the influence of different modes of TSH stimulation and the number of preceding radioiodine therapies on the blood dose were assessed. 198 patients with locally advanced or metastasized DTC received a pre-therapeutic blood dosimetry using 124I. To analyze the influence of the modes of TSH stimulation and the number of preceding RAITs on blood dose subgroups were built as follows: patients with endogenous TSH stimulation versus patients with exogenous TSH stimulation and patients with no preceding RAIT versus patients with at least one preceding RAIT. In 124/198 patients subsequent RAIT was performed. In 73/124 patients, hemograms were performed from day 2 to 12 month after RAIT. There was no high-grade bone marrow toxicity (i.e. ≥ grade 3) in patients receiving less than 2 Gy blood dose-independent of the therapeutic history. Within the first month after radioiodine therapy, there was an overall decrease in the white blood cell and platelet counts. The erythrocyte count was essentially stable. There was a correlation between cell count decrease and predicted blood doses (Spearman's correlation coefficient >-0.6 each) for the white cell line and the platelets. With regard to the subgroups, the blood dose per administered 131I activity (BDpA) was significantly higher in patients with endogenous TSH stimulation (median 0.08 Gy/GBq) than in patients with exogenous TSH stimulation (0.06 Gy/GBq) and in patients with no previous RAIT (0.08 Gy/GBq) compared to patients who had previously undergone at least one RAIT (0.07 Gy/GBq). The range of BDpA among DTC patients is rather wide. Our results suggest that lower blood doses can be expected when using exogenous TSH stimulation and blood doses are generally higher at first RAIT compared to subsequent RAITs. Thus, we advise to make blood dosimetry standard praxis prior to a high-activity RAIT.

Comparison of the Influence on the Liver Function Between Thyroid Hormone Withdrawal and rh-TSH Before High-Dose Radioiodine Therapy in Patients with Well-Differentiated Thyroid Cancer.

An elevated thyroid stimulating hormone level (TSH) is essential to stimulate the uptake of radioiodine into thyroid remnants and metastases of thyroid cancer when a patient undergoes high-dose radioiodine therapy. Nowadays, recombinant human thyroid stimulating hormone (rh-TSH) is increasingly used instead of the classic method of thyroid hormone withdrawal (THW). However, beyond the therapeutic effects, clinical differences between the two methods have not yet been clearly demonstrated. The aim of this work was to investigate the effects of the two methods, especially on liver function. We identified 143 evaluable patients who were further divided into two groups: THW and rh-TSH. We first reviewed the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, which were measured during the admission period for total thyroidectomy. We called these liver enzyme levels "base AST" and "base ALT." We also assessed other chemistry profiles, including AST, ALT, total cholesterol, LDL cholesterol, alkaline phosphatase (ALP), total bilirubin (TB), and triglyceride (TG), which were measured on admission day for high-dose radioiodine therapy. We called these liver enzyme levels "follow-up AST" and "follow-up ALT." We compared the changes in base and follow-up liver enzyme levels and the other chemistry profiles between the two groups. The base AST and base ALT levels of the two groups were within normal range, and there was no significant difference between the two groups. In contrast to these base liver enzyme levels, follow-up liver enzyme levels between the two groups showed significant differences. Patients in the THW group had higher follow-up AST and ALT levels than did the rh-TSH group. Patients in the THW group also had higher levels of total cholesterol and LDL cholesterol than did the patients in the rh-TSH group. However there were no statistically significant differences in ALP, total bilirubin, and triglyceride levels between the two groups. In this retrospective analysis of liver function, the use of rh-TSH for high-dose radioiodine therapy had less of an effect on liver function and cholesterol levels than dose thyroid hormone withdrawal. This suggests that rh-TSH can be used effectively and safely especially for patients with metabolic syndrome.

Unusual Case of Adrenal and Renal Metastases From Papillary Carcinoma of Thyroid

We report a rare case of adrenal and renal metastases from papillary thyroid carcinoma (PTC). A 30-year-old man underwent total thyroidectomy with left neck dissection for cytology proven nodal metastases from PTC. This was followed by high-dose radioiodine therapy with a dose of 265 mCi (9.805 GBq). Thereafter, patient was lost to follow-up. He presented 2 decades later with low backache radiating to both the lower limbs. Magnetic resonance imaging examination of spine detected left SI joint, dorsal and lumbar vertebral metastases. A whole-body radioiodine scan showed extensive iodine avid foci in thyroid bed, mediastinum, bilateral lungs, liver, bones, and in bilateral lumbar regions. An abdominal single photon emission computed tomography-computed tomography (CT) revealed the lumbar lesions to be within bilateral adrenal glands. Contrast-enhanced CT of abdomen revealed lesions in bilateral adrenals and renal regions suggestive of metastases. A CT-guided biopsy of left adrenal focus confirmed metastasis from the carcinoma of thyroid. A high degree of suspicion with further radiologic and cytologic correlation clinched the diagnosis of both adrenal and renal metastases from PTC, which has been rarely reported. Fortunately, radioiodine concentration in adrenal metastases made them amenable to high-dose radioiodine therapy. Therefore, 225 mCi (8.325 GBq) of radioiodine was administered to this patient. This case is a strong reminder of the fact that regular and long-term follow-up is imperative in the management of thyroid cancer patients.