放射性~(131)I照射与分化型甲状腺癌细胞摄碘(~(125)I)率关系的实验研究

目的:探讨分化型甲状腺癌培养细胞接受放射性碘(131I)照射剂量与摄取放射性碘间的相关性,为放射性碘去除治疗甲状腺癌提供新的思路。方法:设两个实验组,对分化型甲状腺癌细胞进行培养,其一应用同一活度(20μCi)的放射性131I对培养细胞进行不同时间的照射,另组应用不同活度的放射性131I对培养细胞进行相同时间(12h)的照射,分别测定两组甲状腺癌细胞摄取放射性125I水平。结果:不同活度或不同时间的放射性131I照射使甲状腺癌细胞摄取碘的水平降低,受照射组与未照射对照组细胞摄碘率比较有显著性差异(P<0.01)。结论:放射性131I照射可以使分化型甲状腺癌细胞摄碘率显著降低。     

GATE based Monte Carlo simulation of planar scintigraphy to estimate the nodular dose in radioiodine therapy for autonomous thyroid adenoma

The recommended target dose in radioiodine therapy of solitary hyperfunctioning thyroid nodules is 300-400 Gy and therefore higher than in other radiotherapies. This is due to the fact that an unknown, yet significant portion of the activity is stored in extranodular areas but is neglected in the calculatory dosimetry. We investigate the feasibility of determining the ratio of nodular and extranodular activity concentrations (uptakes) from post-therapeutically acquired planar scintigrams with Monte Carlo simulations in GATE.The geometry of a gamma camera with a high energy collimator was emulated in GATE (Version 5). A geometrical thyroid-neck phantom (GP) and the ICRP reference voxel phantoms “Adult Female” (AF, 16 ml thyroid) and “Adult Male” (AM, 19 ml thyroid) were used as source regions.Nodules of 1 ml and 3 ml volume were placed in the phantoms. For each phantom and each nodule 200 scintigraphic acquisitions were simulated. Uptake ratios of nodule and rest of thyroid ranging from 1 to 20 could be created by summation. Quantitative image analysis was performed by investigating the number of simulated counts in regions of interest (ROIs). ROIs were created by perpendicular projection of the phantom onto the camera plane to avoid a user dependant bias.The ratio of count densities in ROIs over the nodule and over the contralateral lobe, which should be least affected by nodular activity, was taken to be the best available measure for the uptake ratios. However, the predefined uptake ratios are underestimated by these count density ratios: For an uptake ratio of 20 the count ratios range from 4.5 (AF, 1 ml nodule) to 15.3 (AM, 3 ml nodule).Furthermore, the contralateral ROI is more strongly affected by nodular activity than expected: For an uptake ratio of 20 between nodule and rest of thyroid up to 29% of total counts in the ROI over the contralateral lobe are caused by decays in the nodule (AF 3 ml). In the case of the 1 ml nodules this effect is smaller: 9-11% (AF) respectively 7-8% (AM).For each phantom, the dependency of count density ratios upon uptake ratios can be modeled well by both linear and quadratic regression (quadratic: r² > 0.99), yielding sets of parameters which in reverse allow the computation of uptake ratios (and thus dose) from count density ratios. A single regression model obtained by fitting the data of all simulations simultaneously did not provide satisfactory results except for GP, while underestimating the true uptake ratios in AF and overestimating them in AM.The scintigraphic count density ratios depend upon the uptake ratios between nodule and rest of thyroid, upon their volumes, and their respective position in a non-trivial way. Further investigations are required to derive a comprehensive rule to calculate the uptake or dose ratios based on post-therapeutic scintigraphy.     

^131I照射对分化型甲状腺癌细胞摄碘水平及NIS mRNA表达的影响

目的：探讨^131I不同时间照射后分化型甲状腺癌细胞摄取放射性碘（^131I）水平的变化以及检测是否影响NIS mRNA表达。方法：分化型乳头状甲状腺癌细胞株（GTHW3）培养在DMEM培养基中,应用同一活度（20μCi）的^131I对培养癌细胞进行不同时间（6h、12h、24h、48h）的照射。γ计数仪测定放射性碘（^131I）摄取率。采用RT—PCR法检测甲状腺癌细胞的NIS mRNA表达。结果：不同时间的放射性^131I照射使甲状腺癌细胞摄取^131I降低;凝胶电泳显示放射性^131I照射24h后GTHW3细胞NIS mRNA表达降低;照射组各时间点的^131I摄取率及24h和48h的NIS mRNA表达与未照射对照组比较均有显著性差异。结论：^131I照射可使DTC细胞的NIS mRNA表达降低,提示^131I照射致DTC细胞失分化及其摄碘能力降低可能与DTC细胞NIS mRNA表达降低有关。     

224例分化型甲状腺癌放射性碘治疗分析

目的:对在我科8年来治疗的分化型甲状腺癌(DTC)患者进行回顾性分析,了解DTC发病规律,并证明131碘治疗DTC的疗效。方法:2002至2010年确诊为DTC并有颈部淋巴结转移的患者,进行甲状腺近全切除,并进行颈部淋巴结清扫,术后131碘治疗。131碘治疗后,每半年随访一次。随访指标:颈部超声检查;血清TSH、FT4、FT3;血清Tg、TgAb检查;全身放射性碘扫描;胸部CT或MRI。疗效判定:当血清Tg、TgAb阴性,颈部超声未见肿大淋巴结,全身放射性碘扫描未见放射性浓聚时,为DTC治愈。当上述指标为阳性时,则进行再次131碘治疗。用SPSS软件进行统计学处理。结果:DTC患者数逐年明显增加;乳头癌与滤泡癌的比例约为12(207):1(17),女性患者远多于男性,男:女患者患病比例约为1(57):3(167);DTC在20-55岁之间为高发年龄段,峰值在25-35岁之间;131碘治疗对DTC治愈率约达90%,近10%的顽固性DTC患者多次131碘治疗效果欠佳。结论:分化型甲状腺癌患病率有明显增加趋势,25-35岁为高发年龄,女性多于男性,早期诊断及早期治疗是关键。手术切除甲状腺后进行131碘治疗对DTC治愈率达90%。近10%的患者131碘治疗效果欠佳,需寻求更好的治疗方法。     

224例分化型甲状腺癌放射性碘治疗分析

目的：对在我科8年来治疗的分化型甲状腺癌（DTC）患者进行回顾性分析,了解DTC发病规律,并证明131碘治疗DTC的疗效。方法：2002至2010年确诊为DTC并有颈部淋巴结转移的患者,进行甲状腺近全切除,并进行颈部淋巴结清扫,术后^131碘治疗。^131碘治疗后,每半年随访一次。随访指标：颈部超声检查;血清TSH、FT4、FT3;血清Tg、TgAb检查;全身放射性碘扫描;胸部CT或MRI。疗效判定：当血清Tg、TgAb阴性,颈部超声未见肿大淋巴结,全身放射性碘扫描未见放射性浓聚时,为DTC治愈。当上述指标为阳性时,则进行再次^131碘治疗。用SPSS软件进行统计学处理。结果：DTC患者数逐年明显增加;乳头癌与滤泡癌的比例约为12（207）：1（17）,女性患者远多于男性,男：女患者患病比例约为1（57）：3（167）;DTC在20-55岁之间为高发年龄段,峰值在25-35岁之间;^131碘治疗对DTC治愈率约达90%,近10%的顽固性DTC患者多次^131碘治疗效果欠佳。结论：分化型甲状腺癌患病率有明显增加趋势,25-35岁为高发年龄,女性多于男性,早期诊断及早期治疗是关键。手术切除甲状腺后进行^131碘治疗对DTC治愈率达90%。近10%的患者^131碘治疗效果欠佳,需寻求更好的治疗方法。     

Percutaneous microwave ablation of thyroid nodules: effects on thyroid function and antibodies

Abstract

Purpose: Microwave ablation (MWA) is a new minimally invasive method for thermal ablation of benign thyroid nodules with promising results. The aim of this study was to investigate whether MWA has an impact on thyroid function. Materials and methods: Thirty patients with a total of 34 benign thyroid nodules underwent MWA between January 2013 and July 2014. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobuline (Tg) and additionally antibodies against Tg (anti-Tg), thyrotropin receptors (TRAb) and thyroid peroxidase (anti-TPO) were measured at enrolment, 24?h after MWA, as well as at the 3-month and 6-month follow-up. Moreover, the nodule volume was evaluated to determine effectiveness. Results: Serum TSH, T4, T3 and Tg levels did not change significantly at the 3-month or 6-month follow-up (p?>?0.05); thyroid function was not affected by MWA. Antibody levels did not change significantly either; however, two patients developed antibodies after treatment. A volume reduction of 51.4% or 7.85?mL could be demonstrated after 3 months and a reduction of 55.8% or 14.0?mL after 6 months. Slight complications such as mild pain during the ablation or superficial haematomas emerged. The development of Graves’ disease and mild Horner’s syndrome were observed as more severe side effects. Conclusions: The data suggest MWA as an alternative for the treatment of benign thyroid nodules. While first results for preservation of thyroid function are positive, further measurements of laboratory data and especially antibodies are necessary.     

High-intensity focused ablation (HIFU) of single benign thyroid nodule rarely alters underlying thyroid function

Abstract

Background: High intensity focused ultrasound (HIFU) is a promising ablation technique for benign thyroid nodules. However, its effect on underlying thyroid function remains unknown. We aimed to evaluate the 6?months changes in serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) after HIFU treatment.

Methods: Eighty-three consecutive patients who underwent single HIFU ablation for symptomatic benign thyroid nodule were analysed. Eligible patients had serum TSH and FT4 checked before treatment (baseline), 1 week, 3 and 6 months following HIFU treatment. Primary endpoints were hypothyroidism (FT4?<?12?pmol/L) and hyperthyroidism (FT4?>?23?pmol/L) in the 6?months following treatment. To express extent of nodule ablation relative to the total gland volume, an ablation volume ratio was calculated by [(Ablated nodule volume/total thyroid volume)/(total thyroid volume)]?×?100.

Results: Relative to baseline, 1-week serum TSH significantly dropped (from 1.16 to 0.76 mIU/L, p?<?0.001) while 1-week serum FT4 significantly rose (from 16.0?to 17.8?pmol/L, p?<?0.001). However, 3- and 6-months TSH and FT4 did not changed significantly from baseline (p?>?0.05). No patients developed hyperthyroidism while one (1.4%) developed hypothyroidism (FT4?=?11?pmol/L) at 3 months and 6 months. Interestingly, this patient had a previous lobectomy and an ablation volume ratio of 64.00%.

Conclusions: Hypothyroidism following single HIFU ablation occurred rarely (1.4%) and resulted in little clinical relevance. Given that only one patient developed hypothyroidism following single HIFU ablation, it remains unclear how patients with different amount of parenchyma and relative extent of ablation may affect subsequent thyroid function.     

Comparison of efficacy and complications between radiofrequency ablation and repeat surgery in the treatment of locally recurrent thyroid cancers: a single-center propensity score matching study

Purpose: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers.

Materials and methods: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n?=?96) or repeat surgery (n?=?125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1–10?years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications—voice changes, hypocalcemia, and immediate procedural complications—were compared between the groups. In addition, pretreatment serum thyroglobulin (T_g) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy.

Results: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p?=?.2). There were no significant differences in mean serum T_g levels and their mean decrease after treatment between the groups (p?=?.891 and p?=?.963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p?=?.316, p?=?.084, respectively). Hypocalcemia occurred only in the repeat surgery group (n?=?18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n?=?7; surgery, n?=?27; p?<?.001).

Conclusion: RFA may be an effective and safe alternative to repeat surgery in the treatment of a small number of locally recurrent thyroid cancers.     

Effectiveness of L-thyroxine treatment on TSH suppression during pregnancy in patients with a history of thyroid carcinoma after total thyroidectomy and radioiodine ablation

Introduction.

There are scarce data about the optimal increase of L-thyroxine dose during pregnancy in patients with a history of thyroid carcinoma. The first aim of the study was to find out if routine therapeutic measures enable adequate TSH suppression in pregnancy. The other aim was to find out the optimal dose of L-thyroxine for TSH suppression in pregnant women.

Patients and methods.

In this retrospective observational study, we analysed 36 pregnancies of 32 women with a history of thyroid carcinoma. Before pregnancy, all of them underwent total thyroidectomy and radioiodine ablation of thyroid remnant, and they were on suppressive doses of L-thyroxine. Thyroid function tests were obtained before, during and after pregnancy.

Results

Mean L-thyroxine dose before pregnancy, in the first, second and, third trimester and after delivery was 149, 147, 155, 165 and 158 micrograms daily, respectively. TSH concentration remained suppressed in 9 pregnancies, it was within normal range in 22 and elevated in 5 pregnancies. The mean dose of L-thyroxine in patients with suppressed TSH before pregnancy, in the first, second and, third trimester and after delivery was 154, 154, 164, 160 and 161 micrograms daily, respectively. When the dose had to be changed, the mean increase of the dose was 31.5 micrograms daily.

Conclusions

The range of changes in TSH concentration during pregnancy in the patients who have been on suppressive L-thyroxine therapy before conception is quite wide. TSH was adequately suppressed in only 25% of pregnancies. The dose of L-thyroxine in patients with suppressed TSH in the first, second and third trimester was 154, 164 and 160 micrograms daily, respectively.     

Locoregional control of recurrent papillary thyroid carcinoma by ultrasound-guided percutaneous microwave ablation: A prospective study

Abstract

Purpose: The aim of this study was to evaluate the safety and efficiency of ultrasound-guided percutaneous microwave (MW) ablation for the control of locally recurrent papillary thyroid carcinoma (LR-PTC) in patients for whom surgery is not viable. Materials and methods: The inclusion criteria for MW ablation were three or fewer LR-PTCs and no recurrence beyond the neck, with ineligibility or refusal to undergo surgery. MW ablation was carried out using a 16-gauge MW antenna under local anaesthesia. Patients were then followed at 1, 3, 6 and 12 months after treatment and every 6 months thereafter. Technical success usually meant volume reduction more than 50%. Results: Between October 2010 to March 2013?a total of 17 patients (14 women, 3 men; average age 54.1 years) with 23 LR-PTCs, were treated with MW ablation in our department. All the LR-PTCs were technical successes with the number of treatment sessions for one tumour ranging from 1 to 4 (mean, 2.3?±?0.9). The mean volume reduction ratio of the LR-PTCs was 1?±?86%, 47?±?12%, 70?±?33%, 91?±?14% at the 1, 3, 6 and 18 months follow-up visit respectively (all p?<?0.05). All treated nodules decreased in size: 30.4% nodules (7/23) had completely disappeared, 52.2% nodules (12/23) remained as small scar-like lesions. One patient experienced transient dysphonia immediately after MW ablation. No other severe and permanent complications occurred. Conclusion: Although with some limitations, our preliminary results are encouraging and show MW ablation may be an alternative treatment option for the control of LR-PTCs in selected patients for whom surgery is not viable.     

Ultrasound-guided percutaneous microwave ablation of solitary T1N0M0 papillary thyroid microcarcinoma: Initial experience

Purpose: The aim of this study was to evaluate the feasibility, safety and efficacy of ultrasound-guided percutaneous microwave (MW) ablation for solitary T1N0M0 papillary thyroid microcarcinoma. Materials and methods: A total of 21 patients (six men and 15 women; age range, 29–81 years; mean, 52.1?±?13.6 years) with 21 nodules of pathologically proven solitary papillary carcinoma 3.7 to 10.0?mm in diameter without clinically apparent lymph node, or distant metastasis at diagnosis (T1N0M0) were treated with MW ablation in our department. Microwaves were emitted at 40?W for 400?s and prolonged as necessary to attain confluent ablation zones. All patients were treated with levothyroxine after MW ablation to maintain thyroid stimulating hormone (TSH) levels below 0.1?mU/L. Follow-up consisted of ultrasound in 21 patients, biopsy in five patients, and surgical treatment in three patients. Results: Four patients complained of hoarseness immediately after the MW ablation procedure, and all of them recovered within 3 months spontaneously. All tumours were completely ablated at a single session and no serious or permanent complications occurred. No recurrence at the treatment site and no distant metastases were detected, with a mean follow-up of 11 months. Histological examination showed no evidence of a tumour in the treated lesions in eight patients. Follow-up ultrasound examinations showed disappearance of previously detected colour Doppler flow, as well as mass shrinkage, or both. Conclusion: During the short-term follow-up period, ultrasound-guided percutaneous MW ablation appears to be a safe and effective technique for solitary T1N0M0 papillary thyroid microcarcinoma.     

Radioiodine therapy of carcinoma of the thyroid

The discovery of functioning metastases of thyroid carcinoma and their appropriate treatment with radioiodine are the keys to long-term survival. Functioning metastases can be adequately found only if postsurgical residual normal thyroid tissue is ablated and total body scanning performed. Radioiodine treatment of functioning metastases following appropriate surgery is the treatment of choice, and long-term follow-up with total body scanning techniques is most important.     

Safety of radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: a systematic review and meta-analysis

Abstract

Objective: We performed a systematic review and meta-analysis to evaluate the safety of radiofrequency ablation (RFA) for the treatment of benign thyroid nodules and recurrent thyroid cancers.

Materials and methods: Ovid-MEDLINE, EMBASE, and Library of Cochrane databases were searched up to 12 July 2016 for studies on the safety of RFA for treating benign thyroid nodules or recurrent thyroid cancers. Pooled proportions of overall and major complications were assessed using random-effects modelling. Heterogeneity among studies was determined using the χ² statistic for the pooled estimates and the inconsistency index I².

Results: A total of 24 eligible studies were included, giving a sample size of 2421 patients and 2786 thyroid nodules. 41 major complications and 48 minor complications of RFA were reported, giving a pooled proportion of 2.38% for overall RFA complications [95% confidence interval (CI): 1.42%–3.34%] and 1.35% for major RFA complications (95% CI: 0.89%–1.81%). There were no heterogeneities in either overall or major complications (I²?=?1.24%–21.79%). On subgroup analysis, the overall and major complication rates were significantly higher for malignant thyroid nodules than for benign thyroid nodules (p?=?0.0011 and 0.0038, respectively).

Conclusions: RFA was found to be safe for the treatment of benign thyroid nodules and recurrent thyroid cancers.     

微波消融治疗甲状腺乳头状癌术后淋巴结转移的临床研究和疗效观察

目的 为了提高对超声引导下经皮微波消融术治疗甲状腺乳头状癌术后颈部淋巴结转移癌的认识,并评价其疗效性和安全性。方法 选择84例甲状腺乳头状癌术后复发的患者,接受微波消融治疗后,通过超声造影增强检查,评估消融区内的肿瘤活性,在1、3、6个月以及12个月对患者进行肿瘤大小、体积和血清甲状腺球蛋白的测量临床评估。结果 103个颈部淋巴结转移癌全部成功接受了微波消融治疗,治疗后超声造影增强检查未检测到不完全消融,在最后一次随访中,平均最大直径从10.5±5.7mm减小到0.8±1.5mm(P＜0.05),平均体积从285.9±245.7mm³减小到4.0±8.0mm³(P＜0.05)。治疗后既未检测到已治疗的肿瘤发生进展,也没有新增可疑的淋巴结。结论 超声引导下经皮微波消融术可能成为某些不适合或拒绝进行手术治疗的甲状腺乳头状癌术后淋巴结转移患者的替代疗法,这种手术安全有效,并发症发生率低。     

Sonographic measurement of thyroid nodule changes after microwave ablation: relationship between multiple parameters

Objective: Microwave ablation (MWA) is an effective technique for the treatment of benign thyroid nodules. The aim of this study was to investigate whether it is necessary to study changes in variables other than the volume reduction between follow-up intervals. This study also introduced the index R (S_surface/V) to explore whether it could reflect features of shape between follow-up intervals.

Materials and methods: A total of 236 complex benign thyroid nodules in 230 patients who underwent MWA in our department from October 2013 to February 2017 were included. The D_max, volume (V), volume reduction ratio (VRR) and index R (S_surface/V) parameters were evaluated before treatment and postoperatively at 1, 3, 6 and >12?months. Multiple comparisons of these parameters were performed between the baseline and each follow-up period for the entire patient group and subgroups based on diameter and volume.

Results: All of the thyroid nodules underwent a significant decrease in size after MWA. The mean decrease in the volume of the thyroid nodules was from 17.40?±?22.52?mL to 1.31?±?2.71?mL, with a mean percent decrease of 0.90?±?0.15% after 12?months. Index R increased over time from 2.55?±?1.08 to 8.10?±?5.01, which increased the effectiveness of shape parameterisation between the follow-up periods after the three-month time point, regardless of the initial volume size. For the nodules with a baseline D_max?≤?3.4?cm, the V, VRR and index R demonstrated similar capabilities in the evaluation of efficiency before the six-month follow-up visit.

Conclusions: Long-term follow-up emphasises changes in the shape and spatial structure of complex benign thyroid nodules, rather than size variations, after effective MWA. Index R, which is the surface area to volume ratio, can also reflect the shape change to some degree.     

Efficacy of i ablation therapy using different doses as determined by postoperative thyroid scan uptake in patients with differentiated thyroid cancer

PURPOSE: The optimal dose of I(131) for ablation of functioning residual thyroid tissue after surgery is controversial. The current study was conducted to determine the optimal dose of I(131) for remnant postoperative ablation. A review of the literature is included. METHODS AND MATERIALS: A total of 238 patients with papillary and follicular carcinoma were treated with I(131) for ablation of a postoperative thyroid remnant. The I(131) dose was based on the 24-h percentage of neck uptake in the postoperative thyroid scans. Patients with < 5% uptake received a median of 85 mCi; 6-10% uptake, a median of 80 mCi; 11-15% uptake, a median of 60 mCi; 16-20% uptake, a median of 50 mCi; and > or =21% uptake, a median of 30 mCi. The ablation results were compared with the prognostic factors. RESULTS: Complete ablation was observed in 40 (92%) of 43 patients receiving 85 mCi, in 31 (94%) of 33 who received 80 mCi, in 39 (95%) of 41 who received 60 mCi, in 51 (93%) of 55 who received 50 mCi, in 37 (94%) of 39 who received 30 mCi, and in 18 (96%) of 19 who received 30 mCi. The overall successful ablation rate was 94% (95% confidence interval, 89-100%). CONCLUSION: Our findings suggest that patients with differentiated thyroid cancer can be treated with doses of I(131) according to the percentage of neck uptake of postoperative total body scan, with high complete ablation rates, without exposing patients to higher dose levels of I(131).     

Radiofrequency ablation of primary thyroid carcinoma: efficacy according to the types of thyroid carcinoma

Objective: To evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) according to the types of thyroid carcinoma, particularly in patients with a high-surgical risk.

Materials and methods: Eight patients with nine tumours of pathologically proven papillary and anaplastic carcinoma were treated by US-guided RFA. Patients with primary thyroid carcinoma were divided into three groups; group (1) Anaplastic carcinoma, group (2) papillary macrocarcinoma, and group (3) papillary microcarcinoma. We evaluated changes in clinical symptoms, tumour volume and local tumour recurrence/metastasis after RFA. Patients were followed up at 1, 6 and 12 months and annually thereafter.

Results: Among nine tumours, one anaplastic carcinoma was treated three times and the other anaplastic carcinoma and one papillary macrocarcinoma were treated twice. Group 3 were treated once. The initial mean tumour volume was 107.9?±?78.6 (with neck bulging), 126.9 (with neck bulging) and 0.16?±?0.08?mL (without cosmetic or symptomatic problems) in groups 1–3, respectively. Group 1 showed no improvement in clinical symptoms or neck bulging after RFA, whereas group 2 demonstrated a decreased tumour volume measuring 0.7?mL with improved neck bulging. In group 3, mean volume decreased measuring 0.07?±?0.12?mL. No local tumour recurrence or metastatic lesion was detected during the mean follow-up of 19.3 months in papillary carcinomas. No major complications were encountered.

Conclusions: In patients with primary thyroid carcinoma, RFA achieved excellent local tumour control for papillary macro- and microcarcinoma; however, its clinical effect on anaplastic carcinoma was questionable.     

甲状腺球蛋白抗体对甲状腺乳头状癌131I清甲疗效的影响

背景与目的：甲状腺球蛋白抗体(thyroglobulin antibody,TgAb)在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)中较为常见。该研究旨在探讨PTC患者术后TgAb对¹³¹I清甲疗效的影响。方法：纳入329例非远处转移性PTC患者,根据¹³¹I清甲前TgAb水平分为G1组(大于115 U/mL,n=84)和G2组(<115 U/mL,n=245),G2组再以40 U/mL为界分为S1(大于40 U/mL,n=31)和S2(小于40 U/mL,n=214)两个亚组,中位随访时间24个月,比较两组患者清甲疗效并分析其影响因素,观察¹³¹I清甲剂量对患者疗效的影响。结果：G1组女性居多,年龄更小(P=0.000,P=0.004),其余临床病理基线资料差异均无统计学意义(P均>0.05)。G1组清甲成功率为35.7%,G2组为72.7%,差异有统计学意义(P=0.000);S1和S2两个亚组清甲成功率分别为54.8%和75.2%,差异有统计学意义(P=0.017);G1组高、低剂量¹³¹I清甲后成功率分别为34.1%、37.2%,与G2组的71.9%、73.2%差异均有统计学意义(P均=0.000);G1组与G2组内分别采用低剂量¹³¹I与高剂量¹³¹I清甲的成功率差异均无统计学意义(P均>0.05)。多因素分析显示,清甲疗效仅与清甲前TgAb值有关(P=0.018)。结论：TgAb可以影响PTC患者的¹³¹I清甲疗效,TgAb越高者清甲疗效越差。增加¹³¹I治疗剂量未能进一步提高患者的清甲成功率。     

Comparison between fractionated high dose rate irradiation and continuous low dose rate irradiation in spheroids

Recent interest in clinical brachytherapy focuses on the possible radiobiological equivalence between fractionated high dose rate (HDR) and continuous low dose rate (LDR) irradiations. This study is designed to compare the radiobiological effects between the two in vitro using multicellular spheroids of human tumor. Both HDR and LDR irradiations were delivered by 137Cs source, the dose rates of which were as 1.18 Gy/min and 5.5 mGy/min, respectively. Fractionated HDR irradiation of various fraction sizes was applied twice a day. We found that: (1) The fractionated HDR irradiation (8 Gy/2 fr/day) was more effective radiobiologically than continuous LDR irradiation (8 Gy/day) and the ratio of radiobiological effects of these irradiations was estimated as 0.82, based on the 50% spheroid cure dose (SCD50); (2) the radiobiological effectiveness was independent of the fraction size of HDR irradiation administrated, and the repair of sublethal damage (SLD) was absent, suggesting that the sparing effect of fractionated HDR irradiations was absent in spheroids. Our findings could provide important information for the clinical usage of the fractionated HDR radiotherapy to replace continuous LDR radiotherapy.     

Importance of Postoperative Stimulated Thyroglobulin Level at the Time of 131I Ablation Therapy for Differentiated Thyroid Cancer

Background: Serum thyroglobulin detection plays an essential role during the follow-up of thyroid cancerpatients treated with total/near total thyroidectomy and radioiodine ablation. The aim of this retrospective studywas to evaluate the relationship between stimulated serum thyroglobulin (Tg) level at the time of high dose 131Iablation and risk of recurrence, using a three-level classification in patients with differentiated thyroid cancer(DTC) according to the ATA guidelines. Also we investigated the relationship between postoperative stimulatedTg at the time of ablation and DxWBS results at 8-10 months thereafter. Materials and Methods: Patientswith radioiodine accumulation were regarded as scan positive (scan+). If there was no relevant pathologicalradioiodine accumulation or minimal local accumulation in the thyroid bed region, this were regarded as scannegative (scan-) at the time of DxWBS. We classified patients in 3 groups as low, intermediate and high riskgroup for assessment of risk of recurrence according to the revised ATA guidelines. Also, we divided patients into3 groups based on the stimulated serum Tg levels at the time of 131I ablation therapy. Groups 1-3 consisted ofpatients who had Tg levels of ≤2 ng/ml, 2-10 ng/ml, and ≥10 ng/ml, respectively. Results: A total of 221 consecutivepatients were included. In the high risk group according to the ATA guideline, while 45.5% of demonstratedScan(+) Tg(+), 27.3% of patients demonstrated Scan(-) Tg(-); in the intermediate group, the figures were 2.3%and 90.0% while in the low risk group, they were 0.6% and 96.4%. In 9 of 11 patients with metastases (81.8%),stimulated serum Tg level at the time of radioiodine ablation therapy was over 10, however in 1 patient (9.1%)it was <2ng/mL and in one patient it was 2-10ng/mL (p=0.005). Aggressive subtypes of DTC were found in 8 of221 patients and serum Tg levels were ≤2ng/ml in 4 of these 8. Conclusions: We conclude that TSH-stimulatedserum thyroglobulin level at the time of ablation may not determine risk of recurrence. Therefore, DxWBSshould be performed at 8-12 months after ablation therapy.