分化型甲状腺癌131I治疗的现状

分化型甲状腺癌的系统治疗包括手术切除、131I治疗、促甲状腺激素(TSH)抑制治疗.131I治疗的有效性得到普遍认可,但在治疗过程中还有很多问题存有争议.     

分化型甲状腺癌术后131I治疗的进展

甲状腺癌的发病率近年有增高趋势.南于甲状腺癌多以甲状腺结节首诊,在国内首次手术以肿瘤切除或甲状腺部分切除居多,占90.5%.原发灶再次手术肿瘤残留率达41.3%,颈淋巴结转移率72.8%.鉴于再次手术常伴喉返神经损伤和甲状旁腺功能减低等并发症,多数患者不愿再次手术.131I对术后剩余甲状腺组织可去除隐藏在残留甲状腺组织中的微小癌灶而降低甲状腺癌的复发率,也可破坏或抑制具有吸131I功能的转移灶.有利于长期随访评判及监测肿瘤的复发和转移情况.大量文献报道,低剂量(1.11GBq)131I对于分化型甲状腺癌单叶切除患者的首次去除率接近60%,重复治疗后的去除率超过90%.低利量131I治疗分化型甲状腺癌术后残余组织可以缩短住院时间,减少额外辐射作用,降低可能的不良反应,并减少患者的经济负担,以达到尽可能大的临床去除治疗效果.     

分化型甲状腺癌术后^131I治疗的进展

甲状腺癌的发病率近年有增高趋势。由于甲状腺癌多以甲状腺结节首诊,在国内首次手术以肿瘤切除或甲状腺部分切除居多,占90．5％。原发灶再次手术肿瘤残留率达41．3％,颈淋巴结转移率72．8％。鉴于再次手术常伴喉返神经损伤和甲状旁腺功能减低等并发症,多数患者不愿再次手术。^131I对术后剩余甲状腺组织可去除隐藏在残留甲状腺组织中的微小癌灶而降低甲状腺癌的复发率,也可破坏或抑制具有吸^131I功能的转移灶,有利于长期随访评判及监测肿瘤的复发和转移情况。大量文献报道,低剂量（1．11GBq）^131I对于分化型甲状腺癌单叶切除患者的首次去除率接近60％,重复治疗后的去除率超过90％。低剂量^131I治疗分化型甲状腺癌术后残余组织可以缩短住院时间,减少额外辐射作用,降低可能的不良反应,并减少患者的经济负担,以达到尽可能大的临床去除治疗效果。     

分化型甲状腺癌术后131I治疗的进展

甲状腺癌的发病率近年有增高趋势.南于甲状腺癌多以甲状腺结节首诊,在国内首次手术以肿瘤切除或甲状腺部分切除居多,占90.5%.原发灶再次手术肿瘤残留率达41.3%,颈淋巴结转移率72.8%.鉴于再次手术常伴喉返神经损伤和甲状旁腺功能减低等并发症,多数患者不愿再次手术.131I对术后剩余甲状腺组织可去除隐藏在残留甲状腺组织中的微小癌灶而降低甲状腺癌的复发率,也可破坏或抑制具有吸131I功能的转移灶.有利于长期随访评判及监测肿瘤的复发和转移情况.大量文献报道,低剂量(1.11GBq)131I对于分化型甲状腺癌单叶切除患者的首次去除率接近60%,重复治疗后的去除率超过90%.低利量131I治疗分化型甲状腺癌术后残余组织可以缩短住院时间,减少额外辐射作用,降低可能的不良反应,并减少患者的经济负担,以达到尽可能大的临床去除治疗效果.     

分化型甲状腺癌术后131I治疗患者胸腺生理性摄取131I的临床研究

目的 探讨分化型甲状腺癌（DTC）术后131I治疗患者胸腺生理性摄取131I的临床特点及131I全身显像（WBS）的影像学特征.方法 收集2007年至2013年收治的1882例次DTC术后131I治疗后第3～5天行WBS的患者,分析WBS上纵隔部位有131I摄取,并根据甲状腺球蛋白、甲状腺球蛋白抗体测定、其他影像学检查及临床随访结果最终被证实为胸腺生理性摄取131I的患者资料.结果 胸腺生理性摄取131I者共16例,年龄均＜45岁,其中有15例患者至少接受过2次131I治疗,仅有1例第1次131I治疗后胸腺显影;WBS上胸腺生理性摄取131I主要表现为“弥漫性”或“哑铃状”浓聚灶;且胸腺对131I的生理性摄取随重复131I治疗次数的增加而越来越明显.结论 胸腺生理性摄取131I是45岁以下DTC术后患者多次131I治疗后WBS假阳性的重要原因之一,充分认识到这一现象并予以鉴别,对于患者下一步的恰当诊治是十分必要的.     

维甲酸在^131I治疗分化型甲状腺癌中的应用

分化型甲状腺癌（DTC）细胞在进展过程中可发生失分化,以致于术后^131I治疗或甲状腺素替代疗效差或无效,成为目前DTC治疗的难题之一。维甲酸作为维生素A的生物活性代谢产物,在调控细胞生长、分化、凋亡等生命活动中起着重要的作用。研究表明,维甲酸能够诱导失分化的DTC细胞再分化,提高肿瘤组织对^131I的摄取能力,从而提高DTC治疗的疗效。     

131 I治疗分化型甲状腺癌脑转移

目的：探讨131I治疗分化型甲状腺癌（DTC）脑转移的临床价值。方法：随访8例经131I治疗的DTC脑转移患者，通过临床症状，影像学检查及生存率分析，观察DTC脑转移131I治疗效果。结果：（1）131I一生存期2－35年，2001年底随访时均存活；（2）I期患者131I治疗5次（20．65GBq)，后CT示右小脑占位灶缩小，6次（23．61GBq)后CT示占位灶消失。（3）甲状腺双侧切除者，术后剩余甲状腺平均131I清除次数为2次，平均总清除剂量8．87GBq;单侧切除者，平均清除次数5．7次，平均总清除剂量29．98GBq，后者的清除次数和剂量均明显高于前者（P＜0．01）。（4）合并有肺和（或）骨转移灶仍见131I提取。结论：合并有肺和（或）骨转移的DTC脑转移者治疗难度增加，但术后131I治疗仍有效。     

青少年分化型甲状腺癌与131Ⅰ治疗

青少年分化型甲状腺癌发病率不高,但与成人分化型甲状腺癌相比,具有一些鲜明的特征:发现时往往体积较大,诊断时多出现颈部淋巴结或远处转移,肿瘤细胞钠.碘转运体表达数量和频率多,治疗后复发率高,尽管如此,其总体存活率较高.手术后131Ⅰ去除残余甲状腺组织和131Ⅰ治疗远处转移依然是治疗青少年分化型甲状腺癌的重要手段.     

维甲酸在~(131)I治疗分化型甲状腺癌中的应用

分化型甲状腺癌(DTC)细胞在进展过程中可发生失分化,以致于术后~(131)I治疗或甲状腺素替代疗效差或无效,成为目前DTC治疗的难题之一.维甲酸作为维生素A的生物活性代谢产物,在调控细胞生长、分化、凋亡等生命活动中起着重要的作用.研究表明,维甲酸能够诱导失分化的DTC细胞再分化,提高肿瘤组织对~(131)I的摄取能力,从而提高DTC治疗的疗效.     

分化型甲状腺癌术后131I清甲效果的影响因素

利用131I清除甲状腺癌术后残留甲状腺组织(清甲)是分化型甲状腺癌(DTC)术后治疗中的重要步骤.清甲效果受诸多因素影响,包括口服131I的剂量、DTC的手术方式、术后甲状腺组织残留量、血清促甲状腺激素(TSH)与甲状腺球蛋白(Tg)水平、有无淋巴结及远处转移、手术距13I治疗时间的长短等.使用较大剂量131I进行清甲、采取甲状腺全切或近全切除术方式、131I治疗前较高水平的TSH,以及术后及时开始131I治疗等有助于提高清甲成功率.131I治疗前患者血清Tg水平偏高或存在转移灶,应适当加大131I治疗剂量.患者性别、年龄、病理类型等对清甲成功与否无明显影响.     

Decreased uptake of therapeutic doses of iodine-131 after 185-MBq iodine-131 diagnostic imaging for thyroid remnants in differentiated thyroid carcinoma

We performed a prospective random study to assess possible thyroid stunning by a 185-MBq iodine-131 dose used to diagnose thyroid remnants. Patients with differentiated thyroid carcinoma were included after total or near-total thyroidectomy. They were randomly assigned to two groups. In group 0 (G0, 32 patients), iodine-123 administration only was used to diagnose thyroid remnants and/or metastasis, so that no thyroid stunning by ¹³¹I would occur. In group 1 (G1, 19 patients), diagnostic imaging was performed with ¹²³I and 185 MBq ¹³¹I. ¹²³I imaging was less sensitive than ¹³¹I imaging in identifying thyroid remnants in both groups (94%). Thyroid uptake of ¹²³I was measured in both groups (at 2 h) and was not significantly different between the groups. Patients with thyroid remnants who remained in the study (28/32 in G0, 17/19 in G1) were treated with 370 MBq ¹³¹I, 5 weeks after treatment (mean time, range 12–84 days). In 12/17 G1 patients thyroid uptake measurement was repeated immediately before treatment. Uptake was equal to 1.97%±0.71% and significantly lower (P<0.05) than the previous measurement (3.76%±1.50%). Patients were imaged 7 days after administration of the therapeutic dose and the images were compared with the diagnostic images. In 28/28 G0 patients thyroid remnants were unchanged and clearly seen. In 5/17 G1 patients, however, the remnants were hardly identified, although they had been clearly seen at the time of diagnosis. We conclude the following: (1) a diagnostic dose of 185 MBq ¹³¹I decreases thyroid uptake for several weeks after administration and can impair immediate subsequent ¹³¹I therapy; (2) ¹²³I is slightly less sensitive than ¹³¹I in identifying thyroid remnants; and (3) the need to scan for thyroid remnants remains to be confirmed, since only 2/51 patients enrolled in this study were not treated with ¹³¹I. Received 6 August and in revised form 24 October 1997     

131I治疗分化型甲状腺癌患者体内残留辐射剂量及病房辐射剂量的监测分析

目的 评估住院131I治疗分化型甲状腺癌（DTC）患者体内残留辐射剂量达到出院要求的时间,以及患者所住病房和用具的辐射情况。 方法 选取2015年1月至2017年3月在中山大学附属第三医院核医学科接受术后131I住院治疗的DTC患者143例,其中男性46例、女性97例,年龄（37.6±12.4）岁。按给药剂量分为3.70、5.55和7.40 GBq 3组,每组患者分别为51、51、41例。患者在服用131I后0.5、2、4、8、12、24、36、48、72、80 h,在距离患者1 m外使用实时辐射监测仪测定辐射剂量率,估算患者体内放射性活度的变化情况。在患者出院后当天应用表面辐射污染监测仪对病房环境及患者使用过的床被进行表面污染辐射剂量的监测。对3组辐射剂量率数据进行单因素方差分析。 结果 服131I治疗 0.5 h后3组DTC患者1 m外的辐射剂量率[（597.5±196.3）、（794.5±254.2）、（1114.1±258.5） μSv/h]的差异有统计学意义（F=62.757,P<0.01）,但随着时间的延长,辐射剂量水平按类似指数曲线的变化规律迅速下降,且3组间差距逐渐缩小,在服131I 治疗72 h后3组患者1 m外的辐射剂量率[（13.3±10.7）、（16.1±9.7）、（21.9±14.5） μSv/h]的差异无统计学意义（F=2.313,P>0.05）。服131I治疗后80 h 95.8%（137/143）DTC患者1 m外辐射剂量率低于23.3 μSv/h。出院后患者使用过的床单、病服、病房地面及洗手间门口地面的表面剂量率分别为（3.9±1.2）、（4.1±1.9）、（3.8±1.6）、（6.2±2.6） μSv/h,均低于相应规定的辐射剂量限制水平。 结论 使用不超过7.40 GBq 131I治疗的DTC患者在服用131I治疗80 h后,绝大多数患者体内残留131I剂量低于国家规定的辐射限制水平。出院后患者所处病房环境及使用过的床单、病服的辐射污染均低于限制水平,无需特殊处理。     

The scope of false-positive iodine-131 images for thyroid carcinoma

Iodine-131 is used to detect and treat functioning lesions of papillary and follicular carcinoma of the thyroid. False-positive images although rare, do occur, with major categories being 1) body secretions, 2) pathologic transudates and inflammation, 3) nonspecific mediastinal uptake, and 4) neoplasms of nonthyroidal origin. The authors present eight cases that fall into the first three categories, including three types not previously reported--a lymphoepithelial cyst, a scrotal hydrocele, and a skin burn. The classification of mediastinal uptake as false positive is tentative. High-dose images and those exploiting therapeutic doses have an increased detection rate for both true and spurious lesions. Appropriate caution is advised in the interpretation of I-131 images.     

Superiority of iodine-123 compared with iodine-131 scanning for thyroid remnants in patients with differentiated thyroid cancer

PURPOSE: Iodine-123 is a pure gamma emitter and has excellent characteristics for imaging with modern scintillation cameras. The goal of this study was to compare the performance of I-123 and I-131 as imaging agents for whole-body scanning in patients with differentiated thyroid cancer undergoing ablation for thyroid remnants after initial surgery. METHODS: Fourteen patients with differentiated thyroid cancer who had undergone near-total thyroidectomy and had serum thyroid-stimulating hormone levels greater than 40 mU/I underwent diagnostic scanning 5 hours after administration of 48 to 56 MBq (1.3 to 1.5 mCi) I-123 and 48 hours after administration of 111 MBq (3 mCi) I-131. After receiving ablative I-131 therapy, they also underwent whole-body planar imaging 7 days later. The diagnostic I-123 and I-131 scans were compared with each other and with the post-therapy images by two nuclear medicine physicians and one endocrinologist. RESULTS: The diagnostic scans revealed 35 foci in the thyroid bed and neck. The I-123 images showed all 35 foci, but only 32 of the 35 foci (91 %) were seen on the I-131 scans. The findings of pre- and post-therapy scans were concordant in 11 of 13 patients, and the same general sites of uptake (left and right thyroid bed, midline) were revealed on both sets of images. In one patient, a focus seen on the diagnostic I-123 and I-131 images was not visualized on the post-therapy scan and was thought to represent possible stunning. An additional area of uptake in the lower right neck and upper mediastinum was present on the post-therapy scan of another patient, but it was not seen on diagnostic images. CONCLUSION: These results show improved quality of imaging with 50 MBq (1.5 mCi) I-123 compared with 111 MBq (3 mCi) I-131 for whole-body scanning in patients with differentiated thyroid cancer undergoing thyroid remnant ablation. I-123 imaging may prove to be the preferred procedure in such settings in patients with differentiated thyroid cancer.     

Comparison of 1073 MBq and 3700 MBq iodine-131 in postoperative ablation of residual thyroid tissue in patients with differentiated thyroid cancer

In a randomized prospective study, we compared the efficacy of low dose (1073 MBq) and high dose (3700 MBq) iodine-131 administration in postoperative ablation of residual functioning thyroid tissue in 63 patients with differentiated thyroid cancer. We were unable to demonstrate any difference between the low- and the high-dose of radioactive iodine in scintigraphic ablation of remnant tissue. In 81% (21/26) of the patients, 1073 MBq ablated after the first dose, 77% (21/26 + 3/5 = 24/31) after the first plus second dose, and 69% (24/31 + 0/4 = 24/35) after the first, second, and third dose. Radioiodine (3700 MBq) ablated in 84%, 73%, and 69% of the patients after respectively 1., 1. plus 2., and 1. plus 2. plus 3. dose. Forty percent of the patients ablated with the low dose and 44% ablated with the high dose had elevated thyroglobulin levels at the time of complete scintigraphic ablation. In conclusion, we did not find any difference between 3700 MBq and 1073 MBq iodine-131 as regard to number of doses needed for complete scintigraphic ablation of residual functioning thyroid tissue.     

Cerebral edema following iodine-131 therapy for thyroid carcinoma metastatic to the brain

Brain metastases are rare in well-differentiated thyroid carcinoma but when present they can lead to the patient's death. Iodine-131 therapy for intracerebral thyroid carcinoma metastases causes radiation-induced acute cerebral edema that can lead to CNS complications and even death. We present a case in which a patient with intracerebral 131I uptake developed seizures, slurred speech, and muscle weakness 12 hr following 131I therapy. The patient's CT scan, post-therapy, confirmed an intracranial metastasis with a significant amount of surrounding edema. Radiotherapists, when using external beam radiation to treat intracerebral metastases, commonly place these patients on steroids, glycerol, or mannitol prior to instituting therapy, to prevent complications from radiation-induced cerebral edema. This technique could be applied to 131I therapy of intracranial thyroid carcinoma metastases as well.     

The use of technetium-99m pertechnetate in postoperative thyroid carcinoma. A comparative study with iodine-131

Over 3 years, a prospective comparison was made between Tc-99m pertechnetate and I-131 for the detection of residual and metastatic tissue in the follow-up of patients with cancer of the thyroid. All patients stopped thyroid medication for a minimum of 4 weeks. All patients had imaging done first with Tc-99m pertechnetate followed within a maximum of 2 weeks by I-131. The study included 66 patients in whom 81 studies were done with both Tc-99m and I-131. The results showed that 27 studies were positive with both Tc-99m and I-131 (true positive): 19 in the thyroid bed, four lymph nodes, two bony metastases, and two pulmonary metastases. Five patients had negative results with Tc-99m and positive results with I-131 (false negative): three in the thyroid bed, one lymph node metastasis, and one pulmonary metastasis. Only one case was positive with Tc-99m in the neck but negative with I-131 (false positive). The remaining 48 studies were negative both with Tc-99m and I-131 (true negative). Considering I-131 imaging as the standard procedure, Tc-99m had a sensitivity of 87%, specificity of 97%, and accuracy of 92.5% for the detection of residual or metastatic functioning thyroid tissue.