Hepatic artery injection of I-131-labeled lipiodol. Part II. Preliminary results of therapeutic use in patients with hepatocellular carcinoma and liver metastases

Internal radiation therapy with transarterial injection of iodine-131-labeled iodized oil (Lipiodol Ultra-Fluide [LUF]) was evaluated in 15 patients with hepatocellular carcinoma and eight with hepatic metastases. Five patients with hepatocellular carcinoma received more than one injection. Treatment tolerance was excellent, as assessed clinically and by means of liver function tests. An analgesic effect was noted in the two patients with painful hepatocellular carcinomas. Serum alpha 1-fetoprotein levels dropped rapidly in 11 of the 12 patients with elevated basal values. An average reduction in tumor size of 50% was observed in the nine cases followed up with computed tomography. After 5-12 months of follow-up, six of the 15 patients with hepatocellular carcinoma were alive. Two of them had undergone liver transplantation. Histologic examination of one of the livers, removed 3 months after a third injection, revealed microscopic features highly suggestive of radiation effect in LUF-containing areas. In the group with widespread hepatic metastases, no objective response was noted, except for an analgesic effect in three cases.     

Characterization of focal hepatic lesions with ferumoxides-enhanced T2-weighted MR imaging

OBJECTIVE: The purpose of this study was to evaluate whether ferumoxides-enhanced MR imaging of focal hepatic lesions provides distinctive signal intensity and lesion-to-liver contrast changes for benign and malignant lesions, helping to further characterize and differentiate these lesions. MATERIALS AND METHODS: Data analysis was performed on 70 patients, with previously identified focal hepatic lesions, who underwent MR imaging of the liver before and after IV administration of ferumoxides (10 micromol Fe/kg). Lesions analyzed with pathologically proven diagnoses included metastases (n = 40), hepatocellular carcinoma (n = 11), cholangiocarcinoma (n = 6), hemangioma (n = 4), focal nodular hyperplasia (n = 6), and hepatocellular adenoma (n = 3). Response variables measured and statistically compared included the percentage of signal-intensity change and lesion-to-liver contrast. RESULTS: Focal nodular hyperplasia showed significant signal intensity loss on ferumoxides-enhanced T2-weighted images (mean, -43%+/-6.7%, p < 0.01). All other lesion groups showed no statistically significant change in signal intensity on ferumoxides-enhanced T2-weighted images, although signal intensity loss was seen in some individual hepatocellular adenomas (mean, -6.6%+/-24.0%) and hepatocellular carcinomas (mean, -3.3%+/-10.3%). All lesions, with the exception of hepatocellular carcinoma, had a marked increase in lesion-to-liver contrast on ferumoxides-enhanced T2-weighted images, which was statistically significant for metastases and hemangioma (p < 0.02). CONCLUSION: Focal nodular hyperplasia shows significant decrease in signal intensity on ferumoxides-enhanced T2-weighted images, which may aid in the differentiation of focal nodular hyperplasia from other focal hepatic lesions. Other lesions, namely, hepatocellular adenoma and carcinoma, can have reticuloendothelial uptake, but usually to a lesser degree than that of focal nodular hyperplasia.     

Hepatic intraarterial 131I iodized oil for treatment of hepatocellular carcinoma in patients with impeded portal venous flow.

PURPOSE: To evaluate the efficacy and safety of intraarterial hepatic iodine 131 iodized oil for treatment of hepatocellular carcinoma in patients with impeded portal venous flow. MATERIALS AND METHODS: Twenty-four patients (mean age, 61 years) with hepatocellular carcinoma underwent 38 courses of 131I iodized oil (one to three per patient), with a mean dose of 2,146 MBq injected into the proper hepatic artery. Hepatocellular carcinoma manifested as single nodules (n = 8; mean, 7.75 cm), multiple nodules (n = 13; mean, 5.46 cm), or a mass (n = 3) occupying more than two hepatic segments. Portal venous thrombosis was complete (n = 10), right (n = 9), left (n = 2), or multisegmental (n = 1). Two patients had hepatofugal portal flow. RESULTS: Among the 23 patients with evaluable results, response to treatment was partial in three, and disease was stable in 12 and progressive in eight. Estimated actuarial survival rates were 70%, 33%, 12%, and 6% at 3, 6, 9, and 12 months, respectively, with two patients alive at 9 and 11 months. The median survival time was 147 days. Adverse events were the early death of one patient owing to hepatic failure and transient symptomatic hepatic failure after 12 courses in nine patients. CONCLUSION: In this preliminary experience, intraarterial hepatic 131I iodized oil did not demonstrate high efficacy in the treatment of hepatocellular carcinoma in patients with portal venous thrombosis, as side effects were not rare.     

Clinical importance of technetium-99m-methoxyisobutylisonitrile (MIBI) scintigraphy in differentiated thyroid carcinoma patients with elevated thyroglobulin levels and negative I-131 scanning results

AIMS AND BACKGROUND: The aim of this study was to evaluate the potential contribution of Tc-99m-MIBI scintigraphy to the follow-up of patients with differentiated thyroid carcinoma, who had elevated Tg levels and negative I-131 whole-body scan results. MATERIALS AND METHODS: In this retrospective study, we evaluated 28 patients with differentiated thyroid carcinoma, who had total or near total thyroidectomy followed by an ablative dose of I-131 at various time intervals (15 women, 13 men; mean age 43 +/- 17 years). All patients were treated with T4 suppression. After a mean follow-up period of 6.1 years (range 3-15) all patients were determined to have a high serum Tg concentrations (>2 ng/ml) and previous negative I-131 WBS results. All patients were examined for metastatic sites using Tc-99m-MIBI scan. Scans were visually evaluated for detecting lymph node metastases and/or local recurrence, lung metastases and skeletal metastases. RESULTS: Tc-99m-MIBI scan demonstrated lesions in 23 patients (83.3%). In five patients with negative Tc-99m-MIBI scan findings (FN results): Chest CT showed small-sized mediastinal LN metastases in 2 patients and lung metastases in another 2 patients (<1 cm). Neck CT showed small-sized cervical LN involvement in 1 patient. The sensitivity of detection for neck was 94.4%, for lung 63.6%, and for bone lesions 100%. For all scan sites taken together, the sensitivity of disease detection was 83.3%, the specificity was 50%, positive predictive value (PPV) was 96.2%, and finally negative predictive value (NPV) was 16.7%. CONCLUSION: We concluded that Tc-99m-MIBI scan should be considered as a supplementary scintigraphic method for the follow-up of patients with high serum Tg levels and negative I-131 WBS results, and it can help clinicians in making the decision to treat these patients.     

Evaluation of intrahepatic I-131 ethiodol on a patient with hepatocellular carcinoma. Therapeutic feasibility study

This study assesses the therapeutic efficacy of radiolabeled iodized oil on a patient with hepatocellular carcinoma (HCC). An iodized oil, such as Lipiodol or Ethiodol (Savage Laboratories, Melville, NY), was retained selectively in the tumor vessels of large tumors as well as in the daughter tumors of HCC for long periods of time following intra-arterial injection into the hepatic artery proper. A small fraction of the stable iodine (1 pg of I-127) of the 37% iodine by weight in Ethiodol was replaced by the I-131 with 100% efficiency. A patient with HCC was injected with I-131 Ethiodol into the hepatic artery. Sequential imaging of organs such as the liver, lung, stomach, and thyroid over an eight-day period demonstrated a high tumor-to-normal-liver ratio and a negligible amount of radioactivity in these organs. These findings indicate that I-131 Ethiodol, or Ethiodol labeled with other pure beta emitters, such as Y-90 or P-32, will be effective delivering a high internal radiation dose to HCC with a small radiation effect to normal tissues. To evaluate its potential as a radiotherapeutic agent for HCC, the kinetics, biodistribution, determination of absolute activity in the tumor following intra-arterial injection of I-131 Ethiodol will be studied in the future. At the same time, an effort will be made to label Ethiodol with Y-90 and P-32.     

肝胆特异性磁共振对比剂Gd-EOB-DTPA在肝脏局灶性病变诊断中的应用研究

目的:探讨Gd-EOB-DTPA MRI增强扫描时肝局灶性病变的表现及此新型对比剂的诊断效能,提高对肝脏局灶性病变的诊断准确性。方法:已知或怀疑为肝脏局灶性病变的34例患者共90个病灶,病灶性质依次为肝囊肿20个、肝细胞肝癌16个、胆管细胞癌1个、肝脏转移性肿瘤37个、肝血管瘤9个、退变结节1个、肝脏局灶性结节增生1个、肝细胞腺瘤1个、肝脏炎性病变3个及肝脏淋巴上皮瘤样癌1个。所有患者依次行MRI平扫(抑脂TSE T2WI、抑脂3DVIBE、2DGRE T1WI)、Gd-EOB-DTPA三期(动脉期、门脉期和平衡期)增强扫描(抑脂3DVIBE)及延迟20min肝实质期扫描(抑脂2DGRE T1WI、抑脂TSE T2WI、抑脂3DVIBE)。测量并分析Gd-EOB-DTPA增强前后肝脏和病灶信号变化、病灶-肝脏对比噪声比绝对值(|CNR|)变化情况,并观察病灶Gd-EOB-DTPA增强扫描表现和特征。结果:Gd-EOB-DT-PA增强后各期肝实质信号及病灶-肝脏|CNR|均显著增加(P<0.001)。动脉期、门脉期和平衡期所有病灶符合应用常规含钆(Gd)对比剂时的强化表现和特征;延迟20min肝实质期扫描时,肝脏局灶性结节增生呈等信号-高信号,1个肝细胞肝癌呈相对高信号,其余肝囊肿、肝细胞肝癌、胆管细胞癌、肝脏转移性肿瘤、淋巴上皮瘤样癌、退变结节、肝细胞腺瘤、肝血管瘤和肝脏炎性假瘤等均呈相对低信号。结论:Gd-EOB-DTPA动态增强扫描与延迟肝实质期扫描联合应用,可以提供病变形态、血供、细胞来源及功能等更多相关信息,从而提高诊断信心及诊断准确性。     

131I标记17-丙烯胺基-17-去甲氧基格尔德霉素的制备及生物分布

目的 建立131I标记17-丙烯胺基-17.去甲氧基格尔德霉素(17-AAG)的方法,并观察其在动物体内的生物分布.方法 采用过氧化氢法对17-AAG进行131I标记.测定131I.17.AAG注射后0.5,1,4,8和24 h在ICR健康小鼠体内的生物分布,通过显像动态观察131I-17-AAG在兔Vχ2肝癌模型中的分布.结果 建立了131I过氧化氢法标记17-AAG的最佳条件,131I-17-AAG标记率达85.65%,纯化后其乙酸乙酯相、生理盐水水溶液和4℃下放置5 d的生理盐水水溶液的放化纯分别为(96.51±0.80)%,(95.57±0.09)%和(90.96±1.29)%.尾静脉注射131I-17-AAG,健康ICR小鼠胆囊的摄取(每克组织百分注射剂量率,%ID/g)在0.5 h达到峰值(3.0963±1.3394)%ID/g,胃和小肠的摄取均在4 h达到高峰,24 h时肠道放射性明显减少,肝、肾摄取较少.瘤体给药后于2 h和4,6,14 d进行显像,可见131I-17-AAG在兔肿瘤中持续浓聚,肿瘤/非肿瘤组织放射性(T/NT)比值分别为10.36,3.62,4.32和3.50,其他脏器未见显影.结论 成功建立了131I-17-AAG标记方法,标记物保留了17-AAG生物学活性,体外稳定性好.兔肝肿瘤间质给药提示131I-17-AAG对肿瘤具有理想靶向性作用.     

Hepatocellular carcinoma with skeletal metastasis: management with intraarterial radioactive iodine

Two patients with skeletal metastasis from hepatocellular carcinoma (HCC) treated with internal radiation are presented. An oily contrast medium injected into the hepatic artery accumulates in the hepatic tumor tissue and remains there for long periods: therefore, an oily contrast tagged with radioactive iodine could intensify therapeutic effect on tumors. I-131 was tagged onto Lipiodol, an iodized oil, and injected into the arteries supplying the tumors of skeletal metastasis and hepatocellular carcinoma delivering high internal radiation to both primary and secondary lesions. At 6-month follow-up period, tumor has decreased in size and patients are alive and pain free.     

Arteritis following intra-arterial chemotherapy for liver tumors

Primary and metastatic tumors of the liver can be treated successfully with transcatheter chemoembolization (TACE) during selective arterial catheterism. Arteritis is a possible referred side effect which can lead to tortuosity of the arteries, stenosis and occlusion of vessels. In our hospitals 117 consecutive patients were treated with TACE from January 1990 to December 1992; 61 patients were affected by hepatocellular carcinoma (HCC) and 56 were affected by metastases from colorectal carcinoma. Each patient received from 1 to 4 treatments at monthly intervals using epirubicin/Lipiodol ultrafluid (E/LUF) or a mixture of epirubicin and mitomicin C (MC)/LUF and followed by gelatine sponge injection in the hepatic artery. Selective angiography performed 30–62 days after the first chemoembolization showed artery stenosis in 7 patients and thrombosis in 2 cases related to toxic arteritis due to chemoembolization. Reports about arteritis during TACE treatments are discussed. Received 6 April 1995; Revision received 4 August 1995; Accepted 9 July 1996     

Radioactive iodine treatment of metastatic thyroid carcinoma with clinical thyrotoxicosis

We present a case of well-differentiated follicular carcinoma of the thyroid with hyperfunctioning metastases and clinical thyrotoxicosis. The recommended I-131 treatment dose for patients with widespread bone metastases from thyroid carcinoma is 200 mCi. However, in a patient with hyperfunctioning metastatic tumor and increased radioiodine uptake, the treatment dose should be modified. Radiation dosimetry measurements performed on the patient in this study demonstrated that 132 mCi would be a safe therapeutic I-131 dose which would avoid injury to normal radiosensitive tissues. Consequently, she was given a 130-mCi therapeutic dose.     

Vascular changes in hepatocellular carcinoma: correlation of radiologic and pathologic findings.

OBJECTIVE: Our objective was to analyze the hemodynamic properties and vascular supply changes in the carcinogenesis of hepatocellular carcinoma. MATERIALS AND METHODS: Ten nodules (nine patients) (one early, three early-advanced, and six advanced cases of hepatocellular carcinoma) less than 3 cm in diameter were selected from 45 patients (50 nodules) who underwent CT arteriography and CT during arterial portography. These images were correlated with histopathologic findings. Ratios of all microscopically counted (normal hepatic and abnormal) arteries, normal hepatic arteries, and portal veins in each nodule to those in the surrounding liver were calculated. RESULTS: Early hepatocellular carcinoma (one early case and early areas in three early-advanced cases) had low attenuation on CT arteriography and isoattenuation on CT during arterial portography. Advanced hepatocellular carcinoma (six advanced cases and advanced areas in three early-advanced cases) had high attenuation on CT arteriography and low attenuation on CT during arterial portography. In early hepatocellular carcinoma, the ratios of all arteries, normal hepatic arteries, and portal veins were 1.21 +/- 0.07, 0.60 +/- 0.07, and 0.73 +/- 0.06, respectively. In advanced hepatocellular carcinoma, the ratios were 2.66 +/- 0.26, 0.08 +/- 0.04, and 0.07 +/- 0.03, respectively. CONCLUSION: In early hepatocellular carcinoma, the combination of normal hepatic artery degeneration and preserved portal veins results in low attenuation on CT arteriography and isoattenuation on CT during arterial portography. In advanced hepatocellular carcinoma, the combination of neoplastic (abnormal) arterial development by angiogenesis and obliteration of portal veins results in high attenuation on CT arteriography and low attenuation on CT during arterial portography. These findings are a characteristic difference between early and advanced hepatocellular carcinoma.     

Intraoperative US in patients undergoing surgery for liver neoplasms: comparison with MR imaging

PURPOSE: To retrospectively compare intraoperative ultrasonography (US) and preoperative magnetic resonance (MR) imaging with contrast material enhancement for the depiction of liver lesions in patients undergoing hepatic resection. MATERIALS AND METHODS: A radiologist (D.V.S.) and a surgeon (K.K.T.) retrospectively identified 79 patients (36 female and 43 male patients; age range, 10-78 years; mean age, 57 years) who had undergone surgical resection for primary liver tumor or metastasis and had also undergone preoperative contrast-enhanced MR imaging within 6 weeks before surgery. MR imaging was performed with a 1.5-T system. Dedicated intraoperative US of the liver was performed or supervised by a gastrointestinal radiologist using a 7.5-MHz linear-array transducer, after adequate hepatic mobilization by the surgeon. Histopathologic evaluation of the 159 resected hepatic lesions served as the reference standard. The lesion distribution included colon cancer metastasis (n = 122), hepatocellular carcinoma (n = 23), cholangiocarcinoma (n = 6), cavernous hemangioma (n = 4), focal nodular hyperplasia (n = 2), hamartoma (n = 1), and metastatic embryonal sarcoma (n = 1). RESULTS: Of 159 lesions, 138 (86.7%) were identified at both MR imaging and intraoperative US. Twelve additional lesions (7.5%) in 10 patients were detected only at intraoperative US (eight metastases, one hepatocellular carcinoma, one cholangiocarcinoma, one hemangioma, and one biliary hamartoma). Both modalities failed to depict nine lesions (5.6%) (four metastases, four hepatocellular carcinomas, and one cholangiocarcinoma). The sensitivities of MR imaging and intraoperative US for liver lesion depiction were 86.7% and 94.3%, respectively. Surgical management was altered on the basis of the intraoperative US findings in only three of 10 patients (4%). CONCLUSION: Contrast-enhanced MR imaging is as sensitive as intraoperative US in depicting liver lesions before hepatic resection.     

Postsurgical diagnostic evaluation of patients with differentiated thyroid carcinoma: comparison of ultrasound, iodine-131 scintigraphy and PET with fluorine-18 fluorodeoxyglucose

PURPOSE: The aim of this study was to compare the results of ultrasound (US), whole-body scintigraphy with iodine-131 (I-131 WBS) and positron emission tomography with fluorine-18 deoxyglucose (FDG-PET) in the follow-up of patients after thyroidectomy for differentiated thyroid carcinoma (DTC). MATERIALS AND METHODS: Thirteen patients (3 men, 10 women) were evaluated by neck US, I-131 WBS and FDG-PET. In each patient six anatomical regions (right and left thyroid bed, right and left cervical region, right and left supraclavicular region) were investigated, for a total of 78 regions. Distant metastases were investigated by I-131 WBS and FDG-PET and considered separately in the analysis. Imaging findings were compared with the reference standards, such as fine-needle aspiration cytology (2), biopsy (4) or clinical-radiological studies (7). RESULTS: US, FDG-PET and I-131 WBS showed concordant negative results in most (70, 90%) of the anatomical sites considered. In one patient with left cervical lymph node metastasis, the imaging techniques showed concordant positive results (1%). In the remaining 7 regions (9%), the imaging results were discordant; in particular, tumour lesions, nodal metastases (4) and thyroid bed recurrences (3) were detected by US only (3), by US and I-131 WBS (1) and by FDG-PET only (3). With regard to distant metastases, FDG-PET and I-131 WBS yielded concordant negative results in the majority (77%) of patients (9); in one patient only were the two imaging techniques concordant in their positive result. In the last three patients, the results were discordant; in particular, distant metastases were detected by I-131 WBS only in two patients and by FDG-PET only in one patient. CONCLUSIONS: Our work indicates a fundamental role for US in evaluation of the neck after surgery for DTC. WBS is useful to determine differentiation of tumour lesions, to identify thyroid remnants and to look for distant metastases. FDG-PET has an important role in cases of dedifferentiated thyroid carcinoma in which WBS and thyroglobulin measurements are unable to detect tumour lesions.     

Insensitivity of Tc-99m pertechnetate for detecting metastases of differentiated thyroid carcinoma

To evaluate the use of Tc-99m pertechnetate whole body scanning for the detection of metastases of differentiated thyroid carcinoma, the authors performed sequential Tc-99m pertechnetate and I-131 scans in five patients with known or suspected metastatic thyroid cancer. All five patients had abnormal I-131 uptake, but only two patients had abnormal Tc-99m pertechnetate uptake. A total of 33 abnormal foci were located with I-131; Tc-99m pertechnetate detected only 3 of these foci, and did not demonstrate any foci that were not apparent with I-131. Despite the theoretical advantages of Tc-99m pertechnetate, it cannot be recommended as a substitute for I-131 for locating thyroid cancer metastases.     

Long-term follow-up study of I-131 therapy for Graves' disease--index associated with late-onset hypothyroidism

We have studied the follow-up of thyroid function in the patients with late-onset hypothyroidism and euthyroidism after I-131 therapy of hyperthyroidism. Thirty three patients who did not need the thyroid treatment until ten years after I-131 therapy were classified as euthyroid group. And eleven patients who needed the thyroid supplement of thyroid hormone for late-onset hypothyroidism were classified as hypothyroid group. Patients in both groups who required only a single dose of I-131 for successful treatment of hyperthyroidism had similar age, gland size, 24 hour I-131 uptake, pretreatment serum T3 uptake level and T4 concentration, and I-131 treatment dose. Subclinical hypothyroidism occurred in 28.6% of euthyroid group and 66.7% of hypothyroid group four months after I-131 therapy. The levels of T3 were recovered to higher than normal range at 6 months in euthyroid group, while the levels of T3 were kept within the normal range in the seventy percent of hypothyroid group. Patients who were still lower in the level of T3 uptake than normal range at 6 months had a higher incidence of late-onset hypothyroidism. Our observation showed no significant difference in the course of follow-up studies after I-131 therapy between the patients with late-onset hypothyroidism and euthyroidism.     

Evaluation of hepatic tumors by contrast ultrasonography with carbon dioxide]

For evaluating hepatic tumors, ultrasonograms using carbon dioxide by arterial injection (CO2US) was performed in 37 patients, including 28 hepatocellular carcinomas, 11 hepatic metastases, and 3 hepatic hemangiomas. Hepatic tumors were enhanced by CO2US and easily identified. CO2US of hepatic tumors were classified into six patients. Generally, on CO2US hepatocellular carcinomas were well enhanced, and hepatic metastases had ring-like enhancement. Hepatic hemangiomas showed peripheral patchy enhancement. In the patients with hepatocellular carcinoma, the primary tumors were better identified on CO2US than conventional sonography. The daughter nodules with hepatocellular carcinoma were also better demonstrated than other examinations. CO2US is helpful in evaluating and differentiating hepatic tumors.     

Carcinoid tumors: CT and I-131 meta-iodo-benzylguanidine scintigraphy

The diagnostic value of computed tomography (CT) and iodine-131 meta-iodo-benzylguanidine (MIBG) scintiscanning was studied in nine patients with histologically proved carcinoid tumors of intestinal (n = 4), bronchial (n = 3), or thymic (n = 2) origin. CT scans clearly depicted the tumors and metastases in relation to surrounding vital structures but did not provide findings specific for carcinoids. The appearance on CT of an abdominal soft-tissue mass with a radiating pattern of linear densities was found to be highly suggestive of intestinal carcinoid tumors. I-131 MIBG scintiscans disclosed intense tracer uptake in the tumors and metastases in five patients. MIBG studies correctly depicted nine of nine tumor manifestations in intestinal carcinoids and four of six tumor manifestations in bronchus carcinoids. No MIBG concentration was found in thymus carcinoids. Because of its selective uptake mechanism, I-131 MIBG scintigraphy can allow specific detection and localization of neuroendocrine tumor tissue in patients with suspected carcinoid tumors. MIBG scintigraphy has diagnostic potential as a screening procedure in carcinoid tumors, especially those of intestinal origin.     

Biological investigation of 131I-labeled new water soluble Ru(II) polypyridyl complex.

New [Ru(L1)(dcbpy)(NCS)2] complex was synthesized in a one-pot reaction starting from [RuCl2(p-cymene)]2, where the ligands (dcbpy=4,4'-dicarboxy-2,2'-bipyridine, L1=dipyrido[3,2-a:2',3'-c]phenazine-11-ylcarbonyl)-sodium) are introduced sequentially. The resulting complex was characterized by IR, NMR, and elemental analysis. The complex was labeled with I-131. Biodistribution study of the complex was carried out using 131I-labeled [Ru(L1)(dcbpy)(NCS)2] complex. The biodistribution study performed with albino Wistar male rats has shown that the complex has high uptake in the lung, small intestine, fat, and spleen.     

Compare FDG-PET and Tc-99m tetrofosmin SPECT to detect metastatic thyroid carcinoma

RATIONALE AND OBJECTIVES: The effectiveness of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of neck and chest was evaluated to detect metastatic lesions in well-differentiated thyroid carcinoma after nearly total thyroidectomy and radioiodine (I-131) treatment who present with elevated serum human thyroglobulin levels but negative I-131 whole body scan. MATERIALS AND METHODS: Twenty-three patients with differentiated thyroid carcinoma who underwent nearly total thyroidectomy and I-131 treatments were included in this study. RESULTS: All of the 23 patients had negative I-131 whole body scan and elevated human thyroglobulin levels under thyroid-stimulating hormone stimulation. Metastatic lesions were detected by FDG-PET in 20 patients, while Tc-99m TF SPECT revealed metastatic lesions in only 11 of the 20 patients. Both FDG-PET and Tc-99m TF SPECT failed to demonstrate miliary pulmonary metastases in two of the remaining three patients. The other patient did not show any lesion on FDG-PET, Tc-99m TF SPECT, chest computed tomography, or other imaging techniques. CONCLUSION: This study demonstrated that FDG-PET is more sensitive than Tc-99m TF SPECT to detect metastatic lesions in differentiated thyroid carcinoma with elevated human thyroglobulin but negative I-131 whole body scan. However, miliary pulmonary metastases could be missed by the both techniques.     

Frequency of hepatic visualization during I-131 imaging for metastatic thyroid carcinoma

Sixty-one total body I-131 scans performed on 29 patients who were post-thyroidectomy for differentiated thyroid cancer were retrospectively reviewed to determine the frequency of hepatic visualization. The liver was seen in 52% of the patients. Diffuse liver uptake was present on 5 of 38 (13%) diagnostic (10 mCi) scans and on 12 of 23 (52%) post-therapy (80-150 mCi) scans. None of these patients showed clinical or laboratory evidence of hepatic metastases during a mean follow-up period of 18 months. We conclude that physiological diffuse liver activity is seen frequently on I-131 total-body scans.