Preliminary results of the Phase 1 Lip-Re I clinical trial: biodistribution and dosimetry assessments in hepatocellular carcinoma patients treated with 188Re-SSS Lipiodol radioembolization.

PURPOSE: This study sought to provide preliminary results on the biodistribution and dosimetry following intra-arterial liver injection of 188Re-SSS Lipiodol on hepatocellular carcinoma patients included in the Phase I Lip-Re 1 study. METHODS: Results of the first six patients included are reported. Analysis of the 188Re-SSS Lipiodol biodistribution was based on planar scintigraphic and tomoscintigraphic (SPECT) studies performed at 1, 6, 24, 48, and 72 h post-administration. Quantification in blood, urine, and stool samples was performed. Determination of the tumour to non-tumour uptake ratio (T/NT) was calculated. Absorbed doses to target organs and tumours were evaluated using the MIRD formalism. RESULTS: The mean injected activity of 188Re-SSS Lipiodol was 1645 ± 361 MBq. Uptakes were seen in the liver (tumour and healthy liver) and the lungs only. All these uptakes were stable over time. A mean 1.4 ± 0.7% of 188Re-SSS Lipiodol administered was detected in serum samples at 6 h, declining rapidly thereafter. On average, 1.5 ± 1.6% of administered activity was eliminated in urine and feces over 72 h. Overall, 90.7 ± 1.6% of detected activity on SPECT studies was found in the liver (74.9 ± 1.8% in tumours and 19.1 ± 1.7% in the healthy liver) and 9.3 ± 1.6% in the lungs (5.7 ± 1.1% in right and 3.7 ± 0.5% in left lungs). Mean doses absorbed were 7.9 ± 3.7Gy to the whole liver, 42.7 ± 34.0Gy to the tumours, 10.2 ± 3.7Gy to the healthy liver, and 1.5 ± 1.2Gy to the lungs. Four patients had stable disease on CT scans at 2 months. The first patient with rapidly progressive disease died at 1 month, most probably of massive tumour progression. Due to this early death and using a conservative approach, the trial independent evaluation committee decided to consider this event as a treatment-related toxicity. CONCLUSION: 188Re-SSS Lipiodol has a favorable biodistribution profile concerning radioembolization, with the highest in-vivo stability among all radiolabeled Lipiodol compounds reported to date. These preliminary results must be further confirmed while completing this Phase I Lip Re1 study.

Selective internal radiation therapy compared with sorafenib for hepatocellular carcinoma with portal vein thrombosis.

PURPOSE: Tumoural portal vein thrombosis (PVT) is a major prognostic factor in hepatocellular carcinoma (HCC). The efficacy of sorafenib, the only treatment approved at an advanced stage, is limited. Based on previous data, selective internal radiation therapy (SIRT), or (90)Y radioembolization, seems an interesting option. We aimed to compare both treatments in this population. METHODS: We retrospectively compared patients treated in two centres for HCC with tumoural PVT. We compared overall survival (OS) between patients treated with SIRT and patients treated with sorafenib. Analyses were performed before and after 1:1 matching with a propensity score for controlling indication bias, using a Cox proportional hazards model. RESULTS: A total of 151 patients were analysed, 34 patients treated with SIRT and 117 patients treated with sorafenib only. In the whole population, SIRT was associated with a higher median OS as compared with sorafenib: 18.8 vs 6.5 months (log-rank p < 0.001). There was an imbalance of baseline characteristics between patients treated by SIRT and sorafenib, which justified patient matching with use of a propensity score: 24 patients treated with SIRT could be matched with 24 patients treated with sorafenib. OS was estimated with a median of 26.2 vs 8.7 months in patients treated with SIRT vs sorafenib, respectively (log-rank p = 0.054). Before and after patient matching, the adjusted hazard ratio related to treatment by SIRT was estimated at 0.62 [95 % confidence interval (CI) 0.39-0.97] (p = 0.037) and 0.40 (95 % CI 0.19-0.82) (p = 0.013), respectively. CONCLUSION: SIRT seems more effective than sorafenib in patients presenting with HCC and tumoural PVT. This hypothesis is being tested in prospective randomized trials.

Gemcitabine and Oxaliplatin, but Not Sorafenib or Paclitaxel, Have a Synergistic Effect with Yttrium-90 in Reducing Hepatocellular Carcinoma and Cholangiocarcinoma Cell Line Viability.

Synergy between yttrium-90 (90Y) and antineoplastic drugs was investigated. Viability of HepaRG (hepatocellular carcinoma) and HuCCT1 (cholangiocarcinoma) cells was studied through a tetrazolium dye reduction assay. A combination index (CI) was calculated, with CI < 1 denoting synergy and CI > 1 denoting antagonism. In HepaRG cells, gemcitabine showed synergy with 90Y (CI = 0.70 [95% confidence interval = 0.65-0.75]), whereas oxaliplatin (CI = 1.15 [1.08-1.21]), paclitaxel (CI = 1.26 [1.15-1.37]), and sorafenib (CI = 1.77 [1.65-1.89]) showed antagonism. In HuCCT1 cells, gemcitabine (CI = 0.54 [0.50-0.58]) and oxaliplatin (CI = 0.86 [0.82-0.90]) showed synergy with 90Y, whereas paclitaxel (CI = 1.18 [1.09-1.27]) and sorafenib (CI = 1.21 [1.12-1.30]) showed antagonism. These results suggest that gemcitabine and oxaliplatin should be tested in combination with 90Y radioembolization for treatment of liver cancer.

In vitro demonstration of synergy/additivity between (188)rhenium and sorafenib on hepatoma lines: preliminary results.

BACKGROUND: Hepatocellular carcinoma is generally diagnosed at advanced stages, for which only palliative treatments are possible by intra-arterial route or by targeted therapies. Among these treatments, metabolic radiotherapy using (90)-yttrium or (188)Re and sorafenib are two options adopted in monotherapy. MATERIALS AND METHODS: We address the question of a possible synergy arising from the combination of these two treatments. Two primary malignant hepatoma cell lines, N1S1 (murine HCC) and HepG2 (human hepatoblastoma) were treated in media containing increasing concentrations of sorafenib with/without (188)Re to assess the cellular toxicities of each treatment alone and in combination. The combination index method was used to look for synergy or additivity. RESULTS: A synergistic advantage of a treatment combining (188)Re and sorafenib is shown in vitro on hepatoma cell lines. CONCLUSION: This combined approach is promising and now needs to be confirmed by more complex in vitro models integrating the tumoral stroma, as well as by in vivo studies.

(188)Re-SSS/Lipiodol: Development of a Potential Treatment for HCC from Bench to Bedside.

Hepatocellular carcinoma (HCC) is the 5th most common tumour worldwide and has a dark prognosis. For nonoperable cases, metabolic radiotherapy with Lipiodol labelled with ß-emitters is a promising therapeutic option. The Comprehensive Cancer Centre Eugène Marquis and the National Graduate School of Chemistry of Rennes (ENSCR) have jointly developed a stable and efficient labelling of Lipiodol with rhenium-188 (E(ßmax) = 2.1 MeV) for the treatment of HCC. The major "milestones" of this development, from the first syntheses to the recent first injection in man, are described.

Optimization of hepatocarcinoma uptake with radiolabeled lipiodol: development of new lipiodol formulations with increased viscosity.

The aim of this study was to develop new Lipiodol formulations with increased viscosities to augment Lipiodol embolic effect and optimize efficiency of radiolabeled Lipiodol in hepatocarcinoma treatments. New Lipiodol formulations consist of Lipiodol mixtures with different stearic acid concentrations (0.8%, 1.3%, and 1.8%). These formulations were fully characterized in vitro (viscosity, rheologic profiles) and labeled with 99mTc. Their viscosities at 20°C are 54, 60, and 67cP respectively, versus 45cP for Lipiodol ultra-fluide. Second, their biodistribution profiles were studied in vivo, at 24 and 72 hours, in hepatoma-bearing rats, and compared to control group (99mTc-Lipiodol). Biodistribution at 24 hours show a Gaussian tumor uptake profile with a maximum obtained with 1.3% stearic acid, and a tumor uptake superior to control group (+67%) (p<0.05). At 72 hours, optimal tumor uptake is reached with the 0.8% formulation, with 89% increase compared with control group (p<0.05). Moreover, we show a tendency to the decrease of pulmonary uptake for the new formulations at 24 hours and 72 hours. These results suggest a correlation between viscosity and Lipiodol tumor uptake. The new 0.8% stearic acid/Lipiodol formulation appears to be the optimized formulation for Lipiodol treatments of hepatocarcinoma, since it leads to a significant increase of tumor uptake at 72 hours and possibly to a decrease of undesirable pulmonary effects.

Reduction of ß-radiation exposure during preparation of 188Re-labelled Lipiodol for hepatocellular carcinoma treatment.

Rhenium-188 (188Re) is of widespread interest for treating various diseases because of its attractive physical and chemical properties. The routine preparation of therapeutic doses of 188Re-labelled tracers can result in significant radiation exposure to the operator. We studied the impact of automating the preparation of 188Re-Lipiodol on the radiochemist's exposure, as well as the importance of the model of syringe shielding. To monitor radiation exposure continuously readable electronic personal dosimeters were used. Thermoluminescence dosimeters were fixed to the probable most exposed fingers of the radiochemist during preparation of the radiotracer and during the syringing. Dose rates were measured using a Babyline. Automation of the synthesis reduced personal dose equivalents from 2.60±4.35 to 1.61±1.20 µSv/GBq [Hp(10)] and from 38.37±55.28 to 21.84±16.14 µSv/GBq [Hp(0.07)]. Dose to the extremities was also reduced (-80% for the right hand; -58% for the left one). The Lemer-Pax PSWG syringe shield led to a slightly lower dose to the hands compared with the Medisystem (1.1±0.27 vs. 1.34±0.6 mSv/GBq for the right finger). Automation of the synthesis leads to a significant decrease in radiation exposure to the operator. The Lemer-Pax PSWG syringe shield provides better hand protection than the smaller Medisystem Mediclic.

Meta-analysis of interstitial pneumonia in studies evaluating iodine-131-labeled lipiodol for hepatocellular carcinoma using exact likelihood approach.

PURPOSE: Iodine-131-labeled lipiodol is currently licensed for unresectable hepatocellular carcinoma with portal thrombosis. It is thought to be well tolerated. Cases of interstitial pneumonia have been reported, but their frequency (≈2%) has not been well estimated. Quantifying adverse drug event frequency requires an appropriate statistical approach because standard methods are biased. METHODS: To estimate the frequency of interstitial pneumonia in patients with hepatocellular carcinoma receiving iodine-131-labeled lipiodol, we conducted a systematic review of English articles using MEDLINE and EMBASE. All types of articles were considered except case reports. Primary outcome measure was symptomatic interstitial pneumonia based on investigators' judgment. All pooled analyses were based on a random effects meta-analysis model using an exact likelihood approach based on the binomial within-study distribution. RESULTS: Ten studies, including 142 patients, used low activity per dose, ranging from 0.3 to 1.1 GBq. No respiratory adverse event was noticed in these studies. Eighteen studies, including 542 patients, evaluated higher activity per dose, around 2.2 GBq; 24 cases of interstitial pneumonia were reported in these studies. Estimated frequency of interstitial pneumonia was 1.6% (95%CI, 0.4-6.4%) after one high dose and 4.1% (95%CI, 1.0-16.0%) after two or more high doses. CONCLUSIONS: The frequency of interstitial pneumonia appears higher and more precise than previously estimated. The risk appears to be related to the number of injections and the dose level per injection. Generalized linear mixed models using the exact binomial within-study distribution initially described to summarize data on diagnostic evaluation could be relevant for drug-related adverse reaction frequency assessment.

¹³¹I-labeled lipiodol-induced interstitial pneumonia: a series of 15 cases.

BACKGROUND: The drug (131)I-labeled lipiodol is used as internal radiotherapy for unresectable hepatocellular carcinoma. Although the drug was considered safe during preapproval studies, we observed several cases of interstitial pneumonia following its administration. METHODS: Cases were retrospectively identified through the drug safety unit database of Rennes University Hospital. RESULTS: From 1994 to 2009, interstitial pneumonia developed in 15 patients following (131)I-labeled lipiodol administration, with an estimated prevalence of 15.5 cases (95% CI, 7.7-23.2) per 1,000 treated patients. Mean age of the patients was 60 ± 8 years, and the male to female ratio was 6.5:1. All patients had cirrhosis, mainly related to long-term alcohol intoxication (n = 12). Most (n = 10) cases occurred after the second (131)I-labeled lipiodol injection. The median delay between last (131)I-labeled lipiodol administration and first respiratory symptoms was 30 days (interquartile range, 16.5-45 days). All patients presented with shortness of breath. Physical examination mostly revealed fever (n = 11) and bilateral crackles (n = 12). Chest CT scan showed bilateral ground-glass opacities (n = 8) with septal thickening, retraction, or both (n = 8). BAL (n = 7) was remarkable for increased neutrophils (n = 4) or CD8(+) T cell count (n = 3). Despite corticosteroids, 12 (80%) patients died, mostly of untractable respiratory failure (n = 9). Median delay between last (131)I-labeled lipiodol injection and death was 63 days (interquartile range, 34-129 days). CONCLUSIONS: Interstitial pneumonia may be a serious and not uncommon complication of (131)I-labeled lipiodol administration.

Automation of labelling of Lipiodol with high-activity generator-produced 188Re.

This work describes optimisation of the kit formulation for labelling of Lipiodol with high-activity generator-produced rhenium-188. Radiochemical purity (RCP) was 92.52±2.3% and extraction yield was 98.56±1.2%. The synthesis has been automated with a TADDEO module (Comecer) giving a mean final yield of 52.68±9.6%, and reducing radiation burden to the radiochemist by 80%. Radiolabelled Lipiodol ((188)Re-SSS/Lipiodol) is stable for at least 7 days (RCP=91.07±0.9%).

Increased Lipiodol uptake in hepatocellular carcinoma possibly due to increased membrane fluidity by dexamethasone and tamoxifen.

INTRODUCTION: Lipiodol is used as a vector for chemoembolization or internal radiotherapy in unresectable hepatocellular carcinomas (HCCs). The aim of this study is to improve the tumoral uptake of Lipiodol by modulating membrane fluidizing agents to optimize the effectiveness of Lipiodol vectorized therapy. METHODS: The effect of dexamethasone and tamoxifen on membrane fluidity was studied in vitro by electron paramagnetic resonance applied to rat hepatocarcinoma cell line N1S1. The tumoral uptake of Lipiodol was studied in vivo on rats with HCC, which had been previously treated by dexamethasone and/or tamoxifen, after intra-arterial administration of (99m)Tc-SSS-Lipiodol. RESULTS: The two molecules studied here exhibit a fluidizing effect in vitro which appears dependent on time and dose, with a maximum fluidity obtained after 1 hr at concentrations of 20 µM for dexamethasone and 200 nM for tamoxifen. In vivo, while the use of dexamethasone or tamoxifen alone tends to lead to increased tumoral uptake of Lipiodol, this effect does not reach levels of significance. On the other hand, there is a significant increase in the tumoral uptake of (99m)Tc-SSS-Lipiodol in rats pretreated by both dexamethasone and tamoxifen, with a tumoral uptake (expressed in % of injected activity per g of tumor) of 13.57 ± 3.65% after treatment, as against 9.45 ± 4.44% without treatment (P<.05). CONCLUSIONS: Dexamethasone and tamoxifen fluidify the N1S1 cells membrane, leading to an increase in the tumoral uptake of Lipiodol. These drugs could be combined with chemo-Lipiodol-embolization or radiolabeled Lipiodol, with a view to improving the effectiveness of HCCs therapy.

Treatment of hepatocellular carcinoma with intra-arterial injection of radionuclides.

Hepatocellular carcinoma (HCC) is becoming an important public health concern. Current therapeutic options are limited and new treatments are therefore being developed. The intra-arterial treatment chemoembolization has limited efficacy and few prospects for further progress. One particularly promising, though little used, alternative to chemoembolization is radioembolization with iodine-131 ((131)I) or rhenium-188 labeled lipiodol or yttrium-90 labeled microspheres (glass or resin beads). Three randomized studies have proven the effectiveness of (131)I-lipiodol in patients with HCC-as adjuvant therapy after surgery, compared with chemoembolization, and also in patients who have portal vein thrombosis. Microspheres enable the delivery of high-dose radiation (>200 Gy) to the tumor while sparing the neighboring hepatic tissue from overexposure. Overall, the efficacy of radioembolization has been good and toxic effects have been low. These results are comparable to those obtained with chemoembolization but further improvement can be expected by combining radioembolization with standard chemotherapy or with targeted therapies, such as anti-angiogenic drugs.

Dosimetric evaluation and therapeutic response to internal radiation therapy of hepatocarcinomas using iodine-131-labelled lipiodol.

OBJECTIVE: Vectorized internal radiation therapy using lipiodol-labelled with iodine-131 (131 I-lipiodol) is an effective treatment for inoperable hepatocellular carcinomas. However, few dosimetric data are available based on this approach. We have developed a dosimetric protocol based on scintiscan imaging and that is designed to calculate the tumoural absorbed dose during the treatment of hepatocarcinoma by 131 I-lipiodol. METHODS: This concept was developed on a gamma-camera coupled to a computed tomography scanner. It integrates corrections for attenuation phenomena, scattering and dead time. The tumoural absorbed dose calculation was carried out according to the Medical Internal Radiation Dose Committee formalism. This protocol was applied to a series of 41 patients in the framework of a retrospective study. RESULTS: The mean tumoural absorbed dose with the first treatment is 248 Gy (+/-176), as opposed to 152 Gy (+/-122) during the second. We highlighted a correlation between the tumoural absorbed dose, calculated in tomographic mode, and the morphological response to the first treatment (P=0.0071). Moreover, a tumoural absorbed dose of 280 Gy seems to be an effective absorbed dose threshold in our population. Above this absorbed dose, 84% of the patients are responders after the first treatment, whereas no responses are recorded below this threshold. CONCLUSION: These results are promising because, for the first time, they allow us to predict the effectiveness of a treatment by 131 I-lipiodol. They are required to be validated on a broader exploratory trial, including a dosimetric study of the critical organs, so an individualized dosimetry can be defined for each patient.

Adjuvant intraarterial injection of 131I-labeled lipiodol after resection of hepatocellular carcinoma: progress report of a case-control study with a 5-year minimal follow-up.

UNLABELLED: Recurrences after resection of hepatocellular carcinoma are frequent. A single postoperative injection of (131)I-labeled lipiodol in the hepatic artery was shown in 1999 by Lau and colleagues to be an effective adjuvant treatment, and those results were strengthened by our experience with a case-control study, reported in 2003. The goal of this paper is to update the 2003 results for a minimal follow-up of 5 y. METHODS: Between January 1999 and September 2001, 38 patients were given an adjuvant postoperative intraarterial injection of (131)I-lipiodol and were matched (for Okuda group and tumor size) with 38 patients who had undergone resection between January 1997 and January 1999 without postoperative treatment. The 2 groups were similar. RESULTS: There were 28 recurrences in the control group and 22 in the (131)I-lipiodol group (not statistically significant), and the mean time of recurrence was 21 and 26.5 mo, respectively, after surgery (statistically significant). The number of recurrences was lower in the first 2 y in the (131)I-lipiodol group (statistically significant). Disease-free survival was better (P < 0.03) in the (131)I-lipiodol group than in the control group (2-, 3-, and 5-y rates [+/-95% confidence interval] of 77% +/- 7%, 63% +/- 8%, and 42% +/- 8.5%, respectively, for the (131)I-lipiodol group vs. 47% +/- 8%, 34% +/- 8%, and 27% +/- 8%, respectively, for the control group). Overall survival did not differ between the 2 groups (P = 0.09), even though there was a trend toward better survival in the (131)I-lipiodol group (2-, 3-, and 5-y rates of 76% +/- 7%, 68% +/- 7.5%, and 51% +/- 9%, respectively, vs. 68% +/- 7.5%, 53% +/- 8%, and 39% +/- 8%, respectively, in the control group). CONCLUSION: With a longer follow-up, the results of this retrospective case-control study still favor a single postoperative injection of (131)I-lipiodol. These retrospective findings point out the need for a large-scale, prospective, randomized study.

Intra-arterial injection of iodine-131-labeled lipiodol for treatment of hepatocellular carcinoma.

BACKGROUND/AIM: The therapeutic effect of intra-arterial injection of 131-iodine-labeled lipiodol for treatment of hepatocellular carcinoma in palliative or adjuvant settings has been promising. We report, the results of an open study of this therapy in cirrhotic patients with small hepatocellular carcinoma. PATIENTS AND METHOD: Forty patients with hepatocellular carcinoma were given intra-arterial injections of 131-iodine-labeled lipiodol. These injections were repeated if necessary every 3 months. Tumor response (WHO criteria) was determined on CT scans performed after each treatment and every 3 months during the follow-up. Side effects and the cause of death were recorded. Therapeutic response and survival were analyzed. RESULTS: The median number of treatment was 2 (1-4). There was one complete response, 18 partial responses (47.5% response rate); 19 had stable disease and 2 progressions. Overall survival rates (+/-CI 95%) at 1, 2 and 3 years were: 90+/-4.7%, 60.3+/-8%, and 39+/-8.3%, respectively. Median survival was 27 months; 25 patients have died (4-56 months), 8 of tumor progression with a multifocal spread in the liver. Tolerance was good except for 2 patients who develop a fatal drug-related pulmonary insufficiency. CONCLUSION: These data suggest that intra-arterial therapeutic injection of 131-iodine-labeled lipiodol for treatment of hepatocellular carcinoma can provide high rate response and long survival for individuals not eligible for surgery or local treatment.

Monitoring of early response to neoadjuvant chemotherapy in stage II and III breast cancer by [18F]fluorodeoxyglucose positron emission tomography.

PURPOSE: This study aimed to assess prospectively the efficacy of sequential [18F]fluorodeoxyglucose positron emission tomography (FDG PET) to evaluate early response to neoadjuvant chemotherapy in stage II and III breast cancer patients. PATIENTS AND METHODS: Images were acquired with a PET/computed tomography scanner in 64 patients after administration of FDG (5 MBq/kg) at baseline and after the first, second, third, and sixth course of chemotherapy. Ultrasound and mammography were used to assess tumor size. Decrease in the standardized uptake value (SUV) with PET was compared with the pathologic response. RESULTS: Surgery was performed after six courses of chemotherapy and pathologic analysis revealed gross residual disease in 28 patients and minimal residual disease in 36 patients. Although SUV data did not vary much in nonresponders (based on pathology findings), they decreased markedly to background levels in 94% (34 of 36) of responders. When using 60% of SUV at baseline as the cutoff value, the sensitivity, specificity, and negative predictive value of FDG PET were 61%, 96%, and 68% after one course of chemotherapy, 89%, 95%, and 85% after two courses, and 88%, 73%, and 83% after three courses, respectively. The same parameters with ultrasound (US) and mammography were 64%, 43%, and 55%, and 31%, 56%, and 45%, respectively. Assessment of tumor response with US or mammography was never significant whatever the cutoff. CONCLUSION: Pathologic response to neoadjuvant chemotherapy in stage II and III breast cancer can be predicted accurately by FDG PET after two courses of chemotherapy.

Association of cisplatin and intra-arterial injection of 131I-lipiodol in treatment of hepatocellular carcinoma: results of phase II trial.

PURPOSE: Intra-arterial injections of 131I-lipiodol (131I-Lip) provide an effective treatment for hepatocellular carcinoma. In hepatocellular carcinoma cell cultures, concurrent administration of cisplatin increases the cytotoxicity of 131I. The efficacy and tolerance of intra-arterial injections of 131I-Lip combined with systemic cisplatin was tested in a phase II trial. METHODS AND MATERIALS: The inclusion criteria were proven unresectable nonmetastatic hepatocellular carcinoma, compensated liver disease, and adequate laboratory test findings. Treatment comprised the combination of intra-arterial injection of 131I-Lip (2.2 GBq) with intravenous infusion of low-dose cisplatin. The combined treatment could be repeated. RESULTS: A total of 41 patients were included; 37 had cirrhosis and 38 had measurable tumors. One to four treatments (median, two) were given. The cisplatin dose was 75 mg for the first course and 72 mg for the second. Grade 3-4 (n/n) adverse effects were observed in 14 patients, polymorphonuclear leukocytes (3/0), platelets (5/1), asthenia (1/0), pain (1/0), and vomiting (1/0). Four patients developed pulmonary toxicity; 2 cases were likely related to 131I-Lip administration and 1 was fatal. The response rate was 47% (18 of 38), and the 1- and 2-year survival rate was 73% +/- 7% and 48% +/- 9%, respectively. CONCLUSION: This combination had a tolerable toxicity profile and provided an objective response rate, warranting a phase III trial.

Effect of stabilized iodized oil emulsion on experimentally induced hepatocellular carcinoma in rats.

PURPOSE: Previous studies have shown that the use of Lipiodol UltraFluid (LUF) emulsified with water leads to an increase in the tumoral uptake of iodine I 131-labeled LUF and reduced pulmonary uptake. Although emulsions containing LUF are currently used for chemoembolization of hepatocellular carcinomas (HCCs), this approach is impossible with intraarterial radiation therapy (RT) because of the problems of radiation protection linked to instability of the emulsions. The aims of this study were to develop stabilized emulsions of radiolabeled LUF of different particle sizes and viscosities and to study its biodistribution in rats with HCC. MATERIALS AND METHODS: An emulsifier made of polyethylene glycol and hydrogenated castor oil was used to stabilize emulsions containing water and technetium Tc 99m-labeled Super Six Sulfur LUF. The various emulsions were injected in the hepatic arteries of rats with HCC. Twenty-four hours after injection, the rats were killed and the liver, tumor, and lungs were removed to perform ex-vivo gamma-counting to quantify tumoral, hepatic, and pulmonary uptake. RESULTS: Emulsions of oil in water and water in oil of different viscosities (0.68-1.06 Pa.S) and particle size distributions (21-45 mum) were prepared and kept stable for more than 24 hours. Whatever the type of emulsion, the observed effect on tumoral uptake was the opposite of that expected. Indeed, a decrease in tumoral activity was observed (P < .05 in three of five cases) and a tendency toward increased pulmonary activity was observed (P < .05 in two of five cases) rather than any significant decrease. CONCLUSIONS: This study made it possible to develop emulsions of radiolabeled iodized oil that remain stable for more than 24 hours. However, studies of biodistribution in rats with HCC failed to demonstrate any improvement in tumoral targeting, but rather showed a decrease in tumoral uptake that renders this approach impractical for intraarterial radiolabeled iodized oil RT as well as for intraarterial iodized oil chemoembolization. These results may possibly be explained by the use of an emulsifier containing lipophilic and hydrophilic components that modify the properties of LUF.

188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.

BACKGROUND: Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. AIM: To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. METHODS: 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. RESULTS: Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). CONCLUSIONS: Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.

Development of 99mTc labelled Lipiodol: biodistribution following injection into the hepatic artery of the healthy pig.

BACKGROUND: We develop a method for the radiolabelling of Lipiodol with Tc, using a lipophilic complex, [99mTc-(S2CPh)(S3Ph)2], dissolved in Lipiodol (99mTc-SSS Lipiodol). RESULTS: The labelling yield is high (96 +/- 0.8%), and the radiochemical purity satisfactory (92 +/- 2.6%). This labelling is reproducible and stable for up to 24 h in vitro. Studies carried out after injection into the hepatic artery of the healthy pig show that the biodistribution of 99mTc-SSS Lipiodol is comparable with that observed for 188Re Lipiodol. MATERIALS AND METHODS: The 99mTc-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 99mTc, in cold lipiodol. The radiochemical purity (RCP) of the labelling was checked immediately and at 24 h. The 99mTc-SSS lipiodol was injected into the hepatic artery of four healthy pigs for an ex-vivo biodistribution study. An autoradiographic study was performed in two cases. CONCLUSIONS: Apart from the specific interest of a Lipiodol-bearing technetiated agent for carrying out dosimetric studies, the labelling of Lipiodol with 99mTc is a preliminary step towards the use of radiolabelling with the 188Re analogue.