Small hepatocellular carcinoma: high dose internal radiation therapy with superselective intra-arterial injection of I-131-labeled Lipiodol

Individualization of Radionuclide Therapies: Challenges and Prospects

Simple Summary

Currently, patient-specific treatment plans and dosimetry calculations are not routinely performed for radionuclide therapies. In external beam radiotherapy, it is quite the opposite. As a result, a small fraction of patients receives optimal radioactivity. This conservative approach provides “radiation safety” to healthy tissues but delivers a lower than indicated absorbed dose to the tumors, resulting in a lower response rate and a higher disease relapse rate. Evidence shows that better and more predictable outcomes can be achieved with patient-individualized dose assessment. Therefore, the incorporation of individual planning into radionuclide therapies is a high priority for nuclear medicine physicians and medical physicists alike. Internal dosimetry is used in tumor therapy to optimize the absorbed dose to the target tissue. The main reasons for the difficulties in incorporating patients’ internal dosimetry into routine clinical practice are discussed. The article presents the prospects for the routine implementation of personalized radionuclide therapies.

Abstract

The article presents the problems of clinical implementation of personalized radioisotope therapy. The use of radioactive drugs in the treatment of malignant and benign diseases is rapidly expanding. Currently, in the majority of nuclear medicine departments worldwide, patients receive standard activities of therapeutic radiopharmaceuticals. Intensively conducted clinical trials constantly provide more evidence of a close relationship between the dose of radiopharmaceutical absorbed in pathological tissues and the therapeutic effect of radioisotope therapy. Due to the lack of individual internal dosimetry (based on the quantitative analysis of a series of diagnostic images) before or during the treatment, only a small fraction of patients receives optimal radioactivity. The vast majority of patients receive too-low doses of ionizing radiation to the target tissues. This conservative approach provides “radiation safety” to healthy tissues, but also delivers lower radiopharmaceutical activity to the neoplastic tissue, resulting in a low level of response and a higher relapse rate. The article presents information on the currently used radionuclides in individual radioisotope therapies and on radionuclides newly introduced to the therapeutic market. It discusses the causes of difficulties with the implementation of individualized radioisotope therapies as well as possible changes in the current clinical situation.

Adjuvant I-131 Lipiodol After Resection or Radiofrequency Ablation for Hepatocellular Carcinoma

BACKGROUND AND OBJECTIVES

High rates of recurrence have been observed after curative treatment for hepatocellular carcinoma (HCC). The main aim of this study was to establish the influence of adjuvant transarterial radioembolization-based I-131 lipiodol on survival and recurrence.

METHODS

Between 2004 and 2010, 38 patients were treated with adjuvant I-131 lipiodol therapy, at a dosage of 2220 MBq, within 4 months after surgery. This treated cohort was compared to a control cohort consisting of 42 consecutive patients operated prior to the time the I-131 lipiodol treatment became available.

RESULTS

Recurrence-free survival in the control and in the I-131 lipiodol cohort was 12.6 and 18.7 months, respectively (HR = 1.871, p = 0.025). At 2 and 5 years, the cumulative incidence of a first recurrence or death was, respectively, 50 % and 61 % in the treated cohort versus 69 % and 74 % in the control cohort. Median overall survival was 55 and 29 months, respectively (p = 0.051). Among patients with a recurrence at 2 years, more patients had already experienced such recurrence at 1 year in the control cohort (70 % vs 33 %, p = 0.014).

CONCLUSIONS

Adjuvant I-131 lipiodol improves disease-free survival in patients with HCC.

Therapeutic Strategies in HCC: Radiation Modalities

Patients with hepatocellular carcinoma (HCC) comply with an advanced disease and are not eligible for radical therapy. In this distressed scenario new treatment options hold great promise; among them transarterial chemoembolization (TACE) and transarterial metabolic radiotherapy (TAMR) have shown efficacy in terms of both tumor shrinking and survival. External radiation therapy (RTx) by using novel three-dimensional conformal radiotherapy has also been used for HCC patients with encouraging results while its role had been limited in the past for the low tolerance of surrounding healthy liver. The rationale of TAMR derives from the idea of delivering exceptional radiation dose locally to the tumor, with cell killing intent, while preserving normal liver from undue exposition and minimizing systemic irradiation. Since the therapeutic efficacy of TACE is being continuously disputed, the TAMR with ¹³¹I Lipiodol or ⁹⁰Y microspheres has gained consideration providing adequate therapeutic responses regardless of few toxicities. The implementation of novel radioisotopes and technological innovations in the field of RTx constitutes an intriguing field of research with important translational aspects. Moreover, the combination of different therapeutic approaches including chemotherapy offers captivating perspectives. We present the role of the radiation-based therapies in hepatocellular carcinoma patients who are not entitled for radical treatment.

Mixed-ligand complexes of yttrium-90 dialkyldithiocarbamates with 1,10-phenanthroline as a possible agent for therapy of hepatocellular carcinoma

Yttrium-90 is a radioelement which has found wide use in targeted radionuclide therapy because of its attractive physical and chemical properties. Radioembolisation of hepatocellular carcinoma with radiolabelled Lipiodol is a method of choice. We have synthesised a series of alkyldithiocarbamate yttrium complexes, easily extracted into Lipiodol due to their high lipophilicity. Among the prepared series, a new radioconjugate, which is stable over an extended period of time, has been prepared, and could represent a potential treatment procedure for hepatocellular carcinoma.

How grim is hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is a complex disease and a major cause of death in high endemic areas of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. HCC has gone from being a universal death sentence to a cancer that can be prevented, detected at an early stage and effectively treated. Liver resection or tumour ablation techniques may be effective bridge to liver transplantation if they fulfill the Milan criteria. The areas of progress in HCC are in the control of HBV or HCV and the development of adjuvant or neoadjuvant therapies.

Palliation: treating patients with inoperable biliary tract and primary liver tumors

This article summarizes the current literature in treatment of unresectable biliary tract and primary liver tumors. Locoregional therapies including radiofrequency ablation, percutaneous ethanol injection, cryoablation, microwave ablation, transarterial chemoembolization, hepatic artery infusion, radioembolization ((90)Y), and bland embolization are discussed and clinical trials compared. Palliative strategies including surgical, percutaneous, and endoscopic techniques to decompress the biliary system and improve symptoms are also summarized. Systemic chemotherapy and sorafenib used in conjunction with locoregional therapies or as sole therapeutic options are discussed.

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.

Iodine-131-lipiodol therapy in hepatic tumours

The incidence of hepatocellular carcinoma (HCC) is worldwide sharply on the rise and patients with advanced disease carry a poor prognosis. HCC is the sixth most common cancer and the third leading cause of cancer associated deaths in the world. Intra-arterially administered (131)I-Lipiodol is selectively retained by hepatocellular carcinomas, and has been used as a vehicle for delivery of therapeutic agents to these tumours. In this review we focus on the therapeutic indications, usefulness and methods of treatment with 131-Iodine Lipiodol. The effectiveness of (131)I-Lipiodol treatment is proven both in the treatment of HCC with portal thrombosis and also as an adjuvant to surgery after the resection of HCCs. It is at least as effective as chemoembolization and is tolerated much better. Severe liver dysfunction represents theoretic contraindication for radioembolization as well as for TACE. In such cases (131)I-Lipiodol is an alternative therapy option especially in tumours smaller than 6cm.

Transcatheter Arterial Embolization with 188Rhenium-HDD–labeled Iodized Oil in Rabbit VX2 Liver Tumor

PURPOSE

To evaluate the antitumor effect of transcatheter arterial embolization (TAE) with use of rhenium 188 HDD (4-hexadecyl 2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol)-labeled iodized oil and to compare it with that of transcatheter arterial chemoembolization (TACE) with use of an established chemotherapeutic agent and iodized oil in experimentally induced liver tumor.

MATERIALS AND METHODS

VX2 carcinoma was grown in the livers of 57 rabbits. TAE was performed with (188)Re-HDD-labeled iodized oil (Re-Lp group; n = 21), doxorubicin/iodized oil emulsion (Dx-Lp group; n = 21), and iodized oil alone (n = 15). Sequential conjugated planar imaging was performed for dosimetry of the radioisotope in the Re-Lp group (n = 15). Growth ratio and percentage of viable tumor were estimated by computed tomography and histopathologic examination. Hepatic and hematologic toxicities were evaluated by biochemical analysis.

RESULTS

On conjugated planar imaging, radioactivity was concentrated on the tumor (effective half-life, 16.2 hours), and mean radiation dose to the tumor was 147.7 Gy. The mean growth ratios 1, 2, and 3 weeks after TAE and the percentage of viable tumor in the Re-Lp group (-3.4, -7.6, -11.1, and 0.3%) and the Dx-Lp group (-3.2, -5.3, 29.0, and 2.6%) were significantly lower than the respective values in the iodized oil group (45.5, 145.4, 283.0, and 30.1%; P < .001). However, the differences between the values in the Re-Lp group and those in the Dx-Lp group were not significant (P values of .165-0.497 for growth ratios; P = .134 for percentage of viable tumor). There was similar transient hepatotoxicity in all three groups.

CONCLUSIONS

TAE with (188)Re-HDD-labeled iodized oil has potent antitumor effect in VX2 liver tumor that is comparable with that of TACE with an established chemotherapeutic agent.

Safe radiation exposure of medical personnel by using simple methods of radioprotection while administering 131I-lipiodol therapy for hepatocellular carcinoma

The intra-arterial administration of 131I-lipiodol is a therapeutic approach increasingly used for the treatment of inoperable hepatocellular carcinomas. This technique has even become the reference treatment for hepatocellular carcinomas with portal thrombosis and is the only effective treatment to reduce the risk of recurrence among patients who could benefit from surgical operation. Currently, few data have been published concerning the levels of exposure for personnel carrying out this type of treatment. We undertook a dosimetric study targeted mainly on the exposure of the person performing the injection of 131I-lipiodol to show that this treatment can be carried out with an exposure at the extremities distinctly lower than the regulatory annual threshold by using simple means of radioprotection. The point of puncture was carried out at the level of left femoral artery, the preparation and injection of the therapeutic dose was carried out extemporaneously by the nuclear medicine specialist using a 10 ml syringe (for an injected volume of 4 ml) fitted with an adapted syringe protector. The injection was carried out as rapidly as possible under scopic control while avoiding reflux, with compression carried out by the radiologist. This study comprises 52 intra-arterial injections of 131I-lipiodol (2016+/-92 MBq). For the nuclear medicine specialists, 52 measurements were carried out at the level of the thorax and 41 on the fingers. For the radiologists, 22 measurements were carried out at the level of the thorax and six on their index fingers; nine measurements were carried out at the level of the thorax for the technologist and four at the level of the thorax for the stretcher bearer. For the nuclear medicine specialists, the average dose received at the level of the fingers varies between 140 and 443 microSv (according to the fingers) and the average dose at the thorax is 17 microSv. For the radiologists, the average dose received is 215 microSv at the level of the fingers and 15 microSv at the thorax. These results show that the administration of high therapeutic activities of 131I-lipiodol can be carried out for the exposed personnel with a dose at the level of the fingers much lower than the European regulatory limit of 500 mSv.

Locoregional therapies for hepatocellular carcinoma: a critical review from the surgeon's perspective

OBJECTIVE

This article reviews the current results of various locoregional therapies for hepatocellular carcinoma (HCC), with special reference to the implications for surgeons.

SUMMARY BACKGROUND DATA

Resection or transplantation is the treatment of choice for HCC, but most patients are not suitable candidates. The past decade has witnessed the development of a variety of locoregional therapies for HCC. Surgeons are faced with the challenge of adopting these therapies in the management of patients with resectable or unresectable HCC.

METHODS

A review of relevant English-language articles was undertaken based on a Medline search from January 1990 to August 2001.

RESULTS

Retrospective studies suggested that transarterial chemoembolization is an effective treatment for inoperable HCC, but its perceived benefit for survival has not been substantiated in randomized trials, presumably because its antitumor effect is offset by its adverse effect on liver function. Nonetheless, it remains a widely used palliative treatment for HCC not amenable to resection or ablative therapies, and it also plays an important role as a treatment of postresection recurrence and as a pretransplant therapy for transplantable HCC. Better patient selection, selective segmental chemoembolization, and treatment repetition tailored to tumor response and patient tolerance may improve its benefit-risk ratio. Transarterial radiotherapy is a less available alternative that produces results similar to those of chemoembolization. Percutaneous ethanol injection has gained wide acceptance as a safe and effective treatment for HCCs 3 cm or smaller. Uncertainty in tumor necrosis limits its potential as a curative treatment, but its repeatability allows treatment of recurrence after ablation or resection of HCC that is crucial to prolongation of survival. Cryotherapy affords a better chance of cure because of predictable necrosis even for HCCs larger than 3 cm, but its use is limited by a high complication rate. There has been recent enthusiasm for heat ablation by microwave, radiofrequency, or laser, which provides predictable necrosis with a low complication rate. Preliminary data indicated that radiofrequency ablation is superior to ethanol injection in the radicality of tumor ablation. The advent of more versatile radiofrequency probes has allowed ablation of HCCs larger than 5 cm. Recent studies have suggested that combined transarterial embolization and heat ablation is a promising strategy for large HCCs. Thus far, no randomized trials comparing various thermoablative therapies have been reported. It is also uncertain whether a percutaneous route, laparoscopy, or open surgery affords the best approach for these therapies. Thermoablative therapies have been combined with resection or used to treat postresection recurrence, and they have also been used as a pretransplant therapy. However, the value of such strategies requires further evaluation.

CONCLUSIONS

Advances in locoregional therapies have led to a major breakthrough in the management of unresectable HCC, but the exact role of the various modalities needs to be defined by randomized studies. Novel thermoablative techniques provide the surgeon with an exciting opportunity to participate actively in the management of unresectable HCC. Locoregional therapies are also useful adjuncts in the management of patients with resectable or transplantable disease. Hence, surgeons must be equipped with the latest knowledge and techniques of ablative therapy to provide the most appropriate treatment for the wide spectrum of patients with HCC.

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.

Adjuvant intra-arterial iodine-131-labelled lipiodol for resectable hepatocellular carcinoma: a prospective randomised trial

BACKGROUND

Resection of hepatocellular carcinoma is potentially curative, but local recurrence is common. In this prospective randomised trial, we aimed to find out if one dose of postoperative adjuvant intra-arterial iodine-131-labelled lipiodol could reduce the rate of local recurrence and increase disease-free and overall survival.

METHODS

Patients who underwent curative resection for hepatocellular carcinoma and recovered within 6 weeks were randomly assigned one 1850 MBq dose of 131I-lipiodol or no further treatment (controls). We compared rates of recurrence and disease-free and overall survival (the primary endpoints) between the two groups by intention to treat. We planned an interim analysis when 30 patients (both groups together) had been followed up for a median of 2 years, with the intention of stopping early if the between-group difference in disease-free survival was significant (p=0.029).

FINDINGS

Between April, 1992, and August, 1997, we recruited 43 patients: 21 received intra-arterial 131I-lipiodol and 22 received no adjuvant treatment. During a median follow-up of 34.6 (range 14.1-69.7) months, there were six (28.5%) recurrences among the 21 patients in the adjuvant treatment, compared with 13 (59%) in the controls (p=0.04). Median disease-free survival in the treatment and control groups was 57.2 (0.4-69.7) and 13.6 (2.1-68.3) months, respectively (p=0.037). 3-year overall survival in the treatment and control groups was 86.4% and 46.3%, respectively (p=0.039). The interim analysis showed a significant increase in disease-free survival in the treatment group compared with the controls (p=0.01), so we closed the trial early. 131I-lipiodol had no significant toxic effects.

INTERPRETATION

In patients with hepatocellular carcinoma, one 1850 MBq dose of intra-arterial 131I-lipiodol given after curative resection significantly decreases the rate of recurrence and increases disease-free and overall survival.