Morsal Samim

Posttreatment PET-CT-Confirmed Intrahepatic Radioembolization Performed Without Coil Embolization, by Using the Antireflux Surefire Infusion System

Intra-arterial radioembolization with yttrium-90 microspheres is a safe and effective treatment option for patients with unresectable liver tumors. Pretreatment coil embolization of extrahepatic vessels is recommended to avoid extrahepatic deposition of radioactive microspheres. A novel infusion system with an expandable tip, the Surefire Infusion System (SIS), has recently been developed to minimize reflux. We report three cases of radioembolization with the use of the SIS. In all cases, yttrium-90 radioembolization was performed successfully without coil embolization of extrahepatic vessels. In all patients, positron emission tomography-computed tomography confirmed intrahepatic biodistribution of the microspheres in all targeted liver segments, and no extrahepatic deposition. With the use of the SIS, the need for coil embolization of extrahepatic vessels might be eliminated, and treatment may be extended to patients who were previously deemed unfit.

Radiological heterogeneity in response to chemotherapy is associated with poor survival in patients with colorectal liver metastases

BACKGROUND In patients with colorectal liver metastases (CLM) there is limited knowledge about the occurrence of radiological heterogeneity in response to chemotherapy. METHODS A retrospective analysis was performed in the CAIRO and CAIRO II studies on the incidence of intermetastatic heterogeneity in patients with CLM and its association with survival. Mixed response (MR) was defined as >30% difference in individual lesion response, with all lesions showing a similar behaviour; true mixed response (TMR) as two lesions showing progression versus response; homogeneous response (HR) as similar behaviour of all lesions. Patients were classified according to the Response Evaluation Criteria in Solid Tumours (RECIST) categories (partial response (PR), stable disease (SD), progressive disease (PD), complete response (CR)) and then subdivided into MR and TMR in order to compare survival. RESULTS In the CAIRO and CAIRO II studies, 140 and 150 patients with liver-only disease were identified. 73/290 (25.2%) patients showed MR, and 25/290 (8.6%) patients TMR, and 192/290 (66.2%) patients HR. Overall survival (OS) at 1-4 years was significantly higher for the homogeneous partial responders category compared to other response categories. Median OS was 22.0 months for the entire population. In the partial response category, patients with MR showed significant poorer survival compared to patients with HR (median OS 23.7 versus 36.0 months, respectively, p=0.019). Multivariate analysis identified four independent predictors for OS: serum lactate dehydrogenase (LDH) level (p=0.002), number of first-line chemotherapy cycles (p=0.001), resection of primary tumour (p=0.001) and response category (p=0.012). CONCLUSION Radiological heterogeneity is present in approximately 35% of patients with CLM. Partial responders according to the RECIST criteria, show a significant poorer survival if classified as heterogeneous partial responder compared to homogeneous partial responders.

The role of (90)Y-radioembolization in downstaging primary and secondary hepatic malignancies: a systematic review.

Radioembolization (RE) is an emerging treatment strategy for patients with primary hepatic malignancies and metastatic liver disease. Though RE is primarily performed in the palliative setting, a shift toward the curative setting is seen. Currently, hepatic resection and in selected cases liver transplantation are the only curative options for patients with a hepatic malignancy. Unfortunately, at diagnosis most patients are not eligible for liver surgery due to the imbalance between the necessary liver resection and the remaining liver remnant. However, in borderline resectable cases, tumor volume reduction and/or increasing the future liver remnant can lead to a resectable situation. The combination of selective tumor treatment, the induction of hypertrophy of untreated liver segments, and its favourable toxicity profile make RE an appealing strategy for downstaging. The present review discusses the possibilities for RE in the preoperative setting as a downstaging tool or as a bridge to liver transplantation.

[18F]Fluorodeoxyglucose PET for Interventional Oncology in Liver Malignancy

[(18)F]Fluorodeoxyglucose (FDG) PET is a functional imaging tool that provides metabolic information, which has the potential to detect a lesion before it becomes anatomically apparent. This ability constitutes a strong argument for using FDG-PET/computed tomography (CT) in the management of oncology patients. Many studies have investigated the accuracy of FDG-PET or FDG-PET/CT for these purposes, but with small sample sizes based on retrospective cohorts. This article provides an overview of the role of FDG-PET or FDG-PET/CT in patients with liver malignancies treated by means of surgical resection, ablative therapy, chemoembolization, radioembolization, and brachytherapy, all being liver-directed oncologic interventions.

18F-FDG PET as novel imaging biomarker for disease progression after ablation therapy in colorectal liver metastases

PurposeRecurrent disease following thermal ablation therapy is a frequently reported problem. Preoperative identification of patients with high risk of recurrent disease might enable individualized treatment based on patients’ risk profile. The aim of the present work was to investigate the role of metabolic parameters derived from the pre-ablation 18F-FDG PET/CT as imaging biomarkers for recurrent disease in patients with colorectal liver metastases (CLM).MethodsIncluded in this retrospective study were all consecutive patients with CLM treated with percutaneous or open thermal ablation therapy who had a pre-treatment baseline 18F-FDG PET/CT available. Multivariable cox regression for survival analysis was performed using different models for the metabolic parameters (SULpeak, SULmean, SULmax, partial volume corrected SULmean (cSULmean), and total lesion glycolysis (TLG)) corrected for tumour and procedure characteristics. The study endpoints were defined as local tumour progression free survival (LTP-FS), new intrahepatic recurrence free survival (NHR-FS) and extrahepatic recurrence free survival (EHR-FS). Clinical and imaging follow-up data was used as the reference standard.ResultsFifty-four patients with 90 lesions were selected. Univariable cox regression analysis resulted in eight models. Multivariable analysis revealed that after adjusting for lesion size and the approach of the procedure, none of the metabolic parameters were associated with LTP-FS or EHR-FS. Percutaneous approach was significantly associated with a shorter LTP-FS. It was demonstrated that lower values of SULpeak, SULmax, SULmean , and cSULmean are associated with a significant better NHR-FS, independent of the lesion size and number and prior chemotherapy.ConclusionWe found no association between the metabolic parameters on pre-ablation 18F-FDG PET/CT and the LTP-FS. However, low values of the metabolic parameters were significantly associated with improved NHR-FS. The clinical implication of these findings might be the identification of high-risk patients who might benefit most from adjuvant or combined treatment strategies.

Safety and Efficacy of Y-90 Radioembolization After Prior Major Hepatic Resection: Dosimetric Consideration

With great interest, we read the article by Zimmermann et al., addressing the safety of radioembolization with yttrium-90 resin microspheres (Y RE) in patients with a history of major hepatic resection [1]. In all patients, the body surface area (BSA) method was used for activity calculation. The authors concluded that Y RE was safe in patients with a history of major liver resection (including extended hemihepatectomy) while using the BSA method for activity calculation. This study addresses a clinically important issue that needs attention. There are no guidelines on activity adjustments in patients with a heavily pretreated liver (either surgery or systemic treatment). Clinical studies investigating this issue are clearly needed. However, the results of the presented study should be evaluated critically, before assumptions become guidelines. It has been demonstrated that the volume of the regenerated liver is related to the resected liver volume, resulting in a reduced remnant liver volume (RLV) after more extensive hepatic resections [2]. The reported average remnant liver volume in the cohort of Zimmermann et al. [1] was 1471 mL. Despite the major hepatic resection in these patients, the average remnant liver volume was close to the average expected liver volume. This relatively large remnant liver volume, combined with a mean prescribed activity of 1.3 GBq in their cohort, resulted in a mean liver absorbed dose of 43 Gy (±21 Gy). The actual absorbed dose in patients who received lobar treatment was much lower, namely 37 Gy (±15 Gy). Both doses are comparable or even lower than the recommended mean whole liver absorbed dose, as recommended by several expert groups [3, 4]. Hence, the reported favorable outcomes are not surprising. Another explanation for the favorable safety results is the high percentage of hypervascular tumor lesions in the cohort (60%). It is well known that Y RE treatment of hypervascular tumor lesions results in relatively higher tumor absorbed doses compared with treatment of hypovascular lesions [5]. This, together with the relatively lower whole liver absorbed dose, is a more probable explanation for the low post-treatment toxicity. The validity of theBSA-based activity calculation has been questioned in several previous papers, mainly due to the lack of correlation with the liver volume [5]. Blindly applying this method in patients with a history of major hepatic resection might result in significant overdosing and could therefore be dangerous. Furthermore, incorporating surrogate methods such as a ‘liver part modifier’ in the BSA formula has never been validated in this setting and does not account for regeneration of the liver parenchyma after liver surgery and other factors that affect the future remnant liver volume. The use of the BSA method for activity calculation in patients with a history of major hepatic resection has significant drawbacks. Studies investigating more personalized dosimetric methods that account for the liver volume are needed, especially in patients with reduced remnant liver volume [5]. In the meantime, the MIRD-based dosimetric model (by itself not perfect either) at least considers themean absorbed dose of a volume-of-interest and is a preferable method for activity calculation in these patients [3, 4]. Given the mentioned limitations, the results of this study should be interpreted with caution. Future clinical studies are needed for development and validation of appropriate dosimetric methods in patients with previous liver resection. & Morsal Samim M.samim-3@umcutrecht.nl