Usefulness of administration of SPIO prior to RF ablation for evaluation of the therapeutic effect: an experimental study using miniature pigs. Eur J Radiol. 2011;78:282-286. [PMID: 21296516 DOI: 10.1016/j.ejrad.2011.01.048]

IONPs-Based Medical Imaging in Cancer Care: Moving Beyond Traditional Diagnosis and Therapeutic Assessment

Cancer-related burden of morbidity and mortality is rapidly rising worldwide. Medical imaging plays an important role in every phase of cancer management, including diagnosis, staging, treatment planning and evaluation. Iron oxide nanoparticles (IONPs) could serve as contrast agents or labeling agents to enhance the identification and visualization of pathological tissues as well as target cells. Multimodal or multifunctional imaging can be easily acquired by modifying IONPs with other imaging agents or functional groups, allowing the accessibility of combined imaging techniques and providing more comprehensive information for cancer care. To date, IONPs-enhanced medical imaging has gained intensive application in early diagnosis, monitoring treatment as well as guiding radio-frequency ablation, sentinel lymph node dissection, radiotherapy and hyperthermia therapy. Besides, IONPs mediated imaging is also capable of promoting the development of anti-cancer nanomedicines through identifying patients potentially sensitive to nanotherapeutics. Based on versatile imaging modes and application fields, this review highlights and summarizes recent research advances of IONPs-based medical imaging in cancer management. Besides, currently existing challenges are also discussed to provide perspectives and advices for the future development of IONPs-based imaging in cancer management.

A comprehensive literatures update of clinical researches of superparamagnetic resonance iron oxide nanoparticles for magnetic resonance imaging

This paper aims to update the clinical researches using superparamagnetic iron oxide (SPIO) nanoparticles as magnetic resonance imaging (MRI) contrast agent published during the past five years. PubMed database was used for literature search, and the search terms were (SPIO OR superparamagnetic iron oxide OR Resovist OR Ferumoxytol OR Ferumoxtran-10) AND (MRI OR magnetic resonance imaging). The literature search results show clinical research on SPIO remains robust, particularly fuelled by the approval of ferumoxytol for intravenously administration. SPIOs have been tested on MR angiography, sentinel lymph node detection, lymph node metastasis evaluation; inflammation evaluation; blood volume measurement; as well as liver imaging. Two experimental SPIOs with unique potentials are also discussed in this review. A curcumin-conjugated SPIO can penetrate brain blood barrier (BBB) and bind to amyloid plaques in Alzheime's disease transgenic mice brain, and thereafter detectable by MRI. Another SPIO was fabricated with a core of Fe3O4 nanoparticle and a shell coating of concentrated hydrophilic polymer brushes and are almost not taken by peripheral macrophages as well as by mononuclear phagocytes and reticuloendothelial system (RES) due to the suppression of non-specific protein binding caused by their stealthy ''brush-afforded'' structure. This SPIO may offer potentials for the applications such as drug targeting and tissue or organ imaging other than liver and lymph nodes.

Imaging evaluation of residual cancer after radiofrequency ablation of hepatocellular carcinoma

Primary liver cancer is one of the most common malignant tumors in the world, and only a few patients have the chance of surgical resection. Radiofrequency ablation (RFA) is a good treatment for patients with unresectable liver cancer. The existence of residual cancer after radiofrequency ablation has a direct impact on the prognosis of patients, so it is important to accurately determine whether there is residual cancer after RFA treatment in order to reduce the local recurrence and prolong the survival time of patients. In this paper, we discuss the evaluation of residual cancer after radiofrequency ablation of hepatocellular carcinoma by ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), digital subtraction angiography (DSA) and nuclear medicine modalities.

Clinical usefulness of the ablative margin assessed by magnetic resonance imaging with Gd-EOB-DTPA for radiofrequency ablation of hepatocellular carcinoma

BACKGROUND & AIMS

The aim of this study was to investigate the feasibility of ablative margin (AM) grading by magnetic resonance imaging (MRI) with Gd-EOB-DTPA administered prior to radiofrequency ablation (RFA), and to identify factors for achieving a sufficient AM and predictors for local tumor progression.

METHODS

A total of 124 hepatocellular carcinomas (HCCs) were treated by RFA after Gd-EOB-DTPA administration. MRI and enhanced CT were performed within seven hours and one month after RFA. The AM assessment was categorized using three grades: AM (+), low-intensity area with continuous high-intensity rim; AM zero, low-intensity area with discontinuous high-intensity rim; and AM (-), low-intensity area extends beyond the high-intensity rim. Patients were followed and local tumor progression was observed.

RESULTS

AM (+), AM zero, AM (-), and indeterminate were found in 34, 33, 26, and 31 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 56.8%. The κ coefficient was 0.326 (p<0.001), indicating moderate agreement. Multivariate logistic regression analysis showed that a significant factor for the achievement of AM (+) on MRI was no contiguous vessels. The cumulative local tumor progression rates (0% at 1, 2, and 3 years) in 33 AM (+) nodules were significantly lower than those (3.6%, 11.5%, and 18.3% at 1, 2, and 3 years respectively) in 32 AM zero nodules. A multivariate Cox proportional hazards model identified tumor size as an independent predictor for local tumor progression.

CONCLUSION

Gd-EOB-DTPA-MRI enabled an early assessment of RFA effectiveness in the majority ofHCC nodules. Local tumor progression was not detected in AM (+) nodules during the follow-up.

Enhanced primary tumor delineation in pancreatic adenocarcinoma using ultrasmall super paramagnetic iron oxide nanoparticle-ferumoxytol: an initial experience with histopathologic correlation

Purpose

To evaluate the role of ferumoxytol-enhanced magnetic resonance imaging (MRI) in delineating primary pancreatic tumors in patients undergoing preoperative neoadjuvant therapy.

Materials and methods

Eight patients with pancreatic adenocarcinoma were enrolled in this study, and underwent MRI scans at baseline, immediate post, and at the 48 hour time point after ferumoxytol injection with quantitative T2* sequences. The patients were categorized into two groups; group A received preoperative neoadjuvant therapy and group B did not. The T2* of the primary pancreatic tumor and adjacent parenchyma was recorded at baseline and the 48 hour time point. After surgery, the primary tumors were assessed histopathologically for fibrosis and inflammation.

Results

The mean T2* of the primary tumor and adjacent parenchyma at 48 hours in group A were 22.11 ms and 16.34 ms, respectively; in group B, these values were 23.96 ms and 23.26 ms, respectively. The T2* difference between the tumor and adjacent parenchyma in group A was more pronounced compared to in group B. The tumor margins were subjectively more distinct in group A compared to group B. Histopathologic evaluation showed a rim of dense fibrosis with atrophic acini at the periphery of the lesion in group A. Conversely, intact tumor cells/glands were present at the periphery of the tumor in group B.

Conclusion

Ferumoxytol-enhanced MRI scans in patients receiving preoperative neoadjuvant therapy may offer enhanced primary tumor delineation, contributing towards achieving disease-free margin at the time of surgery, and thus improving the prognosis of pancreatic carcinomas.

Ablative margin states by magnetic resonance imaging with ferucarbotran in radiofrequency ablation for hepatocellular carcinoma can predict local tumor progression

BACKGROUND

Our aim was to determine how well ablative margin (AM) grading assessed by magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation (RFA) predicts local tumor progression in comparison with enhanced computed tomography (CT).

METHODS

101 hepatocellular carcinomas were treated by RFA after ferucarbotran administration. We performed T2*-weighted MRI after 1 week and enhanced CT after 1 month. The assessment was categorized in three grades: AM(+): high-intensity area with continuous low-intensity rim; AM zero: high-intensity area with discontinuous low-intensity rim; and AM(-): high-intensity area extending beyond the low-intensity rim.

RESULTS

AM(+), AM zero, AM(-) and indeterminable were found in 47, 36, 8 and 10 nodules, respectively. The overall agreement rate between MRI and enhanced CT for the diagnosis of AM was 71.3%. The κ coefficient was 0.523 (p < 0.001), indicating moderate agreement. Multivariate logistic regression showed that a significant factor for the achievement of AM(+) on MRI was only segment location (odds ratio 5.9, non-segment 4 + 8 vs. segment 4 + 8). The cumulative local tumor progression rates (4.4, 7.6, and 7.6% in 1, 2, and 3 years) in 47 AM(+) nodules were significantly lower than those (13.9, 33.4, and 41.8% in 1, 2, and 3 years) in 36 AM zero nodules. A multivariate Cox proportional hazards model identified contiguous vessels (odds ratio 12.0) and AM(+) on MRI (odds ratio 0.19) as independent factors for local tumor progression.

CONCLUSION

AM assessment by MRI using ferucarbotran can predict local tumor progression after RFA and enable early and less invasive diagnosis.

A modified radiofrequency ablation approach for treating distant lymph node metastasis in two patients with late-stage cancer

Patients with late-stage cancer commonly have distant lymph node metastasis; however, poor health often contraindicates surgical treatment. Although the quality of life and overall survival for these patients are low, there is neither a consensus nor a guide for treatment. Ablation technique and surrounding tissue damage are two possible reasons for limited study of radiofrequency ablation in patients with superficial distant lymph node metastasis. Here, we report two patients treated successfully with ultrasound-guided radiofrequency ablation for superficial distant lymph node metastasis. In these patients, deionized water was injected to the surrounding tissues of the lymph node to decrease heat injury. Results from these patients suggest that radiofrequency ablation may play an important role in the treatment of patients with distant lymph node metastasis.