Relationship between drug delivery and the intra-arterial infusion rate of SarCNU in C6 rat brain tumor model

Intravascular Treatment Techniques for Locoregional Therapies of Lung Tumors

BACKGROUND

Lung cancer incidence has greatly increased over the past century. Moreover, the lung is the most common site of metastatic involvement. Despite improvements in the diagnosis and treatment of lung malignancies, patient prognosis is still unsatisfactory. Locoregional chemotherapeutic techniques for the treatment of lung malignancies are the current focus of research. The aim of this review article is to present different locoregional intravascular techniques and their treatment principles and to assess the pros and cons of each of them as a palliative and neoadjuvant treatment method in the treatment of lung malignancy.

METHOD

The different methods for the treatment of malignant lung lesions such as isolated lung perfusion (ILP), selective pulmonary artery perfusion (SPAP), transpulmonary chemoembolization (TPCE), bronchial artery infusion (BAI), bronchioarterial chemoembolization (BACE), and intraarteriel chemoperfusion (IACP) are evaluated comparatively.

RESULTS

Locoregional intravascular chemotherapy procedures are proving to be promising treatment options in the management of malignant lung tumors. In order to achieve optimal results, the locoregional technique should be used to achieve the highest possible uptake of the chemotherapeutic agent into the target tissue with rapid systemic clearance.

CONCLUSION

Among the various treatment options for lung malignancies, TPCE is the best evaluated treatment concept. However, further studies are necessary to define the optimal treatment concept with the best clinical outcomes.

KEY POINTS

· There are various intravascular chemotherapy methods for the treatment of lung malignancies.. · Transpulmonary chemoembolization (TPCE) is currently the most extensively evaluated treatment method for lung malignancies.. · Thermoablation after neoadjuvant chemoperfusion is a promising therapy for treating lung malignancies..

CITATION FORMAT

· Vogl TJ, Mekkawy A, Thabet DB. Intravascular Treatment Techniques for Locoregional Therapies of Lung Tumors. Fortschr Röntgenstr 2023; 195: 579 - 585.

Analytical Modeling of Flowrate and Its Maxima in Electrochemical Bioelectronics with Drug Delivery Capabilities

Flowrate control in flexible bioelectronics with targeted drug delivery capabilities is essential to ensure timely and safe delivery. For neuroscience and pharmacogenetics studies in small animals, these flexible bioelectronic systems can be tailored to deliver small drug volumes on a controlled fashion without damaging surrounding tissues from stresses induced by excessively high flowrates. The drug delivery process is realized by an electrochemical reaction that pressurizes the internal bioelectronic chambers to deform a flexible polymer membrane that pumps the drug through a network of microchannels implanted in the small animal. The flowrate temporal profile and global maximum are governed and can be modeled by the ideal gas law. Here, we obtain an analytical solution that groups the relevant mechanical, fluidic, environmental, and electrochemical terms involved in the drug delivery process into a set of three nondimensional parameters. The unique combinations of these three nondimensional parameters (related to the initial pressure, initial gas volume, and microfluidic resistance) can be used to model the flowrate and scale up the flexible bioelectronic design for experiments in medium and large animal models. The analytical solution is divided into (1) a fast variable that controls the maximum flowrate and (2) a slow variable that models the temporal profile. Together, the two variables detail the complete drug delivery process and control using the three nondimensional parameters. Comparison of the analytical model with alternative numerical models shows excellent agreement and validates the analytic modeling approach. These findings serve as a theoretical framework to design and optimize future flexible bioelectronic systems used in biomedical research, or related medical fields, and analytically control the flowrate and its global maximum for successful drug delivery.

Multi-modal imaging probe for assessing the efficiency of stem cell delivery to orthotopic breast tumours

Stem cells have been utilised as anti-cancer agents due to their ability to home to and integrate within tumours. Methods to augment stem cell homing to tumours are being investigated with the goal of enhancing treatment efficacy. However, it is currently not possible to evaluate both cell localisation and cell viability after engraftment, hindering optimisation of therapy. In this study, luciferase-expressing human adipocyte-derived stem cells (ADSCs) were incubated with Indium-111 radiolabelled iron oxide nanoparticles to produce cells with tri-modal imaging capabilities. ADSCs were administered intravenously (IV) or intracardially (IC) to mice bearing orthotopic breast tumours. Cell fate was monitored using bioluminescence imaging (BLI) as a measure of cell viability, magnetic resonance imaging (MRI) for cell localisation and single photon emission computer tomography (SPECT) for cell quantification. Serial monitoring with multi-modal imaging showed the presence of viable ADSCs within tumours as early as 1-hour post IC injection and the percentage of ADSCs within tumours to be 2-fold higher after IC than IV. Finally, histological analysis was used to validate engraftment of ADSC within tumour tissue. These findings demonstrate that multi-modal imaging can be used to evaluate the efficiency of stem cell delivery to tumours and that IC cell administration is more effective for tumour targeting.

Guidelines for the welfare and use of animals in cancer research

Animal experiments remain essential to understand the fundamental mechanisms underpinning malignancy and to discover improved methods to prevent, diagnose and treat cancer. Excellent standards of animal care are fully consistent with the conduct of high quality cancer research. Here we provide updated guidelines on the welfare and use of animals in cancer research. All experiments should incorporate the 3Rs: replacement, reduction and refinement. Focusing on animal welfare, we present recommendations on all aspects of cancer research, including: study design, statistics and pilot studies; choice of tumour models (e.g., genetically engineered, orthotopic and metastatic); therapy (including drugs and radiation); imaging (covering techniques, anaesthesia and restraint); humane endpoints (including tumour burden and site); and publication of best practice.

Intra-arterial Chemotherapy for Malignant Tumors of Head and Neck Region Using Three Types of Modified Injection Method

SUMMARY

Relatively higher infusion rate in the intra-arterial chemotherapy (IA chemotherapy) could induce the higher concentration and the more sufficient distribution of chemotherapeutic agents on tumors. To get the relatively higher infusion rate in IA chemotherapy, we used three types of injection method: high-flow injection, high-dose injection with detoxification and flowcontrolled injection method for the treatment of malignant brain tumors, skull base tumors and head and neck tumors. Between January 1997 and October 2001, twenty-seven patients (mean age 61 y.o.) with supratentorial glioblastoma (4 cases), supratentorial anaplastic astrocytoma (1), CNS lymphoma (2), matastatic skull base tumors (3), and neck tumors (15 squamous cell carcinoma, 1 malignant melanoma and 1 neuroblastoma) received our three types of IA chemotherapy. Sixty- five consecutive procedures were performed. Conventional radiation therapy and/or surgical removal were performed in some of these patients. The median follow-up period was 10 months ranging 2 to 56 months. Fifteen (55.6%) and 6 (22.2%) of 27 patients achieved complete response (CR) and partial response (PR) respectively after initial treatment [CR+PR: 21 (77.8%)]. All responded patients showed clinical improvement. The response rate declined to 55.6% at the end of follow-up period. Eighteen patients are still alive and 15 of them show no evidence of local recurrence. The median post treatment survival was 12 months. There was no serious complication except transient nausea in 4 of 27 (14%) patients, vertigo and granulocytopenia in 1 each (3%) of 27 patients. Our modified IA chemotherapy has provided favorable clinical and radiological results without technical difficulties and serious complications.

Superselective intra-arterial carboplatin for treatment of intracranial neoplasms: experience in 100 procedures

BACKGROUND

The results of animal studies suggest that superselective intra-arterial infusion allows the permeation of a high concentration of chemotherapeutic agents within intracranial neoplasms. In the present report, we review our clinical experience with the 100 intra-arterial infusions of carboplatin in intracranial neoplasms not responsive to other treatment modalities.

METHODS

Carboplatin was infused in 100 separate sessions (24 patients) as a mean dose of 286+/-60 mg/m2 (range 34-377 mg/m2). RMP-7, a bradykinin analog, was used as an adjunct in 28 sessions (6 patients). The infusions were performed through superselective microcatheterization of the following arteries: internal carotid (n = 39), middle cerebral (n = 61), posterior cerebral (n = 21) and anterior cerebral (n = 10). The frequency of neurological and non-neurological complications, and survival were recorded. In a subset of 10 patients, tumor volume was measured by serial magnetic resonance images to assess therapeutic response to therapy.

RESULTS

The mean age of the patients was 44.5 years (range 26-67 years); 13 were men. The tumors were classified as glioblastoma multiforme (n = 12), metastatic tumor (n = 1), high-grade astrocytoma (n = 6), and anaplastic mixed glioma (n = 5). Follow-up was available for 23 patients (mean 22 months, range 2-69 months). Survival beyond 1 year after initiation of intra-arterial carboplatin therapy was documented in 12 of the 23 patients. A total of 13 neurological complications including seizures (n = 7), transient neurological deficits (n = 5), and ischemic stroke (n = 1) were observed in 100 procedures. A lower frequency of complications occurred in men and in patients who received adjunctive RMP-7. Volumetric analysis of serial magnetic resonance images demonstrated tumor mass reduction in 3 out of 10 patients. An increase in tumor mass ranging from 23% to 230% was observed in the other 7 patients over a period ranging from 2.3 to 37.7 months since initiation of carboplatin therapy.

CONCLUSIONS

Superselective intra-arterial administration of carboplatin appears feasible and was associated with predominantly transient neurological complications. The addition of RMP-7 to carboplatin therapy appears to be at least as safe as the administration of carboplatin alone and requires further investigation as a means of chemotherapeutic dose intensification.

Limitations of the C6/Wistar rat intracerebral glioma model: implications for evaluating immunotherapy

OBJECTIVE

Intracranial rat glioma models are a useful method for evaluating the efficacy and toxicity of novel therapies for malignant glioma. The C6/Wistar model has been used extensively as a reproducible in vivo model for studying primary brain tumors including anti-glioma immune responses. The objective of the present study is to provide in vivo evidence that the C6 rat glioma model is allogeneic within Wistar rats and is therefore inappropriate for evaluating immune responses.

METHODS

Growth patterns and immune responses of C6 cells implanted into the brain and flank of Wistar rats were analyzed and compared to an immunogenic syngeneic model (9L/Fischer).

RESULTS

Wistar rats with C6 tumors developed a potent humoral and cellular immune response to the tumor. Wistar rats given simultaneous flank and intracerebral tumors had a survival rate of 100% compared to an 11% survival rate in control animals receiving only intracranial C6 cells.

CONCLUSION

The C6 rat glioma induces a vigorous immune reaction that may mimic a specific anti-tumor response in Wistar rats. Efficacy of immunotherapy within this model must be cautiously interpreted.