Chemically enhanced radiotherapy: visions for the future

Insights into Nanomedicine for Head and Neck Cancer Diagnosis and Treatment

Head and neck cancers rank sixth among the most common cancers today, and the survival rate has remained virtually unchanged over the past 25 years, due to late diagnosis and ineffective treatments. They have two main risk factors, tobacco and alcohol, and human papillomavirus infection is a secondary risk factor. These cancers affect areas of the body that are fundamental for the five senses. Therefore, it is necessary to treat them effectively and non-invasively as early as possible, in order to do not compromise vital functions, which is not always possible with conventional treatments (chemotherapy or radiotherapy). In this sense, nanomedicine plays a key role in the treatment and diagnosis of head and neck cancers. Nanomedicine involves using nanocarriers to deliver drugs to sites of action and reducing the necessary doses and possible side effects. The main purpose of this review is to give an overview of the applications of nanocarrier systems to the diagnosis and treatment of head and neck cancer. Herein, several types of delivery strategies, radiation enhancement, inside-out hyperthermia, and theragnostic approaches are addressed.

Metronomic Chemotherapy

Simple Summary

The present article reviews the state of the art of metronomic chemotherapy use to treat the principal types of cancers, namely breast, non-small cell lung cancer and colorectal ones, and of the most recent progresses in understanding the underlying mechanisms of action. Areas of novelty, in terms of new regimens, new types of cancer suitable for Metronomic chemotherapy (mCHT) and the overview of current ongoing trials, along with a critical review of them, are also provided.

Abstract

Metronomic chemotherapy treatment (mCHT) refers to the chronic administration of low doses chemotherapy that can sustain prolonged, and active plasma levels of drugs, producing favorable tolerability and it is a new promising therapeutic approach in solid and in hematologic tumors. mCHT has not only a direct effect on tumor cells, but also an action on cell microenvironment, by inhibiting tumor angiogenesis, or promoting immune response and for these reasons can be considered a multi-target therapy itself. Here we review the state of the art of mCHT use in some classical tumour types, such as breast and no small cell lung cancer (NSCLC), see what is new regarding most recent data in different cancer types, such as glioblastoma (GBL) and acute myeloid leukemia (AML), and new drugs with potential metronomic administration. Finally, a look at the strategic use of mCHT in the context of health emergencies, or in low –and middle-income countries (LMICs), where access to adequate healthcare is often not easy, is mandatory, as we always need to bear in in mind that equity in care must be a compulsory part of our medical work and research.

A multipurpose brachytherapy catheter to enable intratumoral injection

PURPOSE

To create and test a multipurpose brachytherapy catheter prototype enabling intratumoral injection and brachytherapy after a single catheter insertion.

METHODS AND MATERIALS

The design of the prototype consists of an outer tube and an inner syringe tube that can be filled with injectable agent. The outer sheath and inner syringe tube were constructed using polytetrafluoroethylene tubing, and the other components were 3D printed using dental resin and polylactic acid material. To demonstrate functionality, we injected in vitro phantoms with dyed saline. For proof of concept, we demonstrated the potential for the prototype to deliver cell therapy, enhance tumor delineation, deliver tattoo ink for pathology marking, avoid toxicity through local delivery of chemotherapy, and facilitate combination brachytherapy and immunotherapy.

RESULTS

The prototype enables accurate injection in vitro and in vivo without altering dosimetry. To illustrate the potential for delivery of cell therapies, we injected luciferase-expressing splenocytes and confirmed their delivery with bioluminescence imaging. To demonstrate feasibility of radiographically visualizing injected material, we delivered iohexol contrast intratumorally and confirmed tumor retention using Faxitron x-ray imaging. In addition, we show the potential of intratumoral administration to reduce toxicity associated with cyclophosphamide compared with systemic administration. To demonstrate feasibility, we treated tumor-bearing mice with brachytherapy (¹⁹²Ir source, 2 Gy to 5 mm) in combination with intratumoral injection of 375,000 U of interleukin 2 and observed no increased toxicity.

CONCLUSIONS

These results demonstrate that a prototype multipurpose brachytherapy catheter enables accurate intratumoral injection and support the feasibility of combining intratumoral injection with brachytherapy.

A narrative review of synergistic drug administration in unresectable locally advanced non-small cell lung cancer: current landscape and future prospects in the era of immunotherapy

Based on the PACIFIC study, the standard care of unresectable locally advanced non-small cell lung cancer (LA-NSCLC) shifted from concurrent chemo-radiotherapy (CCRT) alone to CCRT followed by durvalumab consolidation in 2017. In the era of immunotherapy, two kinds of therapeutic drugs are involved in the management of LA-NSCLC: chemotherapeutics and anti-PD-1/PD-L1 agents. However, the best choices of systematic chemotherapy, immunotherapy, and treatment schedule remain controversial. The immune modulation effects of chemotherapy, as well as the potential immunosuppressive impact of pretreatment medications, should be taken into consideration. Indeed, chemotherapeutics are double-edged swords to immunotherapy, with both stimulatory and suppressive effects on the immune system. Moreover, low-dose chemotherapy is reported to enhance anti-tumor immune responses with reduced toxicities. As for glucocorticoids, there is no consensus about its exact impact on the efficacy of immunotherapy. In addition, the timing of anti-PD-1/PD-L1 agent related to CCRT has three modes: induction, concurrent, and consolidation therapy. Although CCRT followed by durvalumab consolidation is the standard of care, the best sequence of immunotherapy and chemo-radiotherapy is still under debate. Furthermore, the efficacy and toxicity of various PD-1/PD-L1 inhibitors should be compared, especially in the background of CCRT. In this review, we will summarize the detailed knowledge about chemotherapeutics and anti-PD-1/PD-L1 axis agents, and discuss the potential implications in designing novel, effective treatment strategies for LA-NSCLC.

Metronomic chemotherapy in non-small cell lung cancer

Metronomic chemotherapy (MCT) is defined as the rhythmic chemotherapy of low-dose cytotoxic drugs with short or no drug-free breaks over prolonged periods. MCT affects tumor cells and the tumor microenvironment. Particularly, the low-dose schedule impairs the repair process of endothelial cells, resulting in an anti-angiogenesis effect. By stimulating the immune system to eliminate tumor cells, MCT induces immunological activation. Furthermore, combined with targeted therapy, anti-angiogenic drugs enhance the efficacy of MCT. The present review is an overview of phase I, II and III clinical trials focusing on the efficacy, toxicity and mechanism of MCT in patients with non-small cell lung cancer (NSCLC). Furthermore, the prospects of MCT in NSCLC have been discussed. The present review indicated that MCT is an efficacious treatment for selected patients with NSCLC, with acceptable systemic side effects and economic viability for public health.

Janus Gold Nanoplatform for Synergetic Chemoradiotherapy and Computed Tomography Imaging of Hepatocellular Carcinoma

There is a pressing need to develop nanoplatforms that integrate multimodal therapeutics to improve treatment responses and prolong the survival of patients with unresectable hepatocellular carcinoma (HCC). Mesoporous silica-coated gold nanomaterials have emerged as a novel multifunctional platform combining tunable surface plasmon resonance and mesoporous properties that exhibit multimodality properties in cancer theranostics. However, their reduced radiation-absorption efficiency and limited surface area hinder their further radiochemotherapeutic applications. To address these issues, we designed Janus-structured gold-mesoporous silica nanoparticles using a modified sol-gel method. This multifunctional theranostic nanoplatform was subsequently modified via the conjugation of folic acid for enhanced HCC targeting and internalization. The loaded anticancer agent doxorubicin can be released from the mesopores in a pH-responsive manner, facilitating selective and safe chemotherapy. Additionally, the combination of chemotherapy and radiotherapy induced synergistic anticancer effects in vitro and exhibited remarkable inhibition of tumor growth in vivo along with significantly reduced systematic toxicity. Additionally, the Janus NPs acted as targeted computed tomography (CT)-imaging agents for HCC diagnosis. Given their better performance in chemoradiotherapy and CT imaging as compared with that of their core-shell counterparts, this new nanoplatform designed with dual functionalities provides a promising strategy for unresectable HCC theranostics.