Aim: There is considerable interest in approaches that could improve the therapeutic window of radiotherapy. In this study, hafnium oxide nanoparticles were designed that concentrate in tumor cells to achieve intracellular high-energy dose deposit. Materials & methods: Conventional methods were used, implemented in different ways, to explore interactions of these high-atomic-number nanoparticles and ionizing radiation with biological systems. Results: Using the Monte Carlo simulation, these nanoparticles, when exposed to high-energy photons, were shown to demonstrate an approximately ninefold radiation dose enhancement compared with water. Importantly, the nanoparticles show satisfactory dispersion and persistence within the tumor and they form clusters in the cytoplasm of cancer cells. Marked antitumor activity is demonstrated in human cancer models. Safety is similar in treated and control animals as demonstrated by a broad program of toxicology evaluation. Conclusion: These findings, supported by good ...

Nanoscale radiotherapy with hafnium oxide nanoparticles.

The epidermal growth factor receptor (EGFR) plays an important role in tissue homeostasis and tumor progression. However, cancer patients treated with EGFR inhibitors (EGFRIs) frequently develop acneiform skin toxicities, which are a strong predictor of a patient's treatment response. We show that the early inflammatory infiltrate of the skin rash induced by EGFRI is dominated by dendritic cells, macrophages, granulocytes, mast cells, and T cells. EGFRIs induce the expression of chemokines (CCL2, CCL5, CCL27, and CXCL14) in epidermal keratinocytes and impair the production of antimicrobial peptides and skin barrier proteins. Correspondingly, EGFRI-treated keratinocytes facilitate lymphocyte recruitment but show a considerably reduced cytotoxic activity against Staphylococcus aureus. Mice lacking epidermal EGFR (EGFR(Δep)) show a similar phenotype, which is accompanied by chemokine-driven skin inflammation, hair follicle degeneration, decreased host defense, and deficient skin barrier function, as well as early lethality. Skin toxicities were not ameliorated in a Rag2-, MyD88-, and CCL2-deficient background or in mice lacking epidermal Langerhans cells. The skin phenotype was also not rescued in a hairless (hr/hr) background, demonstrating that skin inflammation is not induced by hair follicle degeneration. Treatment with mast cell inhibitors reduced the immigration of T cells, suggesting that mast cells play a role in the EGFRI-mediated skin pathology. Our findings demonstrate that EGFR signaling in keratinocytes regulates key factors involved in skin inflammation, barrier function, and innate host defense, providing insights into the mechanisms underlying EGFRI-induced skin pathologies.

Epidermal EGFR Controls Cutaneous Host Defense and Prevents Inflammation

The role of Human papillomavirus in head and neck cancer and the impact on radiotherapy outcome.

The prognosis of patients with advanced head and neck cancer remain dismal. For this tumor type, elevated levels of EGFR are associated with a shorter disease free survival and time to treatment failure, reflecting a more aggressive phenotype. Nimotuzumab is a humanized monoclonal antibody that recognizes domain III of the extracellular region of the EGFR, within an area that overlaps with both the surface patch recognized by cetuximab and the binding site for EGF. In order to assess the efficacy of nimotuzumab in combination with radiotherapy, a controlled, double blind, randomized clinical trial was conducted in 106 advanced squamous cell carcinoma of the head and neck patients, mostly, unfit for chemoradiotherapy. Control patients received a placebo and radiotherapy. Treatment was safe and the most frequent adverse events consisted on grade I or II asthenia, fever, headache and chills. No skin rash was detected. A significant complete response rate improvement was found in the group of patients treated with nimotuzumab as compared to the placebo. In the intent to treat analysis, a trend towards survival benefit for nimotuzumab treated subjects was found. The survival benefit became significant when applying the Harrington-Fleming test, a weighted log-rank that underscores the detection of differences deferred on time. In addition, a preliminary biomarker investigation showed a significant survival improvement for nimotuzumab treated patients as compared to controls for subjects with EGFR positive tumors. All patients showed a quality of life improvement and a reduction of the general and specific symptoms of the disease.

Nimotuzumab plus radiotherapy for unresectable squamous-cell carcinoma of the head and neck.

Based on its potent capacity to induce tumor cell death and to abrogate clonogenic survival, radiotherapy is a key part of multimodal cancer treatment approaches. Numerous clinical trials have documented the clear correlation between improved local control and increased overall survival. However, despite all progress, the efficacy of radiation-based treatment approaches is still limited by different technological, biological, and clinical constraints. In principle, the following major issues can be distinguished: (1) The intrinsic radiation resistance of several tumors is higher than that of the surrounding normal tissue, (2) the true patho-anatomical borders of tumors or areas at risk are not perfectly identifiable, (3) the treatment volume cannot be adjusted properly during a given treatment series, and (4) the individual heterogeneity in terms of tumor and normal tissue responses toward irradiation is immense. At present, research efforts in radiation oncology follow three major tracks, in order to address these limitations: (1) implementation of molecularly targeted agents and ‘omics’-based screening and stratification procedures, (2) improvement of treatment planning, imaging, and accuracy of dose application, and (3) clinical implementation of other types of radiation, including protons and heavy ions. Several of these strategies have already revealed promising improvements with regard to clinical outcome. Nevertheless, many open questions remain with individualization of treatment approaches being a key problem. In the present review, the current status of radiation-based cancer treatment with particular focus on novel aspects and developments that will influence the field of radiation oncology in the near future is summarized and discussed.

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Current concepts in clinical radiation oncology.

High rate of severe radiation dermatitis during radiation therapy with concurrent cetuximab in head and neck cancer: Results of a survey in EORTC institutes

Sophie Maillard

Papers

High rate of severe radiation dermatitis during radiation therapy with concurrent cetuximab in head and neck cancer: Results of a survey in EORTC institutes