Radiation Therapy for Thoracic Malignancies

Study on the value of multi-dimensional conformal radiotherapy and functional imaging in tumor bioimaging

BACKGROUND

To explore the diagnostic and therapeutic effects of multi-dimensional conformal radiotherapy (MD-CRT) combined with functional imaging in tumor bioimaging.

METHODS

A total of 150 cases of patients with brain metastases in First Affiliated Hospital of Xi'an Jiaotong University between December 2020 and December 2021 were retrospectively selected as the research cohort. Participants underwent whole brain imaging guided by MD-CRT combined with volume assessment to assess the patient's recent treatment effect, statistically acceptable dose irradiation treatment, and the incidence of adverse reactions. All patients were followed up to evaluate the long-term efficacy.

RESULTS

Among the 150 patients, 24 cases were in complete remission, 72 cases were in partial remission, 36 cases were in a stable condition, 18 cases were in deterioration, and the treatment of 96 cases (64.00%) was deemed effective. All participants were followed up, the mean survival was (62.37±1.24) months, 96 cases (64.00%) survived, and 54 cases (36.00%) had died. The average dose was (62.09±3.94) Gy. In terms of adverse reactions: brain edema occurred in 57 patients, accounting for 38.00%.

CONCLUSIONS

The MD-CRT and functional imaging techniques for patients with metastatic tumor have high therapeutic accuracy, are associated with improved local control rate, prolonged survival, and cause little damage to normal tissues, with significant therapeutic effect, and can be widely used in clinical practice.

Construction and Biological Evaluation of Multiple Modification Hollow Mesoporous Silicone Doxorubicin Nanodrug Delivery System

The combination of functionalized nanoparticles and chemotherapy drugs can effectively target tumor tissue, which can improve efficacy and reduce toxicity. In this article, pPeptide-PDA@HMONs-DOX nanoparticles (phosphopeptide-modified polydopamine encapsulates doxorubicin-loaded hollow mesoporous organosilica nanoparticles) were constructed that based on multiple modification hollow mesoporous organosilica nanoparticles (HMONs). The pPeptide-PDA@HMONs-DOX nanoparticles retain the biological functions of phosphorylated peptide while exhibiting biological safety that are suitable for effective drug delivery and stimulus responsive release. The degradation behaviors showed that pPeptide-PDA@HMONs-DOX has dual-responsive to drug release characteristics of pH and glutathione (GSH). In addition, the prepared pPeptide-PDA@HMONs-DOX nanoparticles have good biological safety, and their anti-tumor efficacy was significantly better than doxorubicin (DOX). This provided new research ideas for the construction of targeted nanodrug delivery systems based on mesoporous silicon. Scheme 1 The preparation of pPeptide-PDA@HMONs-DOX and the process of drug release under multiple responses. (A) Schematic diagram of the synthesis process of pPeptide-PDA@HMONs-DOX. (B) The process in which nanoparticles enter the cell and decompose and release DOX in response to pH and GSH.

Imaging Strategies in Proton Therapy for Thoracic Tumors: A Mini Review

Proton beam therapy (PBT) is often more attractive for its high gradient dose distributions than other treatment modalities with external photon beams. However, in thoracic lesions treated particularly with pencil beam scanning (PBS) proton beams, several dosimetric issues are addressed. The PBS approach may lead to large hot or cold spots in dose distributions delivered to the patients, potentially affecting the tumor control and/or increasing normal tissue side effects. This delivery method particularly benefits image-guided approaches. Our paper aims at reviewing imaging strategies and their technological trends for PBT in thoracic lesions. The focus is on the use of imaging strategies in simulation, planning, positioning, adaptation, monitoring, and delivery of treatment and how changes in the anatomy of thoracic tumors are handled with the available tools and devices in PBT. Starting from bibliographic research over the past 5 years, retrieving 174 papers, major key questions, and implemented solutions were identified and discussed; the results aggregated and presented following the methodology of analysis of expert interviews.

Construction of Radiation Surviving/Resistant Lung Cancer Cell Lines with Equidifferent Gradient Dose Irradiation

Radiotherapy plays an increasingly crucial role in the treatment of non-small cell lung cancer (NSCLC). Local tumor recurrence and tumor progression caused by intratumoral heterogeneity induced radiotherapy resistance remain the primary causes of radiotherapy failure. However, the lack of a suitable cell line model has hampered the exploration of the dynamic mechanisms of radiation resistance. We established 3 groups of equidifferent gradient dose irradiation surviving/resistant human lung cancer cell lines based on A549, H520, and H460 cells with clinical conventional fractionated radiotherapy (CFRT) (2 Gy × 20 F, 2 Gy × 30 F, and 2 Gy × 40 F). The radiosensitivity of the cells was detected by clone formation assay, EDU cell proliferation assay, neutral comet assay, and γ-H2AX immunofluorescence staining. The radiosensitivity and proliferation viability were increased in a received dose-dependent manner. Compared with parental cells, DNA double-strand breaks (DSBs) in cell lines that received higher-dose irradiation were significantly reduced. We successfully constructed equidifferent gradient dose irradiation surviving/resistant NSCLC cell lines whose radiation surviving and resistant abilities were increased in a received dose-dependent manner. This preclinical cell model could be used to dynamically observe and detect the radiation surviving/resistant biomarkers during radiotherapy stress, elucidate the mechanism of radiation resistance.