Machine learning-based radiomics nomograms to predict number of fields in postoperative IMRT for breast cancer.

BACKGROUND: Breast cancer is now the most commonly diagnosed cancer in women worldwide. Radiotherapy is an important part of the treatment for breast cancer, while setting proper number of fields dramatically affects the benefits one can receive. Machine learning and radiomics have been widely investigated in the management of breast cancer. This study aims to provide models to predict the best number of fields based on machine learning and improve the prediction performance by adding clinical factors. METHODS: Two-hundred forty-two breast cancer patients were retrospectively enrolled for this study, all of whom received postoperative intensity modulated radiation therapy. The patients were randomized into a training set and a validation set at a ratio of 7:3. Radiomics shape features were extracted for eight machine learning algorithms to predict the number of fields. Univariate and multivariable logistic regression were implemented to screen clinical factors. A combined model of rad-score and clinical factors were finally constructed. The area under receiver operating characteristic curve, precision, recall, F1 measure and accuracy were used to evaluate the model. RESULTS: Random Forest outperformed from eight machine learning algorithms while predicting the number of fields. Prediction performance of the radiomics model was better than the clinical model, while the predictive nomogram combining the rad-score and clinical factors performed the best. CONCLUSIONS: The model combining rad-score and clinical factors performed the best. Nomograms constructed from the combined models can be of reliable references for medical dosimetrists.

Dosimetry and plan parameters study of three-dimensional-printed template-based intra-cavitary/interstitial interpolation technology using computed tomography-guided high-dose-rate brachytherapy in locally advanced cervical cancer.

Purpose: To explore differences in dosimetry and planning parameters between intra-cavitary/interstitial interpolation (IC + ISBT) three-dimensional (3D)-printed template-based (3D-printed) and simple intra-cavity (ICBT) radiation techniques using a fixed Rotterdam three-tube applicator (TT) for computed tomography-guided high-dose-rate brachytherapy in locally advanced cervical cancer. Material and methods: This retrospective study included 100 patients (n = 50 each in 3D-printed and Rotterdam three-tube applicator treatment groups) with FIGO stages IIB-IVB cervical cancer from May 2019 to May 2022. Using high-risk clinical target volume, 377 of 400 plans categorized at intervals of 10 cm3 into 20-30, 30-40, 40-50, 50-60, 60-70, and 70-80 cm3; 23 plans with < 20 and > 80 cm3 volume were excluded. Dosimetry parameters (D90 and D98 of high-risk clinical target volume, and D2cc of organs at risk, including bladder, rectum, sigmoid, and bowel) and planning parameters (homogeneity index [HI], conformation number [CN], and organ at risk sparing factor) were compared between the two groups separately for six high-risk clinical target volume plan categories. Results: For the 3D-printing group, target coverage, organs at risk protection, and plan conformity and uniformity were better than those for the Rotterdam three-tube group. Particularly, in high-risk clinical target volume plans between 50-60 cm3, the mean D90 and D98 of high-risk clinical target volume were approximately 0.35 and 0.3 Gy higher, while the average D2cc of the bladder, rectum, sigmoid, and bowel were approximately 1.3, 0.9, 0.9, and 0.8 Gy significantly lower than those of the Rotterdam three-tube group, respectively (p < 0.05). The above-mentioned planning parameters differed significantly between the groups (p < 0.05). Conclusions: For the 3D-printing group, IC/ISBT reduced the dose for organs at risk while ensuring target coverage and conformation. This was especially noticeable for plans with high-risk clinical target volume of 50-60 cm3.

Correction: Elbaz et al. Chitin-Based Anisotropic Nanostructures of Butterfly Wings for Regulating Cells Orientation. Polymers 2017, 9, 386.

In the original publication [...].

The first internal electromagnetic motion monitoring implementation for stereotactic liver radiotherapy in China: procedures and preliminary results.

BACKGROUND: Respiratory motion may compromise the dose delivery accuracy in liver stereotactic body radiation therapy (SBRT). Motion management can improve treatment delivery. However, external surrogate signal may be unstable and inaccurate. This study reports the first case of liver SBRT based on internal electromagnetic motion monitoring (Calypso, Varian Medical Systems, USA) in China. MATERIALS AND METHODS: The patient with a primary liver cancer was treated with respiratory-gated SBRT guided by three implanted electromagnetic transponders. The treatment was carried out in breath-hold end-exhale with beam-on when the centroid of the three transponders drifted within 5 mm (left-right (LR), anterior-posterior (AP) and cranio-caudal (CC) directions) from the planned position. The motion monitoring treatments were delivered in breath-hold end-exhale mode with the energy of 6 MV in FFF mode with 1200 monitor units (MU) per minute. For each fraction, QA results, intertransponder distances, geometric checks as well as tumor motion logs were explicitly recorded. RESULTS: Comparing with the plan data, distance variances between each two transponders were - 0.56 ± 0.32 mm, 0.17 ± 0.33 mm and - 0.82 ± 0.68 mm. Geometric residual, the pitch, roll and yaw angles were 0.48 ± 0.21 mm (threshold 2.0 mm), 2.17° ± 1.85° (threshold 10°), - 2.42° ± 1.51° (threshold 10°) and 1.67° ± 1.07° (threshold 10°), respectively. The delivery time of the five fields were 13.8 s, 13.1 s, 11.2 s, 11.6 s, and 11.6 s with the average value of 12.3 ± 1.1 s. Treatment duration of each fraction ranged from 6.2 to 21.4 min, with the average value of 11.3 ± 5.0 min. CONCLUSIONS: The first case of liver SBRT patient of China based on internal electromagnetic motion monitoring was performed. The system had a high tracking accuracy, and it did not delay the treatment time. In addition, the patient did not show any severe side effects except for grade I myelotoxicity. The internal electromagnetic motion monitoring system provides a real-time and direct way to track liver tumor targets.

Wide-Gamut Biomimetic Structural Colors from Interference-Assisted Two-Photon Polymerization.

Two-photon polymerization (TPP) is an emerging direct laser writing technique for the fabrication of structural colors. However, its coloration ability is suppressed as the vertical resolution is up to several microns. To solve this issue, an interference-assisted TPP technique was employed. Laser interference at a highly reflective interface produced the periodic energy redistribution along the vertical direction, turning the laser voxel into multilayer structures and confirming this technology as a facile and robust method for precise control of its vertical feature size. Biomimetic structural colors (BSCs) inspired from the ridge-lamella configurations in the Morph butterflies were fabricated using this improved TPP technique. The coloration mechanisms of the multilayer interference from the lamella layers, the thin-film interference from the fusion of multilayers, and the hybrid situations were systematically studied. These BSC colors were grouped as pixel palettes with various TPP parameters corresponding to each other, and they spanned almost the entire standard red-green-blue color space. Moreover, under optimized conditions, it was possible to fabricate a 1 cm2 area within 2.5 h. These features make interference-assisted TPP an ideal coloration method for practical applications, such as display, decoration, sensing, and so on.

Robust Carbonated Structural Color Barcodes with Ultralow Ontology Fluorescence as Biomimic Culture Platform.

Photonic crystal (PC) barcodes are a new type of spectrum-encoding microcarriers used in multiplex high-throughput bioassays, such as broad analysis of biomarkers for clinical diagnosis, gene expression, and cell culture. Unfortunately, most of these existing PC barcodes suffered from undesired features, including difficult spectrum-signal acquisition, weak mechanical strength, and high ontology fluorescence, which limited their development to real applications. To address these limitations, we report a new type of structural color-encoded PC barcodes. The barcodes are fabricated by the assembly of monodisperse polydopamine- (PDA-) coated silica (PDA@SiO2) nanoparticles using a droplet-based microfluidic technique and followed by pyrolysis of PDA@SiO2 (C@SiO2) barcodes. Because of the templated carbonization of adhesive PDA, the prepared C@SiO2 PC beads were endowed with simultaneous easy-to-identify structural color, high mechanical strength, and ultralow ontology fluorescence. We demonstrated that the structural colored C@SiO2 barcodes not only maintained a high structural stability and good biocompatibility during the coculturing with fibroblasts and tumor cells capture but also achieved an enhanced fluorescent-reading signal-to-noise ratio in the fluorescence-reading detection. These features make the C@SiO2 PC barcodes versatile for expansive application in fluorescence-reading-based multibioassays.

Chitin-Based Anisotropic Nanostructures of Butterfly Wings for Regulating Cells Orientation.

In recent years, multiple types of substrates have been applied for regulating cell orientation. Among them, surface topography patterns with grooves or ridges have been widely utilizing for cell culturing. However, this construction is still complicated, low cost-effective and exhibits some technological limitations with either "top-down" or "bottom-up" approaches. Here, a simple and green method was developed by utilizing butterfly wings (Morpho menelaus, Papilio ulysses telegonus and Ornithoptera croesus lydius) with natural anisotropic nanostructures to generate cell alignment. A two-step chemical treatment was proposed to achieve more hydrophilic butterfly wings preceding cell culturing. Furthermore, calcein acetoxymethyl ester (Calcein-AM) staining and Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay results demonstrated the appropriate viability of NIH-3T3 fibroblast cells on those butterfly wings. Moreover, the cells displayed a high degree of alignment in each specimen of these wings. We anticipate that those originating from natural butterfly wings will pose important applications for tissue engineering.

Photonic Crystal Hydrogel Enhanced Plasmonic Staining for Multiplexed Protein Analysis.

Plasmonic nanoparticles are commonly used as optical transducers in sensing applications. The optical signals resulting from the interaction of analytes and plamsonic nanoparticles are influenced by surrounding physical structures where the nanoparticles are located. This paper proposes inverse opal photonic crystal hydrogel as 3D structure to improve Raman signals from plasmonic staining. By hybridization of the plasmonic nanoparticles and photonic crystal, surface-enhanced Raman spectroscopy (SERS) analysis of multiplexed protein is realized. It benefits the Raman analysis by providing high-density "hot spots" in 3D and extra enhancement of local electromagnetic field at the band edge of PhC with periodic refractive index distribution. The strong interaction of light and the hybrid 3D nanostructure offers new insights into plasmonic nanoparticle applications and biosensor design.

Cell orientation gradients on an inverse opal substrate.

The generation of cell gradients is critical for understanding many biological systems and realizing the unique functionality of many implanted biomaterials. However, most previous work can only control the gradient of cell density and this has no effect on the gradient of cell orientation, which has an important role in regulating the functions of many connecting tissues. Here, we report on a simple stretched inverse opal substrate for establishing desired cell orientation gradients. It was demonstrated that tendon fibroblasts on the stretched inverse opal gradient showed a corresponding alignment along with the elongation gradient of the substrate. This "random-to-aligned" cell gradient reproduces the insertion part of many connecting tissues, and thus, will have important applications in tissue engineering.

Gold nanoparticle incorporated inverse opal photonic crystal capillaries for optofluidic surface enhanced Raman spectroscopy.

Novel transducers are needed for point of care testing (POCT) devices which aim at facile, sensitive and quick acquisition of health related information. Recent advances in optofluidics offer tremendous opportunities for biological/chemical analysis using extremely small sample volumes. This paper demonstrates nanostructured capillary tubes for surface enhanced Raman spectroscopy (SERS) analysis in a flow-through fashion. The capillary tube integrates the SERS sensor and the nanofluidic structure to synergistically offer sample delivery and analysis functions. Inside the capillary tube, inverse opal photonic crystal (IO PhC) was fabricated using the co-assembly approach to form nanoscale liquid pathways. In the nano-voids of the IO PhC, gold nanoparticles were in situ synthesized and functioned as the SERS hotspots. The advantages of the flow-through SERS sensor are multifold. The capillary effect facilities the sample delivery process, the nanofluidic channels boosts the interaction of analyte and gold nanoparticles, and the PhC structure strengthens the optical field near the SERS hotspots and results in enhanced SERS signals from analytes. As an exemplary demonstration, the sensor was used to measure creatinein spiked in artificial urine samples with detection limit of 0.9 mg/dL.

Bio-inspired vapor-responsive colloidal photonic crystal patterns by inkjet printing.

Facile, fast, and cost-effective technology for patterning of responsive colloidal photonic crystals (CPCs) is of great importance for their practical applications. In this report, we develop a kind of responsive CPC patterns with multicolor shifting properties by inkjet printing mesoporous colloidal nanoparticle ink on both rigid and soft substrates. By adjusting the size and mesopores' proportion of nanoparticles, we can precisely control the original color and vapor-responsive color shift extent of mesoporous CPC. As a consequence, multicolor mesoporous CPCs patterns with complex vapor responsive color shifts or vapor-revealed implicit images are subsequently achieved. The complicated and reversible multicolor shifts of mesoporous CPC patterns are favorable for immediate recognition by naked eyes but hard to copy. This approach is favorable for integration of responsive CPCs with controllable responsive optical properties. Therefore, it is of great promise for developing advanced responsive CPC devices such as anticounterfeiting devices, multifunctional microchips, sensor arrays, or dynamic displays.

Hybrid mesoporous colloid photonic crystal array for high performance vapor sensing.

A hybrid mesoporous photonic crystal vapor sensing chip was developed by introducing fluorescent dyes into mesoporous colloidal crystals. The sensing chip was capable of discriminating various kinds of vapors, as well as their concentrations, according to their fluorescence and reflective responses to vapor analytes.

Rapid and sensitive suspension array for multiplex detection of organophosphorus pesticides and carbamate pesticides based on silica-hydrogel hybrid microbeads.

A technique for multiplex detection of organophosphorus pesticides and carbamate pesticides has been developed using a suspension array based on silica-hydrogel hybrid microbeads (SHHMs). The main advantage of SHHMs, which consist of both silica and hydrogel materials, is that they not only could be distinguished by their characteristic reflection peak originating from the stop-band of the photonic crystal but also have low non-specific adsorption of proteins. Using fluorescent immunoassay, the LODs for fenitrothion, chlorpyrifos-methyl, fenthion, carbaryl and metolcarb were measured to be 0.02ng/mL, 0.012ng/mL, 0.04ng/mL, 0.05ng/mL and 0.1ng/mL, respectively, all of which are much lower than the maximum residue limits, as reported in the European Union pesticides database. All the determination coefficients for these five pesticides were greater than 0.99, demonstrating excellent correlations. The suspension array was specific and had no significant cross-reactivity with other chemicals. The results for the detection of pesticide residues collected from agricultural samples using this method agree well with those from liquid chromatography-tandem mass spectrometry. Our results showed that this simple method is suitable for simultaneous detection of these five pesticides residues in fruits and vegetables.

Molecular imprinted photonic crystal hydrogels for the rapid and label-free detection of imidacloprid.

A novel sensor for the rapid and label-free detection of imidacloprid was developed based on the combination of a colloidal crystal templating method and a molecular imprinting technique. The molecular imprinted photonic hydrogel film was prepared with methacrylic acid as monomers, ethylene glycol dimethylacrylate as cross-linkers and imidacloprid as imprinting template molecules. When the colloidal crystal template and the molecularly imprinted template was removed, the resulted MIPH film possessed a highly ordered three-dimensional macroporous structure with nanocavities. The response of the MIPH film to imidacloprid in aqueous solution can be detected through a readable Bragg diffraction red shift. When the concentration of imidacloprid increased from 10(-13) to 10(-7) g/mL, the Bragg diffraction peak shifted from 551 to 589 nm, while there were no obvious peak shifts for thiamethoxam and acetamiprid. This sensor which comprises of no label techniques and expensive instruments has potential application for the detection of trace imidacloprid.

Simultaneous Detection of Fenitrothion and Chlorpyrifos-Methyl with a Photonic Suspension Array.

A technique was developed for simultaneous detection of fenitrothion (FNT) and chlorpyrifos-methyl (CLT) using a photonic suspension array based on silica colloidal crystal beads (SCCBs). The SCCBs were encoded with the characteristic reflection peak originating from the stop-band of colloidal crystal. This approach avoids the bleaching, fading or potential interference seen when encoding by fluorescence. SCCBs with a nanopatterned surface had increased biomolecule binding capacity and improved stability. Under optimal conditions, the proposed suspension array allowed simultaneous detection of the selected pesticides in the ranges of 0.25 to 1024 ng/mL and 0.40 to 735.37 ng/mL, with the limits of detection (LODs) of 0.25 and 0.40 ng/mL, respectively. The suspension array was specific and had no significant cross-reactivity with other chemicals. The mean recoveries in tests in which samples were spiked with target standards were 82.35% to 109.90% with a standard deviation within 9.93% for CLT and 81.64% to 108.10% with a standard deviation within 8.82% for FNT. The proposed method shows a potentially powerful capability for fast quantitative analysis of pesticide residues.

In situ synthesis of gold nanoparticles (AuNPs) in butterfly wings for surface enhanced Raman spectroscopy (SERS).

Recently, surface enhanced Raman spectroscopy (SERS) has been widely studied for chemical and biological sensing. SERS substrates combined with photonic architectures have attracted more and more attention. Photonic architectures in butterfly wings are too complicated to fabricate with either "top-down" or "bottom-up" approaches. Herein, we developed a simple, reproducible, inexpensive and green method to fabricate SERS substrates from different butterfly wings where the component chitosan/chitin was utilized as in situ reducer to synthesize gold nanoparticles in natural 3D photonic architectures. The SERS performances of three butterfly wings are compared. And the results show that a SERS substrate based on M. menelaus is better than the other three substrates, which could detect 10-9 M 4-ATP and has the lowest RSD and moderate SNR. In situ synthesis of AuNPs in butterfly wings with photonic architectures paves the way for fabricating multiple SERS substrates based on natural materials.