Long-term stability of a PTW 34070 large-area parallel ionization chamber in clinical proton scanning beams.

Purpose: In the modeling of beam data for proton therapy planning systems, absolute dose measurements are performed utilizing a Bragg peak chamber (BPC), which is a parallel-plate ionization chamber. The long-term stability of the BPC is crucial for ensuring accurate absolute dose measurement. The study aims to assess the long-term stability of the BPC in clinical proton pencil beam scanning delivery.

Impact of interplay effects on spot scanning proton therapy with motion mitigation techniques for lung cancer: SFUD versus robustly optimized IMPT plans utilizing a four-dimensional dynamic dose simulation tool.

Background: The interaction between breathing motion and scanning beams causes interplay effects in spot-scanning proton therapy for lung cancer, resulting in compromised treatment quality. This study investigated the effects and clinical robustness of two types of spot-scanning proton therapy with motion-mitigation techniques for locally advanced non-small cell lung cancer (NSCLC) using a new simulation tool (4DCT-based dose reconstruction).

Methods: Three-field single-field uniform dose (SFUD) and robustly optimized intensity-modulated proton therapy (IMPT) plans combined with gating and re-scanning techniques were created using a VQA treatment planning system for 15 patients with locally advanced NSCLC (70 GyRBE/35 fractions).

Comparing Efficacy Between Robust and PTV Margin-based Optimizations for Interfractional Anatomical Variations in Prostate Tomotherapy.

Background/aim: Interfractional anatomical variations cause considerable differences between planned and actual radiotherapy doses. This study aimed to investigate the efficacy of robust and planning target volume (PTV) margin-based optimizations for the anatomical variations in helical tomotherapy for prostate cancer.

Patients And Methods: Ten patients underwent treatment-planning kilovolt computed tomography (kVCT) and daily megavolt computed tomography (MVCT).

Impact of delivery time factor on treatment time and plan quality in tomotherapy.

Delivery time factor (DTF) is a new parameter introduced by the RayStation treatment planning system for tomotherapy treatment planning. This study investigated the effects of this factor on various tomotherapy plans. Twenty-five patients with cancer (head and neck, 6; lung, 9; prostate, 10) were enrolled in this study.

Relative Biological Effectiveness Values of Spot-scanning Proton Beam Therapy at Shonan Kamakura General Hospital.

Background/aim: This study aimed to confirm the relative biological effectiveness (RBE) values of the proton beam therapy (PBT) system installed in Shonan Kamakura General Hospital.

Materials And Methods: Clonogenic cell-survival assays were performed with a human salivary gland (HSG) cell line, a human tongue squamous-cell carcinoma cell line (SAS), and a human osteosarcoma cell line (MG-63). Cells were irradiated with proton beams and X-rays with different doses (1.

Effectiveness of robust optimization against geometric uncertainties in TomoHelical planning for prostate cancer.

Background: Geometrical uncertainties in patients can severely affect the quality of radiotherapy.

Purpose: We evaluated the dosimetric efficacy of robust optimization for helical intensity-modulated radiotherapy (IMRT) planning in the presence of patient setup uncertainty and anatomical changes.

Methods: Two helical IMRT plans for 10 patients with localized prostate cancer were created using either minimax robust optimization (robust plan) or a conventional planning target volume (PTV) margin approach (PTV plan).

Cell penetrating peptides improve tumor delivery of cargos through neuropilin-1-dependent extravasation.

Cell-penetrating peptides (CPPs), also referred to as protein transduction domains (PTDs), can mediate the cellular uptake of a wide range of macromolecules including peptides, proteins, oligonucleotides, and nanoparticles, and thus have received considerable attention as a promising method for drug delivery in vivo. Here, we report that CPP/PTDs facilitate the extravasation of fused proteins by binding to neuropilin-1 (NRP1), a vascular endothelial growth factor (VEGF) co-receptor expressed on the surface of endothelial and some tumor cells. In this study, we examined the capacity of the amphipathic and cationic CPP/PTDs, PTD-3 and TAT-PTD, respectively, to bind cells in vitro and accumulate in xenograft tumors in vivo.

A fluorescent protein scaffold for presenting structurally constrained peptides provides an effective screening system to identify high affinity target-binding peptides.

Peptides that have high affinity for target molecules on the surface of cancer cells are crucial for the development of targeted cancer therapies. However, unstructured peptides often fail to bind their target molecules with high affinity. To efficiently identify high-affinity target-binding peptides, we have constructed a fluorescent protein scaffold, designated gFPS, in which structurally constrained peptides are integrated at residues K131-L137 of superfolder green fluorescent protein.

Preparation of silica coatings heavily doped with spiropyran using perhydropolysilazane as the silica source and their photochromic properties.

Silica coatings doped with spiropyran (SP) were prepared using xylene solutions of perhydropolysilazane (PHPS) as the silica source, where the SP-doped PHPS coatings were prepared by spin-coating and the PHPS-to-silica conversion was achieved by exposing the coatings to the vapor from aqueous ammonia at room temperature. The films could be heavily doped with SP at SP/(SP + PHPS) mass ratio as high as 0.2.