This study was undertaken to investigate the biological effect of monoenergetic neutrons on human lymphocyte DNA and chromosomes. Monoenergetic neutrons of 2.3, 1.0, 0.79, 0.57, 0.37 and 0.186 MeV were generated, and 252Cf neutrons and 60Co gamma-rays were also used for comparison. Biological effect was evaluated two ways. The RBE values with the comet assay were estimated as 6.3 and 5.4 at 0.3...

In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly...

In the previous review, the physical aspect of heavy particles, with a focus on the carbon beam was introduced. Particle beam therapy has many potential advantages for cancer treatment without increasing severe side effects in normal tissue, these kinds of radiation have different biologic characteristics and have advantages over using conventional photon beam radiation during treatment. The re...

Background: Radiation-induced lung injury (RILI) is a serious concern in carbon-ion radiation therapy (CIRT) for thoracic malignancies. To estimate the induction of RILI after CIRT, translation of evidence in X-ray radiation therapy to CIRT is of great importance. However, the relative biological effectiveness (RBE) of carbon-ion beams in normal lung tissues is not fully elucidated, making the ...

To determine the radiobiological mechanisms underlying relative biological effectiveness (RBE) and the repair efficiencies of DNA double-strand breaks (DSBs) as a function of linear energy transfer (LET), we exposed cells of the chicken B-lymphocyte cell line DT40 and its DSB repair pathway-deficient derivatives to heavy-ion beams produced at the Heavy-Ion Medical Accelerator in Chiba (HIMAC) a...

The aim of this report is to present the preliminary results of a Phase II study of high-dose (74 Gy RBE) proton beam therapy (PBT) with concurrent chemotherapy for unresectable locally advanced non-small-cell lung cancer (NSCLC). Patients were treated with PBT and chemotherapy with monthly cisplatin (on Day 1) and vinorelbine (on Days 1 and 8). The treatment doses were 74 Gy RBE for the primar...

Intraoperative radiotherapy differs from conventional, fractionated radiotherapy in several aspects that may influence its biological effect. The radiation quality influences the relative biologic effectiveness (RBE), and the role of the five R's of radiotherapy (reassortment, repair, reoxygenation, repopulation, radiosensitivity) is different. Furthermore, putative special biological effects a...

When compared to photon beams, particle beams have distinct spatial distributions on the energy depositions in both the macroscopic and microscopic volumes. In a macroscopic volume, the absorbed dose distribution shows a rapid increase near the particle range, that is, Bragg peak, as particle penetrates deep inside the tissue. In a microscopic volume, individual particle deposits its energy alo...

The rate-based execution (RBE) task model was developed to support the real-time execution of eventdriven tasks in which no a priori characterization of the actual arrival rates of events is known; only the expected arrival rates of events is known. The RBE model is well suited for systems that must execute in environments that are not well-behaved (i.e., when the arrival rate of events is neit...

The analysis of chromosome aberration in peripheral blood lymphocytes is a sensitive and frequently applied method to assess the individual dose following accidental, occupational or medical exposure to ionizing radiation. According to the standard protocol [1], lymphocytes are cultured in vitro for 48 h. Then, metaphases are harvested and chromosome aberrations are scored with the expectation ...