Inverse planning optimization with lead block effectively suppresses dose to the mandible in high-dose-rate brachytherapy for tongue cancer.

Purpose: In this study, we developed in-house software to evaluate the effect of the lead block (LB)-inserted spacer on the mandibular dose in interstitial brachytherapy (ISBT) for tongue cancer. In addition, an inverse planning algorithm for LB attenuation was developed, and its performance in mandibular dose reduction was evaluated.

Methods: Treatment plans of 30 patients with tongue cancer treated with ISBT were evaluated.

Radiation-induced undifferentiated spindle cell sarcoma following high-dose-rate interstitial brachytherapy for tongue squamous cell carcinoma.

High-dose-rate interstitial brachytherapy (HDR-ISBT) has recently come to be considered one of the most effective treatments for oral cancer. On the other hand, it is important to note that radiation therapy has some side effects. Especially, radiation-induced malignancy is probably the most serious complication affecting long-term survivors.

Dosimetric comparison between volumetric modulated arc therapy planning techniques for prostate cancer in the presence of intrafractional organ deformation.

The purpose of this study was to compare single-arc (SA) and double-arc (DA) treatment plans, which are planning techniques often used in prostate cancer volumetric modulated arc therapy (VMAT), in the presence of intrafractional deformation (ID) to determine which technique is superior in terms of target dose coverage and sparing of the organs at risk (OARs). SA and DA plans were created for 27 patients with localized prostate cancer. ID was introduced to the clinical target volume (CTV), rectum and bladder to obtain blurred dose distributions using an in-house software.

Assessment of Daily Replanning and Geometrical Variation of High-dose-rate Brachytherapy for the Prostate.

Background: The present study aimed to estimate geometric changes in applicators and prostate over 3 days in patients with high-dose-rate brachytherapy (HDR-BT) and to assess the need for daily replanning.

Patients And Methods: This study retrospectively investigated 18 patients who underwent HDR-BT as monotherapy from February 2016 to October 2018.

Results: Without replanning, the planning target volume coverage significantly worsened on day 2 (p<0.

Three-dimensional dose prediction and validation with the radiobiological gamma index based on a relative seriality model for head-and-neck IMRT.

This study proposes a quality assurance (QA) method incorporating radiobiological factors based on the QUANTEC-determined tumor control probability and the normal tissue complication probability (NTCP) of head-and-neck intensity-modulated radiation therapy (HN-IMRT). Per-beam measurements were conducted for 20 cases using a 2D detector array. Three-dimensional predicted dose distributions within targets and organs at risk were reconstructed based on the per-beam QA results derived from differences between planned and measured doses.

Curtailing patient-specific IMRT QA procedures from 2D dose error distribution.

A patient-specific quality assurance (QA) test is conducted to verify the accuracy of dose delivery. It generally consists of three verification processes: the absolute point dose difference, the planar dose differences at each gantry angle, and the planar dose differences by 3D composite irradiation. However, this imposes a substantial workload on medical physicists.

High-Dose-Rate Brachytherapy as Monotherapy for Intermediate- and High-Risk Prostate Cancer: Clinical Results for a Median 8-Year Follow-Up.

Purpose: To present mature results of high-dose-rate brachytherapy (HDR-BT) as monotherapy for intermediate- and high-risk prostate cancer.

Methods And Materials: From 1995 through 2012, 190 patients, 79 with intermediate-risk and 111 with high-risk prostate cancer, were treated with HDR-BT alone using 48 Gy/8 fractions, 54 Gy/9 fractions, or 45.5 Gy/7 fractions over 4 to 5 days.

Influence of Rictor and Raptor Expression of mTOR Signaling on Long-Term Outcomes of Patients with Hepatocellular Carcinoma.

Background: Aberrant signaling mediated by the mammalian target of rapamycin (mTOR) occurs at high frequency in hepatocellular carcinoma (HCC), indicating that mTOR is a candidate for targeted therapy. mTOR forms two complexes called mTORC1 (mTOR complexed with raptor) and mTORC2 (mTOR complexed with rictor). There are minor studies of the expression kinetics of mTORC1 and mTORC2 in HCC.

Impairment of activation of hepatocyte growth factor precursor into its mature form in rats with liver cirrhosis.

Background: Hepatocyte growth factor (HGF) has a crucial role in liver regeneration following injury. The conversion of an inactive precursor form of HGF (proHGF) into a biologically active form (mature HGF) is essential, as HGF is involved in the recovery of liver damage. Liver regeneration is markedly poor in patients with liver cirrhosis after resection.

Exogenously administered HGF activator augments liver regeneration through the production of biologically active HGF.

Hepatocyte growth factor (HGF) plays a crucial role in the recovery of injured liver. Liver functions are mostly impaired in patients with liver diseases including cirrhosis. However, a significant amount of inactive HGF precursor (proHGF) is reported in the plasma of these patients.