Stereotactic body radiation therapy for multiple lung cancers in a patient with six primary cancers: a case report.

Background: Surgery is the standard care for patients with early-stage lung cancer, and stereotactic body radiation therapy is an option for those who are medically inoperable or refuse surgery. Medical developments in diagnostic and therapeutic strategies would prolong prognosis of patients with cancer. The number of patients with multiple cancers has also increased.

Overcoming Problems Caused by Offset Distance of Multiple Targets in Single-isocenter Volumetric Modulated Arc Therapy Planning for Stereotactic Radiosurgery.

Purpose: The purpose of the study is to investigate the impact of large target offset distances on the dose distribution and gamma passing rate (GPR) in single-isocenter multiple-target stereotactic radiosurgery (SIMT SRS) using volumetric modulated arc therapy (VMAT) with a flattening filter-free (FFF) beam from a linear accelerator.

Methods: Two targets with a diameter of 1 cm were offset by "±2, ±4, and ±6 cm from the isocenter in a verification phantom for head SRS (20 Gy/fr). The VMAT plans were created using collimator angles that ensured the two targets did not share a leaf pair from the multi-leaf collimator.

Clinical course of longer than five years after definitive radiotherapy for nasopharyngeal carcinoma.

Background: This study aimed to reveal the long-term outcomes and late toxicities (> 5 years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).

Methods: Data from 43 patients (median age, 55 years; range, 17-72 years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5 years after IMRT.

Dose difference between anisotropic analytical algorithm (AAA) and Acuros XB (AXB) caused by target's air content for volumetric modulated arc therapy of head and neck cancer.

Background: We clarified the dose difference between the anisotropic analytical algorithm (AAA) and Acuros XB (AXB) with increasing target's air content using a virtual phantom and clinical cases.

Materials And Methods: Whole neck volumetric modulated arc therapy (VMAT) plan was transferred into a virtual phantom with a cylindrical air structure at the center. The diameter of the air structure was changed from 0 to 6 cm, and the target's air content defined as the air/planning target volume (PTV) in percent (air/PTV) was varied.

Evaluation of In-room Volumetric Imaging Doses for Image-guided Radiotherapy: A Multi-institutional Study.

Aims: We investigated imaging dose and noise under clinical scan conditions at multiple institutions using a simple and unified method, and demonstrated the need for diagnostic reference levels in image-guided radiotherapy (IGRT).

Materials And Methods: Nine cone-beam and helical computed tomography (CT) scanners (Varian, Elekta, Accuray Inc., and BrainLAB) from seven institutions were investigated in this study.

Long-Term Follow-up of a Randomized Controlled Trial on Accelerated Radiation Therapy Versus Standard Fractionated Radiation Therapy for Early Glottic Cancer (JCOG0701A3).

Purpose: We previously reported the primary results of JCOG0701, a randomized, multicenter, phase 3, noninferiority trial comparing accelerated fractionation (Ax) to standard fractionation (SF) for early glottic cancer. In the primary results, although the similar efficacy of 3-year progression-free survival and toxicity of Ax compared with SF was observed, the noninferiority of Ax was not confirmed statistically. To evaluate the long-term follow-up results of JCOG0701, we conducted JCOG0701A3 as an ancillary study of JCOG0701.

Comparison of the Characteristics of Two Types of Parallel-plate Ionization Chamber Under Small-field Electron Irradiation.

Background/aim: This study compared two types of parallel-plate ionization chamber to clarify the pitfalls of dosimetry in electron radiation therapy.

Materials And Methods: The ion recombination correction factor and polarity effect correction factor, sensitivity, and percentage depth doses (PDDs) of PPC05 and PPC40 parallel-plate ionization chambers were compared in a small-field electron beam. The output ratios were measured for 4-20 MeV electron beams with field sizes of 10 cm × 10 cm, 6 cm × 6 cm, and 4 cm × 4 cm.

Volumetric Modulated Arc Therapy Planning for Craniospinal Irradiation With a New O-ring Linac.

This study aims to determine the feasibility of using a new O-ring linear accelerator (Halcyon, Varian Medical Systems, CA, USA) to perform treatment planning using volumetric modulated arc therapy (VMAT) for craniospinal irradiation (CSI). A 20-year-old male patient with leukemia was selected. The planning target volume (PTV) was contoured to include the entire contents of the brain and spinal canal.

Impact of rectal gas on the planning target volume margin for pelvic bone and prostate matching in prostate cancer patients receiving volumetric-modulated arc therapy.

We performed daily cone-beam computed tomography (CBCT) to determine the impact of rectal gas on the movements of prostate and seminal vesicles (SVs). We aimed to determine the relationship between planning target volume (PTV) margins and rectal gas. In 30 treatments of 15 prostate cancer patients, excessive rectal gas was removed and CBCT images were analyzed.

The development and characterization of an all-purpose bolus for radiotherapy.

The purpose of this study was to develop a new bolus (HM bolus), with tissue equivalence, transparency, reusability, and free shaping at approximately 40 °C for excellent adhesion, and to evaluate the feasibility of clinically using this bolus as an ideal bolus.We summarized the advantages and disadvantages of existing boluses. To evaluate dose characteristics, a vinyl gel sheet bolus (Gel bolus) and HM bolus placed on a water-equivalent phantom were used to obtain the percentage depth dose (PDD) of electron (6 MeV, 9 MeV) and photon (4 MV, 6 MV) beams.

Plan quality association between dummy run and individual case review in a prospective multi-institutional clinical trial of postoperative cervical cancer patients treated with intensity-modulated radiotherapy: Japan clinical Oncology Group study (JCOG1402).

Background And Purpose: The Japan Clinical Oncology Group (JCOG) 1402 conducted a multicenter clinical trial of postoperative intensity-modulated radiotherapy (IMRT) for high-risk uterine cervical cancer patients. We assess effectiveness of the quality assurance (QA) program in central review through dummy runs (DRs) performed before patient enrollment and post-treatment individual case review (ICR), and clarify the pitfalls in treatment planning.

Material And Methods: The ICRs were conducted using the same QA program as the DR for 214 plans.

Visualization of tumor hypoxia and re-oxygenation after stereotactic body radiation therapy in early peripheral lung cancer: A prospective study.

Background And Purpose: In this study, fluoromisonidazole positron emission tomography (F-MISO PET/CT) was used to evaluate tumor hypoxia and re-oxygenation in patients with lung tumors treated with stereotactic body radiation therapy (SBRT).

Materials And Methods: Patients with T1-2 N0 lung cancer were included in this study. The prescribed dose was 48-52 Gy in four fractions.

Double enhancement effect of a surface dose with tungsten rubber bolus in photon radiotherapy for keloids and superficial tumors.

To clarify the dosimetric characteristics of a real-time variable shape rubber-containing tungsten (STR) bolus in a clinical plan and investigate the efficacy of the STR bolus in photon radiotherapy for keloids and other superficial tumors. A 5 mm gel bolus or 1 mm STR bolus was placed on a solid water phantom. Tangential irradiation was performed using a TomoTherapy Radixact-X9 and 6 MV X-ray flattening-filter-free beam, and the surface dose was measured with radiochromic film.

Difference in failure patterns after stereotactic body radiotherapy for lung cancer according to clinical T stage based on 4D computed tomography.

Purpose: Stereotactic body radiotherapy (SBRT) is a treatment option for early-stage lung cancer. We aimed to examine the differences in failure patterns after SBRT according to the clinical T stage.

Methods: A total of 120 patients with early-stage lung cancer (T1-3N0M0) who underwent SBRT were analysed.

A phase II study of concurrent chemoradiotherapy with 5-fluorouracil and mitomycin-C for squamous cell carcinoma of the anal canal (the JROSG 10-2 trial).

This study assessed the efficacy of chemoradiotherapy for squamous cell carcinoma of the anal canal (SCCAC). Patients with T1-4N0-3M0 SCCAC received chemoradiotherapy with 5-fluorouracil (5-FU, 800 mg/m2/day, 96-h infusion) and mitomycin-C (MMC, 10 mg/m2 bolus). Patients treated with 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) were administered 36.

New strategy of a lung compensating technique with STR for total body irradiation.

Purpose: To determine the thickness of a soft variable shape tungsten rubber (STR) as a lung compensating filter in total body irradiation.

Methods: A tough water (TW) phantom and tough lung (TL) phantom were used as water and lung-equivalent phantoms. The TW with a thickness of 3 cm simulating the thoracic wall was used (upper layer).

Organs-at-risk dose constraints in head and neck intensity-modulated radiation therapy using a dataset from a multi-institutional clinical trial (JCOG1015A1).

Background: JCOG1015A1 is an ancillary research study to determine the organ-specific dose constraints in head and neck carcinoma treated with intensity-modulated radiation therapy (IMRT) using data from JCOG1015.

Methods: Individual patient data and dose-volume histograms of organs at risk (OAR) were collected from 74 patients with nasopharyngeal carcinoma treated with IMRT who enrolled in JCOG1015. The incidence of late toxicities was evaluated using the cumulative incidence method or prevalence proportion.

Multi-institutional feasibility study of intensity-modulated radiotherapy with chemotherapy for locally advanced non-small cell lung cancer.

Background: This multi-institutional clinical trial evaluated the feasibility of intensity-modulated radiotherapy (IMRT) for patients with locally advanced non-small cell lung cancer (NSCLC).

Methods: The major inclusion criteria were clinical stage III NSCLC, age 20-74 years, and Eastern Cooperative Oncology Group performance status 0-1. Patients were treated with either cisplatin + S-1 (CS; four cycles every 4 weeks) or carboplatin + paclitaxel (CP; administered weekly with thoracic radiotherapy [RT], plus two consolidation cycles) concurrently with IMRT (60 Gy in 30 fractions).

Weekly Cisplatin Plus Radiation for Postoperative Head and Neck Cancer (JCOG1008): A Multicenter, Noninferiority, Phase II/III Randomized Controlled Trial.

Purpose: The standard treatment for postoperative high-risk locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) is chemoradiotherapy with 3-weekly cisplatin (100 mg/m). However, whether chemoradiotherapy with weekly cisplatin (40 mg/m) yields comparable efficacy with 3-weekly cisplatin in postoperative high-risk LA-SCCHN is unknown.

Patients And Methods: In this multi-institutional open-label phase II/III trial, patients with postoperative high-risk LA-SCCHN were randomly assigned to receive either chemoradiotherapy with 3-weekly cisplatin (100 mg/m) or with weekly cisplatin (40 mg/m) to confirm the noninferiority of weekly cisplatin.

Escalated Maximum Dose in the Planning Target Volume Improves Local Control in Stereotactic Body Radiation Therapy for T1-2 Lung Cancer.

Stereotactic body radiotherapy (SBRT) is a treatment option for early-stage lung cancer. The purpose of this study was to investigate the optimal dose distribution and prognostic factors for local control (LC) after SBRT for lung cancer. A total of 104 lung tumors from 100 patients who underwent SBRT using various treatment regimens were analyzed.