Predictors of Nodal and Metastatic Failure in Early Stage Non-small-cell Lung Cancer After Stereotactic Body Radiation Therapy.

Introduction/background: Many patients with early stage non-small-cell lung cancer (ES-NSCLC) undergoing stereotactic body radiation therapy (SBRT) develop metastases, which is associated with poor outcomes. We sought to identify factors predictive of metastases after lung SBRT and created a risk stratification tool.

Materials And Methods: We included 363 patients with ES-NSCLC who received SBRT; the median follow-up was 5.

Histology, Tumor Volume, and Radiation Dose Predict Outcomes in NSCLC Patients After Stereotactic Ablative Radiotherapy.

Introduction: It remains unclear if histology should be independently considered when choosing stereotactic ablative body radiotherapy dose prescriptions for NSCLC.

Methods: The study population included 508 patients with 561 lesions between 2000 and 2016, of which 442 patients with 482 lesions had complete dosimetric information. Eligible patients had histologically or clinically diagnosed early-stage NSCLC and were treated with 3 to 5 fractions.

Dosimetric impact of gastrointestinal air column in radiation treatment of pancreatic cancer.

Objective: Dosimetric evaluation of air column in gastrointestinal (GI) structures in intensity modulated radiation therapy (IMRT) of pancreatic cancer.

Methods: Nine sequential patients were retrospectively chosen for dosimetric analysis of air column in the GI apparatus in pancreatic cancer using cone beam CT (CBCT). The four-dimensional CT (4DCT) was used for target and organs at risk (OARs) and non-coplanar IMRT was used for treatment.

DMAPT inhibits NF-κB activity and increases sensitivity of prostate cancer cells to X-rays in vitro and in tumor xenografts in vivo.

Constitutive activation of the pro-survival transcription factor NF-κB has been associated with resistance to both chemotherapy and radiation therapy in many human cancers, including prostate cancer. Our lab and others have demonstrated that the natural product parthenolide can inhibit NF-κB activity and sensitize PC-3 prostate cancers cells to X-rays in vitro; however, parthenolide has poor bioavailability in vivo and therefore has little clinical utility in this regard. We show here that treatment of PC-3 and DU145 human prostate cancer cells with dimethylaminoparthenolide (DMAPT), a parthenolide derivative with increased bioavailability, inhibits constitutive and radiation-induced NF-κB binding activity and slows prostate cancer cell growth.

Reirradiation of Recurrent and Second Primary Head and Neck Cancer With Proton Therapy.

Purpose: To report the clinical outcomes of head and neck reirradiation with proton therapy.

Methods And Materials: From 2004 to 2014, 61 patients received curative-intent proton reirradiation, primarily for disease involving skull base structures, at a median of 23 months from the most recent previous course of radiation. Most had squamous cell (52.

Role of belly board device in the age of intensity modulated radiotherapy for pelvic irradiation.

Small bowel dose often represents a limiting factor for radiation treatment of pelvic malignancies. To reduce small bowel toxicity, a belly board device (BBD) with a prone position is often recommended. Intensity modulated radiotherapy (IMRT) could reduce dose to small bowel based on the desired dose-volume constraints.

Quantifying Proton Fields for Midline Brain Tumors: A Benefit/Cost Analysis of Planning Objectives.

Purpose: We sought to quantify the optimum number of beams by using a midline sagittal arrangement for midline brain tumors when considering the competing demands of a high degree of target conformation and maximizing reduction of nontarget brain dose. The volume of nontarget brain tissue receiving between 5 and 20 Gy (V5-V20) was selected to measure "low-dose bath" to normal brain.

Materials And Methods: An exploratory model was developed with 6 midline brain targets created by using spheres of 1-, 3-, and 5-cm diameters located in superficial and deep locations.

Does Graded Prognostic Assessment outperform Recursive Partitioning Analysis in patients with moderate prognosis brain metastases?

Aim: To compare the clinical utility of the Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) in predicting outcomes for moderate prognosis patients with brain metastases.

Methods & Materials: We reviewed 101 whole brain radiotherapy cases. RPA and GPA were calculated.

Proton Radiotherapy for Midline Central Nervous System Lesions: A Class Solution.

Objective: Midline and central lesions of the brain requiring conventional radiotherapy (RT) present complex difficulties in dose avoidance to organs at risk (OAR). In either definitive or adjuvant settings, proper RT coverage of these lesions involves unnecessary treatment of large volumes of normal brain. We propose a class solution for these lesions using proton radiotherapy (PrT).

Effect of Scanning Beam for Superficial Dose in Proton Therapy.

Proton beam delivery technology is under development to minimize the scanning spot size for uniform dose to target, but it is also known that the superficial dose could be as high as the dose at Bragg peak for narrow and small proton beams. The objective of this study is to explore the characteristics of dose distribution at shallow depths using Monte Carlo simulation with the FLUKA code for uniform scanning (US) and discrete spot scanning (DSS) proton beams. The results show that the superficial dose for DSS is relatively high compared to US.

Whole brain radiotherapy for poor prognosis patients with brain metastases: predictably poor results.

Background: Patients with brain metastases from solid tumors can be subdivided by characteristics into separate prognostic groups, such as the Radiation Therapy Oncology Group's Recursive Partitioning Analysis (RPA) or the Graded Prognostic Assessment (GPA). At our institution, patients falling into the poorest prognostic groups are often treated with whole brain radiotherapy (WBRT).

Objective: To determine if observed survival of poor prognosis patients treated with WBRT for brain metastases at our institution matches the survival predicted by RPA and GPA prognostic indices.

Inhibition of NF-κB and DNA double-strand break repair by DMAPT sensitizes non-small-cell lung cancers to X-rays.

We investigated the efficacy and mechanism of dimethylaminoparthenolide (DMAPT), an NF-κB inhibitor, to sensitize human lung cancer cells to X-ray killing in vitro and in vivo. We tested whether DMAPT increased the effectiveness of single and fractionated X-ray treatment through inhibition of NF-κB and/or DNA double-strand break (DSB) repair. Treatment with DMAPT decreased plating efficiency, inhibited constitutive and radiation-induced NF-κB binding activity, and enhanced radiation-induced cell killing by dose modification factors of 1.