Radiotherapy for subependymal giant cell astrocytoma: time to challenge a historical ban? A case report and review of the literature.

Background: Subependymal giant cell astrocytoma is a benign brain tumor that occurs in patients with tuberous sclerosis complex. Surgical removal is the traditional treatment, and expert opinion is strongly against the use of radiotherapy. Recently, success has been reported with the mTor inhibitor everolimus in reducing tumor volume, but regrowth has been observed after dose reduction or cessation.

Low-Dose Bevacizumab for the Treatment of Focal Radiation Necrosis of the Brain (fRNB): A Single-Center Case Series.

Focal radiation necrosis of the brain (fRNB) is a late adverse event that can occur following the treatment of benign or malignant brain lesions with stereotactic radiation therapy (SRT) or stereotactic radiosurgery (SRS). Recent studies have shown that the incidence of fRNB is higher in cancer patients who received immune checkpoint inhibitors. The use of bevacizumab (BEV), a monoclonal antibody that targets the vascular endothelial growth factor (VEGF), is an effective treatment for fRNB when given at a dose of 5-7.

Auranofin radiosensitizes tumor cells through targeting thioredoxin reductase and resulting overproduction of reactive oxygen species.

Auranofin (AF) is an anti-arthritic drug considered for combined chemotherapy due to its ability to impair the redox homeostasis in tumor cells. In this study, we asked whether AF may in addition radiosensitize tumor cells by targeting thioredoxin reductase (TrxR), a critical enzyme in the antioxidant defense system operating through the reductive protein thioredoxin. Our principal findings in murine 4T1 and EMT6 tumor cells are that AF at 3-10 μM is a potent radiosensitizer in vitro, and that at least two mechanisms are involved in TrxR-mediated radiosensitization.

Myeloid-derived suppressor cells reveal radioprotective properties through arginase-induced l-arginine depletion.

Background And Purpose: High arginase-1 (Arg) expression by myeloid-derived suppressor cells (MDSC) is known to inhibit antitumor T-cell responses through depletion of l-arginine. We have previously shown that nitric oxide (NO), an immune mediator produced from l-arginine, is a potent radiosensitizer of hypoxic tumor cells. This study therefore examines whether Arg(+) overexpressing MDSC may confer radioresistance through depleting the substrate for NO synthesis.

A European Organisation for Research and Treatment of Cancer phase III trial of adjuvant whole-brain radiotherapy versus observation in patients with one to three brain metastases from solid tumors after surgical resection or radiosurgery: quality-of-life results.

Purpose: This phase III trial compared adjuvant whole-brain radiotherapy (WBRT) with observation after either surgery or radiosurgery of a limited number of brain metastases in patients with stable solid tumors. Here, we report the health-related quality-of-life (HRQOL) results.

Patients And Methods: HRQOL was a secondary end point in the trial.

Hepatocytes determine the hypoxic microenvironment and radiosensitivity of colorectal cancer cells through production of nitric oxide that targets mitochondrial respiration.

Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases.

Methods And Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription-polymerase chain reaction, Western blotting, and NO/nitrite production.

Adjuvant whole-brain radiotherapy versus observation after radiosurgery or surgical resection of one to three cerebral metastases: results of the EORTC 22952-26001 study.

Purpose: This European Organisation for Research and Treatment of Cancer phase III trial assesses whether adjuvant whole-brain radiotherapy (WBRT) increases the duration of functional independence after surgery or radiosurgery of brain metastases.

Patients And Methods: Patients with one to three brain metastases of solid tumors (small-cell lung cancer excluded) with stable systemic disease or asymptomatic primary tumors and WHO performance status (PS) of 0 to 2 were treated with complete surgery or radiosurgery and randomly assigned to adjuvant WBRT (30 Gy in 10 fractions) or observation (OBS). The primary end point was time to WHO PS deterioration to more than 2.

Activated macrophages as a novel determinant of tumor cell radioresponse: the role of nitric oxide-mediated inhibition of cellular respiration and oxygen sparing.

Purpose: Nitric oxide (NO), synthesized by the inducible nitric oxide synthase (iNOS), is known to inhibit metabolic oxygen consumption because of interference with mitochondrial respiratory activity. This study examined whether activation of iNOS (a) directly in tumor cells or (b) in bystander macrophages may improve radioresponse through sparing of oxygen.

Methods And Materials: EMT-6 tumor cells and RAW 264.

IFN-gamma+ CD8+ T lymphocytes: possible link between immune and radiation responses in tumor-relevant hypoxia.

Activated T lymphocytes are known to kill tumor cells by triggering cytolytic mechanisms; however, their ability to enhance radiation responses remains unclear. This study examined the radiosensitizing potential of mouse CD8+ T cells, obtained by T-cell-tailored expansion and immunomagnetic purification. Activated CD8+ T cells displayed an interferon (IFN)-gamma+ phenotype and enhanced by 1.

The radiosensitizing effect of immunoadjuvant OM-174 requires cooperation between immune and tumor cells through interferon-gamma and inducible nitric oxide synthase.

Purpose: To explore whether antitumor immunoadjuvant OM-174 can stimulate immune cells to produce interferon-gamma (IFN-gamma) and thereby radiosensitize tumor cells.

Methods And Materials: Splenocytes from BALB/c mice were stimulated by OM-174 at plasma-achievable concentrations (0.03-3 mug/mL), and afterward analyzed for the expression and secretion of IFN-gamma by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.

Macrophages enhance the radiosensitizing activity of lipid A: a novel role for immune cells in tumor cell radioresponse.

Purpose: This study examines whether activated macrophages may radiosensitize tumor cells through the release of proinflammatory mediators.

Methods And Materials: RAW 264.7 macrophages were activated by lipid A, and the conditioned medium (CM) was analyzed for the secretion of cytokines and the production of nitric oxide (NO) through inducible nitric oxide synthase (iNOS).

Intraspinal epidermoid cyst successfully treated with radiotherapy: case report.

Objective And Importance: Epidermoid cysts are benign lesions that account for 0.7% of all intraspinal tumors. Standard treatment is complete resection.

Lipid a radiosensitizes hypoxic EMT-6 tumor cells: role of the NF-kappaB signaling pathway.

Purpose: Lipid A has shown promising immunostimulatory effects in both experimental tumor models and advanced stage cancer patients. This study examines whether lipid A may directly modulate the radioresponse of tumor cells by activating inducible nitric oxide synthase (iNOS) or cyclooxygenase-2 (COX-2) through nuclear factor-kappaB (NF-kappaB) signaling.

Methods And Materials: Hypoxic EMT-6 tumor cells were exposed to lipid A and analyzed for the level of COX-2 and iNOS by Western blotting and enzymatic assays.

Clinical use of stereoscopic X-ray positioning of patients treated with conformal radiotherapy for prostate cancer.

Purpose: To evaluate accuracy and time requirements of a stereoscopic X-ray-based positioning system in patients receiving conformal radiotherapy to the prostate.

Methods And Materials: Setup errors of the isocenter with regard to the bony pelvis were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) and infrared marker (IR) based positioning in each of 261 treatments. In each direction, the random error represents the standard deviation and the systematic error the absolute value of the mean position.

Initial clinical experience with infrared-reflecting skin markers in the positioning of patients treated by conformal radiotherapy for prostate cancer.

Purpose: To evaluate an infrared (IR) marker-based positioning system in patients receiving conformal radiotherapy for prostate cancer.

Methods And Materials: During 553 treatments, the ability of the IR system to automatically position the isocenter was recorded. Setup errors were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) in 184 treatments.