Outcomes of Preoperative Versus Postoperative Radiation for Heterotopic Ossification Prevention in Children With Neuromuscular Hip Dysplasia Undergoing Proximal Femoral Resection.

BACKGROUND: Few studies exist to inform the extrapolated practice of irradiating children for heterotopic ossification (HO) prevention. We report the incidence of HO formation following prophylactic preoperative compared with postoperative radiation therapy (RT) in children with neuromuscular hip dysplasia (NHD) following proximal femoral resection (PFR). METHODS: A retrospective, 2-institution chart review was performed. Eligibility was limited to patients with at least 1 year of follow-up. Evaluation included radiographic HO grading by a combined severity scale, assessment of synchronous symptoms of pain or decreased range of motion, and stratification by preoperative versus postoperative reception of RT. A control cohort included 4 nonirradiated hips with NHD after PFR. RESULTS: Twenty-five hips in 20 children met eligibility criteria. Eleven hips were irradiated preoperatively and 14 postoperatively. Radiographic evidence of post-RT development of radiographic evidence of heterotopic ossification (rHO) was found in all 25 hips and earlier in patients irradiated preoperatively (median time to rHO was 4.0 vs. 15.7 mo, P=0.03, 95% confidence interval, 0.24-21.5). There was no statistically significant difference in the development of symptomatic HO (P=0.62) between the preoperative (45.5%) and postoperative (35.7%) groups, nor in HO grade (P=0.34). Seven (28%) of the 25 hips (5 preoperative and 2 postoperative) had documentation of rHO-free intervals after surgery, with an average duration of 5.6 months, while the remaining presented with rHO at first follow-up visit. All eligible control hips (100%) developed rHO and symptomatic heterotopic ossification. CONCLUSIONS: Perioperative RT did not prevent the formation of HO in any child with NHD after PFR. Extrapolation of evidence of the efficacy of RT for HO prevention in ambulatory adults after traumatic hip injury to a population of children with central nervous system injury and NHD may be premature. Additional studies are needed to clarify optimal prevention of HO in this population. LEVEL OF EVIDENCE: Level III-therapeutic retrospective comparative study.

Patient-reported quality-of-life outcomes after de-escalated chemoradiation for human papillomavirus-positive oropharyngeal carcinoma: Findings from a phase 2 trial.

BACKGROUND: The current study represents a subset analysis of quality-of-life (QOL) outcomes among patients treated on a phase 2 trial of de-escalated chemoradiation for human papillomavirus (HPV)-associated oropharyngeal cancer. METHODS: Eligibility included newly diagnosed, (American Joint Committee on Cancer, 7th edition) stage III or IV oropharyngeal squamous cell carcinoma, p16 positivity, age ≥ 18 years, and a Zubrod performance status of 0 to 1. Treatment was induction paclitaxel at a dose of 175 mg/m2 and carboplatin at an area under the curve of 6 for 2 cycles followed by response-adapted, dose-reduced radiation of 54 Gy or 60 Gy with weekly concurrent paclitaxel at a dose of 30 mg/m2 . The University of Washington Quality of Life (UW-QOL) and the Functional Assessment of Cancer Therapy-Head and Neck questionnaires were used to assess patient-reported QOL as a secondary endpoint. RESULTS: A total of 45 patients were registered, 40 of whom completed QOL surveys and were evaluable. Nadirs for overall UW-QOL and Functional Assessment of Cancer Therapy-Head and Neck scores were reached at 4 weeks after treatment but returned to baseline at 3 months. Nearly all functional indices returned to baseline levels by 6 to 9 months. The mean overall UW-QOL score was 71.6 at baseline compared with 70.8, 73.0, 83.3, and 81.1, respectively, at 3 months, 6 months, 1 year, and 2 years after therapy. The percentage of patients rating their overall QOL as "very good" or "outstanding" at 6 months, 1 year, and 2 years using the UW-QOL was 50%, 77%, and 84%, respectively. CONCLUSIONS: This de-escalation regimen achieved QOL outcomes that were favorable compared with historical controls. These results serve as powerful evidence that ongoing de-escalation efforts lead to tangible gains in function and QOL. Cancer 2018;124:521-9. © 2017 American Cancer Society.

NK Cells Preferentially Target Tumor Cells with a Cancer Stem Cell Phenotype.

Increasing evidence supports the hypothesis that cancer stem cells (CSCs) are resistant to antiproliferative therapies, able to repopulate tumor bulk, and seed metastasis. NK cells are able to target stem cells as shown by their ability to reject allogeneic hematopoietic stem cells but not solid tissue grafts. Using multiple preclinical models, including NK coculture (autologous and allogeneic) with multiple human cancer cell lines and dissociated primary cancer specimens and NK transfer in NSG mice harboring orthotopic pancreatic cancer xenografts, we assessed CSC viability, CSC frequency, expression of death receptor ligands, and tumor burden. We demonstrate that activated NK cells are capable of preferentially killing CSCs identified by multiple CSC markers (CD24(+)/CD44(+), CD133(+), and aldehyde dehydrogenase(bright)) from a wide variety of human cancer cell lines in vitro and dissociated primary cancer specimens ex vivo. We observed comparable effector function of allogeneic and autologous NK cells. We also observed preferential upregulation of NK activation ligands MICA/B, Fas, and DR5 on CSCs. Blocking studies further implicated an NKG2D-dependent mechanism for NK killing of CSCs. Treatment of orthotopic human pancreatic cancer tumor-bearing NSG mice with activated NK cells led to significant reductions in both intratumoral CSCs and tumor burden. Taken together, these data from multiple preclinical models, including a strong reliance on primary human cancer specimens, provide compelling preclinical evidence that activated NK cells preferentially target cancer cells with a CSC phenotype, highlighting the translational potential of NK immunotherapy as part of a combined modality approach for refractory solid malignancies.

Promising response to vemurafenib and cobimetinib treatment for BRAF V600E mutated craniopharyngioma: a case report and literature review.

Craniopharyngiomas are tumors that arise from the remnants of Rathke's pouch along the nasopharynx to the diencephalon. Current standard of care includes maximal surgical resection versus adjuvant radiation if a maximal resection is unfeasible. Pharmacological therapy with MAPK targeted agents is an emerging therapeutic option for tumors with BRAF V600E mutations. We report a 45-year-old male with a strictly third ventricle papillary craniopharyngioma with a BRAF V600E mutation. After initial surgery with subtotal resection, the patient demonstrated durable response to targeted BRAF and MEK inhibitor therapy with vemurafenib and cobimetinib. Our report suggests that targeted therapy may reduce the need for radiation and impact surgical interventions in select cases.

A Novel Predictive Model Utilizing Retinal Microstructural Features for Estimating Survival Outcome in Patients with Glioblastoma.

Glioblastoma is a highly aggressive brain tumor with poor prognosis despite surgery and chemoradiation. The visual sequelae of glioblastoma have not been well characterized. This study assessed visual outcomes in glioblastoma patients through neuro-ophthalmic exams, imaging of the retinal microstructures/microvasculature, and perimetry. A total of 19 patients (9 male, 10 female, average age at diagnosis 69 years) were enrolled. Best-corrected visual acuity ranged from 20/20-20/50. Occipital tumors showed worse visual fields than frontal tumors (mean deviation - 14.9 and - 0.23, respectively, p < 0.0001). Those with overall survival (OS) < 15 months demonstrated thinner retinal nerve fiber layer and ganglion cell complex (p < 0.0001) and enlarged foveal avascular zone starting from 4 months post-diagnosis (p = 0.006). There was no significant difference between eyes ipsilateral and contralateral to radiation fields (average doses were 1370 cGy and 1180 cGy, respectively, p = 0.42). A machine learning algorithm using retinal microstructure and visual fields predicted patients with long (≥ 15 months) progression free and overall survival with 78% accuracy. Glioblastoma patients frequently present with visual field defects despite normal visual acuity. Patients with poor survival duration demonstrated significant retinal thinning and decreased microvascular density. A machine learning algorithm predicted survival; further validation is warranted.

Improved clinical outcomes with multi-modality therapy for sinonasal undifferentiated carcinoma of the head and neck.

OBJECTIVE: To examine outcomes among patients treated for sinonasal undifferentiated carcinoma (SNUC) of the head and neck. STUDY DESIGN: Retrospective review. METHODS: The records of 16 consecutive patients with newly diagnosed, non-metastatic SNUC were analyzed. Initial treatment consisted of: surgery alone (6 patients), surgery with post-operative chemoradiotherapy (4 patients), and primary radiation therapy with concurrent chemotherapy (6 patients). RESULTS: The median survival for patients treated by surgery followed by postoperative chemoradiotherapy was 30 months compared to 7 months and 9 months for patients treated by surgery alone and upfront chemoradiotherapy, respectively (p=0.20). The 2-year locoregional control was 18% for patients treated with upfront chemoradiotherapy, 37% for patients treated with surgery alone, and 78% for patients treated with surgery plus chemoradiotherapy (p=0.49). CONCLUSION: While the potential role of selection bias must be considered, multi-modality therapy using surgery and post-operative chemoradiotherapy yielded the most favorable outcomes for SNUC and should be recommended whenever feasible.

Application of Machine Learning to Metabolomic Profile Characterization in Glioblastoma Patients Undergoing Concurrent Chemoradiation.

We here characterize changes in metabolite patterns in glioblastoma patients undergoing surgery and concurrent chemoradiation using machine learning (ML) algorithms to characterize metabolic changes during different stages of the treatment protocol. We examined 105 plasma specimens (before surgery, 2 days after surgical resection, before starting concurrent chemoradiation, and immediately after chemoradiation) from 36 patients with isocitrate dehydrogenase (IDH) wildtype glioblastoma. Untargeted GC-TOF mass spectrometry-based metabolomics was used given its superiority in identifying and quantitating small metabolites; this yielded 157 structurally identified metabolites. Using Multinomial Logistic Regression (MLR) and GradientBoostingClassifier (GB Classifier), ML models classified specimens based on metabolic changes. The classification performance of these models was evaluated using performance metrics and area under the curve (AUC) scores. Comparing post-radiation to pre-radiation showed increased levels of 15 metabolites: glycine, serine, threonine, oxoproline, 6-deoxyglucose, gluconic acid, glycerol-alpha-phosphate, ethanolamine, propyleneglycol, triethanolamine, xylitol, succinic acid, arachidonic acid, linoleic acid, and fumaric acid. After chemoradiation, a significant decrease was detected in 3-aminopiperidine 2,6-dione. An MLR classification of the treatment phases was performed with 78% accuracy and 75% precision (AUC = 0.89). The alternative GB Classifier algorithm achieved 75% accuracy and 77% precision (AUC = 0.91). Finally, we investigated specific patterns for metabolite changes in highly correlated metabolites. We identified metabolites with characteristic changing patterns between pre-surgery and post-surgery and post-radiation samples. To the best of our knowledge, this is the first study to describe blood metabolic signatures using ML algorithms during different treatment phases in patients with glioblastoma. A larger study is needed to validate the results and the potential application of this algorithm for the characterization of treatment responses.

Fatty acid oxidation fuels glioblastoma radioresistance with CD47-mediated immune evasion.

Glioblastoma multiforme (GBM) remains the top challenge to radiotherapy with only 25% one-year survival after diagnosis. Here, we reveal that co-enhancement of mitochondrial fatty acid oxidation (FAO) enzymes (CPT1A, CPT2 and ACAD9) and immune checkpoint CD47 is dominant in recurrent GBM patients with poor prognosis. A glycolysis-to-FAO metabolic rewiring is associated with CD47 anti-phagocytosis in radioresistant GBM cells and regrown GBM after radiation in syngeneic mice. Inhibition of FAO by CPT1 inhibitor etomoxir or CRISPR-generated CPT1A-/-, CPT2-/-, ACAD9-/- cells demonstrate that FAO-derived acetyl-CoA upregulates CD47 transcription via NF-κB/RelA acetylation. Blocking FAO impairs tumor growth and reduces CD47 anti-phagocytosis. Etomoxir combined with anti-CD47 antibody synergizes radiation control of regrown tumors with boosted macrophage phagocytosis. These results demonstrate that enhanced fat acid metabolism promotes aggressive growth of GBM with CD47-mediated immune evasion. The FAO-CD47 axis may be targeted to improve GBM control by eliminating the radioresistant phagocytosis-proofing tumor cells in GBM radioimmunotherapy.

Durable clinical response to the multidisciplinary management of neurosurgery, radiation and chemoimmunotherapy in a patient with PD-L1/PD-L2/JAK2 (PDJ)-amplified, refractory triple-negative breast cancer.

Patients with refractory metastatic triple-negative breast cancer (mTNBC) and symptomatic brain metastases have poor prognosis and are challenging to treat. The addition of an programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitor (pembrolizumab or atezolizumab) to first line chemotherapy has prolonged survivals in mTNBC patients with PD-L1-positive tumor and/or tumor-infiltrating immune cells. The clinical efficacy of the chemoimmunotherapy combination in patients with refractory mTNBC, especially brain metastasis, is unknown. Co-amplification of PD-L1, PD-L2, and Janus kinase 2 (PD-L1/PD-L2/JAK2) genes (PDJ amplification) is associated with high PD-L1 protein expression and a 65-87% response rate to PD-1/PD-L1 inhibitors in patients with lymphomas. But the utility of PDJ amplification as a biomarker predictive of response to PD-1/PD-L1 inhibitors is unknown for mTNBC patients. Here, we report a 46-year-old woman who had rapid tumor progression in the brain and lung within 3 months after chemotherapy, neurosurgery, and gamma knife stereotactic radiosurgery for brain metastasis. Next-generation sequencing of her brain metastasis specimen revealed 9 copies of PDJ amplification and a tumor mutational burden of 5 mutations per megabase. Although high PDJ mRNA expression levels were detected, PD-L1 protein expression was negative on tumor cells and 10% on tumor-associated immune cells. After the debulking brain tumor resection, she received pembrolizumab monotherapy, whole brain radiation, and then atezolizumab and nab-paclitaxel with good intracranial and extracranial responses for >16 months. To the best of our knowledge, this is the first report that PDJ amplification is associated with durable clinical response to the PD-1/PD-L1 inhibitor-containing, multidisciplinary management in a patient with refractory, PD-L1 protein-negative, PDJ-amplified mTNBC. Further study is warranted to understand the underlying mechanism and validate PDJ amplification as a biomarker for clinical response to PD-1/PD-L1 inhibitor-containing therapy in patients with mTNBC.

Effect and Safety of Radiation Therapy Boost to Extramesorectal Lymph Nodes in Rectal Cancer.

PURPOSE: In rectal cancer, the presence of extramesorectal/lateral pelvic lymph node (LPN) is associated with higher risk of locoregional and distant recurrences. LPNs are not typically resected during a standard total mesorectal excision (TME) procedure, and the optimal management for these patients is controversial. We assessed the safety and efficacy of adding a radiation therapy boost to clinically positive LPN during neoadjuvant chemoradiation therapy for rectal cancer. METHODS AND MATERIALS: We analyzed nonmetastatic, lymph node positive rectal adenocarcinoma patients treated with neoadjuvant chemoradiation therapy followed by TME between May 2011 and February 2018. Patients without LPN involvement received external beam radiation therapy (45 Gy in 25 fractions) to the primary tumor and regional draining lymph node basins followed by a boost (5.4 Gy in 3 fractions) to gross disease. Patients with clinically positive LPN that would not be removed during TME received an additional boost (up to a total dose between 54.0 and 59.4 Gy) to the involved LPNs. We compared locoregional control, overall survival, progression-free survival, and treatment-related toxicity between these 2 groups. RESULTS: Fifty-three patients were included in this analysis with median follow-up of 30.6 months for the LPN- group (n = 41) and 19.9 months for the LPN+ group (n = 12). There was no difference in 3-year overall survival (90.04% vs 83.33%, P = .890) and progression-free survival (80.12% vs 80.21%, P = .529) between the 2 groups. We did not observe any LPN recurrences. There were no differences in rates of acute grade 3+ or chronic toxicities. CONCLUSIONS: Despite the well-documented negative prognostic effect of LPN metastasis, we observed promising outcomes for LPN+ patients treated with an additional radiation boost. Our results suggest that radiation therapy boost to clinically involved, unresected LPN is an effective treatment approach with limited toxicity. Additional studies are needed to optimize treatment strategies for this unique patient subset.

Glioblastoma Multiforme of the Conus Medullaris-Management Strategies and Complications.

Primary spinal glioblastoma multiforme (GBM) of the conus medullaris is a rare and devastating pathologic entity. The presenting symptoms commonly include progressive neurologic deficits in the lower extremities, bowel and bladder dysfunction, and low back pain. Histologically, these tumors have high-grade features similar to their intracranial counterparts. However, recent advancements in the field of molecular oncology have been beginning to elucidate a unique molecular blueprint for these spinal gliomas. Given the lack of standardized treatment strategies, we have presented our institutional experience in treating a small series of patients with conus medullaris GBM and have reviewed the reported data on the relevant molecular markers, management strategies, and complication avoidance for this malignant pathologic entity.

Dual blockage of STAT3 and ERK1/2 eliminates radioresistant GBM cells.

Radiotherapy (RT) is the major modality for control of glioblastoma multiforme (GBM), the most aggressive brain tumor in adults with poor prognosis and low patient survival rate. To improve the RT efficacy on GBM, the mechanism causing tumor adaptive radioresistance which leads to the failure of tumor control and lethal progression needs to be further elucidated. Here, we conducted a comparative analysis of RT-treated recurrent tumors versus primary counterparts in GBM patients, RT-treated orthotopic GBM tumors xenografts versus untreated tumors and radioresistant GBM cells versus wild type cells. The results reveal that activation of STAT3, a well-defined redox-sensitive transcriptional factor, is causally linked with GBM adaptive radioresistance. Database analysis also agrees with the worse prognosis in GBM patients due to the STAT3 expression-associated low RT responsiveness. However, although the radioresistant GBM cells can be resensitized by inhibition of STAT3, a fraction of radioresistant cells can still survive the RT combined with STAT3 inhibition or CRISPR/Cas9-mediated STAT3 knockout. A complementally enhanced activation of ERK1/2 by STAT3 inhibition is identified responsible for the survival of the remaining resistant tumor cells. Dual inhibition of ERK1/2 and STAT3 remarkably eliminates resistant GBM cells and inhibits tumor regrowth. These findings demonstrate a previously unknown feature ofSTAT3-mediated ERK1/2 regulation and an effective combination of two targets in resensitizing GBM to RT.

Label-free fluorescence lifetime spectroscopy detects radiation-induced necrotic changes in live brain in real-time.

Current clinical imaging modalities do not reliably identify brain tissue regions with necrosis following radiotherapy. This creates challenges for stereotaxic biopsies and surgical-decision making. Time-resolved fluorescence spectroscopy (TRFS) provides a means to rapidly identify necrotic tissue by its distinct autofluorescence signature resulting from tissue breakdown and altered metabolic profiles in regions with radiation damage. Studies conducted in a live animal model of radiation necrosis demonstrated that necrotic tissue is characterized by respective increases of 27% and 108% in average lifetime and redox ratio, when compared with healthy tissue. Moreover, radiation-damaged tissue not visible by MRI but confirmed by histopathology, was detected by TRFS. Current results demonstrate the ability of TRFS to identify radiation-damaged brain tissue in real-time and indicates its potential to assist with surgical guidance and MRI-guided biopsy procedures.

Converting Treatment Plans From Helical Tomotherapy to L-Shape Linac: Clinical Workflow and Dosimetric Evaluation.

This work evaluated a commercial fallback planning workflow designed to provide cross-platform treatment planning and delivery. A total of 27 helical tomotherapy intensity-modulated radiotherapy plans covering 4 anatomical sites were selected, including 7 brain, 5 unilateral head and neck, 5 bilateral head and neck, 5 pelvis, and 5 prostate cases. All helical tomotherapy plans were converted to 7-field/9-field intensity-modulated radiotherapy and volumetric-modulated radiotherapy plans through fallback dose-mimicking algorithm using a 6-MV beam model. The planning target volume (PTV) coverage ( D1, D99, and homogeneity index) and organs at risk dose constraints were evaluated and compared. Overall, all 3 techniques resulted in relatively inferior target dose coverage compared to helical tomotherapy plans, with higher homogeneity index and maximum dose. The organs at risk dose ratio of fallback to helical tomotherapy plans covered a wide spectrum, from 0.87 to 1.11 on average for all sites, with fallback plans being superior for brain, pelvis, and prostate sites. The quality of fallback plans depends on the delivery technique, field numbers, and angles, as well as user selection of structures for organs at risk. In actual clinical scenario, fallback plans would typically be needed for 1 to 5 fractions of a treatment course in the event of machine breakdown. Our results suggested that <1% dose variance can be introduced in target coverage and/or organs at risk from fallback plans. The presented clinical workflow showed that the fallback plan generation typically takes 10 to 20 minutes per case. Fallback planning provides an expeditious and effective strategy for transferring patients cross platforms, and minimizing the untold risk of a patient missing treatment(s).

Stereotactic Ablative Radiation Therapy Induces Systemic Differences in Peripheral Blood Immunophenotype Dependent on Irradiated Site.

PURPOSE: Despite the strong interest in combining stereotactic ablative radiation therapy (SAR) with immunotherapy, limited data characterizing the systemic immune response after SAR are available. We hypothesized that the systemic immune response to SAR would differ by irradiated site owing to inherent differences in the microenvironment of various organs. METHODS AND MATERIALS: Patients receiving SAR to any organ underwent prospective blood banking before and 1 to 2 weeks after SAR. Peripheral blood mononuclear cells (PBMCs) and serum were isolated. PBMCs were stained with fluorophore-conjugated antibodies against T and natural killer (NK) cell markers. Cells were interrogated by flow cytometry, and the results were analyzed using FlowJo software. Serum cytokine and chemokine levels were measured using Luminex. We analyzed the changes from before to after therapy using paired t tests or 1-way analysis of variance (ANOVA) with Bonferroni's post-test. RESULTS: A total of 31 patients had evaluable PBMCs for flow cytometry and 37 had evaluable serum samples for Luminex analysis. The total number of NK cells and cytotoxic (CD56dimCD16+) NK cells decreased (P = .02) and T-cell immunoglobulin- and mucin domain-containing molecule-3-positive (TIM3+) NK cells increased (P = .04) after SAR to parenchymal sites (lung and liver) but not to bone or brain. The total memory CD4+ T cells, activated inducible co-stimulator-positive and CD25+CD4+ memory T cells, and activated CD25+CD8+ memory T cells increased after SAR to parenchymal sites but not bone or brain. The circulating levels of tumor necrosis factor-α (P = .04) and multiple chemokines, including RANTES (P = .04), decreased after SAR to parenchymal sites but not bone or brain. CONCLUSIONS: Our data suggest SAR to parenchymal sites induces systemic immune changes, including a decrease in total and cytotoxic NK cells, an increase in TIM3+ NK cells, and an increase in activated memory CD4+ and CD8+ T cells. SAR to nonparenchymal sites did not induce these changes. By comparing the immune response after radiation to different organs, our data suggest SAR induces systemic immunologic changes that are dependent on the irradiated site.

The effect of radiation dose on the onset and progression of radiation-induced brain necrosis in the rat model.

PURPOSE: To provide a comprehensive understanding of how the selection of radiation dose affects the temporal and spatial progression of radiation-induced necrosis in the rat model. MATERIALS AND METHODS: Necrosis was induced with a single fraction of radiation exposure, at doses ranging between 20 and 60 Gy, to the right hemisphere of 8-week-old Fischer rats from a linear accelerator. The development and progression of necrosis in the rats was monitored and quantified every other week with T1- and T2-weighted gadolinium contrast-enhanced MRI studies. RESULTS: The time to onset of necrosis was found to be dose-dependent, but after the initial onset, the necrosis progression rate and total volume generated was constant across different doses ranging between 30 and 60 Gy. Radiation doses less than 30 Gy did not develop necrosis within 33 weeks after treatment, indicating a dose threshold existing between 20 and 30 Gy. CONCLUSION: The highest dose used in this study led to the shortest time to onset of radiation-induced necrosis, while producing comparable disease progression dynamics after the onset. Therefore, for the radiation-induced necrosis rat model using a linear accelerator, the most optimum results were generated from a dose of 60 Gy.

Intraoperative Extracorporeal Irradiation for the Treatment of the Meningioma-Infiltrated Calvarium.

Objectives Complete removal of infiltrated bone is required to achieve a Simpson Grade 1 meningioma resection. Reconstruction of the resulting bone defect is typically achieved with a nonnative implant that can result in poor cosmesis, foreign body reaction, or infection. Extracorporeal irradiation and reimplantation of tumorous bone has been used for limb-sparing surgery with excellent results, but this treatment option is not routinely considered in meningioma surgery. We present a case of anterior fossa meningioma with tumorous overlying calvarium that was successfully managed with intraoperative extracorporeal irradiation and reimplantation. Design, Setting, and Participant A 37-year-old woman with persistent chronic headaches was found to have an anterior skull base meningioma with extension into the forehead frontal bone. Concurrently with mass resection, the bone flap was irradiated intraoperatively with 120 Gy. After resection of the tumor, the bone flap was replaced in its native position. Main Outcome Measures and Results Twenty-nine months postoperatively, the patient had an excellent cosmetic outcome with no radiographic evidence of tumor recurrence or significant bone flap resorption. Conclusion Intraoperative extracorporeal irradiation of tumorous calvaria during meningioma surgery is an effective, logistically feasible treatment option to achieve local tumor control and excellent cosmetic outcome.

Fractionated stereotactic radiation therapy improves cranial neuropathies in patients with skull base meningiomas: a retrospective cohort study.

BACKGROUND: Skull base meningiomas commonly present with cranial neuropathies. Fractionated stereotactic radiation therapy (FSRT) has been used to treat these tumors with excellent local control, but rates of improvement in cranial neuropathies have not been well defined. We review the experience at Thomas Jefferson University using FSRT in the management of these patients with a focus on symptom outcomes. METHODS: We identified 225 cases of skull base meningiomas treated with FSRT at Thomas Jefferson University from 1994 through 2009. The target volume was the enhancing tumor, treated to a standard prescription dose of 54 Gy. Symptoms at the time of RT were classified based on the cranial nerve affected. Logistic regression was performed to determine predictors of symptom improvement after FSRT. RESULTS: The median follow-up time was 4.4 years. In 92% of cases, patients were symptomatic at the time of RT; the most common were impaired visual field/acuity (58%) or extraocular movements (34%). After FSRT, durable improvement of at least one symptom occurred in 57% of cases, including 40% of visual acuity/visual field deficits, and 40% of diplopia/ptosis deficits. Of all symptomatic patients, 27% experienced improvement of at least one symptom within 2 months of the end of RT. CONCLUSIONS: FSRT is very effective in achieving improvement of cranial neuropathies from skull base meningiomas, particularly visual symptoms. Over half of treated patients experience a durable improvement of at least one symptom, frequently within 2 months from the end of RT.

Design and development of masked therapeutic antibodies to limit off-target effects: application to anti-EGFR antibodies.

Therapeutic antibodies frequently cause side effects by binding antigen in non-target tissues. Here we demonstrate a novel molecular design of antibodies that addresses this problem by reversibly "masking" antibody complementarity determining regions until they reach diseased tissues containing disease-associated proteases. Specifically, two distinct single-chain Fv (scFv) fragments derived from antibodies against the epidermal growth factor receptor (cetuximab and 425) were fused a protease susceptible linker to their epitopes, which were engineered to encourage intermolecular association. Surface plasmon resonance and flow cytometry were used to confirm that the masked complex poorly interacts with native antigen, whereas protease treatment restores antigen recognition. Minimally, the "masked" scFvs possesses an eight-fold lower association with the epitope compared with the individual scFvs unmasked by proteolytic cleavage. This molecular design may have general utility for targeted release of therapeutic antibodies at disease sites.