An open-label single-arm phase II study of regorafenib for the treatment of angiosarcoma.

PURPOSE: Angiosarcomas represents a diverse group of aggressive high-grade vascular tumours with limited therapeutic options. We sought to determine the safety and efficacy of regorafenib, a small-molecule multikinase inhibitor, in the treatment of metastatic or locally advanced unresectable angiosarcoma. PATIENTS AND METHODS: In this single-arm multicentre, open-label phase II clinical trial, 31 patients were enrolled and received regorafenib 160 mg PO daily for 21 days of a 28-day cycle. The primary endpoint for the study was progression-free survival at 4 months. Secondary endpoints included overall survival, response rate, and safety. Patients (≥18 years) with an Eastern Cooperative Oncology Group (ECOG) score of 0-1, a life expectancy of at least 4 months who had progressed on at least one but no more than 4 prior lines of therapy were eligible. RESULTS: Of the 23 patients evaluable for efficacy, 2 had a complete response (8.7%), and 2 had a partial response (8.7%), for a total overall response rate of 17.4%. Median PFS was 5.5 months, and 12/23 patients (52.2%) had a PFS of greater than 4 months. 10/31 (32.3%) patients evaluable for toxicity had a grade 3 or higher adverse events. CONCLUSIONS: Regorafenib is a safe and active treatment for refractory metastatic and unresectable angiosarcoma. Rates of adverse events were comparable to prior studies of regorafenib for other tumour types. Regorafenib, the single agent, could be considered as therapy for patients with metastatic or unresectable AS.

CLR 125 Auger Electrons for the Targeted Radiotherapy of Triple-Negative Breast Cancer.

PURPOSE: Auger electrons emitted by radioisotopes such as 125I have a high linear energy transfer and short mean-free path in tissue (<10 µm), making them suitable for treating micrometastases while sparing normal tissues. The authors developed and subsequently investigated a cancer cell-selective small molecule phospholipid ether analog to deliver 125I to triple-negative breast cancer (TNBC) cells in vivo. METHODS: A Current Good Manufacturing Practice (cGMP) method to radiolabel 125I-CLR1404 (CLR 125) with >95% radiochemical purity was established. To estimate CLR 125 in vivo dosimetry and identify dose-limiting organs, the biodistribution of the analog compound 124I-CLR1404 (CLR 124) was investigated using micro-positron emission tomography (PET)/computed tomography (CT) in conjunction with a Monte Carlo dosimetry platform to estimate CLR 125 dosimetry. In vivo antitumor efficacy was tested by injecting nude mice bearing either MDA-MB-231-luc orthotopic xenografts or lung metastases with 74 MBq (3.7 GBq/kg) of CLR 125 or an equivalent mass amount of nonradiolabeled CLR 125. Longitudinal tumor measurements using calipers and bioluminescence imaging were obtained for the xenografts and lung metastases, respectively. RESULTS: Dosimetry analysis estimated that CLR 125 would impart the largest absorbed dose to the tumor per injected activity (0.261 ± 0.023 Gy/MBq) while the bone marrow, which is generally the dose-limiting organ for CLR1404, appears to have the lowest (0.063 ± 0.005 Gy/MBq). At administered activities of up to 74 MBq (3.7 GBq/kg), mice did not experience signs of toxicity. In addition, a single dose of CLR 125 reduced the volume of orthotopic primary TNBC xenografts by ∼60% compared to control vehicle (p < 0.001) and significantly extended survival. In addition, CLR 125 was efficacious against preclinical metastatic TNBC models by inhibiting the progression of micrometastases (p < 0.01). CONCLUSIONS: Targeted radionuclide therapy with CLR 125 displayed significant antitumor efficacy in vivo, suggesting promise for treatment of TNBC micrometastases.

The effect of Optune™ Tumor Treating Fields transducer arrays on skin radiation dose during radiotherapy.

A Phase 3 clinical study demonstrated that the addition of 200kHz Tumor Treating Fields (TTF) to temozolomide in the post-radiation (RT) phase of therapy in newly diagnosed glioblastoma increases progression free and overall survival (resulting in FDA and European Union approval). Preclinical studies have demonstrated the ability of TTF to act as a radiosensitizer, suggesting concurrent TTF and RT may have clinical utility. The removal and replacement of TTF transducer arrays from the scalps of patients on a daily basis, i.e., just before and after RT treatments, would be extremely cumbersome. Based on these considerations, phantom studies of the effect of Optune (TM) transducer arrays on radiation dose distribution were performed to evaluate the feasibility of leaving arrays in place during RT. Film measurements were performed using Gafchromic EBT3 film and an Epson 11000XL scanner. Film calibration was done based on the ratio of the red to blue color channel data. A Siemens Oncor linear accelerator operating at 6MV, 10cm×10cm field size, and 100cm source-to-film distance was used for all measurements. For each exposure, two films were stacked, providing planes of measurement that were ∼0.1 and 0.4mm in depth. Data accrued demonstrated that radiation attenuation should not be a clinically significant issue. However, TTF transducer arrays were found to cause both a radiation bolus effect, as well as an increased exit dose effect. These studies predict increased skin toxicity, which merits significant caution for further clinical development of this combination.

Triolimus: A Multi-Drug Loaded Polymeric Micelle Containing Paclitaxel, 17-AAG, and Rapamycin as a Novel Radiosensitizer.

Triolimus is a multi-drug loaded polymeric micelle containing paclitaxel (PTX), 17-allylamino-17-demethoxygeldanamycin (17-AAG), and rapamycin (RAP). This study examines the radiosensitizing effect of Triolimus in vitro and in vivo. Radiosensitizing effects of Triolimus on A549 cells are dose dependent and at 2 × 10-9 m, Triolimus shows significant radiosensitization even at low radiation doses (2 Gy). By sensitivity enhancement ratio, PTX alone, dual drug combinations, and Triolimus treatment at 2 × 10-9 m have radiosensitizing effects with potency as follows: PTX alone (PTX) > PTX and RAP (P/R) > Triolimus (TRIO) > PTX and 17-AAG (P/17) >17-AAG and RAP (17/R). In vivo, fractionated radiation of 15 Gy preceded by infusion of PTX alone, dual drug combinations, or an intermediate dose of Triolimus (Int. TRIO: PTX/17-AAG/RAP at 15/15/7.5 mg kg-1 ) strongly inhibits A549 tumor growth. Notably, pretreatment with high dose of Triolimus (High TRIO: PTX/17-AAG/RAP at 60/60/30 mg kg-1 ) before the fractionated radiation leads to tumor control for up to 24 weeks. An enhanced radiosensitizing effect is observed without an increase in acute toxicity compared to PTX alone or radiation alone. These results suggest that further investigations of Triolimus in combination with radiation therapy are merited.

Injectable (-)-gossypol-loaded Pluronic P85 micelles for cancer chemoradiotherapy.

PURPOSE: The aim of tumor-specific chemoradiotherapy is to achieve synergistic anticancer effects with clinically acceptable toxicity. Our previous studies showed that Pluronic P85 augments radiation cancer cell killing of (±)-gossypol in vitro. In this study, the radiosensitizing effect of (-)-gossypol, more potent Bcl protein inhibitor, with Pluronic P85 was investigated. MATERIALS AND METHODS: The inhibitory effect of (-)-gossypol solubilized Pluronic P85 with 0-8 Gy of radiation on clonogenic survival rate of A549 human lung adenocarcinoma cells was investigated in vitro. The anticancer effect of (-)-gossypol-solubilized Pluronic P85 with fractionated radiation of 15 Gy was assessed by A549 tumor-bearing mice. RESULTS: (-)-Gossypol-loaded Pluronic P85 was found to be a more potent radiosensitizer in vitro. Pluronic P85 increased the anti-proliferative activity of (-)-gossypol against A549 cells (82 ± 42 versus 190 ± 60 nM). In addition, the combination of P85 and (-)-gossypol effectively reduced clonogenic survival of A549 cells: (11 ± 5%) compared to (-)-gossypol and P85 alone (62 ± 27% and 93 ± 13%, respectively), and enhanced radiation cancer cell killing. In vivo, P85 (200 mg/kg/day) and (-)-gossypol (15 mg/kg/day) could be safely injected intravenously over 5 days and enhanced radiation-related tumor control in an A549 xenograft model. CONCLUSION: Pluronic P85 and (-)-gossypol act as a novel dual agent radiosensitizer and holds promise as a chemoradiotherapeutic strategy.

Clinical Activity of Pazopanib in Metastatic Extraosseous Ewing Sarcoma.

We report a response to pazopanib in a 69-year-old man with heavily pre-treated metastatic extraosseous Ewing sarcoma in addition to molecular profiling of his tumor. To our knowledge, this case is the earliest to demonstrate activity of an oral multi-targeted kinase inhibitor in Ewing sarcoma. This case provides rationale for adding a Ewing sarcoma arm to SARC024, a phase II study of regorafenib, another multi-targeted kinase inhibitor, in patients with liposarcoma, osteosarcoma and Ewing and Ewing-like sarcomas (NCT02048371). This national multi-institutional study is ongoing.

Impact of a Contralateral Tumor Nodule on Survival in Non-Small-Cell Lung Cancer.

INTRODUCTION: Contralateral lung tumors in non-small-cell lung cancer (NSCLC) are classified as stage M1a yet may represent hematogenous metastases or synchronous primary tumors. The impact of these tumors on overall survival (OS) is poorly understood. Here, we aim to determine whether NSCLC patients with M1a disease due only to a contralateral tumor nodule exhibit a favorable prognosis relative to other M1a or M1b patients. METHODS: Retrospective evaluation of the impact of contralateral tumor nodules on OS in NSCLC stratified by primary tumor size and N stage attained from Surveillance, Epidemiology, and End Results database. RESULTS: Of 173,640 patients, 5161 M1a-contra patients were identified. Median and 3-year OS for these patients exceeded that of patients with M1b (p < 0.0001) or other M1a disease (p < 0.0001). Primary tumor size and N stage were strongly associated with OS in M1a-contra patients. Three-year OS demonstrated a delayed convergence between M1a-contra and other M1a patients with primary tumors greater than or equal to 3 cm or mediastinal lymph node involvement. Proportional hazard modeling indicated that T1-2N0-1M1a-contra patients exhibit OS not significantly different (p = 0.258) from that predicted with comparable T and N stage disease plus a second early-stage primary. CONCLUSIONS: Contralateral tumors in NSCLC carry a more favorable prognosis than other M1a or M1b disease. Primary tumor size and N stage may help distinguish M1a-contra patients with hematogenous metastasis from those with a synchronous, second primary.

Examination of Gossypol-Pluronic Micelles as Potential Radiosensitizers.

Chemoradiotherapy, the combination of chemotherapy and radiotherapy to treat cancer, has the potential to enhance local therapeutic effects and simultaneously treat systemic disease. However, chemoradiotherapy may also enhance normal tissue effects leading to both acute and late toxicities. Furthermore, subtherapeutic chemoradiotherapy may result in aggressive tumor repopulation. Tumor-specific radiosensitizing chemotherapy may yield a synergistic therapeutic effect and avoid augmentation of normal tissue toxicity. In this study, the radiosensitizing effects of gossypol were investigated. Also, Pluronics were studied for gossypol solubilization and co-radiosensitization effects. Gossypol inhibits Bcl-2 and Bcl-XL, antiapoptotic proteins that are overexpressed in various cancer cells. Pluronic micelles (P85, F88, L35, and P123) effectively encapsulated gossypol, raising its water solubility by more than 1000-fold. Cytotoxic, anticlonogenic, and radiosensitizing effects were evaluated to characterize gossypol and Pluronic combinations. Gossypol and P85 had the strongest antiproliferative effect on A549 human lung adenocarcinoma cells in a cell viability assay. The IC50 value was seven times lower than gossypol only treatment (330 ± 70 nM vs 2400 ± 400 nM, (mean ± SE)). Gossypol and P85 showed significant inhibition of clonogenic survival, approximately 30% inhibition, compared to treatment with gossypol alone. An experimental sequencing study demonstrated greater inhibition of clonogenic survival when drug treatment followed radiation compared to a sequence of drug treatment followed by radiation. These results suggest that Pluronic micelles readily solubilize gossypol and that the combination of gossypol and P85 may augment the therapeutic effects of ionizing radiation.

Statin use in cancer patients with brain metastases: a missed communication opportunity at the end of life.

PURPOSE: Preventive care, referring to medical interventions with anticipated long-term benefits, is often inappropriately continued near the end of life. We examined the use of statin medications in patients with brain metastases receiving whole brain radiation therapy to determine the effect of short life expectancy and regular interaction with oncology providers on statin discontinuation. We propose reasons for the unnecessary continuation of preventive care and suggest that it is a frequently missed communication opportunity to discuss prognosis in a concrete manner. METHODS: This is a retrospective study examining statin use in patients receiving whole brain radiotherapy for brain metastases. A total of 206 patients at two cancer centers were studied, and information on statin use and clinical characteristics was obtained from review of the medical record. RESULTS: Of the 206 patients, 53 (26 %) were on a statin at their initial radiation oncology consultation. Of these patients, 13 (25 %) had their statin discontinued by the time of their last follow-up visit, but 40 patients (75 %) were continued on their statin despite their limited life expectancy and low likelihood of benefit. CONCLUSIONS: The majority of patients who were on statins prior to starting palliative whole brain radiation therapy remained on a statin after completing treatment despite an estimated survival of months and regular visits with an oncologist. This represents a missed opportunity for doctors and patients to discuss the appropriateness of continuing preventive care as part of an important conversation about prognosis.

Cardiac and inflammatory biomarkers do not correlate with volume of heart or lung receiving radiation.

BACKGROUND: Thoracic and cardiac irradiation increases the risk of pulmonary and cardiovascular disease. In addition, radiation, often in combination with chemotherapy, can cause treatment-related pneumonitis. Previously, we showed that the common marker for cardiac damage, troponin T, was not elevated by chemoradiation [Lung Cancer 62:351-355, 2008]. In this study, we explore whether dose-volume metrics and biomarkers for cardiac damage, inflammation or angiogenesis could identify patients receiving thoracic radiation who would later have cardiac or pulmonary complications. FINDINGS: To this end, we quantified cardiac biomarkers including c-reactive protein (cRP) as well as a panel of angiogenic and inflammatory molecules in thirty patients who received radiation therapy to the thorax with or without concurrent chemotherapy between May 2006 and May 2007. Serum was collected at baseline, 2 weeks into radiation treatment and at the completion of radiation therapy. Heart and lung dosimetric parameters and clinical risk factors were also examined, along with the monitoring of adverse pulmonary and cardiac events during follow-up. Contrary to our hypothesis, there was no correlation between serum biomarker levels and cardiac radiation dose. Similarly there was little association between lung dose-volume metrics and inflammatory or angiogenic biomarkers. Furthermore, there was no correlation with serum biomarkers and adverse pulmonary or cardiovascular events. CONCLUSION: Based on these data, acute elevations in serum biomarkers of cardiac damage, inflammation or angiogenesis should not be attributed to thoracic (chemo)radiation and elevations in such biomarkers of tissue damage should be further evaluated.

Choroid plexus tumor epidemiology and outcomes: implications for surgical and radiotherapeutic management.

Choroid plexus tumors (CPTs) are rare neoplasms of the central nervous system whose optimal management is not well defined. The Surveillance Epidemiology and End Results (SEER) Database from 1978 to 2009 was queried to define population-based outcomes for all patients with CPTs. Patient demographic data, histological classification (choroid plexus papilloma [CPP], atypical CPP [aCPP], and choroid plexus carcinoma [CPC]), extent of surgery, and use of radiation therapy (RT) as part of an initial course of therapy were analyzed for impact on overall survival (OS) and cause-specific survival (CSS). Chemotherapy data were not available within the SEER database. A total of 349 patients with CPTs were identified (120 CPCs, 26 aCPPs, and 203 CPPs). Patients with CPC presented at a younger age (median 3, mean 14.8 years) relative to CPP (median 25, mean 28.4 years; p < 0.0001). Histology was a significant predictor of OS, with 5-year OS rates of 90, 77, and 58 % for CPP, aCPP, and CPC, respectively. Older age and male sex were prognostic for worse OS and CSS for CPP. Only extent of surgery had a significant impact on survival for CPC. The use of adjuvant RT in patients with CPC undergoing surgery was not associated with a significantly improved OS (p = 0.17). For patients undergoing GTR without RT as part of an initial course of therapy, estimated 5- and 10-year OS were 70 % (±7 %) and 67 % (±8 %), respectively. Prospective data are required to define the optimal combination of surgery with adjuvant therapies, including chemotherapy.

A phase 1 study of 131I-CLR1404 in patients with relapsed or refractory advanced solid tumors: dosimetry, biodistribution, pharmacokinetics, and safety.

INTRODUCTION: (131)I-CLR1404 is a small molecule that combines a tumor-targeting moiety with a therapeutic radioisotope. The primary aim of this phase 1 study was to determine the administered radioactivity expected to deliver 400 mSv to the bone marrow. The secondary aims were to determine the pharmacokinetic (PK) and safety profiles of (131)I-CLR1404. METHODS: Eight subjects with refractory or relapsed advanced solid tumors were treated with a single injection of 370 MBq of (131)I-CLR1404. Whole body planar nuclear medicine scans were performed at 15-35 minutes, 4-6, 18-24, 48, 72, 144 hours, and 14 days post injection. Optional single photon emission computed tomography imaging was performed on two patients 6 days post injection. Clinical laboratory parameters were evaluated in blood and urine. Plasma PK was evaluated on (127)I-CLR1404 mass measurements. To evaluate renal clearance of (131)I-CLR1404, urine was collected for 14 days post injection. Absorbed dose estimates for target organs were determined using the RADAR method with OLINDA/EXM software. RESULTS: Single administrations of 370 MBq of (131)I-CLR1404 were well tolerated by all subjects. No severe adverse events were reported and no adverse event was dose-limiting. Plasma (127)I-CLR1404 concentrations declined in a bi-exponential manner with a mean t½ value of 822 hours. Mean Cmax and AUC(0-t) values were 72.2 ng/mL and 15753 ng • hr/mL, respectively. An administered activity of approximately 740 MBq is predicted to deliver 400 mSv to marrow. CONCLUSIONS: Preliminary data suggest that (131)I-CLR1404 is well tolerated and may have unique potential as an anti-cancer agent. TRIAL REGISTRATION: ClinicalTrials.gov NCT00925275.

Vascular endothelial growth factor-C enhances radiosensitivity of lymphatic endothelial cells.

Radiation therapy after lymph node dissection increases the risk of developing painful and incurable lymphedema in breast cancer patients. Lymphedema occurs when lymphatic vessels become unable to maintain proper fluid balance. The sensitivity of lymphatic endothelial cells (LECs) to ionizing radiation has not been reported to date. Here, the radiosensitivity of LECs in vitro has been determined using clonogenic survival assays. The ability of various growth factors to alter LEC radiosensitivity was also examined. Vascular endothelial growth factor (VEGF)-C enhanced radiosensitivity when LECs were treated prior to radiation. VEGF-C-treated LECs exhibited higher levels of entry into the cell cycle at the time of radiation, with a greater number of cells in the S and G2/M phases. These LECs showed higher levels of γH2A.X-an indicator of DNA damage-after radiation. VEGF-C did not increase cell death as a result of radiation. Instead, it increased the relative number of quiescent LECs. These data suggest that abundant VEGF-C or lymphangiogenesis may predispose patients to radiation-induced lymphedema by impairing lymphatic vessel repair through induction of LEC quiescence.

Current status and recommendations for the future of research, teaching, and testing in the biological sciences of radiation oncology: report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, executive summary.

In early 2011, a dialogue was initiated within the Board of Directors (BOD) of the American Society for Radiation Oncology (ASTRO) regarding the future of the basic sciences of the specialty, primarily focused on the current state and potential future direction of basic research within radiation oncology. After consideration of the complexity of the issues involved and the precise nature of the undertaking, in August 2011, the BOD empanelled a Cancer Biology/Radiation Biology Task Force (TF). The TF was charged with developing an accurate snapshot of the current state of basic (preclinical) research in radiation oncology from the perspective of relevance to the modern clinical practice of radiation oncology as well as the education of our trainees and attending physicians in the biological sciences. The TF was further charged with making suggestions as to critical areas of biological basic research investigation that might be most likely to maintain and build further the scientific foundation and vitality of radiation oncology as an independent and vibrant medical specialty. It was not within the scope of service of the TF to consider the quality of ongoing research efforts within the broader radiation oncology space, to presume to consider their future potential, or to discourage in any way the investigators committed to areas of interest other than those targeted. The TF charge specifically precluded consideration of research issues related to technology, physics, or clinical investigations. This document represents an Executive Summary of the Task Force report.

Angiosarcoma outcomes and prognostic factors: a 25-year single institution experience.

OBJECTIVE: Angiosarcoma is an aggressive malignancy with endothelial differentiation and notoriously poor prognosis despite aggressive therapy. Limited data are available to guide management decisions. To address this limitation, we present a large retrospective analysis of angiosarcoma patients treated at a single institution over a 25-year period. METHODS: To identify factors that impact angiosarcoma outcomes, we reviewed demographic, tumor, and treatment characteristics of angiosarcoma patients evaluated at the University of Wisconsin Hospital between 1987 and 2012. RESULTS: The cohort included 81 patients diagnosed at ages 19 to 90 years (median, 67 y). Fifty-five (68%) patients presented with localized disease, whereas 26 (32%) presented with metastases. The primary sites were visceral/deep soft tissue (42%), head and neck/cutaneous (37%), breast (16%), and limbs in the setting of Stewart-Treves (5%). The 5-year overall survival was 40% with a median of 16 months. By univariate analysis, significant adverse predictors of survival included metastases at presentation, visceral/deep soft tissue tumor location, tumor size > 5 cm, tumor necrosis, and the absence of surgical excision. A trend toward prolonged survival was observed with radiation therapy and for chemotherapy in patients with metastases. Age, sex, and prior radiation showed no correlation with survival. CONCLUSIONS: Our large single institution series confirms the poor prognosis of angiosarcoma, supports a central role for surgical excision in management, and highlights the need for novel therapies particularly in patients who present with metastatic disease.

The role of radiation in retroperitoneal sarcomas.

OPINION STATEMENT: Retroperitoneal sarcomas form a group of rare malignancies that require expertise in every aspect of management. Patients benefit from referral to cancer centers that can provide comprehensive, multidisciplinary, oncologic management. The role of radiation in retroperitoneal sarcoma management is, appropriately, the subject of considerable controversy due to the absence of high-level evidence proving its efficacy. Nonetheless, the preponderance of available data suggests that radiation therapy likely improves local control and, in some settings, may favorably impact resectability and survival. These outcome observations coupled with the lower doses (45-54 Gy) and normal tissue displacement characteristic of preoperative radiation therapy leads us to favor preoperative radiotherapy followed by oncologic resection for most retroperitoneal sarcomas. This strategy appears to provide the highest chance of safe and successful delivery of multimodal therapy, which can otherwise be hindered by postoperative complications as a result of technically challenging surgery and normal tissue radiation dose tolerances. Dose-escalation and selective integrative boosts to "at-risk" margins are attractive strategies that merit, and arguably require, further clinical evaluation. We believe that postoperative radiotherapy should be reserved for very high-risk cases and should be treated to a dose of ≥60 Gy respecting normal tissue dose tolerances. An additional approach that we consider in the postoperative setting is close surveillance with consideration of preoperative radiotherapy at recurrence before repeat surgical resection. Highly conformal radiotherapy techniques, such as IMRT with image guidance, should be employed to minimize dose to normal tissues and thereby allow delivery of efficacious radiation doses. If feasible, referral to a treatment facility with proton beam therapy should be discussed with the patient, especially if normal tissue dose constraints cannot be met using IMRT/IGRT. Participation in prospective studies should be highly encouraged.

Expression of angiopoietin-TIE system components in angiosarcoma.

Angiosarcoma is an aggressive malignancy of endothelial differentiation. Potential roles of the endothelial angiopoietin-tunica interna endothelial cell kinase (ANGPT-TIE) system in angiosarcoma diagnosis, pathogenesis, prognosis and treatment are undefined. To examine the expression and prognostic significance of angiopoietin-1, angiopoietin-2, TIE1 and TEK (TIE2) proteins in angiosarcoma, we immunohistochemically evaluated clinically annotated human angiosarcoma samples. Correlations of protein expression with overall survival and pathological features were explored. The cohort included 51 patients diagnosed with angiosarcoma at the age of 30-86 years (median 67). The 5-year overall survival was 45% with a median of 26 months. Moderate to strong expression of angiopoietin-1, TIE1 and TEK (TIE2) was identified in the majority of angiosarcomas and moderate to strong expression of angiopoietin-2 was observed in 42% of angiosarcomas. Increased angiopoietin-1 expression correlated with improved survival. Non-significant trends toward longer survival were also observed with increased TIE1 and TEK (TIE2) expression. Increased expression of angiopoietin-2, TIE1 and TEK (TIE2) was associated with vasoformative architecture. No differences in expression of these proteins were observed when patients were segregated by age, gender, presence or absence of metastases at diagnosis, primary tumor location, radiation association or the presence of necrosis. We conclude that components of the ANGPT-TIE system are commonly expressed in angiosarcomas. Reduced expression of these proteins is associated with non-vasoformative and clinically more aggressive lesions.

Dosimetric comparison of photon and proton treatment techniques for chondrosarcoma of thoracic spine.

Chondrosarcomas are relatively radiotherapy resistant, and also delivering high radiation doses is not feasible owing to anatomic constraints. In this study, the feasibility of helical tomotherapy for treatment of chondrosarcoma of thoracic spine is explored and compared with other available photon and proton radiotherapy techniques in the clinical setting. A patient was treated for high-grade chondrosarcoma of the thoracic spine using tomotherapy. Retrospectively, the tomotherapy plan was compared with intensity-modulated radiation therapy, dynamic arc photon therapy, and proton therapy. Two primary comparisons were made: (1) comparison of normal tissue sparing with comparable target volume coverage (plan-1), and (2) comparison of target volume coverage with a constrained maximum dose to the cord center (plan-2). With constrained target volume coverage, proton plans were found to yield lower mean doses for all organs at risk (spinal cord, esophagus, heart, and both lungs). Tomotherapy planning resulted in the lowest mean dose to all organs at risk amongst photon-based methods. For cord dose constrained plans, the static-field intensity-modulated radiation therapy and dynamic arc plans resulted target underdosing in 20% and 12% of planning target volume2 volumes, respectively, whereas both proton and tomotherapy plans provided clinically acceptable target volume coverage with no portion of planning target volume2 receiving less than 90% of the prescribed dose. Tomotherapy plans are comparable to proton plans and produce superior results compared with other photon modalities. This feasibility study suggests that tomotherapy is an attractive alternative to proton radiotherapy for delivering high doses to lesions in the thoracic spine.