The use of radiotherapy, either in the form of stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT), remains the cornerstone for the treatment of brain metastases (BM). As the survival of patients with BM is being prolonged, due to improved systemic therapy (i.e., for better extra-cranial control) and increased use of SRS (i.e., for improved intra-cranial control), patients are clinically manifesting late effects of radiotherapy. One of these late effects is radiation necrosis (RN). Unfortunately, symptomatic RN is notoriously hard to diagnose and manage. The features of RN overlap considerably with tumor recurrence, and misdiagnosing RN as tumor recurrence may lead to deleterious treatment which may cause detrimental effects to the patient. In this review, we will explore the pathophysiology of RN, risk factors for its development, and the strategies to evaluate and manage RN.

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The purpose of this study was to report the outcomes of patients with symptomatic locally advanced/recurrent gastric cancer treated with radiotherapy (RT) using modern 3-dimensional conformal techniques.We retrospectively reviewed patients who had palliative RT for index symptoms of gastric bleeding, pain, and obstruction. Study endpoints included symptom response, median survival, and treatment toxicity.Of 115 patients with median age of 77 years, 78 (67.8%) patients had metastatic disease at the time of treatment. Index symptoms were gastric bleeding, pain, and obstruction in 89.6%, 9.2%, and 14.3% of patients, respectively. Dose fractionation regimen ranged from 8-Gy single fraction to 40 Gy in 16 fractions. One hundred eleven patients (93.3%) were computed tomography (CT) planned. Median follow-up was 85 days. Response rates for bleeding, pain, and obstruction were 80.6% (83/103), 45.5% (5/11), and 52.9% (9/17), respectively, and median duration of response was 99 days, 233 days, and 97 days, respectively. Median survival was 85 days. Actuarial 12-month survival was 15.3%. There was no difference in response rates between low (≤39 Gy) and high (>39 Gy) biologically effective dose (BED) regimens (α/β ratio = 10). Median survival was significantly longer in patients who responded to RT compared with patients who did not (113.5 vs 47 days, P < 0.001). Three patients (2.6%) had grade 3 Common Toxicity Criteria equivalent toxicity (nausea/vomiting/anorexia).External beam RT delivered using 3-dimensional conformal techniques is highly effective and well tolerated in the local palliation of gastric cancer, with palliation lasting the majority of patient’s lives. Short (≤39 Gy BED) RT schedules are adequate for effective symptom palliation. A phase II study of palliative gastric RT is ongoing.

Background/PurposeTo review the efficacy and toxicity of palliative radiotherapy (RT) for symptomatic locally advanced gastric cancer (GC) and to determine the optimal RT schedule for symptom palliation.MethodsWe searched MEDLINE and CENTRAL for eligible studies published from 1995 to 2015. Outcomes of interest were relief of bleeding, pain and obstruction.RESULTSSeven non-comparative observational studies were included. There were large variations in RT dose and fractionation. The pooled overall response rates for bleeding, pain and obstruction symptoms were 74%, 67% and 68% respectively. There was no difference in response rate of bleeding between regimens with high biological equivalent dose (BED) of = 39Gy versus regimens with low BED<39Gy regimens (p value =0.39). Grade 3 to 4 toxicities occurred in up to 15% of patients for patients treated with RT alone and up to 25% of patients treated with chemoradiotherapy. Health-related quality of life (HRQL) outcomes were not reported.ConclusionMore than two-thirds of patients receiving RT would have a clinical benefit. Low BED regimens appear to be adequate for symptom palliation. Toxicity rates appear acceptable for patients treated with RT alone. The optimal dose fractionation regimen for symptom palliation remains unclear. Prospective studies to determine the effects of palliative gastric RT on HRQL outcomes are warranted.

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This paper analyzes the question: What does it take for science parks and technology districts to evolve and grow? We propose an analytical framework to examine the gestation, evolution, and sustainability of science parks and related but broader regional phenomena such as technology districts. The framework comprises three aspects of a science park's development: growth mechanisms, level of technological capabilities, and nature of its integration with national or global markets. The main growth mechanisms we identify are government-led infrastructure provision, agglomeration effects, and continual self-renewal through the creation of new businesses. We apply this framework to analyze Singapore's science park strategy and the recent One-North initiative. D