Local residents' perception on factors affecting the willingness to pay for improved urban canal water: a case study in Can Tho city of Vietnam.

Urbanization and economic development cause water pollution in the inner-city canals and rivers globally. Bung Xang canal in Can Tho city of Vietnam is facing problems with water pollution due to the lack of centralized wastewater treatment plants and low public awareness on environmental protection. Perception of local residents was collected using structured questionnaires including both qualitative and quantitative information. Regression analysis was employed to evaluate the factors affecting the decision of respondents on the willingness to pay (WTP) to improve water quality in the Bung Xang canal. Knowledge about the environmental protection fee for domestic wastewater (10% of the VAT-excluded from the selling price of 1 m3 of tap water purchased), age of the respondents and their education levels affected the WTP positively, while respondents' perception on water quality affected the WTP negatively. There was 58.33% of the respondents showed the WTP for improved water quality in the canal. They agreed to pay a small fee of VND 10,000 to 15,000 (equivalent to USD 0.42-0.63)/month (1 US$= 23,700 VND). The result indicates that environmental education is the only way forward for a successful sustainable urban city.

Screening Wetland and Forage Plants for Phytoremediation of Salt-Affected Soils in the Vietnamese Mekong Delta.

This study evaluated the salt tolerance and sodium (Na) bioaccumulation of Typha orientalis, Lepironia articulata, Eleocharis dulcis, Scirpus littoralis, Brachiaria mutica, Paspalum atratum and Setaria sphacelata at five salinity levels of 0, 5, 10, 15 and 20‰ (corresponding to 0, 2.4, 6.9, 12.6 and 18 g NaCl L-1). S. littoralis showed zero-reduction in total dry biomass and was classified as a salt tolerant plant based on the membership function value. The highest Na+ accumulation was observed in S. sphacelata (307.9 mg plant-1) in spite of its salt sensitivity, followed by S. littoralis and T. orientalis at concentration of 155 mg plant-1. Consequently, the Na+ phytoextraction potential of these species can be estimated as 46.2, 23.3 and 23.3 kg ha-1 over 49 days, respectively. Taken together, they show high potential as Na+ hyperaccumulators, and can be selected in the national reclamation program for salt-affected soils in the context adaptation to climate change.

Local Therapies Can Improve Intracerebral Control in Patients with Cerebral Metastasis from Gynecological Cancers.

BACKGROUND/AIM: Patients with gynecological malignancies account for 2% of patients with cerebral metastases. Many patients receive whole-brain irradiation (WBI) alone. Local therapies (resection, stereotactic radiosurgery (SRS)) are becoming more popular. This study compared intracerebral control after local therapy to WBI alone in patients with gynecological malignancies. PATIENTS AND METHODS: Of 56 patients, 45 received WBI alone, 6 SRS alone and 5 resection plus WBI. Treatment type, age, performance score, cancer site, number of cerebral lesions, metastases outside the brain, recursive partitioning analysis (RPA) class and period from gynecological cancer diagnosis to brain metastasis treatment were evaluated. RESULTS: On univariate analyses, local therapy (p=0.003), single cerebral lesion (p<0.001) and RPA class 1/2 (p=0.027) were positively related to intracerebral control. On Cox regression analysis, local therapy (p=0.013) and RPA class 1/2 (p=0.014) were significant. CONCLUSION: Local therapies led to better intracerebral control than WBI alone and should be considered for brain metastasis from gynecological malignancies whenever reasonable.

Predicting Survival After Irradiation for Brain Metastases from Head and Neck Cancer.

AIM: Patients with cerebral metastases from head and neck cancer are not common. This study aimed to create an instrument for estimating survival in this particular group of patients. PATIENTS AND METHODS: Survival was significantly influenced by Eastern Cooperative Oncology Group (ECOG) performance score, number of cerebral lesions and extracranial metastatic disease. These characteristics were included in our score. RESULTS: Scoring was based on 6-month survival data: ECOG 0-1=1 point, ECOG 2-3=0 points, 1-3 cerebral lesions=1 point, ≥4 cerebral lesions=0 points, lack of extracranial metastases=1 point, and presence of extracranial metastases=0 points. Addition of these points for each patient resulted in 0-3 points. Three groups were built comprising 0-1, 2 and 3 points. Six-month survival rates for these groups were 0%, 50% and 100%, respectively. CONCLUSION: This new instrument guides physicians in choosing optimal irradiation programs for patients with cerebral metastases from head-and-neck cancer.

A New Predictive Tool for Optimization of the Treatment of Brain Metastases from Colorectal Cancer After Stereotactic Radiosurgery.

AIM: To develop a predictive tool for survival after stereotactic radiosurgery of brain metastases from colorectal cancer. PATIENTS AND METHODS: Out of nine factors analyzed for survival, those showing significance (p<0.05) or a trend (p≤0.06) were included. For each factor, 0 (worse survival) or 1 (better survival) point was assigned. Total scores represented the sum of the factor scores. RESULTS: Performance status (p=0.010) and interval from diagnosis of colorectal cancer until radiosurgery (p=0.026) achieved significance, extracranial metastases showed a trend (p=0.06). These factors were included in the tool. Total scores were 0-3 points. Six-month survival rates were 17% for patients with 0, 25% for those with 1, 67% for those with 2 and 100% for those with 3 points; 12-month rates were 0%, 0%, 33% and 67%, respectively. Two groups were created: 0-1 and 2-3 points. Six- and 12-month survival rates were 20% vs. 78% and 0% vs. 44% (p=0.002), respectively. CONCLUSION: This tool helps optimize the treatment of patients after stereotactic radiosurgery for brain metastases from colorectal cancer.

Defining the Optimal Dose of Stereotactic Radiosurgery for Treating Cerebral Metastases in Elderly Patients.

BACKGROUND/AIM: In oncology, elderly people are a separate group of patients requiring special consideration. This applies to the treatment of cerebral metastases as well. The present study focused on elderly patients receiving stereotactic radiosurgery (SRS) for few cerebral lesions. PATIENTS AND METHODS: In 95 patients aged ≥65 years, two SRS doses, 16-18 Gy (n=44) and 20 Gy (n=51), were compared regarding outcomes of SRS. RESULTS: The overall intracerebral control rates at 12 months were 30% after 16-18 Gy and 45% after 20 Gy (p=0.53). Twelve-month rates of freedom from new intracerebral lesions were 41% and 52%, respectively (p=0.63). Twelve-month local control rates of the irradiated lesions were 55% and 81%, respectively (p=0.069). Overall survival rates at 12 months were 29% and 31%, respectively (p=0.67). CONCLUSION: SRS with 16-18 Gy was not significantly inferior to SRS with 20 Gy in elderly patients with few cerebral metastases.

Estimation of the Six-month Survival Probability After Radiosurgery for Brain Metastases from Kidney Cancer.

AIM: To generate an overall survival score for patients with kidney cancer who underwent radiosurgery for brain metastases. PATIENTS AND METHODS: Thirty-six patients who received radiosurgery alone for 1-3 brain metastases from kidney cancer were included. On multivariate analysis of a preceding study of such patients, Karnofsky performance score (KPS) and extracranial spread were significantly associated with overall survival and formed the basis for this score. For each patient, the prognostic score was derived from adding the points of KPS and extracranial spread resulting in a score of 9, 12, 15 or 18 points. RESULTS: Six-month overall survival rates were 13% for patients with 9 points, 80% for those with 12 points, 79% for those with 15 points and 100% for those with 18 points, respectively. Three groups of patients were defined with scores of 9, 12-15 and 18 points. Six-month overall survival rates were 13%, 79% and 100%, respectively (p=0.004). CONCLUSION: This new score facilitates personalized treatment decisions for patients with kidney cancer with very few brain metastases.

Impact of stereotactic radiosurgery dose on control of cerebral metastases from renal cell carcinoma.

AIM: Renal cell carcinoma (RCC) is a relatively radioresistant tumor and may require for higher radiation doses than other tumor types. PATIENTS AND METHODS: Nineteen patients treated with 20 Gy of stereotactic radiosurgery (SRS) alone for one to three cerebral metastases were compared to nine patients treated with 16-18 Gy. RESULTS: SRS with 20 Gy led to significantly better local control than did 16-18 Gy (81% vs. 50% at 12 months; p<0.001). Results were also significant on multivariate analysis (risk ratio: 6.30; p=0.033). SRS dose did not associate with freedom from new cerebral metastases (75% vs. 62% at 12 months; p=0.42) or survival (16% vs. 56% at 12 months; p=0.46). On multivariate analyses, better survival was associated with higher Karnofsky performance score (p<0.001) and absence of extracranial metastatic disease (p=0.006). CONCLUSION: In patients treated with SRS alone, local control of cerebral metastases from RCC was better after 20 Gy than after 16-18 Gy.

Comparison of two dose levels of stereotactic radiosurgery for 1-3 brain metastases from non-small cell lung cancer.

AIM: Two dose groups of patients treated with stereotactic radiosurgery (SRS) alone for 1-3 brain metastases from non-small cell lung cancer (NSCLC) were compared for outcomes. PATIENTS AND METHODS: Based on the SRS dose administered to the margins of the brain lesions, 46 patients were assigned to groups treated with 15-18 Gy (n=13) or with 20 Gy (n=33). Seven additional factors were investigated: age (≤ 58 vs. ≥ 59 years), gender, Karnofsky performance score (KPS 70-80 vs. 90-100), number of brain metastases (1 vs. 2-3), histology (adenocarcinoma vs. other) extracerebral metastases and interval from NSCLC diagnosis to SRS (≤ 6 vs. >6 months). RESULTS: Local control rates for 15-18-Gy and 20-Gy groups were 75% and 92% at one year (p=0.043). SRS dose was significant on multivariate analysis (p=0.030). SRS dose was not associated with freedom from new brain metastases (p=0.24) or survival (p=0.37). CONCLUSION: SRS with 20 Gy resulted in better control of the irradiated metastases than 15-18 Gy did.

A new score predicting survival prognosis after whole-brain radiotherapy alone for brain metastases in elderly patients.

BACKGROUND/AIM: Elderly patients represent an important subgroup of patients with brain metastases. A survival score has been developed specifically for these patients. PATIENTS AND METHODS: A total of 544 elderly patients (aged ≥65 years) receiving whole-brain radiotherapy alone were divided into a test (n=272) and a validation group (n=272). In the multivariate analysis of the test group, survival was significantly associated with gender, performance status, and number of organs involved by extracranial metastases. These factors were included in the score. Total scores representing the sum of the three factor scores were 3-13 points. Four prognostic groups were formed. RESULTS: The 6-month survival rates were 2% for those with 3-6 points, 17% for those with 7-9 points, 56% for those with 10-12 points and 90% for those with 13 points in the test group (p<0.001), and 4%, 21%, 50% and 86%, respectively, in the validation group (p<0.001). CONCLUSION: This score is reproducible and helps estimate the survival prognosis of elderly patients with brain metastasis.

Stereotactic radiosurgery for newly diagnosed brain metastases: comparison of three dose levels.

BACKGROUND AND PURPOSE: Three doses were compared for local control of irradiated metastases, freedom from new brain metastases, and survival in patients receiving stereotactic radiosurgery (SRS) alone for one to three newly diagnosed brain metastases. PATIENTS AND METHODS: In all, 134 patients were assigned to three groups according to the SRS dose given to the margins of the lesions: 13-16 Gy (n = 33), 18 Gy (n = 18), and 20 Gy (n = 83). Additional potential prognostic factors were evaluated: age (≤ 60 vs. > 60 years), gender, Karnofsky Performance Scale score (70-80 vs. 90-100), tumor type (non-small-cell lung cancer vs. melanoma vs. others), number of brain metastases (1 vs. 2-3), lesion size (< 15 vs. ≥ 15 mm), extracranial metastases (no vs. yes), RPA class (1 vs. 2), and interval of cancer diagnosis to SRS (≤ 24 vs. > 24 months). RESULTS: For 13-16 Gy, 18 Gy, and 20 Gy, the 1-year local control rates were 31, 65, and 79%, respectively (p < 0.001). The SRS dose maintained significance on multivariate analysis (risk ratio: 2.25; 95% confidence interval: 1.56-3.29; p < 0.001). On intergroup comparisons of local control, 20 Gy was superior to 13-16 Gy (p < 0.001) but not to 18 Gy (p = 0.12); 18 Gy showed a strong trend toward better local control when compared with 13-16 Gy (p = 0.059). Freedom from new brain metastases (p = 0.57) and survival (p = 0.15) were not associated with SRS dose in the univariate analysis. CONCLUSION: SRS doses of 18 Gy and 20 Gy resulted in better local control than 13-16 Gy. However, 20 Gy and 18 Gy must be compared again in a larger cohort of patients. Freedom from new brain metastases and survival were not associated with SRS dose.