Plant diversity in Sabkha ecosystems of arid region: spatial and environmental drivers.

This study investigated the effects of spatial and environmental factors and their interactions on plant species composition in salt marsh (Sabkha) ecosystem located in arid region (Saudi Arabia). The plant species and environmental variables were investigated in 38 sites located in three regions. A total of 15 environmental variables were measured in each site and the geographical coordinates were used to extract spatial variables (using PCNM). A total of 81plant species were reported from 38 sites. The three regions showed patterns of homogeneity of multivariate dispersions (i.e. beta diversity). The PCNM analysis extracted 18 PCNM vectors and only 3 vectors were retained after forward selection. The spatial variables (selected PCNM vectors) explained only 3.21% of the variation in species composition of plants (using variation partitioning technique). However, eight environmental variables were selected after forward selection (Lead, Copper, total organic matter, Potassium, Magnesium, pH, Zinc and Iron, F= 4.72, P<0.05) and explained 19.61% of the total variation in the species composition. In conclusion, the plant communities in Sabkhas were not spatially structured due to the low percentage of variation explained by the spatial variables (PCNM vectors). The environmental variables were corresponded to the high fraction of variation explained. On the other hand, Sabkhas in Saudi Arabia are considered a hot spot for diversity not only for plants but for other animals (birds, vertebrates and invertebrates). Therefore, immediate conservation plans should be implemented to reduce the adverse effect of urbanization, industrialization as well as other anthropogenic activities.

Five years treatment outcomes of postoperative radiotherapy in saudi women with uterine cancers: single institutional experience.

UNLABELLED: We aimed to evaluate long-term treatment outcomes and toxicity profile of postoperative radiotherapy (PORT) in Saudi women with uterine cancers. METHODS AND MATERIALS: Medical records of patients with histopathologically proven uterine cancers were reviewed and identified those who received PORT (45-50.4 Gy in 25-28 fractions) followed by vaginal brachytherapy (15-20 Gy in 3 to 4 sessions) after total abdominal hystrectomy and bilateral salpingo-oophorectomy (TAHBSO) in our center between August 2007 and April 2012. Data regarding the safety profile, locoregional control (LRC) or distant metastases control (DMC) and overall survival (OS) rates were analyzed. RESULTS: Median follow-up period was 60 months (range, 12-70) for 89 patients. Predominant histological type was endometrial (59 patients), followed by carcinosarcoma (17 patients) and leiomyosarcoma (13 patients). Median age at time of diagnosis was 57.6, 56 and 51.1 years for endometrial, carcinosarcoma and leiomyosarcoma respectively. LRC rates were 80.9%, 87.1% and 100% for leiomyosarcoma, carcinosarcoma and endometrial carcinoma respectively (p 0.4). DMC rates were 69.3%, 45% and 16.3% for endometrial, leiomyosarcoma and carcinosarcoma respectively (p 0.0001). Five-year OS rates were 71.1%, 60% and 16.3% for endometrial, leiomyosarcoma and carcinosarcoma respectively (p 0.001). Coxproportional hazard ratio model showed body mass index, FIGO stage, lymphovascular invasion in endometrial carcinoma, tumor size in leiomyosarcoma and histology in carcinosarcoma important prognostic factors for LRC. Acute grade 3 and 4 proctitis/enteritis seen only in 4 patients (4.5%) and late toxicities were minimal. CONCLUSION: PORT in Saudi women with uterine cancers showed better LRC, DMC and OS rates with minimal toxicity.

Optimal prophylactic and definitive therapy for bicalutamide-induced gynecomastia: results of a meta-analysis.

OBJECTIVE: Bicalutamide is approved as an adjuvant to primary treatments (radical prostatectomy or radiotherapy) or as monotherapy in men with locally advanced, nonmetastatic prostate cancer (pca). However, this treatment induces gynecomastia in most patients, which often results in treatment discontinuation. Optimal therapy for these breast events is not known so far. We undertook a meta-analysis to assess the efficacy of various treatment options for bicalutamide-induced gynecomastia. METHODS: The medline, cancerlit, and Cochrane library databases were searched and the Google search engine was used to identify prospective and retrospective controlled studies published in English from January 2000 to December 2010 comparing prophylactic or curative treatment options with a control group (no treatment) for pca patients who developed bicalutamide-induced gynecomastia. Radiotherapy-induced cardiotoxicity was also evaluated. RESULTS: The search identified nine controlled trials with a total patient population of 1573. Pooled results from prophylactic trials showed a significant reduction of gynecomastia in pca patients treated with prophylactic tamoxifen 20 mg daily (odds ratio: 0.06; 95% confidence interval: 0.05 to 0.09; p = 0.09), and pooled results from treatment trials showed a significant response of gynecomastia to definitive radiotherapy (odds ratio: 0.06; 95% confidence interval: 0.01 to 0.24; p < 0.0001). Aromatase inhibitors and weekly tamoxifen were not found to be effective as prophylactic and curative options. For the radiotherapy, skin-to-heart distance was found to be an important risk factor for cardiotoxicity (p = 0.006). A funnel plot of the meta-analysis showed significant heterogeneity (Egger test p < 0.00001) because of low sample size. CONCLUSIONS: Our meta-analysis suggests using prophylactic tamoxifen 20 mg daily as the first-line preventive measure and radiotherapy as the first-line treatment option for bicalutamide-induced gynecomastia. Aromatase inhibitors and weekly tamoxifen are not recommended.

Assessment of three-dimensional set-up errors in head and neck cancer patients treated by intensity modulated radiotherapy using electronic portal imaging device.

BACKGROUND: Set-up errors are an inherent part of radiation treatment process. Coverage of target volume is a direct function of set-up margins, which should be optimized to prevent inadvertent irradiation of adjacent normal tissues. The aim of this study is to evaluate set-up errors and propose optimum margins for target volume coverage in head and neck radiotherapy. METHODS: Twenty six head and neck cancer patients received intensity modulated radiation therapy (IMRT) included in the study. The weekly portal images taken after correction of the systematic error -if any- were evaluated. The systematic error tested and corrected by taking portal images in the 1st 3 days of treatment by using the VARIS offline review system. Three hundred sixty four portal images matched anatomically with anterior and lateral digitally reconstructed radiographs (DRRs). Five hundred forty six points used to evaluate isocenter displacement in antero-posterior direction (AP), supero-inferior direction (SI) and right-left direction (RL). RESULTS: The mean isocenter displacement in AP, RL, and SI directions were 1.5 +/- 1.6 mm, 1.3 +/-1.4 mm and 2.13 +/- 1.6 mm. Ninety six percent of the isocenter deviations were within 4 mm in all three directions. The displacement more than 4 mm (negative or positive) was 4% in the vertical direction, 7% in the longitudinal direction and 1.6% in the lateral direction. There is insignificant increase of the isocenter shift in the last weeks of radiotherapy especially in the vertical and longitudinal directions. CONCLUSION: The current setup for irradiating head and neck cancer patients using IMRT in our department is accurate. The 4 mm CTV-PTV margin is enough.

Nasopharyngeal carcinoma in Saudi Arabia: clinical presentation and diagnostic delay.

Nasopharyngeal carcinoma is commonly advanced at diagnosis. In this study we evaluated the clinical presentation, diagnostic delay and factors affecting delay in nasopharyngeal carcinoma. Data were collected prospectively for 307 newly diagnosed patients, including detailed demographic data, disease history, health care consultations and referral process. Diagnostic delay was classified as patient, professional and overall. Neck lump and nasal obstruction were the commonest presenting symptoms. There was a significant association between delay time of > or = 3 months and advanced stage. Patient's age and otological symptoms were associated with increased overall delay time. Advanced clinical stage at diagnosis was associated with paitents' sociodemographic characteristics.

Nasopharyngeal carcinoma in Saudi Arabia: clinical presentation and diagnostic delay

Nasopharyngeal carcinoma is commonly advanced at diagnosis. In this study we evaluated the clinical presentation, diagnostic delay and factors affecting delay in nasopharyngeal carcinoma. Data were collected prospectively for 307 newly diagnosed patients, including detailed demographic data, disease history, health care consultations and referral process. Diagnostic delay was classified as patient, professional and overall. Neck lump and nasal obstruction were the commonest presenting symptoms. There was a significant association between delay time of >/= 3 months and advanced stage. Patient's age and otological symptoms were associated with increased overall delay time. Advanced clinical stage at diagnosis was associated with paitents' sociodemographic characteristics

Frequency of occurrence of cytomegalovirus and Chlamydia pneumoniae in lymphocytes of atherosclerotic patients.

Forty-three blood samples from atherosclerotic donors and 28 samples from normal individuals were analyzed to determine the frequency of occurrence of cytomegalovirus (CMV) and Chlamydia pneumoniae DNA sequences in lymphocytes of Saudi Arabian donors using Polymerase Chain Reaction (PCR). In non-atherosclerotic donors, no CMV DNA was detectable and only one sample was positive for C-pneumoniae DNA sequences. Of the 43 atherosclerotic patients, 22 were infected with CMV, 23 were infected with C-pneumoniae and 11 showed no infection. Thirteen of the 43 donors showed simultaneous infection with both CMV and C-pneumoniae. These results demonstrate that atherosclerotic patients are more frequently infected with CMV or C-pneumoniae or both.

Early stage carcinoma of oral tongue: prognostic factors for local control and survival.

The purpose of this study was to assess prognostic factors, treatment outcomes and patterns of relapse in patients with early stage (T1-2 N0) squamous cell carcinoma of oral tongue treated primarily by surgery. The medical records of all patients with early stage (T1-2 N0) oral tongue cancer, radically treated at King Faisal Specialist Hospital and Research Center between January 1980 and December 1997, were reviewed. Eighty-five patients were identified for analysis, 38 male and 47 female. With a median follow-up for surviving patients of 64 months, 5-year actuarial overall, disease-specific (DSS), and relapse-free survival (RFS) were 71, 75, and 63%, respectively. Univariate analysis for DSS showed survival advantage for patients with tumor thickness (TT) of < or =10 mm (P=0.0002) and distance from resection margin (DFRM) of > 5 mm (P=0.005). The effect of TT of < or =10 mm was maintained (P=0.001) on multivariate analysis. Higher RFS was observed with TT of < or =10 mm (P=0.0002), DFRM of > 5 mm (P=0.0002) and DFRM of >10 mm (P=0.007). On multivariate analysis higher RFS was also found for TT < or =10 mm (P=0.01) and DFRM >5 mm (P=0.01). Salvage of local tongue recurrence was higher than neck node failure, with 5-year DSS of 71 and 19%, respectively (P=0.007). Time interval for recurrence showed no significant impact on outcome. In T1-2 N0 oral tongue cancer, TT, and DFRM are significant prognostic factors for both local control and survival. Neck node recurrence is associated with poor prognosis and low salvage rate.

Squamous cell carcinoma of the oral tongue: an analysis of prognostic factors.

AIM: To identify the prognostic significance of different factors in patients with squamous cell carcinoma of the tongue. PATIENTS AND METHODS: Seventy-seven patients with carcinoma of the tongue were treated radically at the King Faisal Specialist Hospital and Research Centre between 1980 and 1989. Twenty patients (26%) were treated by resection alone, 11 (14%) with radiotherapy alone, and 46 (60%) with combined resection and radiotherapy. RESULTS: Forty-seven patients (61%) had T(1-2), 28 (36%) T(3-4), and two T(x) tumours. The regional nodes were clear in 53 (69%) and contained metastases in 24 patients (31%). Thirty patients (39%) developed recurrences, which were local in 9, regional in 14, locoregional in 5, and locoregional with metastatic disease in 2. The five and 10-year overall actuarial survival for all patients were 65% and 53%, respectively, and the corresponding relapse-free survival 56% and 50%. Univariate and multivariate analyses were done of seven variables - age (<40 compared with >/=40 years), sex, chewing tobacco use, smoking, TNM stage, surgical margins (clear or invaded), and treatment (resection, radiotherapy, or the combination). On univariate analysis chewing tobacco (P=0.04), smoking (P=0.01), invaded resection margins (P=0.04), involved regional lymph nodes (P=0.009), T4 tumours, and patients treated with radiotherapy alone (P=0.001) were associated with poor overall survival. Factors associated with shorter relapse-free survival were age >40 (P=0.03), chewing tobacco (P=0.04), invaded resection margins (P=0.01), and smoking (P=0.01). On multivariate analysis, invaded resection margins and smoking (P=0.04)(P=0.02) were associated with shorter overall survival and relapse-free survival (P=0.03 and (P=0.01), while chewing tobacco independently influenced relapse-free survival only (P=0.03). CONCLUSION: Invaded resection margins and smoking were the only independent prognostic factors that affected both overall and relapse-free survival. Those who chewed tobacco were at high risk of locoregional failure.

F-18 fluorodeoxyglucose chest uptake in lung inflammation and infection.

PURPOSE: F-18 fluorodeoxyglucose (FDG) may accumulate at sites of inflammation or infection, making interpretation of whole-body scans difficult in patients with cancer. METHODS: More than 650 whole-body positron emission tomographic (PET) scans performed to examine patients with cancer were reviewed to identify uptake in pulmonary infection or inflammation based on the appearance of F-18 FDG chest uptake, chest radiographs, computed tomography, or all of these. RESULTS: Ten patients had uptake in benign lung disease. Eight patients had head and neck tumors and two patients had breast cancer. Intense focal or multifocal F-18 FDG chest uptake was seen in 6 of 10 scans. This was difficult to distinguish from pulmonary metastases based on the scan appearance. However, in the remaining patients, the uptake was atypical for malignancy and displayed an apical, segmental, or lobar pattern. In all patients, the F-18 FDG lung uptake corresponded to benign radiologic changes (infiltration, consolidation, or atelectasis), and the final diagnosis was pulmonary inflammation or infection. Nine patients were asymptomatic and one patient had clinical aspiration pneumonia. Follow-up PET scans were performed in five patients to evaluate their conditions. Chest uptake disappeared completely in three patients and partially in two patients, and there were no new findings. Variable degrees of F-18 FDG chest uptake have been reported with more than 40 different benign causes. They can be classified based on the underlying mechanism into four major categories: 1) Inflammation or infection, 2) benign tumor, 3) physiologic activity, and 4) iatrogenic. Most of these false-positive cases are included in the first category. CONCLUSIONS: Pulmonary infection or inflammation might predispose patients to localized F-18 FDG chest uptake mimicking pulmonary metastases and limiting the specificity of whole-body scans performed in patients with cancer.

The integral biologically effective dose to predict brain stem toxicity of hypofractionated stereotactic radiotherapy.

OBJECTIVE: The aim of this work was to develop a parameter for use during fractionated stereotactic radiotherapy treatment planning to aid in the determination of the appropriate treatment volume and fractionation regimen that will minimize risk of late damage to normal tissue. MATERIALS & METHODS: We have used the linear quadratic model to assess the biologically effective dose at the periphery of stereotactic radiotherapy treatment volumes that impinge on the brain stem. This paper reports a retrospective study of 77 patients with malignant and benign intracranial lesions, treated between 1987 and 1995, with the dynamic rotation technique in 6 fractions over a period of 2 weeks, to a total dose of 42 Gy prescribed at the 90% isodose surface. From differential dose-volume histograms, we evaluated biologically effective dose-volume histograms and obtained an integral biologically-effective dose (IBED) in each case. RESULTS: Of the 77 patients in the study, 36 had target volumes positioned so that the brain stem received more than 1% of the prescribed dose, and 4 of these, all treated for meningioma, developed serious late damage involving the brain stem. Other than type of lesion, the only significant variable was the volume of brain stem exposed. An analysis of the IBEDs received by these 36 patients shows evidence of a threshold value for late damage to the brain stem consistent with similar thresholds that have been determined for external beam radiotherapy. CONCLUSION: We have introduced a new parameter, the IBED, that may be used to represent the fractional effective dose to structures such as the brain stem that are partially irradiated with stereotactic dose distributions. The IBED is easily calculated prior to treatment and may be used to determine appropriate treatment volumes and fractionation regimens minimizing possible toxicity to normal tissue.