Gamma Knife Radiosurgery as a Salvage Treatment for Nasopharyngeal Carcinoma with Skull Base and Intracranial Invasion (T4b).

It is usually difficult to achieve good outcomes with salvage treatment for recurrent nasopharyngeal carcinoma (NPC) because of its deep-seated location, surrounding critical structures, and patient history of high-dose irradiation. Gamma Knife radiosurgery (GKS) is a treatment option for malignancies with skull base and intracranial invasion. We conducted a retrospective, observational, single-center study including 15 patients with recurrent NPC (stage T4b) involving the skull base and intracranial invasion, who underwent GKS as a salvage treatment. Patients were enrolled over 12 years. Per a previous study, the TNM classification T4b was subclassified into T4b1 and T4b2, defined as the involvement of the skull base or cavernous sinus with an intracranial extension of <5 mm and >5 mm, respectively. The effect of prognostic factors, including age, sex, survival period, magnetic resonance imaging (MRI) presentation, presence of other distant metastases, tumor volume, marginal dose, maximal dose, and Karnofsky Performance Status (KPS), on outcomes was analyzed. The patients with T4b1 NPC (p = 0.041), small tumor volume (p = 0.012), higher KPS (p < 0.001), and no other metastasis (p = 0.007) had better outcomes after GKS treatment, suggesting that it is a viable treatment modality for NPC. We also suggest that detailed brain imaging studies may enable the early detection of intracranial invasion.

Radiotherapy After Endoscopic Biopsy in an Adult with Pineocytoma, the Rare Brain Tumor in an Adult: A Case Report and Literature Review.

Tumors in the pineal region usually present with acute hydrocephalus. Histologic diagnosis is most important, as it greatly influences treatment, because over 17 tumor types occur in this area. Biopsies of these lesions play an important role in further management. Pineocytomas are benign and rare tumors that typically exhibit a slow progression. However, the appropriate treatment for pineocytoma varies. Surgical excision was considered for good long-term outcomes; however, this may not always be possible. Radiotherapy also appears to be effective in patients with residual pineocytomas. We report a case of pineocytoma with hemorrhagic transformation and complicated hydrocephalus. The patient refused to undergo aggressive tumor excision. Thus, the patient only underwent endoscopic biopsy and external ventricular drain (EVD) implantation, but the outcome was acceptable. In addition, we reviewed the current management strategies for pineocytomas in the literature.

A Machine Learning Approach for Spatial Mapping of the Health Risk Associated with Arsenic-Contaminated Groundwater in Taiwan's Lanyang Plain.

Groundwater resources are abundant and widely used in Taiwan's Lanyang Plain. However, in some places the groundwater arsenic (As) concentrations far exceed the World Health Organization's standards for drinking water quality. Measurements of the As concentrations in groundwater show considerable spatial variability, which means that the associated risk to human health would also vary from region to region. This study aims to adapt a back-propagation neural network (BPNN) method to carry out more reliable spatial mapping of the As concentrations in the groundwater for comparison with the geostatistical ordinary kriging (OK) method results. Cross validation is performed to evaluate the prediction performance by dividing the As monitoring data into three sets. The cross-validation results show that the average determination coefficients (R2) for the As concentrations obtained with BPNN and OK are 0.55 and 0.49, whereas the average root mean square errors (RMSE) are 0.49 and 0.54, respectively. Given the better prediction performance of the BPNN, it is recommended as a more reliable tool for the spatial mapping of the groundwater As concentration. Subsequently, the As concentrations estimated obtained using the BPNN are applied to develop a spatial map illustrating the risk to human health associated with the ingestion of As-containing groundwater based on the noncarcinogenic hazard quotient (HQ) and carcinogenic target risk (TR) standards established by the U.S. Environmental Protection Agency. Such maps can be used to demarcate the areas where residents are at higher risk due to the ingestion of As-containing groundwater, and prioritize the areas where more intensive monitoring of groundwater quality is required. The spatial mapping of As concentrations from the BPNN was also used to demarcate the regions where the groundwater is suitable for farmland and fishponds based on the water quality standards for As for irrigation and aquaculture.

Optimal Cut-Off Points of Sagittal Spinopelvic Parameters as a Morphological Parameter to Predict Efficiency in Nerve Block and Pulsed Radiofrequency for Lumbar Facet Joint Pain: A Retrospective Study.

BACKGROUND: After proper patient selection, anatomically correct pulsed radiofrequency of the lumbar facet joints provide long-term pain relief in a routine clinical setting. In the study, we performed an analysis of clinical and radiological predictive factors and provide the scientific basis for this promising modality. METHODS: The study included 198 patients with lower back pain due to lumbar facet joint disease who underwent medial branch block and pulsed radiofrequency during the period 2015-2019. According to the improvement in pain score, the patients were divided into good and poor outcome groups. Clinical and radiological data were collected and analyzed. RESULTS: The multivariable analysis revealed the predictive factors, including lumbar lordosis, lower lumbar lordosis, pelvic tilt, the number of facet joints, old compression fracture with/without vertebroplasty, and post lumbar fusion procedures. CONCLUSION: With the results of this study, we demonstrated that the improved outcome after the surgery was related to lumbar lordosis, lower lumbar lordosis, pelvic tilt, the number of facet joints, old compression fracture with/without vertebroplasty, and the lumbar fusion procedures. Old compression fractures and lumbar fusion would change the radiological factors and cause refractory lumbar facet joint pain.

Spatial Analysis of Human Health Risk Due to Arsenic Exposure through Drinking Groundwater in Taiwan's Pingtung Plain.

Chronic arsenic (As) exposure continues to be a public health problem of major concern worldwide, affecting hundreds of millions of people. A long-term groundwater quality survey has revealed that 20% of the groundwater in southern Taiwan's Pingtung Plain is clearly contaminated with a measured As concentration in excess of the maximum level of 10 µg/L recommended by the World Health Organization. The situation is further complicated by the fact that more than half of the inhabitants in this area continue to use groundwater for drinking. Efforts to assess the health risk associated with the ingestion of As from the contaminated drinking water are required in order to determine the priorities for health risk management. The conventional approach to conducting a human health risk assessment may be insufficient for this purpose, so this study adopts a geostatistical Kriging method to perform a spatial analysis of the health risk associated with ingesting As through drinking groundwater in the Pingtung Plain. The health risk is assessed based on the hazard quotient (HQ) and target cancer risk (TR) established by the U.S. Environmental Protection Agency. The results show that most areas where the HQ exceeds 1 are in the southwestern part of the study area. In addition, the high-population density townships of Daliao, Linyuan, Donggang, Linbian, Jiadong, and Fangliao presently have exceedingly high TR values that are two orders of magnitude higher than the acceptable standard. Thus, the use of groundwater for drinking in these townships should be strictly avoided. A map that delineates areas with high TR values and high population densities is provided. The findings broaden the scope of the spatial analysis of human health risk and provide a basis for improving the decision-making process.

Clinical outcome following DIAM implantation for symptomatic lumbar internal disk disruption: a 3-year retrospective analysis.

BACKGROUND/OBJECTIVE: Internal disk disruption (IDD), an early event of lumbar disk degeneration, is the most common cause of low back pain. Since increased intradiskal pressure (IDP) is associated with symptoms and progression of disk degeneration, unloading a painful disk with an interspinous process device (IPD) is a rational treatment option. The goal of this study was to evaluate the effectiveness of dynamic stabilization with an IPD in the treatment of symptomatic IDD of the lumbar spine. PATIENTS AND METHODS: Patients with symptomatic IDD were treated with implantation of an IPD, the device for intervertebral assisted motion (DIAM). Diagnosis of IDD was based on typical MRI finding of posterior annular high-intensity zone and positive provocative test on discography. IDP was analyzed intraoperatively. Axial back and leg pain was evaluated with visual analog scale, functional status with Oswestry Disability Index, and final clinical outcomes with Odom criteria. Data from 34 patients followed up for at least 3 years were collected. RESULTS: DIAM implantation significantly reduced IDP (n=11, P<0.0001). All 34 patients reported symptom relief. Thirty-one patients (91%) remained symptom free until the last followups. Three patients (9%) experienced recurrence of pain, of which the causes were unrelated to the IDD or surgery. Disk status at the DIAM-implanted segments remained stable. Segmental flexion/extension mobility was preserved in 27 of 30 patients with preoperative mobility. No proximal or distal adjacent segment degeneration was observed. The final clinical outcomes were excellent/good in 31 and fair/poor in three patients. CONCLUSION: For patients with symptomatic IDD, dynamic stabilization with DIAM provides pain relief and functional improvement. The implantation maintains disk status and prevents progression of disk degeneration, without compromising segmental flexion/extension mobility or causing adjacent segment degeneration.

Health risk assessment of groundwater arsenic pollution in southern Taiwan.

Residents of the Pingtung Plain, Taiwan, use groundwater for drinking. However, monitoring results showed that a considerable portion of groundwater has an As concentration higher than the safe drinking water regulation of 10 µg/L. Considering residents of the Pingtung Plain continue to use groundwater for drinking, this study attempted to evaluate the exposure and health risk from drinking groundwater. The health risk from drinking groundwater was evaluated based on the hazard quotient (HQ) and target risk (TR) established by the US Environmental Protection Agency. The results showed that the 95th percentile of HQ exceeded 1 and TR was above the safe value of threshold value of 10-6. To illustrate significant variability of the drinking water consumption rate and body weight of each individual, health risk assessments were also performed using a spectrum of daily water intake rate and body weight to reasonably and conservatively assess the exposure and health risk for the specific subgroups of population of the Pingtung Plain. The assessment results showed that 0.01-7.50 % of the population's HQ levels are higher than 1 and as much as 77.7-93.3 % of the population being in high cancer risk category and having a TR value >10-6. The TR estimation results implied that groundwater use for drinking purpose places people at risk of As exposure. The government must make great efforts to provide safe drinking water for residents of the Pingtung Plain.

Reduction in adjacent-segment degeneration after multilevel posterior lumbar interbody fusion with proximal DIAM implantation.

OBJECT Multilevel long-segment lumbar fusion poses a high risk for future development of adjacent-segment degeneration (ASD). Creating a dynamic transition zone with an interspinous process device (IPD) proximal to the fusion has recently been applied as a method to reduce the occurrence of ASD. The authors report their experience with the Device for Intervertebral Assisted Motion (DIAM) implanted proximal to multilevel posterior lumbar interbody fusion (PLIF) in reducing the development of proximal ASD. METHODS This retrospective study reviewed 91 cases involving patients who underwent 2-level (L4-S1), 3-level (L3-S1), or 4-level (L2-S1) PLIF. In Group A (42 cases), the patients received PLIF only, while in Group B (49 cases), an interspinous process device, a DIAM implant, was put at the adjacent level proximal to the PLIF construct. Bone resection at the uppermost segment of the PLIF was equally limited in the 2 groups, with preservation of the upper portion of the spinous process/lamina and the attached supraspinous ligament. Outcome measures included a visual analog scale (VAS) for low-back pain and leg pain and the Oswestry Disability Index (ODI) for functional impairment. Anteroposterior and lateral flexion/extension radiographs were used to evaluate the fusion status, presence and patterns of ASD, and mobility of the DIAM-implanted segment. RESULTS Solid interbody fusion without implant failure was observed in all cases. Radiographic ASD occurred in 20 (48%) of Group A cases and 3 (6%) of Group B cases (p < 0.001). Among the patients in whom ASD was identified, 9 in Group A and 3 in Group B were symptomatic; of these patients, 3 in Group A and 1 in Group B underwent a second surgery for severe symptomatic ASD. At 24 months after surgery, Group A patients fared worse than Group B, showing higher mean VAS and ODI scores due to symptoms related to ASD. At the final follow-up evaluations, as reoperations had been performed to treat symptomatic ASD in some patients, significant differences no longer existed between the 2 groups. In Group B, flexion/extension mobility at the DIAM-implanted segment was maintained in 35 patients and restricted or lost in 14 patients, 5 of whom had already lost segmental flexion/extension mobility before surgery. No patient in Group B developed ASD at the segment proximal to the DIAM implant. CONCLUSIONS Providing a dynamic transition zone with a DIAM implant placed immediately proximal to a multilevel PLIF construct was associated with a significant reduction in the occurrence of radiographic ASD, compared with PLIF alone. Given the relatively old age and more advanced degeneration in patients undergoing multilevel PLIF, this strategy appears to be effective in lowering the risk of clinical ASD and a second surgery subsequent to PLIF.

Probabilistic health risk assessment for ingestion of seafood farmed in arsenic contaminated groundwater in Taiwan.

Seafood farmed in arsenic (As)-contaminated areas is a major exposure pathway for the ingestion of inorganic As by individuals in the southwestern part of Taiwan. This study presents a probabilistic risk assessment using limited data for inorganic As intake through the consumption of the seafood by local residents in these areas. The As content and the consumption rate are both treated as probability distributions, taking into account the variability of the amount in the seafood and individual consumption habits. The Monte Carlo simulation technique is utilized to conduct an assessment of exposure due to the daily intake of inorganic As from As-contaminated seafood. Exposure is evaluated according to the provisional tolerable weekly intake (PTWI) established by the FAO/WHO and the target risk based on the US Environmental Protection Agency guidelines. The assessment results show that inorganic As intake from five types of fish (excluding mullet) and shellfish fall below the PTWI threshold values for the 95th percentiles, but exceed the target cancer risk of 10(-6). The predicted 95th percentile for inorganic As intake and lifetime cancer risks obtained in the study are both markedly higher than those obtained in previous studies in which the consumption rate of seafood considered is a deterministic value. This study demonstrates the importance of the individual variability of seafood consumption when evaluating a high exposure sub-group of the population who eat higher amounts of fish and shellfish than the average Taiwanese.

Brain stem cavernous malformations.

We retrospectively reviewed the clinical experience of 30 patients with brain stem cavernous malformations (BSCM) treated operatively and non-operatively at our hospital between 1983 and 2005 to elucidate the natural history of BSCM and the factors that affect surgical outcome. Inpatient charts, imaging studies, operative records, and follow-up results were evaluated. The average follow up was 48.5 months. Twenty-two patients (73.3%) received surgical extirpation and of these 86.4% improved or stabilized and 13.6% deteriorated with permanent or severe morbidity. There was no mortality. Size, preoperative status, and surgical timing were factors related to surgical outcome. In the non-operative group, 50% of the patients were the same or better, 25% deteriorated, and 25% died. With appropriate patient selection, resection of BSCM can be achieved with acceptable morbidity compared with the ominous natural history of these lesions.