A Needs Assessment Exploring Radiation Oncology Nursing Confidence in Caring for Patients with Acute and Late Radiation Therapy Effects

PURPOSE/OBJECTIVE(S)

Registered Nurses (RN) have a critical and growing role in providing RO patient care. Moskalenko et al. published the first RO nursing needs assessment in the USA in 2021, reporting that RO nurses lacked standardized, structured education and certification programs for onboarding and continuing education. Herein, we report RN confidence in providing RO survivorship care.

MATERIALS/METHODS

With permission from Moskalenko et al., an adapted version of their needs assessment survey was administered to RNs at a single academic medical center RO department in an IRB-exempt study. This survey used a Likert-type scale ranging from 1 (Not At All Confident) to 5 (Extremely Confident) to assess confidence across the following clinical domains: managing acute and late radiation effects, providing patient education regarding imaging, external beam radiation therapy (EBRT), high-dose rate brachytherapy (HDR), concurrent systemic therapy, anesthesia recovery, radiation safety, and general cancer knowledge.

RESULTS

RNs in RO were surveyed with a 100% (n = 14) response rate. Respondents were 61.5% oncology-certified nurses (OCN). 84.6% attended schools without affiliated RO departments or RO clinical experiences. 69.2% reported ≥5 years of oncology experience, and 45% had ≥5 years of RO experience. All RNs reported performing patient education. RNs expressed a high degree of confidence in managing triage phone calls (median 4, IQR [4-5]). RNs had moderate confidence in their general understanding of radiation (3 [3-4]), RO care team responsibilities (3 [3-4]), radiation treatment planning (3 [2-4]) and set up (3 [2-4]). RNs expressed the lowest confidence in regulatory aspects of radiation safety (2.5 [2-3]). RN confidence with patient education included the following domains: CT (3 [3-4]), MRI (3 [3-4]), PET (3 [3-4]), simulation (3 [2-4]), EBRT (3 [3-4]), anesthesia recovery (3 [3-4]), HDR (2.5 [1-5]), medication side effect management (4 3-4]), hormone treatments (3 [2-4]), and concurrent chemoradiation (3 [3-4]). Regarding acute toxicity management, RNs reported highest confidence with prostate/genitourinary (4 [3-4]), lung (4 [3-4]), and sarcoma cancers (3.5 [2-4]); with lower scores across hematologic (2.5 [2-4]) and pediatric cancers (2 [1-4]). Regarding late side effect management, the highest scores were observed among prostate/genitourinary (3 [2-4]), sarcoma (3 [2-4]), and breast (3 [2-3]) cancers; with comparatively lower scores for skin (2 [2-4]), CNS (2 [2-3]), GI (2 [2-3]), hematologic (2 [2-3]), and pediatric cancers (2 [1-2]).

CONCLUSION

While this single-site pilot project is limited by small sample size, it highlights the need for a formalized curriculum, scope of practice, and credentialing for RO nurses. These data can help to target education needs while guiding curriculum development.

Pretreatment Clinical Parameters Associated with Intracranial Progression Burden Following an Initial Stereotactic Radiosurgery Course in a Multi-Institutional Brain Metastases Cohort

PURPOSE/OBJECTIVE(S)

While brain metastasis (BM) velocity is a valuable prognostic metric at time of intracranial progression (ICP), pre-SRS risk factors for post-SRS high-burden intracranial progression (ICP) remain poorly characterized. We hypothesized that pre-SRS clinical parameters are associated with subsequent high-burden (ICP), defined as either ≥5 (ICP5) or new/progressive ≥11 BMs (ICP11).

MATERIALS/METHODS

All patients completing an initial SRS course for BMs at two institutions from 1/2015-12/2020 were retrospectively identified. Patients with prior whole brain radiation therapy (WBRT) and/or BM resection were eligible. Demographic and clinical parameters were collected. ICP was defined as any radiographic concern for distant and/or in-field progression per multidisciplinary consensus. Overall survival (OS) and freedom from ICP were estimated via the Kaplan Meier method. Cox models assessed association between parameters and freedom from ICP5 and ICP11.

RESULTS

We identified 1383 patients completed SRS, with a median follow up of 8.7 months. Patients were 54.8% female, 45.6% with KPS ≥90, and a median of 63.4 years old. Primary tumor types included non-small cell lung (48.7%), breast (14.7%), and melanoma (8.5%). 46.9% had oligometastatic disease (≤5 metastatic foci: including BMs) at SRS, and 53.4% underwent SRS for >1 BM. 10.3% of patients had undergone prior WBRT and 26.1% surgical resection. 555 patients (40.1%) experienced ICP following SRS, of whom 72.6% had 1-4, 11.5% had 5-10, and 15.9% had ≥11 new/progressive BMs. Among patients with ICP, 6-month freedom from ICP was 35.5% (95% CI: 31.1-40.5%) for those with 1-4 BMs at time of ICP, 29.7% (95% CI: 20.4-43.3%) for 5-10 BMs, and 20.5% (95% CI: 13.5-30.1%) for ≥11 BMs (p = 0.016). Respective 12-month OS rates were 56.8% (95% CI: 52.1-61.9%), 46.0% (95% CI: 35.1-60.1%), and 38.7% (95% CI: 29.4-50.9%; p<0.001). Neurologic symptoms at time of ICP were observed in 21.1% of patients with 1-4 BMs, 28.1% with 5-10 BMs, and 50.0% with new/progressive ≥11 BMs (p<0.001). On multivariable analysis, superior freedom from high-burden ICP was associated with the following pre-SRS parameters: oligometastatic burden (ICP5: HR 0.68, 95% CI: 0.47-0.99; ICP11: 0.59; 95% CI: 0.36-0.97), no prior immunotherapy (ICP11: HR 0.57, 95% CI: 0.34-0.57), and a single BM at time of initial SRS (1 vs 2 BM, ICP 5: HR 0.51, 95% CI: 0.31-0.82; ICP11: HR 0.45, 95% CI: 0.24-0.84), while primary tumor type was not associated with ICP5 or ICP11.

CONCLUSION

Pre-SRS parameters including polymetastatic burden, prior receipt of immunotherapy, and >1 BM were associated with post-SRS high-burden ICP. High burden ICP developed earlier following SRS completion and was associated with higher rates of neurologic decline and inferior OS.

ChatGPT is an Unreliable Tool for Reviewing Radiation Oncology Literature

PURPOSE/OBJECTIVE(S)

To assess whether ChatGPT, a popular deep learning text generation tool, can serve as a resource for in-training and practicing clinicians by accurately identifying and summarizing studies related to radiation oncology.

MATERIALS/METHODS

Three question templates (Q1-Q3, shown in Table 1) were applied to eight cancer types to compile 24 questions posed to ChatGPT. Cancer types were designated as either common (breast, non-small cell lung, prostate, p16 positive oropharyngeal, and rectal) or uncommon (hypopharyngeal, medulloblastoma, and vulvar). ChatGPT's responses to each question were then reviewed to quantify the number of studies referenced in the response, the percentage of studies listed that were real studies, and the percentage of studies listed that were correctly summarized. Outcomes were compared between cancer types (common vs uncommon) and question types using Wilcoxon rank sum tests. As a secondary analysis, we assessed internal consistency of ChatGPT's responses by querying ChatGPT with three identical iterations of Q1-Q3 for breast cancer and comparing its responses between iterations.

RESULTS

Across all 24 of ChatGPT's responses, there were 78 studies referenced, of which 37 (47.4%) were real studies and 7 (9.0%) were correctly summarized. On average, each response included 3.25 (standard deviation (SD): 0.74) studies, of which 44.0% (SD: 44.2%) were real studies and 7.8% (SD: 14.6%) were correctly summarized. The proportion of correctly summarized studies was not significantly different between common vs uncommon cancers [p = 0.29], between questions that specified randomized-control trials (Q3) vs not (Q1 or Q2) [p = 0.94], or between questions that specified intensity modulated radiotherapy (Q2) vs not (Q1 or Q3) [p = 0.31]. Across the three iterations of ChatGPT queries for breast cancer, the number of studies listed for Q1, Q2, and Q3 ranged from 3 to 5, 2 to 3, and 3 to 5, respectively; the number of correctly summarized studies listed for each question ranged from 0 to 2, 0 to 1, and 0 to 1, respectively.

CONCLUSION

ChatGPT's responses consistently included a large proportion of non-existent and incorrectly summarized studies. Furthermore, our secondary analysis suggests variability in the content and accuracy of ChatGPT responses to identical questions, raising further concerns regarding reliability. Overall, our findings argue against the use of ChatGPT as a tool for reviewing literature related to radiation oncology.

Multi-Institutional Outcomes Following Stereotactic Radiosurgery for Gastrointestinal Brain Metastases

PURPOSE/OBJECTIVE(S)

Outcomes following stereotactic radiosurgery (SRS) for gastrointestinal (GI) brain metastases (BM) are poorly defined. We analyzed our multi-institutional database of SRS patients, comparing outcomes between GI and non-GI BM patients after SRS.

MATERIALS/METHODS

We retrospectively identified all patients completing an initial SRS course across two institutions from 1/2015-12/2020. Demographic and clinical parameters were manually captured. Intracranial progression (ICP) was defined as any concern on post-SRS imaging for recurrence determined by multidisciplinary consensus. Overall survival (OS) and freedom from ICP (FFICP) were estimated via Kaplan Meier models. Cox proportional hazard models were used to assess associations between ICP and parameters.

RESULTS

Among 1383 total patients completing SRS for BM, 102 (7.4%) had GI BM. Among these, 46 (45.1%) were of colorectal (CRC) and 34 (33.3%) esophageal origin. Other GI sites (21.6%) included anal, pancreatic, gastric, GI of unknown origin, and hepatocellular carcinoma. Median follow up was 8.7 mos. GI BM patients were more likely to be younger (mean 59.1 vs 63.5 yrs, p = 0.001), male (56.9% vs 44.3%, p = 0.014 ), have more extracranial metastases (mean 1.9 vs 1.6, p = 0.003), have received systemic therapy (73.5% vs 63.9%, p = 0.049) or resection of BM (45.1% vs 25.0%, p < 0.001) prior to SRS, have larger planned target volumes of all BMs (mean 20.3 ccs vs 15.0 ccs, p = 0.013), and were less likely to receive whole brain radiation therapy (WBRT) prior to SRS (3.9% vs 10.8%, p = 0.028) or systemic therapy after SRS (54.9% vs 68.9%, p = 0.004). Among GI patients, median OS was 28.2 mos (95% CI 16.5-35.3), with no significant differences between GI and non-GI patients (p = 0.220) or among GI subgroups (CRC vs other GI: p = 0.731; esophageal vs other GI: p = 0.478). Median FFICP was significantly worse for GI patients (6.2 mos, 95% CI 4.0-9.6 mos) than for non-GI patients (12.4 mos, 95% CI 10.8-13.9 mos; p = 0.004). After accounting for age, sex, performance status, number of irradiated BMs, extracranial disease burden, extracranial disease control, interval from primary cancer diagnosis to BM diagnosis, resection status, receipt of prior WBRT, and receipt of post-SRS systemic therapy, GI origin was significantly associated with worse FFICP (HR 1.50, 95% CI 1.15-2.02, p = 0.007). FFICP was not significantly different between GI subgroups, with CRC and esophageal patients demonstrating median times to ICP of 5.0 mos (95% CI 3.4-9.6) and 7.2 mos (95% CI 2.7-14.1), respectively. Only 2 GI patients (2.0%) had ICP at site of prior SRS.

CONCLUSION

Across a modern, multi-institutional SRS cohort comparing GI to non-GI primary patients, BMs of GI origin demonstrated inferior FFICP to those of non-GI origin. OS did not vary significantly across GI and non-GI cases. Among GI subtypes, no significant differences were identified across FFICP or OS. These data may help inform treatment decisions and post-SRS surveillance.

Clinical Outcomes Following an Initial Stereotactic Radiosurgery Course for Brain Metastases from Melanoma

PURPOSE/OBJECTIVE(S)

Brain metastases (BM) are common in melanoma patients. The effect of gene mutations is not well characterized since first-line metastatic therapy has shifted from chemotherapy (CHT) to molecularly targeted therapies (TT) and immunotherapy (IO). We report outcomes of melanoma BM patients stratified by molecular subtype and pre-stereotactic radiosurgery (SRS) systemic therapy.

MATERIALS/METHODS

We identified all patients completing an initial SRS course for BM at two institutions between 1/2015 and 12/2020. Patients who had prior WBRT and/or resection were eligible. Demographic and clinical parameters were collected, along with melanoma tumor molecular characteristics. Intracranial progression (ICP) was defined as any radiographic distant and/or in-field progression per multidisciplinary consensus. Overall survival (OS) and freedom from ICP (FFICP) were estimated via the Kaplan Meier method.

RESULTS

From a total of 1383 SRS BM patients, we identified 118 (8.5%) with melanoma. Median follow up was 8.7 months, median age 64 years (IQR 51-72), 81% had cutaneous origin, and 55% had a KPS of 90-100. Molecular subtypes included BRAF (45%), NRAS (9.3%), and c-KIT (3.4%). Overall, 61% received IO prior to SRS, while 25% and 9.3% received TT and CHT prior to SRS respectively. 60% of patients harboring a mutation received IO as first line therapy, 10% received TT, and 30% received both TT and IO prior to SRS. BRAFmut patients more likely to have received TT prior to SRS (43% vs 9.2%, p<0.001) compared to BRAFwt patients. Median OS was 9.7 months (95% CI 7.8-13) and was not significantly different from non-melanoma patients (p = 0.6). Median FFICP was worse for melanoma patients (5.9 mos, 95% CI 3.5-8.5) than non-melanoma patients (8.96 mos, 95% CI 8.2-9.7, p = 0.009). A total of 72 ICP events occurred, with 56 (77.8%) distant ICP cases, 3 (4.2%) in-field ICP, and 13 (18%) ICP events that were radionecrosis (RN) only. RN was associated with the presence of a targetable mutation (18% vs 2%, p = 0.006) and receipt of TT pre-SRS (36% vs 9.8%, p = 0.001). BRAFmut patients had significantly worse FFICP (3.8 mos, 95% CI 3.0-6.8) compared to BRAFwt patients (8.5 mos, 95% CI 5.8-30.2, p = 0.006), although median OS was not significantly different (9.6 mos, 95% CI 6.9-16 vs 10.7 mos, 95% CI 6.7-15.5, p = 0.8). NRASmut was associated with better FFICP (29 mos, 95% CI 2.94-NA, p = 0.02).

CONCLUSION

In this modern, multi-institutional cohort of SRS patients, melanoma BM patients had worse FFICP compared to non-melanoma BM patients, and BRAFmut patients had worse FFICP than BRAFwt patients. RN was associated with mutational status and receipt of TT pre-SRS. OS did not vary significantly across groups. This analysis may help inform systemic therapy decisions and future genomic studies for patients with BMs from melanoma.

Evaluating the Reliability of Chat-GPT Model Responses for Radiation Oncology Patient Inquiries

PURPOSE/OBJECTIVE(S)

To determine if ChatGPT, a popular deep learning text generation tool, accurately and comprehensively answers patient questions related to radiation oncology.

MATERIALS/METHODS

A total of 28 common patient-centered questions were selected across various radiation oncology content domains, including diagnosis (4), workup (3), treatment (8), toxicity (4), and survivorship (9). To assess whether ChatGPT could detect inaccurate assumptions and/or respond negatively, we included two "negative control" questions in the treatment and toxicity domains. All questions were applied to common cancer types (breast, non-small cell lung, prostate, p16+ oropharyngeal, and rectal), uncommon cancer types (hypopharyngeal, medulloblastoma, and vulvar), and colon cancer as an additional "negative control." The ChatGPT responses were graded as 0 for any incorrect information, 1 for missing essential content, and 2 for correct and appropriately comprehensive for the length of the response. Each response was graded by two blinded MD reviewers, with discordant answers resolved by a third MD reviewer. Score distribution was compared across content domains, question type ("negative control" vs other), cancer type, and cancer commonality using the Chi-squared test.

RESULTS

Overall, a total of 252 questions were submitted to ChatGPT. A total of 86 (34.1%) answers were found to contain inaccurate information, 66 (26.2%) contained correct information but were found to be missing essential context, and 100 (39.7%) responses to questions were graded as correct and comprehensive. There was no significant difference in response score by question domains (p = 0.07). However, there was significant difference in response score across cancer type (p<0.001). The top scoring cancer types were breast (grade 0 = 10%; grade 1 = 21%, grade 2 = 68%) and prostate (grade 0 = 18%, grade 1 = 25%, grade 2 = 57%), while the two lowest scoring cancer types were colon (grade 0 = 61%, grade 1 = 21%, grade 2 = 18%) and vulvar (grade 0 = 50%, grade 1 = 25%, grade 2 = 25%). ChatGPT responses were also significantly different among common, uncommon and negative control questions, with the model performing best with responses to common cancer types (p = 0.003). ChatGPT performed significantly worse when responding to "negative control" questions (p<0.001).

CONCLUSION

ChatGPT failed to consistently generate accurate and comprehensive responses to the majority of radiation oncology patient centered questions, particularly across less common cancers and with "negative control" questions that included incorrect assumptions. This raises concern for the possible ChatGPT mediated reinforcement of patient misperceptions regarding radiotherapy.

A Multi-Institutional Analysis of MRI-Based Brachytherapy for Medically Inoperable Endometrial Cancer

PURPOSE/OBJECTIVE(S)

Patients with medically inoperable endometrial cancer (MIEC) are curable with brachytherapy (BT)-based treatment yet have competing comorbidities making definitive treatment challenging. MRI demonstrates superior soft tissue anatomy and target volume delineation but with limited data in MIEC patients. We aim to report disease and toxicity outcomes with MRI-based BT and identify dose-volume relationships for toxicities in the treatment of MIEC patients treated with MRI-based BT.

MATERIALS/METHODS

We conducted a retrospective multi-institutional analysis of MIEC patients undergoing definitive MRI-based BT (+/- EBRT). MRI-based BT was delivered with the applicator in situ or coregistered to a planning CT. We identified patient, tumor, and dosimetric factors associated with disease and toxicity outcomes. Kaplan-Meier method was used for survival estimates. Log rank test and Cox proportional hazards were used for univariate and multivariate analyses, respectively. T-test was used for dose-volume toxicity analysis.

RESULTS

A total of 120 patients were included with a median follow up of 28.0 months. Median age was 68.5 years. ECOG PS was 0-1 in 70%. Clinical stage I was 83.3% and II-IV, 16.7%. Most patients (91.7%) were node negative. Endometrioid and high risk histologies comprised 83.3%, and 16.7%, respectively. EBRT + BT was delivered in 97 patients (80.8%) and BT alone in 23 patients (19.2%). Chemotherapy or hormonal therapy was delivered during treatment in 10 (8.3%) and 11 (9.2%) patients, respectively. Estimated 3-year freedom from local, nodal, and distant recurrence were 88.0%, 96.0%, and 89.1% respectively. Estimated 3-year PFS and OS were 60.9% and 62.9%, respectively. On UVA, older age, PS ≥2, high risk histology, higher grade, and larger GTV at BT were significant (p<0.1). On MVA, older age, higher grade, and larger GTV at BT (p<0.05) predicted for inferior PFS. Fifteen late grade ≥3 toxicities were experienced in 14 (11.6%) patients, 13 of whom received EBRT and BT and 1 who received BT alone. Grade ≥3 toxicities were rectal (2, 1.7%), sigmoid (8, 6.7%), bowel (1, 0.8%), bladder (3, 2.5%), and osseous (1, 0.8%). EBRT was delivered in 7 of 8 sigmoid toxicities. Median sigmoid doses (EQD2a/b = 3Gy) for patients with and without late grade ≥3 sigmoid toxicity were 69.6 Gy and 64.3 Gy, respectively (p = 0.009).

CONCLUSION

MRI-based BT for MIEC patients results in high rates of local control and favorable rates of late grade ≥3 morbidity. Older age, higher grade, and larger GTV at BT predicted for poorer PFS. Sigmoid colon was the predominant organ at risk for grade ≥3 toxicity with a dose -volume relationship observed. Attention to the location of the sigmoid throughout the treatment course may add insight into its predilection for risk. Future work will include additional institutions and dose-volume relationships of target volumes and normal tissues for further disease control and toxicity analysis.

Radiation technique and outcomes following moderately hypofractionated treatment of low risk prostate cancer: A secondary analysis of the NRG oncology RTOG 0415 randomized clinical trial

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Background: While intensity-modulated radiotherapy (IMRT) is commonly used to deliver moderately hypofractionated radiotherapy (MHRT) for prostate cancer (PC), IMRT has not been prospectively compared to three-dimensional conformal radiotherapy (3D-CRT) in the context of MHRT. This secondary analysis of the phase III RTOG 0415 trial compares survival outcomes and toxicity across RT technique between IMRT and 3D-CRT for low-risk PC. Methods: The phase III, non-inferiority trial RTOG 0415 randomized patients with low risk PC to either MHRT (70Gy at 2.5Gy/fraction) or conventionally fractionated radiation (CFRT; 73.8Gy at 1.8Gy/fraction) with stratification by RT technique. A secondary analysis for differences in overall (OS), biochemical recurrence free survival (BRFS), or toxicity by EPIC scores and Common Terminology Criteria for Adverse Events (CTCAE) was performed. For patient and tumor characteristics, continuous data were compared with Wilcoxon rank sum test and categorical data with Chi-squared test, as appropriate. Rates of BRFS and overall survival (OS) were calculated using the Kaplan-Meier method. Results: 1079 patients received the allocated intervention with a median follow up of 5.8 years. RT technique was balanced between treatment arms, with 79.1% of patients receiving IMRT. RT protocol compliance was > 95% for both IMRT and 3D-CRT. There were no significant differences in BRFS between patients treated with 3D-CRT versus IMRT for all patients (p = 0.33), those randomized to CFRT (p = 0.78), or those randomized to MHRT (p = 0.24). Overall survival did not differ by RT technique as well. For all patients, there was no difference in acute and late GI and GU toxicity rates across RT technique. For patients treated with MHRT, late grade 2 GU toxicity was more common with IMRT than 3D-CRT (31.3% vs 23.4%; p = 0.004). On logistic regression analysis, only poor baseline urinary function, defined as an EPIC score of 90 or below, correlated with acute (p < 0.001) or late (p < 0.001) GU toxicity. Baseline bowel function did not correlate to GI toxicity. Conclusions: RT technique did not impact survival outcomes or toxicity rates following MHRT for low risk PC. Higher rates of late CTCAE grade 2+ GU and GI toxicity observed within the RTOG 0415 MHRT arm were not disproportionally observed following 3D-CRT than IMRT. These data highlight the need for careful consideration of target delineation and normal tissue constraints in the selection and delivery of appropriate RT technique.

Human immunology studies using organ donors: Impact of clinical variations on immune parameters in tissues and circulation

Organ donors are sources of physiologically healthy organs and tissues for life-saving transplantation, and have been recently used for human immunology studies which are typically confined to the sampling of peripheral blood. Donors comprise a diverse population with different causes of death and clinical outcomes during hospitalization, and the effects of such variations on immune parameters in blood and tissues are not known. We present here a coordinate analysis of innate and adaptive immune components in blood, lymphoid (bone marrow, spleen, lymph nodes), and mucosal (lungs, intestines) sites from a population of brain-dead organ donors (2 months-93 years; n = 291) across eight clinical parameters. Overall, the blood of donors exhibited similar monocyte and lymphocyte content and low serum levels of pro-inflammatory cytokines as healthy controls; however, donor blood had increased neutrophils and serum levels of IL-8, IL-6, and MCP-1 which varied with cause of death. In tissues, the frequency and composition of monocytes, neutrophils, B lymphocytes and T cell subsets in lymphoid or mucosal sites did not vary with clinical state, and was similar in donors independent of the extent of clinical complications. Our results reveal that organ donors maintain tissue homeostasis, and are a valuable resource for fundamental studies in human immunology.

Assessment of wetland/upland vegetation communities and evaluation of soil-plant contamination by polycyclic aromatic hydrocarbons and trace metals in regions near oil sands mining in Alberta

Oil sands mining in Alberta, Canada, has been steadily increasing over the last 50years. The extent to which the surrounding vegetation has been altered/contaminated by pollutants released during bitumen extraction has not been a focus of oil sands environmental monitoring efforts. The objectives of this study were to assess plant species richness and composition in wetlands and uplands in the vicinity of oil sands mining areas and to measure levels of contamination of trace metals and polycyclic aromatic hydrocarbons (PAHs) in soils and plants. Twenty-two sites were selected in three locations: near to (OS, n=7), West (n=7), and East (n=8) of oil sands mining operations. Aboveground plant species were inventoried and soil was collected for a seedbank study. Soils and plants were collected for analyses of 28 metals and 40 parent and alkylated PAHs. Plant species richness and composition differed significantly among locations. More species were found in the OS sites, many of them being non-native, than in East and West sites, which contained almost exclusively native perennials. PAH levels were significantly higher in OS sites, and were mostly comprised of alkylated PAHs. Patterns of PAH distribution indicated contamination from bitumen/petroleum in four sites; other combustion types may have affected five additional sites at different levels. Metals were also elevated in OS sites. Metal levels were significantly correlated with distance to upgrader facilities. Ratios of some metals in soil vs. above- and belowground plant parts were significantly higher in West and East than in OS sites, likely due in part to pH as soil was acidic at the East and West locations but alkaline at OS sites. This study showed that sites located near oil sands mining operations were contaminated with PAHs and metals, and that the vegetation composition at these sites greatly differed from less disturbed areas.

Evaluating trivalent chromium toxicity on wild terrestrial and wetland plants

Elevated chromium levels in soil from mining can impact the environment, including plants. Mining of chromium is concentrated in South Africa, several Asian countries, and potentially in Northern Ontario, Canada, raising concerns since chromium toxicity to wild plants is poorly understood. In the first experiment, concentration-response tests were conducted to evaluate effects of chromium on terrestrial and wetland plants. Following established guidelines using artificial soil, seeds of 32 species were exposed to chromium (Cr(3+)) at concentrations simulating contamination (0-1000 mg kg(-1)). This study found that low levels of chromium (250 mg kg(-1)) adversely affected the germination of 22% of species (33% of all families), while higher levels (500 and 1000 mg kg(-1)) affected 69% and 94% of species, respectively, from 89% of the families. Secondly, effects on seedbanks were studied using soil collected in Northern Ontario and exposed to Cr(3+) at equivalent concentrations (0-1000 mg kg(-1)). Effects were less severe in the seedbank study with significant differences only observed at 1000 mg kg(-1). Seeds exposed to Cr(3+) during stratification were greatly affected. Seed size was a contributing factor as was possibly the seed coat barrier. This study represents an initial step in understanding Cr(3+) toxicity on wild plants and could form the basis for future risk assessments.

Evaluating trivalent chromium toxicity on wild terrestrial and wetland plants

Elevated chromium levels in soil from mining can impact the environment, including plants. Mining of chromium is concentrated in South Africa, several Asian countries, and potentially in Northern Ontario, Canada, raising concerns since chromium toxicity to wild plants is poorly understood. In the first experiment, concentration-response tests were conducted to evaluate effects of chromium on terrestrial and wetland plants. Following established guidelines using artificial soil, seeds of 32 species were exposed to chromium (Cr(3+)) at concentrations simulating contamination (0-1000 mg kg(-1)). This study found that low levels of chromium (250 mg kg(-1)) adversely affected the germination of 22% of species (33% of all families), while higher levels (500 and 1000 mg kg(-1)) affected 69% and 94% of species, respectively, from 89% of the families. Secondly, effects on seedbanks were studied using soil collected in Northern Ontario and exposed to Cr(3+) at equivalent concentrations (0-1000 mg kg(-1)). Effects were less severe in the seedbank study with significant differences only observed at 1000 mg kg(-1). Seeds exposed to Cr(3+) during stratification were greatly affected. Seed size was a contributing factor as was possibly the seed coat barrier. This study represents an initial step in understanding Cr(3+) toxicity on wild plants and could form the basis for future risk assessments.

Effectiveness of a videotaped behavioral intervention for dental anxiety: the role of gender and the need for information

The authors evaluated the effectiveness of a videotaped behavioral treatment program in reducing dental anxiety. They compared patients who witnessed the intervention videotape with patients who saw a placebo program and with a no-treatment control group. The subjects were 66 patients who visited a dentistry clinic for prophylaxis and general dental treatment. Groups were balanced for gender and level of preference for information as measured by the Krantz Health Opinion Survey--Information subscale. Self-report, physiological, and observed behavioral measures were assessed at specified times. Results demonstrated significant Group X Gender interaction effects during the different assessment periods, with men responding best to the treatment videotape, whereas women responded best to the placebo videotape. The level of information preference was found to a be a significant contributing factor at certain assessment periods. Overall, these results suggest that preparatory videotaped interventions are particularly effective in decreasing dental anxiety when patient characteristics are matched with characteristics of the intervention.

The public health significance of trypanosomiasis (sleeping sickness) in Nigeria

Although trypanosomiasis is no longer a major public health problem in the Federal Republic of Nigeria, it nevertheless remains a significant economic bane to farmers whose livestock suffer high morbidity and mortality and a significant loss of weight. This disease probably leaves many Nigerians, without adequate protein intake either from lost beef or from the inability of the cattle to produce milk. Ford (1970) stated that trypanosomiasis may be what is holding back the development of large areas of Africa--a statement which has credence especially when viewed in terms of the thousands of square miles of Nigeria which remain under the infestation of tsetse--land which could be employed in food production. It is therefore important that the history, epidemiology and control methods for this disease be reviewed from time to time in an attempt to ensure that the surveillance mechanisms in place are functional.