Assessment of Physics Quality Assurance in United States Radiotherapy Facilities and Comparison With American College of Radiology Standard for Radiation Oncology Physics for External Beam Therapy

We have assessed radiation therapy physics quality assurance (QA) elements in the United States and compared the results with the Patterns of Care Study (PCS) Consensus Guidelines for Treatment Planning and the American College of Radiology (ACR) Standard for Radiation Oncology Physics for External Beam Therapy. Data were obtained during PCS site visits to 73 facilities randomly selected from the 1,321 radiation therapy facilities in the United States: 21 academic, 26 hospital, and 26 freestanding. The following is a representative sample of results. The estimated national averages for facilities having QA programs for treatment planning systems, simulators, accelerators, film processors, and blocking systems are 44%, 79%, 94%, 62%, and 55%, respectively. Only 63% of facilities obtain an independent check of their accelerator calibrations from a source outside the facilities obtain an independent check of their accelerator calibrations from a source outside the facility. Twenty-six percent of facilities surveyed did not have in vivo dosimetry capability. These results and others in the study were compared with PCS consensus guidelines and ACR standards, This is the first such study performed in the United States, and the results establish a baseline for future studies. A recommendation for a comprehensive national physics QA study is based on deficiencies found in this study and the implementation of new technologies in radiation therapy.     

Association of race and other potential risk factors with nonvertebral fractures in community-dwelling elderly women.

This study determined potential associations of sociodemographic, lifestyle, health, and drug use factors known to affect bone metabolism with incident nonvertebral fractures. The baseline sample consisted of 2,590 female, nonproxy subjects from the Duke Established Populations for Epidemiologic Studies of the Elderly, which focuses on five adjacent counties in the Piedmont area of North Carolina. Information about potential risk factors was collected during a baseline in-home interview during 1986-1987. Subsequent nonvertebral fractures were reported at follow-up interviews during the annual follow-up periods (1988-1993). The authors used multivariate analyses in which weighted data were adjusted for sampling design. After controlling for other potential confounding sociodemographic, lifestyle, health, and drug use factors, they found that African American race (adjusted odds ratio (OR) = 0.43, 95% confidence interval (CI) 0.31-0.58), age (adjusted OR = 1.04, 95% CI 1.01-1.06), alcohol consumption (adjusted OR = 1.61, 95% CI 1.01-2.57), being underweight (adjusted OR = 1.63, 95% CI 1.13-2.34), cognitive impairment (adjusted OR = 1.67, 95% CI 1.12-2.48), impaired mobility (adjusted OR = 1.15, 95% CI 1.03-1.29), and phenytoin use (adjusted OR = 2.93, 95% CI 1.04-8.30) were associated with first fracture occurrence. Similar findings were observed for nonhip, nonvertebral fractures. African Americans were less likely than Whites to have nonvertebral fractures, and these differences were not related to lifestyle or health factors examined in this study.     

Design and synthesis of potent, selective, and orally bioavailable tetrasubstituted imidazole inhibitors of p38 mitogen-activated protein kinase.

Novel potent and selective diarylimidazole inhibitors of p38 MAP (mitogen-activated protein) kinase are described which have activity in both cell-based assays of tumor necrosis factor-alpha (TNF-alpha) release and an animal model of rheumatoid arthritis. The SAR leading to the development of selectivity against c-Raf and JNK2alpha1 kinases is presented, with key features being substitution of the 4-aryl ring with m-trifluoromethyl and substitution of the 5-heteroaryl ring with a 2-amino substituent. Cell-based activity was significantly enhanced by incorporation of a 4-piperidinyl moiety at the 2-position of the imidazole which also enhanced aqueous solubility. In general, oral bioavailability of this class of compounds was found to be poor unless the imidazole was methylated on nitrogen. This work led to identification of 48, a potent (p38 MAP kinase inhibition IC50 0.24 nM) and selective p38 MAP kinase inhibitor which inhibits lipopolysaccharide-stimulated release of TNF-alpha from human blood with an IC50 2.2 nM, shows good oral bioavailability in rat and rhesus monkey, and demonstrates significant improvement in measures of disease progression in a rat adjuvant-induced arthritis model.     

The cost effectiveness of 3D conformal radiation therapy compared with conventional techniques for patients with clinically localized prostate cancer

Background: We previously demonstrated the advantages of three-dimensional conformal radiation therapy (3DCRT) in improved rates of biochemical (bNED) control in certain subsets of patients with clinically localized prostate cancer. However, in this era of cost consciousness and limited resources, the cost effectiveness of 3DCRT compared with conventional external beam irradiation (CRT) remains unexamined.

Methods and Materials: Between October 1, 1987 and November 30, 1991, 193 patients with clinically localized prostate cancer received definitive external beam irradiation at Fox Chase Cancer Center. The 1998 Medicare fee schedule was used to determine treatment charges and to provide a reference for a national comparison. Complete charges for pretreatment work-up, treatment, and follow-up were tabulated for each patient. The mean total charges (MTC) using the Lin method of estimating medical costs was used to analyze and compare costs between groups. A matched case/control analysis was performed to further evaluate the effect of cost between techniques. The median follow-up was 72 months (range 3–118).

Results: The overall 5-year actuarial rate of bNED control was 41% and 53%, respectively, for the CRT and 3DCRT patients (p = 0.03). The MTC for the CRT patients was $10,544.53. For the 3DCRT patients, the MTC was $8,955.48. The sample mean of the total costs from the observed deaths for the two patient groups by follow-up interval ranged from $9,800.63 to $59,635.01 for the CRT patients to $17,259.00 to $24,250.38 for the 3DCRT patients. No statistically significant difference in cost was observed between groups using the matched case/control analysis.

Conclusion: Initial work-up and treatment costs were greater for patients treated with 3DCRT compared with patients treated with conventional techniques. However, with longer follow-up, the mean total cost of treatment was not statistically different between the two treatment groups. Because of improved rates of bNED control for these patients and the increased costs associated with the treatment of a greater fraction of patients with recurrent disease following CRT, 3DCRT was cost effective for patients with clinically localized prostate cancer.     

Outcome evaluation of the 1997 American Joint Committee on Cancer staging system for prostate carcinoma treated by radiation therapy

BACKGROUND: The 1997 American Joint Committee on Cancer (AJCC) staging system condensed unilobular tumors into one entity and continues the use of both imaging and biopsy to alter classification status in T2 and T3 carcinomas. This study analyzes the biochemical freedom from disease recurrence (bNED) outcome in a large database to determine whether these changes reflect outcome differences. METHODS: Five hundred and thirty-seven patients with adenocarcinoma of the prostate were treated with radiation therapy to a median dose of 7180 centigrays (cGy) (range, 6316-8074 cGy) between November 1987 and November 1994. The median age of the patients was 70 years and the median follow-up was 51 months. The median pretreatment prostate specific antigen (PSA) was 11.0 ng/mL. Patients were analyzed using 1992 AJCC stage comparing bNED outcome after radiation therapy for T2a versus T2b versus T2c tumors using Kaplan-Meier estimation and the log rank test. Patients then were analyzed multivariately using Cox regression with the known prognostic variables of dose, pretreatment PSA, palpation stage, and grade in addition to palpation plus imaging stage and palpation plus biopsy stage. The prognostic endpoint was bNED with failure as defined by the 1997 American Society for Therapeutic Radiology and Oncology Consensus Panel. RESULTS: The 1992 AJCC palpation classifications T2a versus T2b versus T2c have a significantly different (P = 0.02) bNED outcome. Prognostic significance is lost by pooling these three classifications in the 1997 AJCC staging system. Adding imaging information to palpation did not improve the ability of palpation alone to assess bNED status (P = 0.33). However, the addition of biopsy information to palpation significantly (P = 0.02) increased the accuracy of palpation stage alone to predict for bNED outcome for T2 and T3 tumors. CONCLUSIONS: The subdivision of T2 tumors in the 1992 AJCC classification (T2a, T2b, and T2c) should be used in the next revision of the 1997 AJCC staging system. The addition of imaging data does not discriminate bNED outcome any better than palpation stage alone in T2 and T3 tumors and should not be used. The addition of biopsy information to palpation stage did significantly improve the predicted outcome compared with palpation alone and should continue to be used.     

Phoenix date palm injuries: a review of injuries from the Phoenix date palm treated at the Starship Children's Hospital

BACKGROUND: The purpose of this study was to review patients treated for penetrating Phoenix date palm injuries. Documentation of the clinical behaviour of these injuries was sought as they have different clinical outcomes to other foreign body injuries. METHODS: Data was collected via a retrospective review of patient files and imaging studies of all patients with foreign body injury admitted to the Orthopaedic Service of Starship Children's Hospital between 1992 and 1997. RESULTS: Of 250 patients admitted with foreign body injuries, 21 cases were identified as caused by the Phoenix date palm. The age range was 5 to 12 years. There was a median delay of 43 days between the time of injury and presentation to hospital. An average of 1.3 operations were performed on each patient. Ultrasound was used in 12 cases, foreign body was identified in 10 patients--a sensitivity of 83%. Intraoperative ultrasound was also found to be beneficial in three of these cases. CONCLUSIONS: Phoenix date palm injuries often have a protracted course. The initial diagnosis and treatment of such injuries is often delayed. Fracturing and fragmentation of the barbs may occur and multiple surgical procedures may be required to remove all of the foreign material. The Phoenix date palm barbs may cause a severe tissue reaction with sterile granulomatous synovitis and bony pseudotumour formation. A high level of suspicion on history taking and surgical exploration is needed. Total synovectomy for delayed joint or tendon sheath involvement may be required when fragmentation has occurred. Ultrasound has higher sensitivity for detection of thorn foreign bodies than magnetic resonance imaging.     

心肌血流储备分数在选择冠脉介入治疗中的应用

目的 评价心肌血流储备(myocardial fractional flowreserve，FFRmyo)分数在选择冠脉介入治疗中的作用。方法 选择冠脉狭窄在50％～70％之间、FFRmyo≥0．75的患者12例，随机分成进行和不进行冠脉介入治疗两组，治疗后每3个月进行活动平板试验，对心脏状况进行评价，共12个月。结果 对于FFRmyo值≥0．75的患者，无论是否进行冠脉介入治疗，心脏事件发生率、临床症状改善程度均无明显差别。结论 FFRmyo是冠脉狭窄功能评价的理想指标，对指导临床治疗以及治疗的正确选择具有重要价值。