Generating lung tumor internal target volumes from 4D-PET maximum intensity projections.

PURPOSE: Positron emission tomography (PET) of lung tumors suffers from breathing-motion induced blurring. Respiratory-correlated PET ameliorates motion blurring and enables visualization of lung tumor functional uptake throughout the breathing cycle but has achieved limited clinical use in radiotherapy planning. In this work, the authors propose a process for generating a gated PET maximum intensity projection (MIP), a breathing-phase projection of the 4D image set comprising gated PET images, as a technique to quantitatively and efficiently incorporate respiratory-correlated PET information into radiotherapy treatment planning. METHODS: 4D-CT and respiratory-gated PET using [(18)F]fluorodeoxyglucose (FDG) were acquired of three patients with a total of four small (4-18 cc), clearly defined lower-lobe lung tumors. Internal target volumes (ITVs) for the lung tumors were generated by threshold-based segmentation of PET-MIP images and ungated PET images (ITV(PET-MIP) and ITV(3D-PET), respectively), and by manual contouring of CT-MIP and end-exhale and end-inhale phases of 4D-CT (ITV(CT-MIP)) by a radiation oncologist. Because of the sensitivity of tumor segmentation to threshold value, several different thresholds were tested for ITV generation, including 40%, 30%, and 20% of maximum standardized uptake value (SUV(max)) for FDG as well as absolute SUV thresholds of 2.5 and 3.0. The normalized overlap and relative volumes of ITV(PET-MIP) and ITV(3D-PET) with respect to ITV(CT-MIP) were compared. The images were also visually compared. ITV(CT-MIP) was considered a gold standard for these tumors with CT-visible morphology. RESULTS: The mean and standard deviation normalized overlap and relative volumes between ITV(PET-MIP) and ITV(CT-MIP) were 0.68 ± 0.07 and 1.07 ± 0.42, respectively, averaged over all four tumors and all five threshold values. The mean and standard deviation normalized overlap and relative volumes of ITV(3D-PET) and ITV(CT-MIP) were 0.47 ± 0.12 and 0.69 ± 0.56, respectively. CONCLUSIONS: PET-MIP images better match CT-MIP images for this sample of four small CT-visible tumors as compared to ungated PET images, based on the metrics of volumetric overlap and relative volumes as well as visual interpretation. The PET-MIP is a way to incorporate 4D-PET imaging into the process of lung tumor contouring that is time-efficient for the radiation oncologist and involves minimal effort to implement in treatment planning software, because it requires only a single PET image beyond contouring on CT alone.

The relationship between plasma t-PA and PAI-1 levels is dependent on epistatic effects of the ACE I/D and PAI-1 4G/5G polymorphisms.

Thrombus formation and degradation is partly due to a complex interplay between tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1). There is accumulating evidence that plasma levels of t-PA and PAI-1 may be influenced by an interaction between the fibrinolytic and renin-angiotensin systems. The goal of this study was to conduct an exploratory data analysis to determine whether there is evidence that the relationship (i.e. correlation) between plasma t-PA and PAI-1 is influenced by interactive effects of the angiotensin converting enzyme (ACE) insertion/deletion (I/D) and plasminogen activator inhibitor 1 (PAI-1) 4G/5G polymorphisms in a sample of 50 unrelated African Americans and 117 unrelated Caucasians. In a single-locus analysis, no evidence for heterogeneity of plasma t-PA and PAI-1 correlations among either ACE I/D or PAI-1 4G/5G genotypes was detected. However, using the combinatorial partitioning method for exploratory data analysis, we identified evidence that is suggestive of heterogeneity of plasma t-PA and PAI-1 correlations among multilocus ACE I/D and PAI-1 4G/5G genotypes in African American females, Caucasian females, Caucasian males, but not African American males. From these results, we propose as a working hypothesis that the correlation between plasma t-PA and PAI-1 may be dependent on epistatic effects of the ACE I/D and PAI-1 4G/5G polymorphisms. This study supports the idea that interactions between the fibrinolytic and renin-angiotensin systems play an important role in the genetic architecture of plasma t-PA and PAI-1.

A comparison of combinatorial partitioning and linear regression for the detection of epistatic effects of the ACE I/D and PAI-1 4G/5G polymorphisms on plasma PAI-1 levels.

The detection and characterization of epistasis or non-additive gene-gene interactions remains a statistical challenge in genetic epidemiology. The recently developed combinatorial partitioning method (CPM) may overcome some of the limitations of linear regression for the exploratory analysis of non-additive epistatic effects. The goal of this study was to compare CPM with linear regression analysis for the exploratory analysis of non-additive interactive effects of the angiotensin converting enzyme (ACE) insertion/deletion (I/D) and plasminogen activator inhibitor 1 (PAI-1) 4G/5G polymorphisms on plasma PAI-1 levels in a sample of 50 unrelated African Americans and 117 unrelated Caucasians. Using linear regression, we documented the additive effects of the ACE and PAI-1 genes on plasma PAI-1 levels in African American females (R(2) = 0.10), African American males (R(2) = 0.16), Caucasian females (R(2) = 0.11), and Caucasian males (R2 = 0.09). Using CPM, we found evidence for non-additive effects of the ACE and PAI-1 genes in both African American females (R(2) = 0.22) and African American males (R(2) = 0.24) but not in Caucasian females (R(2) = 0.10) or Caucasian males (R(2) = 0.11). The results of this exploratory data analysis support previous experimental, clinical, and epidemiological studies that have proposed as a working hypothesis that the ACE gene mediates interaction effects of the fibrinolytic and renin-angiotensin systems on plasma levels of PAI-1.

Sensitivity and specificity of the indicators of sincere effort of the EPIC lift capacity test on a previously injured population.

STUDY DESIGN: Randomized control post-test only. OBJECTIVES: To investigate the reliability and validity of the EPIC Lift Capacity test's indicators of sincere effort. SUMMARY OF BACKGROUND DATA: The EPIC Lift Capacity test (ELC) (Employment Potential Improvement Corp., Santa Ana, CA) is a functional evaluation tool used to identify physical limitations involved in lifting and manual materials handling. Identification of insincere effort is an integral component of such functional testing because of the potential secondary gain issues surrounding the various populations typically involved in this form of testing. The purpose of this study was to determine the sensitivity and specificity of the "indicators of sincere effort" of the EPIC Lift Capacity test when used on a previously injured population typical of subjects for which the test is designed. METHODS: Subjects consisted of 41 volunteers (age 22 to 58 years) with a previously diagnosed musculoskeletal pathology of the spine or extremities. Volunteers were randomized into either the control group, instructed to give a sincere maximum effort, or the experimental group, instructed to give an insincere effort at 50% of their perceived maximum effort. All tests were administered by certified clinical evaluators according to the standardized EPIC Lift Capacity test protocol.- RESULTS: Overall accuracy in identifying participants' level of effort was 86.84%. The indicators of valid effort exhibited both high positive (94.44%) and negative (80.00%) predictive values. The indicators of valid effort accounted for 94.9% of the total variance in the determination of the subjects' overall effort level. Interrater reliability for agreement of subjects' overall effort was good (interclass correlation coefficient = 0.82). CONCLUSIONS: Through use of standardized indicators of sincere effort, certified EPIC Lift Capacity test evaluators were able to predict sincerity of effort with a high degree of reliability and validity. The rater's systematicobservational evaluation of effort was shown to be the single best indicator of sincere effort.

School-based intervention to promote coping in rural teens.

PURPOSE: To evaluate a program designed to help high school students with depressive symptomology to effectively cope. DESIGN: Two-phase experimental study. METHODS: Rural high school students (N = 222), ages 14 through 19 years, were surveyed to identify teens with depressive symptomatology, identify stressful life events and coping styles of at-risk subjects, and evaluate a cognitive-behavioral group intervention to enhance students' coping and affect levels of depression. Students with depressive symptomatology were randomized into control (n = 18) or intervention (n = 23) groups. Intervention subjects were treated with a nurse-led, 8-week cognitive skills group, conducted at school. RESULTS: On posttesting, the intervention groups demonstrated reduced depressive symptoms in females and a wider range of coping compared with controls. CLINICAL IMPLICATIONS: School-based nurses are in an ideal position to provide assessment, referral, and intervention programs in the natural setting of the school. Results of this study indicate that such programs can be implemented successfully in schools and have the potential to promote mental health in teenagers.

Consideration of factors prior to implementing a smoking cessation program.

This small feasibility study evaluated access, recruitment, and retention of pregnant African-American teens for a subsequent smoking cessation intervention program. A clinic and a school site were selected to assess these factors. Only the school site proved successful. Strengths of the school site included: structure and routine for students, a comfortable and familiar setting, recruitment by school personnel who had a relationship with students, and full support by administrators and staff.

When a baby dies: rights of the baby and parents.

The Rights of Parents When a Baby Dies and Rights of the Baby were developed by the Perinatal Bereavement Team at Women's College in Toronto, Canada. With permission, the National Office of SHARE: Pregnancy and Infant Loss Support, Inc. has revised and expanded these documents for distribution within the United States. The Rights are intended to help caregivers and institutions provide parents with information about their options regarding the death of their baby and allow them time and support for decision making.

Examining the common stressors and coping methods of rural adolescents.

The major objective of this study was to explore and examine common stressors and coping strategies of rural adolescents. Coping was defined as a cognitive and transactional process between a person and the person's environment. A survey of 222 normal adolescents attending a rural southwestern Pennsylvania high school reported experiencing stressful events related to school, family, friendship, health, and transportation. The coping strategy reported as being the most commonly used was optimistic. However, the coping strategy reported to be most effective in dealing with stressful events was supportant. The results of this study contribute to the limited information on adolescent coping in rural areas. This study should help health care providers further their understanding of this vulnerable population. Clinicians can enhance the effective coping and overall health of the rural adolescent by screening for and discussing coping strategies.

Conservative treatment for adenocarcinoma of the pancreas.

The records of 71 patients with the diagnosis of adenocarcinoma of the pancreas were reviewed. Seventeen patients were treated without surgery, 13 underwent exploratory laparotomy for diagnosis with no further palliative or curative operative procedure, six underwent pancreaticoduodenal resection, and 35 patients had a palliative gastric and/or biliary bypass procedure at initial operation. No preoperative signs or symptoms, routine laboratory tests, or radiologic evaluation were helpful as early diagnostic or prognostic indicators. Surgical mortality rates were not significantly different among the four groups; however, the survival time differences between the palliative group (4.8 mo) and the medically managed group (2.0 mo) was significant (p = 0.01 chi 2). Surgical morbidity did not differ significantly among the four groups of patients. The implications of these data in the treatment of patients with adenocarcinoma of the pancreas are discussed.

The rapprochement subphase of the separation-individuation process.

The dynamics of the rapprochement subphase of the separation-individuation process are examined. Individual solutions to rapprochement as well as the mother's role in promoting a successful outcome of this process are discussed.

Factors involved in disruption of intestinal anastomoses.

Bowel anastomoses, as performed on 181 dogs, were studied: (1) by interposing segments of colon into small bowel and vice versa, (2) by comparing clean anastomoses to those contaminated by feces before and after suturing, (3) with and without parenteral preoperative antibiotic, and (4) with and without coaptation of an inverted serosa. All animals with a timed sacrifice as well as an unexplained death had careful autopsy. Results demonstrated no difference in the healing capacity of large (91%) versus small (92%) intestine under identical circumstances. Intraluminal bacteria were of importance only if spillage caused contamination during operation and thereby subsequent infection of the peritoneal surface of the suture line. Peritonitis preceded all 28 leaks, yet the converse never occurred. Likelihood of a complicating peritonitis (67%) and thus an anastomotic leak (24%) was significantly reduced through the preoperative administration of prophylactic cefazolin (19 and 4%, respectively). A "serosal seal" also appeared important in obviating suture line disruption. Our data emphasize the value of an inverted and serosal lined anastomosis, bowel preparatory measures, prophylactic antibiotic, and the disruptive action of local bacterial peritonitis.

Use of pedicled omentum as an autogenous pack for control of hemorrhage in major injuries of the liver.

Since massive hemorrhage from the traumatized liver is usually caused by disruption of the deeply situated hepatic veins, repair or resection is seldom practical. Instead, after appropriate debridement has been accomplished, such venous bleeding can rapidly and effectively be controlled by packing autogenous omentum, based on its respective gastroepiploic vessels, into the hepatic fracture crease. The liver edges are then oversewn, and sump drainage is installed. An experience with the use of this technique in 37 patients has demonstrated its almost uniform success.