Contamination dose from photoneutron processes in bodily tissues during therapeutic radiation delivery

Dose to the total body from induced radiation resulting from primary exposure to radiotherapeutic beams is not detailed in routine treatment planning though this information is potentially important for better estimates of health risks including secondary cancers. This information can also allow better management of patient treatment logistics, suggesting better timing, sequencing, and conduct of treatment. Monte Carlo simulations capable of taking into account all interactions contributing to the dose to the total body, including neutron scattering and induced radioactivity, provide the most versatile and accurate tool for investigating these effects. MCNPX code version 2.2.6 with full IAEA library of photoneutron cross sections is particularly suited to trace not only photoneutrons but also protons and heavy ion particles that result from photoneutron interactions. Specifically, the MCNPX code is applied here to the problem of dose calculations in traditional (non-IMRT) photon beam therapy. Points of calculation are located in the head, where the primary irradiation has been directed, but also in the superior portion of the torso of the ORNL Mathematical Human Phantom. We calculated dose contributions from neutrons, protons, deutrons, tritons and He-3 that are produced at the time of photoneutron interactions in the body and that would not have been accounted for by conventional radiation oncology dosimetry.

High-dose-rate brachytherapy for vaginal cancer: Learning from treatment complications

Abstract.

Tyree WC, Cardenes H, Randall M, Papiez L. High-dose-rate brachytherapy for vaginal cancer: learning from treatment complications.

Historically, early stage vaginal cancer has been treated with low-dose-rate (LDR) brachytherapy with or without external beam radiation therapy (EBRT). Complication rates have been low and treatment efficacious. Although high-dose-rate (HDR) brachytherapy has been used for cervical cancer in many countries for over a decade, only more recently has it been integrated into treatment plans for vaginal cancer. This paper describes three patients treated with HDR brachytherapy who experienced significant late effects. Given the very limited amount of literature regarding the use of HDR brachytherapy in vaginal cancer, this analysis potentially contributes to an understanding of treatment-related risk factors for complications among patients treated with this modality.

A focused review of hospital and departmental treatment records was done on three patients treated with HDR brachytherapy. Abstracted information included clinical data, treatment parameters (technique, doses, volume, combinations with other treatments) and outcomes (local control, survival, early and late effects). A review of the available literature was also undertaken.

All patients had significant complications. Although statistical correlations between treatment parameters and complications are impossible given the limited number of patients, this descriptive analysis suggests that vaginal length treated with HDR brachytherapy is a risk factor for early and late effects, that the distal vagina has a lower radiation tolerance than the upper vagina with HDR as in LDR, and that combining HDR with LDR as done in our experience carries a high risk of late toxicity.

Integration of HDR brachytherapy techniques into treatment plans for early stage vaginal cancers must be done cautiously. The etiology of the significant side effects seen here is likely to be multifactorial. For users of HDR brachytherapy in vaginal cancer, there is a need to further refine and standardize treatment concepts and treatment delivery. Ideally this will be based on continued careful observation and reporting of both favorable and unfavorable outcomes and experiences.

High-dose-rate brachytherapy for vaginal cancer: learning from treatment complications

Historically, early stage vaginal cancer has been treated with low-dose-rate (LDR) brachytherapy with or without external beam radiation therapy (EBRT). Complication rates have been low and treatment efficacious. Although high-dose-rate (HDR) brachytherapy has been used for cervical cancer in many countries for over a decade, only more recently has it been integrated into treatment plans for vaginal cancer. This paper describes three patients treated with HDR brachytherapy who experienced significant late effects. Given the very limited amount of literature regarding the use of HDR brachytherapy in vaginal cancer, this analysis potentially contributes to an understanding of treatment-related risk factors for complications among patients treated with this modality.A focused review of hospital and departmental treatment records was done on three patients treated with HDR brachytherapy. Abstracted information included clinical data, treatment parameters (technique, doses, volume, combinations with other treatments) and outcomes (local control, survival, early and late effects). A review of the available literature was also undertaken. All patients had significant complications. Although statistical correlations between treatment parameters and complications are impossible given the limited number of patients, this descriptive analysis suggests that vaginal length treated with HDR brachytherapy is a risk factor for early and late effects, that the distal vagina has a lower radiation tolerance than the upper vagina with HDR as in LDR, and that combining HDR with LDR as done in our experience carries a high risk of late toxicity. Integration of HDR brachytherapy techniques into treatment plans for early stage vaginal cancers must be done cautiously. The etiology of the significant side effects seen here is likely to be multifactorial. For users of HDR brachytherapy in vaginal cancer, there is a need to further refine and standardize treatment concepts and treatment delivery. Ideally this will be based on continued careful observation and reporting of both favorable and unfavorable outcomes and experiences.

Reliability of the Melbourne assessment of unilateral upper limb function

This study examines the reliability of the Melbourne Assessment of Unilateral Upper Limb Function: a quantitative test of quality of movement in children with neurological impairment. The assessment was administered to 20 children aged from 5 to 16 years (mean age 9 years 10 months, SD 2 years 10 months) who had various types and degrees of cerebral palsy (CP). The performances of the 20 children during assessment were videotaped for subsequent scoring by 15 occupational therapists. Scores were analyzed for internal consistency of test items, inter- and intrarater reliability of scorings of the same videotapes, and test-retest reliability using repeat videotaping. Results revealed very high internal consistency of test items (alpha=0.96), moderate to high agreement both within and between raters for all test items (intraclass correlations of at least 0.7) apart from item 16 (hand to mouth and down), and high interrater reliability (0.95) and intrarater reliability (0.97) for total test scores. Test-retest results revealed moderate to high intrarater reliability for item totals (mean of 0.83 and 0.79) for each rater and high reliability for test totals (0.98 and 0.97). These findings indicate that the Melbourne Assessment of Unilateral Upper Limb Function is a reliable tool for measuring the quality of unilateral upper-limb movement in children with CP.

2-microm Doppler lidar transmitter with high frequency stability and low chirp

A coherent Doppler lidar system was frequency stabilized in a master-slave configuration by a phase-modulation technique. The short-term frequency stability, ~0.2 MHz rms, was maintained in a vibrational environment on a ship during a field campaign in the tropical Pacific Ocean. The long-term frequency stability was <2.6 kHz/h. Thus, in many applications, shot-to-shot frequency correction can be disregarded, which will result in increased speed and simplicity of the data-acquisition system. A frequency chirp could not be detected. These properties permit Doppler wind measurements with high efficiency and duty cycles to be made, even on airborne and spaceborne platforms.

Comparison of outcomes by gender and for fee-for-service versus managed care: a study of nine community programs

During-treatment services and 7-month posttreatment entry outcome of cocaine- or alcohol-dependent men (n = 145) and women (n = 149) Target City patients receiving either standard fee-for-services (n = 183) or managed care treatment funding (n = 111) in nine community outpatient programs were compared. No differences were found in treatment services received by the various subgroups. Regression analyses compared the four described subgroups (Gender x Type of Funding) on their seven Addiction Severity Index composite scores at 7 months postadmission controlling for the respective baseline composite score and several background variables on which the groups differed. Surprisingly few outcome differences were revealed between men and women patients and patients receiving the two forms of treatment funding. The only difference noted was that patients treated via managed care showed more improvement in the drug area. The need for further evaluation of the effects of managed care is emphasized.

Risk of transmission of tuberculosis among inmates of an Australian prison

In a prison in Victoria, Australia, our objectives were contact tracing of inmates and staff at risk of exposure to an identified index case; and to determine risk factors for prevalent and incident infection. Inmates and staff who were potentially exposed to the index case were screened with a Mantoux skin test and a questionnaire. Inmate movements within the prison were compared to movements of the index case. Logistic regression was used to determine risk factors for infection. The index case had smear positive, cavitating pulmonary tuberculosis (TB), which was undiagnosed for 3 months. This was the period of potential exposure. The prevalence of positive skin test reactions in 190 inmates and staff at the prison was 10%. Significant predictors of a positive skin test were being an inmate (odds ratio (OR) 15.5), older age (OR 8.3) and being born overseas (OR 10.7). Bacille Calmette Guerin (BCG) vaccination, proximity to the index case in various prison sites, duration of incarceration, number of incarcerations and number of inmates per cell were not significant. There were three recent skin test conversions from negative to positive, representing a conversion rate of 3.5%. We did not find evidence of significant transmission of TB from a single index case. The prevalence of infection in this Australian prison was lower than published rates in other countries. Better prison conditions and different demographics of prison inmates in Australia may explain these differences.

FIGO stage IIIC endometrial carcinoma with metastases confined to pelvic lymph nodes: analysis of treatment outcomes, prognostic variables, and failure patterns following adjuvant radiation therapy

OBJECTIVES

This study was undertaken to evaluate the prognostic significance of isolated positive pelvic lymph nodes on survival and to analyze other prognostic variables, overall survival, and failure patterns in surgically staged endometrial carcinoma patients with positive pelvic lymph nodes and negative para-aortic lymph nodes following radiation therapy (RT).

METHODS

Between January 1, 1987, and December 31, 1997, 782 women underwent primary treatment for uterine cancer at Indiana University Medical Center. Through a review of the medical records, we identified 58 patients with pathologic stage IIIA, 27 patients with pathologic stage IIIB, and 77 patients with pathologic stage IIIC endometrial carcinoma. Patients with pathologically positive or unsampled para-aortic lymph nodes and patients who received preoperative radiation therapy were excluded, leaving a study group of 17 patients with nodal metastases confined to pelvic lymph nodes. Thirteen patients received adjuvant pelvic RT using AP-PA or four-field technique. A median dose of 5040 cGy was delivered. Four patients received whole abdominal irradiation (WAI) delivering a median dose of 3000 cGy. Two patients received vaginal cuff boosts of 1000 and 3560 cGy to 0.5 cm from the vaginal surface mucosa via Cs-137 brachytherapy. Two patients also received adjuvant chemotherapy (cis-platinum and doxorubicin) and/or hormonal therapy (megestrol acetate). Disease-free and overall survivals were estimated using the Kaplan-Meier method of statistical analysis and prognostic variables were analyzed using the log-rank test.

RESULTS

With a median follow-up of 51 months the actuarial 5-year disease-free survival was 81% and the actuarial 2-year and 5-year overall survival rates were 81 and 72%, respectively. Univariate analysis revealed that positive peritoneal cytology in conjunction with positive pelvic lymph nodes imparts a greater risk of recurrence and decreased overall survival. There were no pelvic and/or upper abdominal failures, but there were recurrences in the para-aortic lymph nodes (two patients) and distantly (two patients).

CONCLUSION

Surgery followed by postoperative pelvic RT is a viable treatment option for pathologically staged stage IIIC endometrial carcinoma with disease confined to the pelvic lymph nodes. Failures in the para-aortic region suggest a possible role for extended-field RT. Patients with positive peritoneal cytology in conjunction with nodal metastasis fared poorly with pelvic RT. Studies evaluating the efficacy of WAI are ongoing. Finally, substages within FIGO stage IIIC are recommended in an effort to better understand and define treatment strategies which might be appropriate for these patients.

CO(2) microdialysis in retrotrapezoid nucleus of the rat increases breathing in wakefulness but not in sleep

Central chemoreceptors are widespread within the brain stem. We suggest that their function at some sites may vary with the state of arousal. In this study, we tested the hypothesis that the function of chemoreceptors in the retrotrapezoid nucleus (RTN) varies with sleep and wakefulness. In unanesthetized rats, we produced focal acidification of the RTN by means of a microdialysis probe (tip containing the semipermeable membrane = 1-mm length, 240-microm diameter, and 45-nl volume). With the use of a dialysate equilibrated with 25% CO(2), the tissue pH change (measured in anesthetized animals) was 1) limited to within 550 microm of the probe and, 2) at the probe tip, was equivalent to that observed with end-tidal PCO(2) of 63 Torr. This focal acidification of the RTN increased ventilation significantly by 24% above baseline, on average, in 13 trials in seven rats only during wakefulness. The effect was entirely due to an increase in tidal volume. During sleep defined by behavioral criteria, ventilation was unaffected, on average, in 10 trials in seven rats. During sleep, the chemoreceptors in the RTN appear to be inactive, or, if active, the respiratory control system either is not responding or is responding with very low gain. Because ventilation is increased during sleep with all central chemoreceptor sites stimulated via systemic CO(2) application, other central chemoreceptor locations must have enhanced effectiveness.

Tuberculosis. The old and the new

BACKGROUND

The overall incidence of tuberculosis (TB) in the general Australian population is low and has been stable over the past 10 years. The incidence is, however, much higher in certain subgroups of the population and these include overseas-born people (especially from countries in Asia) and Aboriginal and Torres Strait Islander populations. Other groups regarded as at increased risk of TB are nursing home residents, the homeless, prison populations and immunosuppressed patients, especially those who are HIV positive.

OBJECTIVE

Patients regarded as high risk should be investigated promptly if they present with signs or symptoms suggestive of TB.

DISCUSSION

The best method of preventing the transmission of TB and preventing the emergence of drug resistant strains of the organism are by ensuring that sputum smear positive patients are isolated till non-infectious; that any patient with TB receives prompt and adequate treatment; that all patients with TB comply with a full course of treatment till cured: and that contact tracing is undertaken to detect newly infected patients so as to offer chemoprophylaxis and to detect previously unrecognised cases.

Assessment of psychosocial stressors and maladjustment among foreign students of the University of the Ryukyus

An extensive survey of problems encountered by foreign students of the University of the Ryukyus and the resulting levels of stress was carried out in order to determine the main stressors hindering academic progress and personal adjustment. Subjectively perceived stress levels after arrival in Japan were obtained from 134 subjects through a comprehensive questionnaire for reporting specific stressors. The 30-item General Health Questionnaire (GHQ) was included to assess mental health state. Differences in scores by area of origin were also determined for the total GHQ scores and its sub-scales. The GHQ results showed that regardless of length of time in Japan, more than 60% of the subjects scored within a range usually indicative of a mental health risk. Mean scores by area of origin showed a 50% reduction over time for non-Chinese Asians and North American/Europeans, but only a reduction of 1.1% or less for Chinese, Latin American, Middle/Near Eastern and African subjects. Limitations in achievement of academic goals were reported by the greatest number of students as causing moderate to excessive stress (57.5%); most frequently reported causes were language inadequacy (55.2%), reference materials unavailable (34.3%), unfamiliarity with Japanese study methods (32.1%), and inadequate guidance from teachers/advisors (26.9%). Various social, personal and daily life problems in the non-academic setting were also reported as causing high stress levels. Most of the stressors identified are not considered inevitable and point toward directions to pursue in preventive strategies in mitigating psychological distress and maladjustment of students.

Problem-service 'matching' in addiction treatment. A prospective study in 4 programs

BACKGROUND

Our initial attempts to "match" substance-abuse patients from an employee assistance program to an optimal setting or program failed. Scientifically, we found no differential predictors of better outcomes by setting or program. From a practical perspective, it was impossible to place patients in the intended programs. This led to a second study, designed to identify specific patient problems and match professional services to those problems within each of the 4 programs.

METHODS

Ninety-four new patients admitted to 4 substance-abuse treatment programs were randomly assigned to standard treatment and treated in the usual manner or were assigned to "matched" services, in which patients received at least 3 professional sessions directed at their important employment, family, or psychiatric problems.

RESULTS

Matched patients stayed in treatment longer, were more likely to complete treatment, and had better posttreatment outcomes than did the standard patients treated in the same programs.

CONCLUSIONS

For logistical, financial, and clinical reasons, it is improbable that patients will be matched to specific types of programs. However, within any program, it is possible and practical to match appropriate services to patients' specific treatment problems. This strategy was clinically and administratively practical, attractive to patients, and responsible for a 20% to 30% increase in the effectiveness of this substance-abuse treatment system.

"Intensive" outpatient substance abuse treatment: comparisons with "traditional" outpatient treatment

Do "intensive," freestanding outpatient substance abuse treatment programs actually provide more intensive services than "traditional" outpatient programs? Three hundred and thirty-eight patients in 6 "intensive" outpatient (IO) programs (three or more times weekly) were compared with 580 patients from 10 "traditional" outpatient (TO) programs (one or two times weekly) on severity of admission problems, treatment services received and six month outcomes.

RESULTS

1. IO subjects generally had the most severe medical, employment, legal and psychiatric problems at admission. 2. IO patients received more alcohol and drug focused services; but fewer medical and employment focused services than the TO patients. Both groups received very few psychosocial services. 3. There were not significant differences between the IO and TO program samples at follow-up. However, both groups showed significant reductions in substance use, improvements in personal health and social function.

Attitudes of medical students towards persons with mental disorders: a comparative study between Japan and Thailand

This study was conducted at three universities, two in Japan and one in Thailand, in order to elucidate the effects of medical education, especially with regard to contact experience on medical students' attitudes toward persons with mental disorders. Questionnaires, which included the Attitudes Towards Disabled Persons Scale (ATDP) and the Contact with Disabled Persons Scale (CDP), were distributed to 1st year students prior to the commencement of their medicine/psychiatry studies and distributed to 6th (or 5th) year students who had completed their psychiatric curriculum. The ATDP scores were lower for 6th year students at all universities, suggesting that post-education students had a more unfavorable attitude than pre-education students. Thai students indicated more unfavorable attitudes than did the Japanese students. Three factors were extracted from the ATDP scale and termed: negation of character, negation of ability and affirmation of normality. Four factors from the CDP scale were extracted and labeled intimate contact experience, ordinary contact experience, unpleasant contact experience and pleasant contact experience. Greater negative attitudes of post-education students than pre-education students were thought to attribute mainly to an increase in factor score of negation of ability and this result was correlated with an increase in factor score of ordinary contact experience in post-education students. Of the three ATDP factor scores, the higher score of Thai students for negation of character contributed to their overall unfavorable attitude scores. The cross-national similarities and differences of students' attitudes towards and contact experience with mentally disordered persons were discussed from the viewpoint of medical education.

Sexual violence in women's lives. Findings from the Women's Safety Project, a community-based survey

This article is a summary of the methods and quantitative prevalence findings from a community-based study of sexual violence in women's lives. The research was based on in-depth face-to-face interviews with 420 women who comprised a random sample of women living in the city of Toronto, Canada's largest urban center. The study generated findings on the prevalence and effects of various forms of sexual abuse and violence in women's lives, including an exploration of the links between these forms of violence over the course of women's lifetimes. Sexual abuse in childhood (including incest), sexual assault, sexual harassment, and physical assault in intimate relationships were documented, as was revictimization and the increased vulnerability for sexual assault and violence experienced by many women sexually abused in childhood. Among the findings were that 1 in 4 women in the sample was physically assaulted by a male intimate, 1 in 2 women reported being raped or experiencing an attempted rape, and nearly half of the respondents reported experiencing some kind of sexual abuse before reaching 16 years of age.

Reliability and validity of the Addiction Severity Index with a homeless sample

The Addiction Severity Index (ASI) is an instrument widely used to assess the treatment problems of substance users. Its psychometric properties have been tested and found satisfactory for many types of substance abusers entering treatment. However, there are many other subgroups of substance users not in formal treatment, such as homeless substance users. While the ASI has been used with this subgroup, its psychometric properties remain questionable. This study examined the reliability and validity of the ASI in a sample of 98 homeless substance users awaiting temporary housing placement. Test-retest reliability found the ASI to have moderate to high reliability coefficients in each of the seven domains assessed. Both composite score and severity rating measures were found to be quite independent with low intercorrelations. Three of the seven ASI composite scores were tested for and found to have moderate concurrent validity: alcohol (r = .31 to .36), drug (r = .46), and psychiatric (r = .53 to .66). Composite score interitem correlations were .70 or greater in each of the domains except for employment (.50) and family (.52). These data suggest that, although there are some limitations in using the ASI with homeless substance users, it demonstrated acceptable reliability and validity.

Infection in immunocompromised patients with malignant blood disorders in a district general hospital

The pattern and management of infection in immunocompromised patients over a period of 3 years in a district general hospital has been studied. A total of 222 positive cultures was obtained in 607 episodes of suspected infection all involving patients with malignant blood disorders. Febrile episodes requiring intravenous antibiotics occurred in 248 instances involving 107 patients. The pattern of organisms cultured and the responses to various antibiotic regimes are reported. The costs of antibiotic therapy are considered in the light of the overall response. Of the patients studied, 54 died, infection having a likely causative or contributory part in 21 of them (less than 10% of infective episodes). We conclude that the infective complications of these disorders, particularly in older patients, can be efficiently managed in a district general hospital when full supportive facilities are available.

Comparative voice results after laser resection or irradiation of T1 vocal cord carcinoma

OBJECTIVE

To compare voice results following laser resection or radiation therapy for T1a glottic carcinomas.

DESIGN

Objective recordings of acoustical data that were analyzed and calculated by an acoustic analyzer and subjective scores by patients, speech therapists, surgeons, and radiation therapists are compared.

SETTING

Academic medical center speech laboratory at an institution where patients had been treated. Archival files were searched and patients were solicited by letter to participate in this analysis.

PATIENTS

Men treated at least 6 months previously and who were without active laryngeal disease. Criteria were unilateral vocal cord carcinomatous involvement with no subglottic, anterior commissure, or arytenoid extension and tumor invasion clinically judged to be less than half of the cordal depth.

INTERVENTIONS

Thirteen patients had received approximately 63 Gy in 28 fractions, five fractions a week, with laterally opposed fields using a linear accelerator. Eleven patients had had resection of less than half of the cordal depth by using a carbon dioxide laser with a 300-microns spot size working at a 400-mm distance; 13- to 15-W power intensity with a one tenth of a second burn in a noncontinuous mode.

RESULTS

No statistically significant differences between the two study groups were found. Patients and physicians subjectively rated (1 indicates normal; 5, aphonic) the quality of voices of patients in the irradiation group (1.5 and 2.0) as slightly better than the quality of voices of patients in the laser group (2.0 and 2.4). Speech pathologists rated the voices of patients in the laser and irradiation group as indistinguishable and mildly abnormal (2.75 and 2.73).

CONCLUSION

Voice quality in highly selected patients with vocal cord carcinoma treated by laser resection can be as good as that in patients whose cancer was similarly staged after radiation therapy.

Can you trust patient self-reports of drug use during treatment?

This study compared two frequently used measures of drug use, urine testing and self-report in a sample of subjects currently enrolled in methadone treatment for a minimum of six months. A comparison between the percentage of positive opiate urine screens and subjects' self-reported opiate use indicated that more patients self-reported opiate use (80%) than had been detected by urinalysis (57%). Similar results were found for cocaine use. We present arguments that a more inclusive method of measuring drug use during treatment should include the combination of both urinalysis and self-reports.