Marker-less online MR-guided stereotactic body radiotherapy of liver metastases at a 1.5 T MR-Linac - Feasibility, workflow data and patient acceptance

INTRODUCTION

Stereotactic body radiotherapy (SBRT) is an established ablative treatment for liver tumors with excellent local control rates. Magnetic resonance imaging guided radiotherapy (MRgRT) provides superior soft tissue contrast and may therefore facilitate a marker-less liver SBRT workflow. The goal of the present study was to investigate feasibility, workflow parameters, toxicity and patient acceptance of MRgSBRT on a 1.5 T MR-Linac.

METHODS

Ten consecutive patients with liver metastases treated on a 1.5 T MR-Linac were included in this prospective trial. Tumor delineation was performed on four-dimensional computed tomography scans and both exhale triggered and free-breathing T2 MRI scans from the MR-Linac. An internal target volume based approach was applied. Organ at risk constraints were based on the UKSABR guidelines (Version 6.1). Patient acceptance regarding device specific aspects was assessed and toxicity was scored according to the common toxicity criteria of adverse events, version 5.

RESULTS

Nine of ten tumors were clearly visible on the 1.5 T MR-Linac. No patient had fiducial markers placed for treatment. All patients were treated with three or five fractions. Median dose to 98% of the gross tumor volume was 38.5 Gy. The median time from "patient identity check" until "beam-off" was 31 min. Median beam on time was 9.6 min. Online MRgRT was well accepted in general and no treatment had to be interrupted on patient request. No event of symptomatic radiation induced liver disease was observed after a median follow-up of ten month (range 3-17 months).

CONCLUSION

Our early experience suggests that online 1.5 T MRgSBRT of liver metastases represents a promising new non-invasive marker-free treatment modality based on high image quality, clinically reasonable in-room times and high patient acceptance. Further studies are necessary to assess clinical outcome, to validate advanced motion management and to explore the benefit of online response adaptive liver SBRT.

Antibody H3 Structure Prediction

Antibodies are proteins of the immune system that are able to bind to a huge variety of different substances, making them attractive candidates for therapeutic applications. Antibody structures have the potential to be useful during drug development, allowing the implementation of rational design procedures. The most challenging part of the antibody structure to experimentally determine or model is the H3 loop, which in addition is often the most important region in an antibody's binding site. This review summarises the approaches used so far in the pursuit of accurate computational H3 structure prediction.

Cervical human papillomavirus infections in commercial sex workers—risk factors and behaviours

We have investigated the prevalence of, and risk factors for, cervical human papillomavirus (HPV) infection in commercial sex workers (CSWs) and controls attending the same sexual health clinics in Sydney. A self-administered 'risk factor' questionnaire was completed and a Pap smear and a specimen for HPV detection and typing were taken. Results from the 288 CSWs and 266 controls were assessed by univariate and multivariate analyses. No significant difference in the rates of cervical HPV infection in CSWs (31.6%) and controls (24.4%) was found but HPV related cytological abnormalities were more common on the CSWs ( P <0.05). In both groups, factors independently associated with HPV infection were the use of non-barrier contraception, cytological abnormalities, age under 36 and the number of non-paying sexual partners. A risk factor for CSWs only was sex-work in Japan. A detailed 'work' history from CSWs may be useful to identify unsafe practices or work in countries where safer sex may be less acceptable.

[Dermatological conditions requiring intensive care]

Some skin conditions may require treatment in intensive care units. The early diagnosis of life-threatening dermatoses is a considerable challenge. We review skin diseases which may require intensive care. In addition to Stevens-Johnson syndrome and toxic epidermal necrolysis, representing adverse skin reactions, we discuss staphylococcal scalded skin syndrome and necrotizing fasciitis as infection-associated dermatoses, as well as angioedema. We focus on the course of disease describing clinical presentations, diagnostics and therapeutic strategies with respect to critical medical conditions.

Ontogenetic oxygen changes alter zebra fish size, behavior, and blood glucose

Four male and four female zebra fish were crossed in all possible combinations, resulting in 389 offspring. These offspring were divided among four treatments: normoxia for 90 d, hypoxia for 90 d, normoxia for 30 d followed by hypoxia for 60 d, and hypoxia for 30 d followed by normoxia for 60 d. The effects of early oxygen environment, later oxygen environment, and genotype were then assessed with respect to zebra fish behavior, size, and blood glucose. Fish were tested in an arena where they could shoal with conspecifics before, during, and after the introduction of a novel stimulus. Blood glucose and size were also measured. Early oxygen environment influenced fish size, time spent swimming, and reactivity to a novel stimulus. Environmentally induced plasticity was predominate, with little evidence of among-sire variation for any of the measured parameters.

Effect of induced hypotensive anaesthesia vs isovolaemic haemodilution on blood loss and transfusion requirements in orthognathic surgery: a prospective, single-blinded, randomized, controlled clinical study

Induced hypotensive anaesthesia and isovolaemic haemodilution are well-established blood-sparing techniques in major surgery. This prospective study compared them for blood loss, transfusion requirements, and surgical field quality during standardized orthognathic operations. In a surgeon-blinded trial, 60 healthy patients requiring either Le Fort I osteotomy or bimaxillary surgery were randomly allocated to receive normotensive anaesthesia, induced hypotensive anaesthesia, or induced hypotensive anaesthesia combined with isovolaemic haemodilution. Blood loss and haemoglobin level were measured intraoperatively and calculated on postoperative day 3. The surgeons rated surgical field quality. Mean blood loss was 1021.63, 392.38 (p<0.05) and 1191.65ml in the normotensive, hypotensive and haemodilution groups, respectively. Mean haemoglobin level immediately after surgery was 9.3, 10.3, and 7.4g/dl (p<0.05), respectively. No hypotensive group patients received transfusions; four normotensive group patients required allogenic transfusions; seven haemodilution group patients needed autogenous retransfusions (p<0.05). Surgical field quality was significantly better in the hypotensive than in the normotensive (p<0.05) or haemodilution (p<0.05) groups. In orthognathic surgery, hypotensive anaesthesia significantly reduces blood loss and transfusion requirements and minimizes allogenic transfusions risks. Induced hypotensive anaesthesia combined with isovolaemic haemodilution has no additional blood-sparing effects but impairs surgical field quality.

Metabolism, nitrogen excretion, and heat shock proteins in the central mudminnow (Umbra limi), a facultative air-breathing fish living in a variable environment

The central mudminnow ( Umbra limi (Kirtland, 1841)) is a continuous, facultative air-breathing freshwater fish found in swamps of central Canada and northeastern USA. The first goal of this field and laboratory-based study was to characterize the physicochemical conditions of mudminnow habitat during the summer. Our second goal was to determine the metabolic, stress response, and nitrogen excretion strategies of this fish following variations in water temperature, dissolved oxygen, external ammonia, and short-term periods of air exposure. We report profound diurnal fluctuations in water temperature (13–31 °C), dissolved oxygen (2%–159% air saturation), and ammonia levels (10–240 μmol·L−1) in habitat of central mudminnow measured on three dates at six different sites over 24 h. The central mudminnow does not induce urea synthesis as a mechanism of ammonia detoxification, either in response to emersion (6 or 20 h) or elevated external ammonia (10 mmol·L–1). Acute exposure to high temperature (~31 °C), aquatic hypoxia, or air resulted in significant increases in blood glucose and liver heat shock protein (Hsp) 70 and hypoxia also caused an increased reliance on anaerobic metabolism. This is the first description of the heat shock response in a facultative air-breathing fish following either hypoxia or air exposure. These metabolic and molecular responses are part of a strategy that allows the mudminnow to thrive in extremely variable freshwater environments.

Development of a Children's Trust in General Physicians Scale

BACKGROUND

Researchers have developed scales assessing adults' trust beliefs in physicians and found that those are associated with measures of health behaviour and physical health. The purpose of the research was to develop a Children's Trust in General Physicians Scale (CTGPS) and examine its relation to health behaviour: adherence to medical regimes.

METHODS

The participants were 128 children (68 girls and 60 boys) in Study 1 and 198 children (105 girls and 93 boys) in Study 2 who attended years 5 and 6 of elementary school in UK (mean ages = 10 years and 10 months and 10 years and 7 months respectively). The children completed the nine-item CTGPS and reported their trust in doctors and (in Study 2) adherence to medical regimes. Parents also reported those behaviours.

RESULTS

Principal components analysis and confirmatory factor analysis of the CTGPS yielded the expected three factors: Honesty, Emotional and Reliability. The CTGPS had acceptable internal consistency and, as evidence for its validity, was associated with reported trust in doctors. The results from Study 2 confirmed that the CTGPS was associated with adherence to medical regimes.

CONCLUSION

A CTGPS was developed that is associated with adherence to medical regimes.

Propofol increased the interleukin-6 to interleukin-10 ratio more than isoflurane after surgery in long-term alcoholic patients

This study investigated the effect of an anaesthetic regimen on the immune response in 40 long-term alcoholic patients undergoing surgery. Patients were randomly allocated to receive either propofol or isoflurane during surgery. Plasma cytokines interleukin (IL)-6 and IL-10 were measured at defined times and rates of post-operative infections were documented. The IL-6/IL-10 ratio significantly increased with propofol compared with isoflurane on day 1 after surgery and the IL-10 level significantly increased with isoflurane on day 1 after surgery. The overall post-operative infection rate was significantly higher in isoflurane-treated patients. Our findings indicate that propofol anaesthesia might be the more favourable regimen, with the IL-6/IL-10 ratio indicating an attenuation of the immune imbalance after surgery in long-term alcoholic patients. These results support the undertaking of a properly powered clinical trial to determine if propofol anaesthesia can reduce the postoperative infection rate in this special patient population.

Increase in rates of herpes simplex virus type 1 as a cause of anogenital herpes in western Sydney, Australia, between 1979 and 2003

BACKGROUND/OBJECTIVE

Recent studies suggest that herpes simplex virus type 1 (HSV-1) is becoming more common as a cause for genital herpes, relative to HSV-2. We aimed to calculate trends in HSV type from isolates and serology samples sent to a reference virology laboratory in New South Wales (NSW), Australia.

METHODS

We compared the proportions of HSV-1 and HSV-2 positive samples, adjusting for age and sex of source patient, in three datasets: anogenital isolates from 1979 to 1988; anogenital isolates from 1989 to 2003; and HSV type specific IgM seropositivity from 1994 to 2003.

RESULTS

The number of specimens in each analysis was 17 512, 4359, and 497, respectively. There was a progressive rise in the proportions of typed specimens being HSV-1 in all analyses. The proportion of isolates that were HSV-1 ranged from 3% in 1980 to 41% in 2001. Female sex and age under 25 were associated with a greater proportion of HSV-1 isolates in both time periods. In the period 1979-88, comparing the proportions of HSV-1 and HSV-2 gave an odds ratio (OR) per additional year of 1.24 (95% confidence interval (CI) 1.20 to 1.27; p<0.005) after adjustment for age and sex. In the period 1989-2003 there was a steeper rise in the proportion of isolates that were HSV-1 in samples from younger individuals (OR per year 1.17, 1.12 to 1.22) compared to those over 25 (OR per year 1.06, 1.03 to 1.08). The rise in the proportion of IgM seropositive results reactive for HSV-1 compared to HSV-2 gave an OR of 1.36 per year (1.26 to 1.47; p<0.005).

CONCLUSIONS

These data suggest that HSV-1 has become more common as a cause of anogenital herpes in NSW.

Sex work practices and condom use in female sex workers in Sydney

The aim of this study was to determine sex work practices and predictors of condom use among female sex workers (SWs) in Sydney. SWs from two centres completed a self-administered questionnaire covering demographic and sexual characteristics and sex work practices. One hundred and forty-eight international (born in Asia) and 141 local SWs (born in Australia, New Zealand or the UK) were recruited. Local SWs saw more clients per shift than international SWs (P = 0.002), but international SWs worked more shifts per week than local SWs (P = 0.001). International SWs used condoms less consistently at work than local SWs (P = 0.001). About 37% of international SWs never used condoms with non-paying partners, compared with 14% of local SWs (P = 0.01). Speaking Thai (odds ratio [OR] 8.9, 95% confidence interval [CI]; 3.19-24.87) or Chinese (OR 17.4; 95% CI 4.98-60.89) (both P < 0.001) and previous sex work in Thailand (OR 10.0 95% CI 2.31-43.52; P = 0.02) were associated with inconsistent condom use. Strategies to improve condom use need to be evaluated.

Risk of colorectal cancer in general practice patients presenting with rectal bleeding, change in bowel habit or anaemia

The aim was to use data routinely collected in general practice to assess the absolute risk of colorectal cancer in patients newly presenting to their general practitioner (GP) with relevant symptoms. Three cohorts were identified from patients attending a sample of UK general practices. Patients with new symptoms of rectal bleeding, changes in bowel habit or anaemia were identified, and their incident rate for colorectal cancer and the positive predictive value (PPV) of each symptom in the following 12 months were calculated by age and gender. The total population over the age of 40 years was 2.8 million, and 9143 incident cases of colorectal cancer were identified. A total of 67,164 patients (28% men) were identified with anaemia, 27,524 (40% men) with changes in bowel habit and 44,741 (48% men) with rectal bleeding. For each cohort, the absolute risk rose with increasing age, and men were twice as likely to develop colorectal cancer. The PPV for developing colorectal cancer in the subsequent 12 months in those aged 60-69 years with anaemia was 3.02% for men, 1.38% for women; with changes in bowel habit 6.89% for men, 2.42% for women; and with rectal bleeding was 5.99% for men, 3.50% for women. A combination of any two signs and symptoms doubled the risk of an underlying cancer. In UK general practice, men are less likely to present with symptoms and signs of colorectal cancer compared with women, but after investigation are much more likely to have a colorectal cancer diagnosed. This should be taken into account in guidelines for referral.

Prevalence of infection with herpes simplex virus types 1 and 2 in Australia: a nationwide population based survey

BACKGROUND

Studies demonstrating previous herpes simplex virus (HSV) type 2 infection as a risk factor for HIV transmission, and the development of a HSV vaccine candidate, have emphasised the need for worldwide population based studies of HSV seroprevalence. The only nationwide seroprevalence studies have been conducted in the United States.

METHODS

An Australia-wide, population based study of HSV-1 and HSV-2 seroprevalence was conducted, using serum and sociodemographic data collected between 1999-2000, for a representative study of risk factors for diabetes in over 11 000 adults. A stratified random sample of 4000 was tested for HSV-2 and 1000 for HSV-1, with sampling and weighting for various demographic factors.

RESULTS

Seroprevalence of HSV-2 in Australian adults was 12%. Prevalence in women (16%) was twice that in men (8%). Rural populations had a lower prevalence (9%) than metropolitan (13%), and Indigenous had a higher prevalence (18%) than the non-Indigenous populations (12%). The seroprevalence of HSV-1 was 76% with significant differences by age group, sex and Indigenous status.

CONCLUSION

These are the first nationwide data to compare with US studies. HSV-2 infection is less common in Australia than the United States, and this will allow planning for combating HIV transmission in high prevalence populations in northern Australia. In addition, the high HSV-1 seroprevalence will be important for future deployment of genital herpes vaccines.

Subdural haemorrhage following endoscopic third ventriculostomy. A rare complication

Subdural collections or hematomas are frequently observed after shunt placement [7-9, 13], but rarely after ETV [6]. A review of literature revealed 7 cases [1, 5, 6, 10, 12], of which only 1 was symptomatic [5]. We will discuss the causes, management, and methods of prevention of this complication and we will present a case of symptomatic subdural haematoma, following endoscopic third ventriculostomy for illustration.

Emergency contraception: who are the users?

The objective was to describe the demographic and sexual characteristics of clients attending a Sexual Health Clinic for emergency contraception (EC). Information about women attending the Parramatta Sexual Health Clinic (PSHC) who received EC between January 1999 and July 2002 was derived from the clinic database. Age-matched controls were randomly selected. Univariate and logistic regression analysis was performed to establish which factors were associated with use of EC. Two hundred and sixty-seven women requesting EC, and an equal number of controls, were studied. Factors that were independently associated with EC use were being a student, (OR=1.7 [95% CI 1.02-2.69]) and having a regular sexual partner (OR=2.3 [95% CI 1.14-4.73]). Women requiring EC were significantly less likely to have had a sexually transmitted infection (STI) (OR=0.3 [95% CI 0.16-0.60]) or a previous pregnancy (OR=0.2 [95% CI 0.09-0.67]) than controls. We concluded that users of EC are at low-risk for STIs, but need counselling about safer sex.

Is HSV serology useful for the management of first episode genital herpes?

BACKGROUND

First episode genital herpes simplex virus (HSV) infections can be classified into three groups, primary genital herpes (no previous exposure to HSV), non-primary first episode (IgG antibody to HSV of the non-presenting type), and first episode with pre-existing IgG HSV antibodies. The use of IgM to classify first episode genital herpes has not been evaluated.

OBJECTIVE

To evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of HSV-1 and HSV-2 IgM antibodies for the diagnosis of first episode genital herpes, when compared with clinical diagnosis.

METHODS

Patients with a first clinical episode of genital herpes were recruited. Sera were tested for IgG antibodies to HSV-2 using an indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. HSV-1 IgG and IgM and HSV-2 IgM antibodies were detected using western blot.

RESULTS

157 patients were recruited. 31 were excluded (missing data or no detectable antibodies and negative viral isolation). Therefore, 126 patients were included in the analysis. 23 (18.3%) had primary genital herpes, 34 (27.0%) non-primary first episode, and 69 (54.8%) had pre-existing genital herpes. The specificity and PPV of HSV IgM was 100%; the sensitivity was 79% and the NPV 85%.

CONCLUSION

IgM HSV serology may be useful in the management of some patients with first episode genital herpes and provide an indication of the source of infection. Drawbacks include the low sensitivity and NPV, lack of availability, IgM antibodies may occasionally be produced in response to recurrent infection and, finally, IgM antibodies may take up to 10 days to develop and last 7-10 days.

Sexual behaviour and social class in Australian women

Sexual behaviour is determined by social, cultural and personal factors. Sexual behaviour studies have been conducted in many countries. However, information from Australia is limited. This study was conducted in Obstetrics Department, Westmead Hospital, Sydney. Questionnaire-derived demographic and behavioural characteristics for public and private patients were compared using bivariate and logistic regression analyses. Of the patients, 3036 were public, and 595 private. On bivariate analysis some significant differences were private patients more likely to be born in Australia and have a higher education level whereas public patients were more likely to have had a greater number of lifetime sexual partners and younger age at first sex. Public patients were more likely to be herpes simplex virus type 2 (HSV-2) antibody positive (12%) than private patients (6%). On logistic regression significant variables included country of birth, being HSV-2 antibody positive, and age at first sex. A number of sexual and social variables were significantly different, comparing patients in the public and private sectors. Evaluation of interventions to reduce the sexual risk to women in the public sector should be considered, including encouraging young women to delay their sexual debut, and reducing the number of sexual partners.

Mouse models of human cancer web-based resources

The Mouse Models of Human Cancers Consortium (MMHCC) is a collaborative program designed to derive and characterize mouse models of human malignancies. To enhance information and resource exchange among the MMHCC investigators and other cancer research scientists, the NCI Center for Bioinformatics (NCICB, http://ncicb.nci.nih.gov/) has developed web-based resources that are freely available to the cancer research community. These resources include a website (http://emice.nci.nih.gov) and databases for cancer models (http://cancermodels.nci.nih.gov) and cancer images (http://cancerimages.nci.nih.gov).

Practical infra-red illumination and observation techniques for wildlife studies using ICI-962 perspex

MAMMALS do not normally visually perceive infrared (IR) or ultra-violet (UV) light that exists on either side of the visual spectrum from 390 to 760 nanometers (nm) (Wolken 1975). There is no evidence to suggest that nocturnal mammals have become more sensitive to long wavelength light as an adaptive response (Lythgoe 1979), although some reptiles can sense longer wavelength, thermal IR radiation (Barrett et al. 1970). Because it is not perceived, and is unlikely to affect animal behaviour, IR observation can be an invaluable tool for wildlife researchers. This paper describes the construction and use of simple IR radiation sources that can be used for non-invasive behavioural observations of captive and free-ranging mammals.

Preoperative evaluation of chronic alcoholics assessed for surgery of the upper digestive tract

BACKGROUND

Alcoholics are at risk of developing major complications in the postoperative period. Adequate prophylactic treatment, as well as preoperative abstinence, can significantly decrease the rate of complications. However, the preoperative diagnosis of alcoholism is difficult to establish. The purpose of this study was to assess whether three preoperative visits, an alcohol-related questionnaire (CAGE), and the laboratory markers carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GGT) would increase the rate of detection of chronic alcoholics.

METHODS

The study included the Departments of ENT, Facial and Maxillofacial Surgery, and General Surgery of a university hospital; 705 male patients were assessed for tumor surgery of the upper digestive tract and were allocated to 5 different groups. All patients were seen three times, and five different strategies were used to detect chronic alcoholics. The gold standard was the diagnosis of alcohol misuse made by an experienced (blinded) investigator according to the DSM-III-R. The main outcome measurements were the detection rates of the different test strategies.

RESULTS

By clinical routine alone, only 16% were detected during the first visit and 34% after three visits. If the CAGE questionnaire was added, sensitivity increased to 64%. The further addition of GGT or CDT led to 80 and 85% detections, respectively. A combination of all tests had a sensitivity of 91%.

CONCLUSIONS

To detect more alcoholic patients at risk for major complications, patients should be seen more often, and additional diagnostic tools such as the CAGE, CDT, and GGT should be used before surgery.

Sexual and demographic risk factors for herpes simplex type 1 and 2 in women attending an antenatal clinic

OBJECTIVE

To establish risk factors for the presence of HSV-2 and HSV-1 infections in pregnant women. DESIGN, POPULATION, AND SETTING: A prospective study of 3306 women attending the antenatal department Westmead Hospital, Sydney, between June 1995 and April 1998.

METHODS

Women completed a self administered questionnaire to establish risk factors for the presence of HSV-2 and HSV-1. Sera were tested for antibodies to HSV-2 and HSV-1. Data were analysed using SPSS and SAS.

MAIN OUTCOME MEASURES

Seroprevalence of and risk factors for HSV-2 and HSV-1.

RESULTS

375 (11.3% (95% CI 10.3-12.5)) women were HSV-2 antibody positive. Increasing age, Asian country of birth, lower education level, public hospital status, confirmed genital herpes, a partner with genital herpes, early age of first sex, more than one lifetime sexual partner, and previous chlamydia infection were independently associated with HSV-2 seropositivity. Of 408 women tested for HSV-1 antibodies, 323 (79.2% (95% CI 74.9-83.0)) were positive. Oral herpes, oral blisters or sores, and being HSV-2 seropositive were independently associated with HSV-1 seropositive status. When the logistic regression model was rerun without HSV-2 status, parity of two or more and one or more sexual partners in the past 3 months were significant predictors of HSV-1 seropositivity.

CONCLUSIONS

The presence of antibodies to HSV-2 and HSV-1 is related to a number of sexual and demographic risk factors. Public health campaigns directed at encouraging young people to delay the onset of sexual activity and reduce the number of sexual partners need to be evaluated. However, the possible availability of an HSV-2 vaccine that is able to protect over 70% of women offers the best hope for control of genital herpes.