Highly Conformal Craniospinal Radiotherapy Techniques Can Underdose the Cranial Clinical Target Volume if Leptomeningeal Extension through Skull Base Exit Foramina is not Contoured

AIMS

Craniospinal irradiation (CSI) remains a crucial treatment for patients with medulloblastoma. There is uncertainty about how to manage meningeal surfaces and cerebrospinal fluid (CSF) that follows cranial nerves exiting skull base foramina. The purpose of this study was to assess plan quality and dose coverage of posterior cranial fossa foramina with both photon and proton therapy.

MATERIALS AND METHODS

We analysed the radiotherapy plans of seven patients treated with CSI for medulloblastoma and primitive neuro-ectodermal tumours and three with ependymoma (total n = 10). Four had been treated with a field-based technique and six with TomoTherapy™. The internal acoustic meatus (IAM), jugular foramen (JF) and hypoglossal canal (HC) were contoured and added to the original treatment clinical target volume (Plan_CTV) to create a Test_CTV. This was grown to a test planning target volume (Test_PTV) for comparison with a Plan_PTV. Using Plan_CTV and Plan_PTV, proton plans were generated for all 10 cases. The following dosimetry data were recorded: conformity (dice similarity coefficient) and homogeneity index (D₂ - D₉₈/D₅₀) as well as median and maximum dose (D_2%) to Plan_PTV, V_95% and minimum dose (D_99.9%) to Plan_CTV and Test_CTV and Plan_PTV and Test_PTV, V_95% and minimum dose (D_98%) to foramina PTVs.

RESULTS

Proton and TomoTherapy™ plans were more conformal (0.87, 0.86) and homogeneous (0.07, 0.04) than field-photon plans (0.79, 0.17). However, field-photon plans covered the IAM, JF and HC PTVs better than proton plans (P = 0.002, 0.004, 0.003, respectively). TomoTherapy™ plans covered the IAM and JF better than proton plans (P = 0.000, 0.002, respectively) but the result for the HC was not significant. Adding foramen CTVs/PTVs made no difference for field plans. The mean D_min dropped 3.4% from Plan_PTV to Test_PTV for TomoTherapy™ (not significant) and 14.8% for protons (P = 0.001).

CONCLUSIONS

Highly conformal CSI techniques may underdose meninges and CSF in the dural reflections of posterior fossa cranial nerves unless these structures are specifically included in the CTV.

Quantifying uncertainty in radiotherapy demand at the local and national level using the Malthus model

The Malthus programme produces a model for the local and national level of radiotherapy demand for use by commissioners and radiotherapy service leads in England. The accuracy of simulation is dependent on the population cancer incidence, stage distribution and clinical decision data used by the model. In order to quantify uncertainty in the model, a global sensitivity analysis of the Malthus model was undertaken. As predicted, key decision points in the model relating to stage distribution and indications for surgical or non-surgical initial management of disease were observed to yield the strongest effect on simulated radiotherapy demand. The proportion of non-small cell lung cancer patients presenting with stage IIIB/IV disease had the largest effect on fraction burden in the four most common cancer types treated with radiotherapy, where a 1% change in stage IIIb/IV disease yielded a 1.3% change in fraction burden for lung cancer patients. A 1% change in mastectomy rate yielded a 0.37% change in fraction burden for breast cancer patients. The model is also highly sensitive to changes in the radiotherapy indications in colon and gastric cancer. Broadly, the findings of the sensitivity analysis mirror those previously published by other groups. Sensitivity analysis of the local-level population and cancer incidence data revealed that the cancer registration rate in the 50-64 year female population had the highest effect on simulation results. The analysis reveals where additional effort should be undertaken to provide accurate estimates of important parameters used in radiotherapy demand models.

Breast cancer risk following Hodgkin lymphoma radiotherapy in relation to menstrual and reproductive factors

BACKGROUND

Women treated with supradiaphragmatic radiotherapy (sRT) for Hodgkin lymphoma (HL) at young ages have a substantially increased breast cancer risk. Little is known about how menarcheal and reproductive factors modify this risk.

METHODS

We examined the effects of menarcheal age, pregnancy, and menopausal age on breast cancer risk following sRT in case-control data from questionnaires completed by 2497 women from a cohort of 5002 treated with sRT for HL at ages <36 during 1956-2003.

RESULTS

Two-hundred and sixty women had been diagnosed with breast cancer. Breast cancer risk was significantly increased in patients treated within 6 months of menarche (odds ratio (OR) 5.52, 95% confidence interval (CI) (1.97-15.46)), and increased significantly with proximity of sRT to menarche (Ptrend<0.001). It was greatest when sRT was close to a late menarche, but based on small numbers and needing reexamination elsewhere. Risk was not significantly affected by full-term pregnancies before or after treatment. Risk was significantly reduced by early menopause (OR 0.55, 95% CI (0.35-0.85)), and increased with number of premenopausal years after treatment (Ptrend=0.003).

CONCLUSION

In summary, this paper shows for the first time that sRT close to menarche substantially increases breast cancer risk. Careful consideration should be given to follow-up of these women, and to measures that might reduce their future breast cancer risk.

The value of image-guided intensity-modulated radiotherapy in challenging clinical settings

OBJECTIVE

To illustrate the wider potential scope of image-guided intensity-modulated radiotherapy (IG-IMRT), outside of the "standard" indications for IMRT.

METHODS

Nine challenging clinical cases were selected. All were treated with radical intent, although it was accepted that in several of the cases the probability of cure was low. IMRT alone was not adequate owing to the close proximity of the target to organs at risk, the risk of geographical miss, or the need to tighten planning margins, making image-guided radiotherapy an essential integral part of the treatment. Discrepancies between the initial planning scan and the daily on-treatment megavoltage CT were recorded for each case. The three-dimensional displacement was compared with the margin used to create the planning target volume (PTV).

RESULTS

All but one patient achieved local control. Three patients developed metastatic disease but benefited from good local palliation; two have since died. A further patient died of an unrelated condition. Four patients are alive and well. Toxicity was low in all cases. Without daily image guidance, the PTV margin would have been insufficient to ensure complete coverage in 49% of fractions. It was inadequate by >3 mm in 19% of fractions, and by >5 mm in 9%.

CONCLUSION

IG-IMRT ensures accurate dose delivery to treat the target and avoid critical structures, acting as daily quality assurance for the delivery of complex IMRT plans. These patients could not have been adequately treated without image guidance.

ADVANCES IN KNOWLEDGE

IG-IMRT can offer improved outcomes in less common clinical situations, where conventional techniques would provide suboptimal treatment.

Development of an electronic medical record based intervention to improve medical care of osteoporosis

Osteoporosis is infrequently addressed during hospitalization for osteoporotic fractures. An EMR-based intervention (osteoporosis order set) was developed with physician and patient input. There was a trend toward greater calcium supplementation from July 2008 to April 2009 (s = 0.058); however, use of antiresorptives (13%) or discharge instructions for BMD testing and osteoporosis treatment (10%) remained low.

INTRODUCTION

Osteoporosis is infrequently addressed during hospitalization for osteoporotic fractures. The study population consisted of patients over 50 years of age.

METHODS

Northwestern Memorial Hospital is a tertiary care academic hospital in Chicago. This study was conducted from September 1, 2007 through June 30, 2009.

RESULTS

Physicians reported that barriers to care comprised nonacute nature of osteoporosis, belief that osteoporosis should be addressed by the PCP, low awareness of recurrent fractures, and radiographs with terms such as "compression deformity", "wedge deformity", or "vertebral height loss" which in their opinion were not clearly indicative of vertebral fractures. An EMR-based intervention was developed with physician and patient input. Over the evaluation period, 295 fracture cases in individuals over the age of 50 years in the medicine floors were analyzed. Mean age was 72 ± 11 years; 74% were female. Sites of fracture included hip n = 78 (27%), vertebral n = 87 (30%), lower extremity n = 61 (21%), upper extremity n = 43 (15%) and pelvis n = 26 (9%). There was no increase in documentation of osteoporosis in the medical record from pre- to post-EMR implementation (p = 0.89). There was a trend toward greater calcium supplementation from July 2008 to April 2009 (p = 0.058); however, use of antiresorptives (13%) or discharge instructions for BMD testing and osteoporosis treatment (10%) remained low.

CONCLUSION

An electronic medical record intervention without electronic reminders created with physician input achieves an increase in calcium supplementation but fails to increase diagnosis or treatment for osteoporosis at the time of hospitalization for a fragility fracture.

Primary testicular lymphoma

Primary testicular non-Hodgkin lymphoma (PTL) comprises around 9% of testicular cancers and 1-2% of all non-Hodgkin lymphomas. Its incidence is increasing and it primarily affects older men, with a median age at presentation of around 67 years. By far the most common histological subtype is diffuse large B-cell lymphoma, accounting for 80-90% of PTLs. Most patients present with a unilateral testicular mass or swelling. Up to 90% of patients have stage I or II disease at diagnosis (60 and 30%, respectively) and bilateral testicular involvement is seen in around 35% of patients. PTL demonstrates a continuous pattern of relapse and propensity for extra-nodal sites such as the central nervous system and contralateral testis. Retrospective data have emphasised the importance of prophylactic radiotherapy in reducing recurrence rates within the contralateral testis. Recent outcome data from the prospective IELSG-10 trial have shown far better progression-free and overall survival than historical outcomes. This supports the use of orchidectomy followed by Rituximab- cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP), central nervous system prophylaxis and prophylactic radiotherapy to the contralateral testis with or without nodal radiotherapy in patients with limited disease. Central nervous system relapse remains a significant issue and future research should focus on identifying the best strategy to reduce its occurrence. Here we discuss the evidence supporting combination chemotherapy and radiotherapy in PTL.

Lung spirometry parameters and diffusion capacity are decreased in patients with Type 2 diabetes

AIMS

In cohort studies, Type 2 diabetes mellitus has been associated with decreased forced 1 s expiratory volume and forced vital capacity. We examined if forced vital capacity, forced 1 s expiratory volume and diffusion lung capacity correlate with diabetes mellitus across different races in a clinical setting.

METHODS

We examined the medical records of 19,882 adults 18-97 years of age in our centre from 1 January 2000 to 1 May 2009. After excluding patients with diseases causing abnormal lung function, 4164 subjects were available for analysis. We used multiple linear regressions to examine cross-sectional differences in forced vital capacity, forced 1 s expiratory volume and carbon monoxide diffusing capacity between patients with and without diabetes mellitus, after adjustment for age, sex, race, height, smoking, BMI and heart failure.

RESULTS

Patients with diabetes (n = 560) were older (62 ± 12 vs. 55 ± 16 years), more likely to be men (56 vs. 43%), overweight (BMI 31.7 ± 8.5 vs. 27.3 ± 6.7 kg/m2 ), have heart failure (33 vs. 14%) and less likely to be Caucasians (65 vs. 76%) and never smokers (66 vs. 72%) compared with patients without diabetes (n = 3604). The mean unadjusted values in patients with diabetes vs. those without were: forced vital capacity 2.78 ± 0.91 vs. 3.19 ± 1.03 l; forced 1 s expiratory volume 2.17 ± 0.74 vs. 2.49 ± 0.0.83; and carbon monoxide diffusing capacity 16.67 ± 5.53 vs. 19.18 ± 6.72 ml(-1) min(-1) mmHg, all P < 0.0001. These differences remained significant after adjustment for covariates. After race stratification, only Caucasians with diabetes had a significant decrease in all lung function measures.

CONCLUSIONS

Patients with diabetes have decreased lung function compared with those without diabetes. Caucasians with diabetes have more global lung function impairment compared with African-Americans and Hispanics.

Accelerated BEP: a phase I trial of dose-dense BEP for intermediate and poor prognosis metastatic germ cell tumour

Background:

We used bleomycin, etoposide, cisplatin (BEP), the most effective regimen in the treatment of germ cell tumours (GCTs) and increased dose-density by using pegfilgrastim to shorten cycle length. Our aim was to assess safety and tolerability.

Methods:

Sixteen male patients with intermediate or poor prognosis metastatic GCT were treated with four cycles of 3-day BEP with G-CSF on a 14-day cycle for a planned relative dose-density of 1.5 compared with standard BEP.

Results:

Eleven intermediate and five poor prognosis patients were treated. In all, 14 of 16 patients completed the study treatment. Toxicities were comparable to previous studies using standard BEP, except for mucositis and haematological toxicity that were more severe. The overall relative dose-density for all 16 patients was mean 1.38 (range 0.72–1.5; median 1.46). Complete response was achieved after chemotherapy alone in two patients (13%) and following chemotherapy plus surgery in nine additional patients (56%). Four patients (25%) had a partial response and normalised their marker levels. At a median follow-up of 4.4 years (range 2.1–6.8) the estimated 5-year progression-free survival probability is 81% (95% CI 64–100%).

Conclusion:

Accelerated BEP is tolerable without major additional toxicity. A randomised controlled trial will be required to obtain comparative efficacy data.

Organisational culture: variation across hospitals and connection to patient safety climate

CONTEXT

Bureaucratic organisational culture is less favourable to quality improvement, whereas organisations with group (teamwork) culture are better aligned for quality improvement.

OBJECTIVE

To determine if an organisational group culture shows better alignment with patient safety climate.

DESIGN

Cross-sectional administration of questionnaires. Setting 40 Hospital Corporation of America hospitals.

PARTICIPANTS

1406 nurses, ancillary staff, allied staff and physicians.

MAIN OUTCOME MEASURES

Competing Values Measure of Organisational Culture, Safety Attitudes Questionnaire (SAQ), Safety Climate Survey (SCSc) and Information and Analysis (IA).

RESULTS

The Cronbach alpha was 0.81 for the group culture scale and 0.72 for the hierarchical culture scale. Group culture was positively correlated with SAQ and its subscales (from correlation coefficient r = 0.44 to 0.55, except situational recognition), ScSc (r = 0.47) and IA (r = 0.33). Hierarchical culture was negatively correlated with the SAQ scales, SCSc and IA. Among the 40 hospitals, 37.5% had a hierarchical dominant culture, 37.5% a dominant group culture and 25% a balanced culture. Group culture hospitals had significantly higher safety climate scores than hierarchical culture hospitals. The magnitude of these relationships was not affected after adjusting for provider job type and hospital characteristics.

CONCLUSIONS

Hospitals vary in organisational culture, and the type of culture relates to the safety climate within the hospital. In combination with prior studies, these results suggest that a healthcare organisation's culture is a critical factor in the development of its patient safety climate and in the successful implementation of quality improvement initiatives.

Patterns of nurse-physician communication and agreement on the plan of care

BACKGROUND

Interdisciplinary communication is critically important to provide safe and effective care, yet it has been inadequately studied for hospitalised medical patients. Our objective was to characterise nurse-physician communication and their agreement on patients' plan of care.

METHODS

During a one-month period, randomly selected hospitalised patients, their nurses and their physicians were interviewed. Nurses and physicians were asked to identify one another, whether communication had occurred, and about six aspects of the plan of care. Two internists rated nurse-physician agreement on aspects of the plan of care as none, partial or complete agreement. Measures included the percentage of nurses and physicians able to identify one another and reporting communication and the percentage of nurse-physician pairs in agreement on aspects of the plan of care.

RESULTS

310 (91%) and 301 (88%) of 342 eligible nurses and physicians completed interviews. Nurses correctly identified patients' physicians 71% of the time and reported communicating with them 50% of the time. Physicians correctly identified the patients' nurses 36% of the time and reported communicating with them 62% of the time. Physicians and nurses showed no agreement on aspects of the plan of care ranging from 11% for planned procedures to 42% for medication changes.

CONCLUSIONS

Nurses and physicians did not reliably communicate with one another and were often not in agreement on the plan of care for hospitalised medical patients.

Geographical variation in radiotherapy services across the UK in 2007 and the effect of deprivation

AIMS

Modelling of demand has shown substantial underprovision of radiotherapy in the UK. We used national audit data to study geographical differences in radiotherapy waiting times, access and dose fractionation across the four countries of the UK and between English strategic health authorities.

MATERIALS AND METHODS

We used a web-based tool to collect data on diagnosis, dose fractionation and waiting times on all National Health Service patients in the UK starting a course of radiotherapy in the week commencing 24 September 2007. Cancer incidence for the four countries of the UK and for England by primary care trust was used to model demand for radiotherapy aggregated by country and by strategic health authority.

RESULTS

Across the UK, excluding skin cancer, 2504 patients were prescribed 33 454 fractions in the audit week. Waits for radical radiotherapy exceeded the recommended 4 week maximum for 31% of patients (range 0-62%). Fractions per million per year ranged from 17 678 to 36 426 and radical fractions per incident cancer ranged from 3.0 to 6.7. Patients who were treated received similar treatment in terms of fractions per radical course of radiotherapy (18.2-23.0). Access rates ranged from 25.2 to 48.8%, nearing the modelled optimum of 50.7% in three regions. Fractions per million prescribed as a first course of treatment varied from 43.9 to 90.3% of modelled demand. The percentage of patients failing to meet the 4 week Joint Council for Clinical Oncology target for radical radiotherapy rose as activity rates increased (r=0.834), indicating a mismatch of demand and capacity. In England, a comparison between strategic health authorities showed that increasing deprivation was correlated with lower rates of access to radiotherapy (r=-0.820).

CONCLUSIONS

There are substantial differences across the UK in the radiotherapy provided to patients and its timeliness. Radiotherapy capacity does not reflect regional variations in cancer incidence across the UK (3618-5800 cases per million per year). In addition, deprivation is a major unrecognised influence on radiotherapy access rates. In regions with higher levels of deprivation, fewer patients with cancer receive radiotherapy and the proportion treated radically is lower. This probably reflects late presentation with advanced disease, poor performance status and co-morbid illness. To provide an equitable, evidence-based service, the needs of the local population should be assessed using demand modelling based on local cancer incidence. Ideally this should include data on deprivation, performance status and stage at presentation. The results should be compared with local radiotherapy activity data to understand waits, access and dose fractionation in order to plan adequate provision for the future. The development of a mandatory radiotherapy data set in England will facilitate this, but to assist change it is essential that the results are analysed and fed back to clinicians and commissioners.

Distinct clinical phenotypes of airways disease defined by cluster analysis

Airways disease is currently classified using diagnostic labels such as asthma, chronic bronchitis and emphysema. The current definitions of these classifications may not reflect the phenotypes of airways disease in the community, which may have differing disease processes, clinical features or responses to treatment. The aim of the present study was to use cluster analysis to explore clinical phenotypes in a community population with airways disease. A random population sample of 25-75-yr-old adults underwent detailed investigation, including a clinical questionnaire, pulmonary function tests, nitric oxide measurements, blood tests and chest computed tomography. Cluster analysis was performed on the subgroup with current respiratory symptoms or obstructive spirometric results. Subjects with a complete dataset (n = 175) were included in the cluster analysis. Five clusters were identified with the following characteristics: cluster 1: severe and markedly variable airflow obstruction with features of atopic asthma, chronic bronchitis and emphysema; cluster 2: features of emphysema alone; cluster 3: atopic asthma with eosinophilic airways inflammation; cluster 4: mild airflow obstruction without other dominant phenotypic features; and cluster 5: chronic bronchitis in nonsmokers. Five distinct clinical phenotypes of airflow obstruction were identified. If confirmed in other populations, these findings may form the basis of a modified taxonomy for the disorders of airways obstruction.

Waiting times for systemic cancer therapy in the United Kingdom in 2006

This audit was conducted to measure waiting times for systemic cancer therapy across the United Kingdom. All patients, aged 16 years or older, commencing their first course of systemic therapy between 13 November and 19 November 2006 were eligible for inclusion. Data on 936 patients from 81 hospital sources were collected. Systemic therapy is largely given in compliance with national waiting time targets. In terms of the Joint Council for Clinical Oncology (JCCO) targets, 84% of patients commence treatment within 21 days and 98% of patients complied with the Department of Health target that treatment should follow within 31 days of the decision being agreed with the patient. Only 76% complied with the Department of Health 62-day target from GP referral to first definitive treatment. However, the date of urgent referral by the GP was not submitted for most patients in our survey, leaving a sample of only 84 out of 936 patients (9% of total) suitable for this analysis. There was only a 3- to 5-day difference between the waiting times for systemic therapy for patients categorised as urgent compared with routine. Locally agreed definitions had little impact on patients' priority for treatment. This audit has established a baseline measurement of waiting times for systemic therapy across the United Kingdom. The continuing introduction of novel therapies is likely to have a significant effect on the service and we recommend that service managers model the likely impact on resource requirements. In addition, urgent treatment should be clearly defined as that required within 24 h (maximum 48 h) to avoid the risk of clinical deterioration, particularly in patients with acute leukaemia, lymphoma or germ cell tumour.

Proportional classifications of COPD phenotypes

BACKGROUND

Chronic obstructive pulmonary disease (COPD) encompasses a group of disorders characterised by the presence of incompletely reversible airflow obstruction with overlapping subsets of different phenotypes including chronic bronchitis, emphysema or asthma. The aim of this study was to determine the proportion of adult subjects aged >50 years within each phenotypic subgroup of COPD, defined as a post-bronchodilator ratio of forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) <0.7, in accordance with current international guidelines.

METHODS

Adults aged >50 years derived from a random population-based survey undertook detailed questionnaires, pulmonary function tests and chest CT scans. The proportion of subjects in each of 16 distinct phenotypes was determined based on combinations of chronic bronchitis, emphysema and asthma, with and without incompletely reversible airflow obstruction defined by a post-bronchodilator FEV(1)/FVC ratio of 0.7.

RESULTS

A total of 469 subjects completed the investigative modules, 96 of whom (20.5%) had COPD. Diagrams were constructed to demonstrate the relative proportions of the phenotypic subgroups in subjects with and without COPD. 18/96 subjects with COPD (19%) had the classical phenotypes of chronic bronchitis and/or emphysema but no asthma; asthma was the predominant COPD phenotype, being present in 53/96 (55%). When COPD was defined as a post-bronchodilator FEV(1)/FVC less than the lower limit of normal, there were one-third fewer subjects with COPD and a smaller proportion without a defined emphysema, chronic bronchitis or asthma phenotype.

CONCLUSION

This study provides proportional classifications of the phenotypic subgroups of COPD which can be used as the basis for further research into the pathogenesis and treatment of this heterogeneous disorder.

A radiotherapy technique to improve dose homogeneity around bone prostheses

Purpose. Following limb conserving surgery for bone or soft tissue sarcoma, patients may require post-operative radiotherapy to minimise the risk of local recurrence. In such circumstances the metal prosthesis reduces the dose in its shadow by approximately 10% when using opposed fields. We describe a technique to boost the underdosed area to overcome this problem.Patients or subjects. Seven sequential patients presenting between 1995 and 2001 had their treatment individualised because they had metal prosthesis in the treatment volume.Methods. To improve the target dose homogeneity we used a custom-made keyhole cutout to boost the area in the shadow of the prosthesis. The degree of attenuation caused by the metal prosthesis was estimated and a boost dose calculated. Exit thermoluminescent dosimetry (TLD) was used to confirm the estimates made.Results and discussion. Variation between patients was seen, demonstrating the need for exit TLD to individualise the treatment plan. The use of a boost field provides a method to overcome under-dosage in the shadow of a metal prosthesis. It improves dose homogeneity throughout the target volume and ensures adequate dose intensity around the prosthesis, the site most at risk of local recurrence.