Improvement in Dysphagia Outcomes Following Clinical Target Volume Reduction in the De-ESCALaTE Study

AIMS

The De-ESCALaTE study showed an overall survival advantage for the administration of synchronous cisplatin chemotherapy with radiotherapy in low-risk oropharyngeal cancer when compared with synchronous cetuximab. During the trial, a radiotherapy quality assurance protocol amendment permitted centres to swap from the original radiotherapy contouring protocol (incorporating the whole oropharynx into the high-dose clinical target volume (CTV); anatomical protocol) to a protocol that incorporated the gross tumour volume with a 10 mm margin into the CTV (volumetric protocol). The purpose of this study was to examine both toxicity and tumour control related to this protocol amendment.

MATERIALS AND METHODS

Overall survival and recurrence at 2 years were used to compare tumour control in the two contouring cohorts. For toxicity, the cohorts were compared by both the number of severe (grades 3-5) and all grades acute and late toxicities. In addition, quality of life and swallowing were compared using EORTC-C30 and MD Anderson Dysphagia Inventory, respectively.

RESULTS

Of 327 patients included in this study, 185 were contoured according to the anatomical protocol and 142 by the volumetric protocol. The two cohorts were well balanced, with the exception of significantly more patients in the anatomical cohort undergoing prophylactic feeding tube insertion (P < 0.001). With a minimum of 2 years of follow-up there was no significant difference in overall survival or recurrence between the two contouring protocols. Similarly, there was no significant difference in the rate of reported severe or all grades acute or late toxicity and no sustained significant difference in quality of life. However, there was a significant difference in favour of volumetric contouring in several domains of the MD Anderson Dysphagia Inventory questionnaire at 1 year, which persisted to 2 years in the dysphagia functional (P = 0.002), dysphagia physical (P = 0.009) and dysphagia overall function (P = 0.008) domains.

CONCLUSION

In the context of the unplanned post-hoc analysis of a randomised trial, measurable improvement in long-term dysphagia has been shown following a reduction in the CTV. Further reductions in the CTV should be subject to similar scrutiny within the confines of a prospective study.

Radiotherapy for Oropharyngeal Carcinoma With an Uninvolved Contralateral Neck: The Safety of Omission of Contralateral High Level II and Retropharyngeal Lymph Nodes From Elective Target Volumes

AIMS

To analyse outcomes and patterns of failure in patients with oropharyngeal carcinoma (OPC) treated with definitive volumetric modulated arc therapy with omission of contralateral high level II lymph nodes (HLII) and retropharyngeal lymph nodes (RPLN) in the contralateral uninvolved neck.

MATERIALS AND METHODS

Patients with OPC treated between January 2016 and July 2019 were retrospectively identified. In the absence of contralateral neck disease, institutional protocols allowed omission of contralateral HLII and contralateral RPLN in the additional absence of ipsilateral RPLN, soft palate/posterior pharyngeal wall primary.

RESULTS

In total, 238 patients with OPC and an uninvolved contralateral neck received definitive (chemo)radiotherapy with bilateral neck treatment. The median follow-up was 30.6 months. Two-year local control, regional control and overall survival were 91.0, 91.6 and 86.5%, respectively. Contralateral HLII were omitted in 159/238 (66.8%) patients; this included 106 patients in whom the primary tumour was at/crossed the midline. The contralateral RPLN region was omitted from elective target volumes for 175/238 (73.5%); this included 114 patients with a primary tumour at/crossed the midline. The mean contralateral parotid dose when contralateral HLII and RPLN were both omitted was 24.4 Gy, compared with 28.3 Gy without HLII/RPLN omission (P < 0.001). Regional progression occurred in 18/238 (7.6%) patients, all involving the ipsilateral neck with one bilateral. There were no recurrences in the contralateral HLII or RPLN regions.

CONCLUSION

In patients with OPC and an uninvolved contralateral neck receiving bilateral (chemo)radiotherapy, the omission of contralateral RPLN and HLII from elective target volumes was safe and could lead to reduced contralateral parotid doses.

Highly specific enrichment of rare nucleic acid fractions using Thermus thermophilus argonaute with applications in cancer diagnostics

Detection of disease-associated, cell-free nucleic acids in body fluids enables early diagnostics, genotyping and personalized therapy, but is challenged by the low concentrations of clinically significant nucleic acids and their sequence homology with abundant wild-type nucleic acids. We describe a novel approach, dubbed NAVIGATER, for increasing the fractions of Nucleic Acids of clinical interest Via DNA-Guided Argonaute from Thermus thermophilus (TtAgo). TtAgo cleaves specifically guide-complementary DNA and RNA with single nucleotide precision, greatly increasing the fractions of rare alleles and, enhancing the sensitivity of downstream detection methods such as ddPCR, sequencing, and clamped enzymatic amplification. We demonstrated 60-fold enrichment of the cancer biomarker KRAS G12D and ∼100-fold increased sensitivity of Peptide Nucleic Acid (PNA) and Xenonucleic Acid (XNA) clamp PCR, enabling detection of low-frequency (<0.01%) mutant alleles (∼1 copy) in blood samples of pancreatic cancer patients. NAVIGATER surpasses Cas9-based assays (e.g. DASH, Depletion of Abundant Sequences by Hybridization), identifying more mutation-positive samples when combined with XNA-PCR. Moreover, TtAgo does not require targets to contain any specific protospacer-adjacent motifs (PAM); is a multi-turnover enzyme; cleaves ssDNA, dsDNA and RNA targets in a single assay; and operates at elevated temperatures, providing high selectivity and compatibility with polymerases.

A Multicentre UK Study of Outcomes of Nasopharyngeal Carcinoma Treated With Intensity-Modulated Radiotherapy ± Chemotherapy

AIMS

To report the outcomes of nasopharyngeal carcinoma in adults across three large centres in a non-endemic region in the era of intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Adult patients with nasopharyngeal carcinoma treated in three large cancer centres with IMRT ± chemotherapy with curative intent between 2009 and 2016 were identified from institutional databases. Radiotherapy was delivered with 70 Gy in 33-35 daily fractions. A univariable analysis was carried out to evaluate the relationship of patient, tumour and treatment factors with progression-free survival (PFS) and overall survival.

RESULTS

In total, 151 patients were identified with a median follow-up of 5.2 years. The median age was 52 years (range 18-85). Seventy-five per cent were of Caucasian origin; 75% had non-keratinising tumours; Epstein Barr virus status was only available in 23% of patients; 74% of patients had stage III or IV disease; 54% of patients received induction chemotherapy; 86% of patients received concurrent chemotherapy. Five-year overall survival, PFS, local disease-free survival, regional disease-free survival and distant disease-free survival were 70%, 65%, 91%, 94% and 82%, respectively. Keratinising squamous cell carcinoma, older age, worse performance status, smoking and alcohol intake were associated with inferior overall survival and PFS.

CONCLUSIONS

Local, regional and distant disease control are relatively high following IMRT ± chemotherapy in a non-endemic population. There was considerable heterogeneity in terms of radiotherapy treatment and the use of chemotherapy, encouraging the development of treatment protocols and expert peer review in non-endemic regions.

An integrated enrichment system to facilitate isolation and molecular characterization of single cancer cells from whole blood

Circulating tumor cells (CTCs) carry valuable biological information. While enumeration of CTCs in peripheral blood is an FDA-approved prognostic indicator of survival in metastatic prostate and other cancers, analysis of CTC phenotypic and genomic markers is needed to identify cancer origin and elucidate pathways that can guide therapeutic selection for personalized medicine. Given the emergence of single-cell mRNA sequencing technologies, a method is needed to isolate CTCs with high sensitivity and specificity as well as compatibility with downstream genomic analysis. Flow cytometry is a powerful tool to analyze and sort single cells, but pre-enrichment is required prior to flow sorting for efficient isolation of CTCs due to the extreme low frequency of CTCs in blood (one in billions of blood cells). While current enrichment technologies often require many steps and result in poor recovery, we demonstrate a magnetic separator and acoustic microfluidic focusing chip integrated system that enriches rare cells in-line with FACS™ (fluorescent activated cell sorting) and single-cell sequencing. This system analyzes, isolates, and index sorts single cells directly into 96-well plates containing reagents for Molecular Indexing (MI) and transcriptional profiling of single cells. With an optimized workflow using the integrated enrichment-FACS system, we performed a proof-of-concept experiment with spiked prostate cancer cells in peripheral blood and achieved: (i) a rapid one-step process to isolate rare cancer cells from lysed whole blood; (ii) an average of 92% post-enrichment cancer cell recovery (R² = 0.9998) as compared with 55% recovery for a traditional benchtop workflow; and (iii) detection of differentially expressed genes at a single cell level that are consistent with reported cell-type dependent expression signatures for prostate cancer cells. These model system results lay the groundwork for applying our approach to human blood samples from prostate and other cancer patients, and support the enrichment-FACS system as a flexible solution for isolation and characterization of CTCs for cancer diagnosis. © 2018 International Society for Advancement of Cytometry.

Flow based single cell analysis of the immune landscape distinguishes Barrett's esophagus from adjacent normal tissue

Barrett’s esophagus (BE) is metaplasia of the squamous epithelium to a specialized columnar epithelium. BE progresses through low- and high-grade dysplasia before developing into esophageal adenocarcinoma. The BE microenvironment is not well defined. We compare 12 human clinical BE and adjacent normal squamous epithelium biopsies using single cell immunophenotyping by flow cytometry. A cassette of 19 epithelial and immune cell markers was used to detect differences between cellular compartments in normal and BE tissues. We found that the BE microenvironment has an immunological landscape distinct from adjacent normal epithelium. BE has an increased percentage of epithelial cells with a concomitant decrease in the percentage of immune cells, accompanied by a shift in the immune landscape from a predominantly T cell rich microenvironment in normal tissue to a B cell rich landscape in BE tissue. Hierarchical clustering separates BE and normal samples into two discrete groups based upon our 19-marker panel, but also reveals unexpected, shared phenotypes for three patients. Our results suggest that flow based single cell analysis may have the potential for revealing clinically relevant differences between BE and normal adjacent tissue, and that surface immunophenotypes could identify specific subpopulations from dysplastic tissue for further investigation.

Rare Event Phenotyping and Molecular Characterization: Circulating Tumor Cells

Noninvasive isolation of circulating tumor cells (CTCs) from patient blood samples allows for interrogation of valuable molecular and phenotypic information useful for disease diagnosis and monitoring response to therapy. However, CTCs are extremely rare relative to red and white blood cells (R/WBC), thus making CTC isolation from unmanipulated whole blood very time-consuming. Moreover, single CTC analysis often requires hand-picking, a step that can result in more CTC loss and compromised cell integrity. Here we describe an automated flow cytometry-based approach for isolation and analysis of single, viable CTCs that combines gentle RBC lysis and magnetic, no-wash negative-depletion of WBCs, followed by a highly adaptable sorting protocol for rare cells of interest. Multiparametric flow-cytometric panels allow probing of numerous extracellular markers for immunophenotyping, while whole transcriptome analysis contributes to molecular characterization of individual CTCs. Index sorting links single CTC proteogenomics information.

Measurement and immunophenotyping of pleural fluid EpCAM-positive cells and clusters for the management of non-small cell lung cancer patients

OBJECTIVES

A malignant pleural effusion (MPE) is a common complication in non-small cell lung cancer (NSCLC) with important staging and prognostic information. Patients with MPEs are often candidates for advanced therapies, however, the current gold standard, cytological analysis of pleural fluid samples, has limited sensitivity. We aimed to demonstrate the feasibility of non-invasive enumeration and immunophenotyping of EpCAM-positive cells in pleural fluid samples for the diagnosis of a MPE in NSCLC patients.

MATERIALS AND METHODS

Pleural fluid specimens were prospectively collected from patients with NSCLC and the CellSearch® technology was utilized for the enumeration of pleural EpCAM-positive cells (PECs) and determination of PD-L1 expression on PECs from pleural fluid samples. The diagnostic performance of the enumeration of single PECs and PEC clusters was assessed using receiver operating characteristic (ROC) curves. The Kaplan-Meier method and Cox proportional hazards model was used to assess the impact of PECs and PEC clusters on overall survival (OS).

RESULTS

101 NSCLC patients were enrolled. The median number of PECs was significantly greater in the malignant (n = 84) versus non-malignant group (n = 17) (730 PECs/mL vs 1.0 PEC/mL, p < 0.001). The area under the ROC curve was 0.91. A cutoff value of 105 PECs/mL had a sensitivity and specificity of 73% and 100% for the diagnosis of a MPE, respectively. Among 69 patients with a pathology-confirmed MPE and tissue immunohistochemistry (IHC) results, 15 (22%) had greater than 50% PD-L1+ PECs. Overall concordance between tissue and PEC PD-L1 expression was 76%. Higher numbers of pleural effusion single PECs were associated with inferior overall survival (Cox adjusted HR 1.8, 95% CI: 1.02-3.05 p = 0.043).

CONCLUSION

Non-invasive measurement of PECs in NSCLC patients, using an automated, clinically available approach, may improve the diagnostic accuracy of a MPE, allow for immunophenotyping of PECs, and provide prognostic information.

Comparison of the mechanical properties of platelet-rich fibrin and ankaferd blood stopper-loaded platelet-rich fibrin

Background and Aim

Platelet-rich fibrin (PRF) can be named as a natural fibrin-based biomaterial favorable to increasing vascularization and able to guide epithelial cell migration to its surface. The membrane has a significant positive effect on protecting open wounds and accelerating healing. Similar to PRF Ankaferd Blood Stopper (ABS) also has positive effects on wound healing. The aim of this study was to detect if we can improve known physical properties of PRF combining with ABS. This idea was based on the known mechanism of ABS in forming protein network without damaging any blood cells. Materials and Methods: A total of 25 adult rabbits used for collecting 5-7 ml of blood passively with the help of winged blood collection needle to the test tube. Collected samples were centrifuged at 3000 rpm for 10 min. Two similar samples obtained from each animal and one of the samples was placed in 20% ABS 80% saline solution for 5 min. Mechanical properties of the membrane samples were measured using Universal Testing Machine. Results: There is the statistically significant difference between PRF and ABS added PRF in elongation/mm (dL) and elongation/% at break values. Maximum force (fMax) and modulus values did not show any statistically significant differences.

Conclusion

ABS loaded PRF causes better physical properties. This combination seems to exhibit superior performance when used as a membrane barrier solely. Advanced studies can be done on biological properties of ABS loaded PRF, especially on tissue healing.

Changes in Patient-reported Swallow Function in the Long Term After Chemoradiotherapy for Oropharyngeal Carcinoma

AIMS

To assess long-term patient-reported swallow function after chemoradiotherapy for oropharyngeal carcinoma and to evaluate the frequency of deterioration/improvement over years.

MATERIALS AND METHODS

Fifty-nine patients with oropharyngeal carcinoma treated with parotid-sparing intensity-modulated radiotherapy and concurrent chemotherapy between 2010 and 2012 had previously completed the MD Anderson Dysphagia Inventory (MDADI) at a median of 34 months (range 24-59) after treatment. An MDADI was posted to 55 alive and disease-free patients after a 30 month interval; 52/55 replies were received, a median of 64 months (range 52-88) after treatment; 27/52 (52%) had been managed with a prophylactic gastrostomy. A 10 point or greater change in the MDADI scores was defined as clinically significant.

RESULTS

Overall, in the whole cohort, patient-reported swallow function showed a small absolute improvement in MDADI composite score on the second MDADI questionnaire (>5 years after treatment) compared with the first MDADI (>2 years after treatment); mean 68.0 (standard deviation 19.3) versus 64.0 (standard deviation 16.3), P = 0.021. Using the composite score, swallow function was stable over time in 29/52 (56%) patients; a clinically significant improvement in swallow function over time was noted in 17/52 (33%) patients; conversely 6/52 (12%) patients experienced a clinically significant deterioration with time. Abnormality of pre-treatment diet and a prophylactic gastrostomy correlated with an inferior MDADI composite score on the later questionnaire (P = 0.029 and P = 0.044, respectively).

CONCLUSIONS

Long-term dysphagia is prevalent >5 years after treatment. Although long-term swallow function is stable in most patients, it is not static in a minority. On MDADI composite summary scores, 33% of patients experienced an improvement, whereas 12% deteriorated with time. Further investigation is needed to determine underlying mechanisms behind these divergent outcomes.

An integrated flow cytometry-based platform for isolation and molecular characterization of circulating tumor single cells and clusters

Comprehensive molecular analysis of rare circulating tumor cells (CTCs) and cell clusters is often hampered by low throughput and purity, as well as cell loss. To address this, we developed a fully integrated platform for flow cytometry-based isolation of CTCs and clusters from blood that can be combined with whole transcriptome analysis or targeted RNA transcript quantification. Downstream molecular signature can be linked to cell phenotype through index sorting. This newly developed platform utilizes in-line magnetic particle-based leukocyte depletion, and acoustic cell focusing and washing to achieve >98% reduction of blood cells and non-cellular debris, along with >1.5 log-fold enrichment of spiked tumor cells. We could also detect 1 spiked-in tumor cell in 1 million WBCs in 4/7 replicates. Importantly, the use of a large 200μm nozzle and low sheath pressure (3.5 psi) minimized shear forces, thereby maintaining cell viability and integrity while allowing for simultaneous recovery of single cells and clusters from blood. As proof of principle, we isolated and transcriptionally characterized 63 single CTCs from a genetically engineered pancreatic cancer mouse model (n = 12 mice) and, using index sorting, were able to identify distinct epithelial and mesenchymal sub-populations based on linked single cell protein and gene expression.

Impact of a dedicated emergency surgical unit on early laparoscopic cholecystectomy for acute cholecystitis

INTRODUCTION

Emergency general surgery (EGS) accounts for 50% of the surgical workload, and yet outcomes are variable and poorly recorded. The management of acute cholecystitis (AC) at a dedicated emergency surgical unit (ESU) was assessed as a performance target for EGS.

METHODS

The outcomes for AC admissions were compared one year before and after inception of the ESU. The impact on cost and compliance with national guidance recommending early laparoscopic cholecystectomy (ELC) within seven days of diagnosis was assessed.

RESULTS

The overall ELC rate increased from 26% for the 126 patients admitted in the pre-ESU period to 45% for the 152 patients admitted in the post-ESU period (p=0.001). With those unsuitable for ELC excluded, the ELC rate increased from 34% to 82% (p<0.001). The proportion of patients precluded from ELC for avoidable reasons, particularly owing to 'surgeon preference/skill', was reduced from 69% to 18% (p<0.001). The mean total length of stay (LOS) and postoperative LOS fell by 1.7 days (from 8.3 to 6.6 days, p=0.040) and 2 days (from 5.6 to 3.6 days, p=0.020) respectively. The higher ELC rate and the reduction in LOS produced additional tariff income (£111,930) and estimated savings in bed day (£90,440) and readmission (£27,252) costs.

CONCLUSIONS

A dedicated ESU incorporating national recommendations for EGS improves alignment of best practice with best evidence and can also result in financial rewards for a busy district general hospital.

Assessment of outcomes with delayed (18)F-FDG PET-CT response assessment in head and neck squamous cell carcinoma

OBJECTIVE

To assess the accuracy of a 4-month post-(chemo)radiotherapy 18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)-CT for head and neck squamous cell carcinoma (HNSCC).

METHODS

105 patients who underwent a baseline and response assessment (18)F-FDG PET-CT scan between 2008 and April 2013 were identified. (18)F-FDG PET-CT outcomes were analysed with reference to clinicopathological outcomes.

RESULTS

79 of 105 (75%) (18)F-FDG PET-CT scans demonstrated a complete metabolic response; 19 of 101 (19%) for assessable primary tumours were positive; and 19 of 93 (20%) for patients with nodal disease were equivocal (n = 10) or positive (n = 9). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for primary and nodal disease were 90%, 89%, 47%, 99% and 91%, 89%, 53% and 99%, respectively. Eight of nine patients with a positive nodal response scan had clinicopathological evidence of residual nodal disease (PPV, 89%). 2 of 10 patients with equivocal nodal responses had clinicopathological evidence of residual nodal disease (PPV, 20%).

CONCLUSION

(18)F-FDG PET-CT 4 months post treatment has a very high NPV. A positive (18)F-FDG PET-CT has a high PPV for residual nodal disease. By contrast, patients who have an equivocal nodal response have a low PPV.

ADVANCES IN KNOWLEDGE

Response assessment (18)F-FDG PET-CT is a valuable tool in guiding the selective use of neck dissection following (chemo)radiotherapy for HNSCC. An equivocal lymph node response has a limited predictive value for persistent disease, and optimal management remains a clinical challenge.

Implementation of a novel emergency surgical unit significantly improves the management of gallstone pancreatitis

INTRODUCTION

Emergency surgery is changing rapidly with a greater workload, early subspecialisation and centralisation of emergency care. We describe the impact of a novel emergency surgical unit (ESU) on the definitive management of patients with gallstone pancreatitis (GSP).

METHODS

A comparative audit was undertaken for all admissions with GSP before and after the introduction of the ESU over a six-month period. The impact on compliance with British Society of Gastroenterology (BSG) guidelines was assessed.

RESULTS

Thirty-five patients were treated for GSP between December 2013 and May 2014, after the introduction of the ESU. This was twice the nationally reported average for a UK trust over a six-month period. All patients received definitive management for their GSP and 100% of all suitable patients received treatment during the index admission or within two weeks of discharge. This was a significantly greater proportion than that prior to the introduction of the ESU (57%, p=0.0001) as well as the recently reported national average (34%). The mean length of total inpatient stay was reduced significantly after the ESU was introduced from 13.7 ± 4.7 days to 7.8 ± 2.1 days (p=0.03). The mean length of postoperative stay also fell significantly from 6.7 ± 2.6 days to 1.8 ± 0.8 days (p=0.001).

CONCLUSIONS

A dedicated ESU following national recommendations for emergency surgery care by way of using dedicated emergency surgeons and a streamlined protocol for common presentations has been shown by audit of current practice to significantly improve the management of patients presenting to a busy district general hospital with GSP.

Arsenic removal from contaminated groundwater by membrane-integrated hybrid plant: optimization and control using Visual Basic platform

A simulation software (ARRPA) has been developed in Microsoft Visual Basic platform for optimization and control of a novel membrane-integrated arsenic separation plant in the backdrop of absence of such software. The user-friendly, menu-driven software is based on a dynamic linearized mathematical model, developed for the hybrid treatment scheme. The model captures the chemical kinetics in the pre-treating chemical reactor and the separation and transport phenomena involved in nanofiltration. The software has been validated through extensive experimental investigations. The agreement between the outputs from computer simulation program and the experimental findings are excellent and consistent under varying operating conditions reflecting high degree of accuracy and reliability of the software. High values of the overall correlation coefficient (R (2) = 0.989) and Willmott d-index (0.989) are indicators of the capability of the software in analyzing performance of the plant. The software permits pre-analysis, manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. Performance analysis of the whole system as well as the individual units is possible using the tool. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for removal of arsenic from contaminated groundwater.

Wnt signaling in rheumatoid synoviocyte activation

Abstract Rheumatoid arthritis (RA) is a joint-specific disease with complex pathogenesis. It is characterized by synovial inflammation, cartilage loss, and joint destruction. The reasons why joint damage recurs when therapy is discontinued are not clearly understood. Several lines of evidence suggest that cartilage damage is promoted by the transformed and invasive fibroblast-like synoviocytes (FLS) of the rheumatoid joint. It has been demonstrated in several systems that aberrant wnt-mediated signaling causes blockade of cartilage differentiation and malformation of joints. In this review, we have discussed the importance of wnt-frizzled-mediated signaling in the autonomous activation of FLS in patients with RA. Anti-wnt/anti-frizzled antibodies, frizzled receptor antagonists, or small molecule inhibitors of wnt-frizzled signaling might be useful for therapeutic interventions in RA.

Effects of the Pringle manoeuvre on the healing of left colonic anastomoses in rats

BACKGROUND

Whether to perform colorectal cancer and liver metastasis resections simultaneously or in separate procedures is controversial. The aim of the present study was to investigate the effect of the Pringle manoeuvre on the healing of left-sided colonic anastomoses in rats.

METHODS

Sixteen rats were randomly separated into two groups. In Groups 1 and 2, 1 cm of descending colon was resected and a primary anastomosis was performed. In Group 2, an intermittent pedicle clamp (the Pringle manoeuvre) was performed. On postoperative day 5, laparotomy was performed and the bursting pressures of all colon anastomoses were determined. Tissues were sampled for assay of hydroxyproline levels. Cultures of intraperitoneal swabs were also performed.

RESULTS

Clostridium was twice as abundant in the Pringle manoeuvre group as in the control group (p < 0.05). Anastomosis-bursting pressures and tissue hydroxyproline levels were significantly lower in the Pringle manoeuvre group than in the control group (p < 0.05).

CONCLUSIONS

The Pringle manoeuvre may compromise the viability of colonic anastomoses.

Improving target definition for head and neck radiotherapy: a place for magnetic resonance imaging and 18-fluoride fluorodeoxyglucose positron emission tomography?

Defining the target for head and neck radiotherapy is a critical issue with the introduction of steep dose gradients associated with intensity-modulated radiotherapy. Tumour delineation inaccuracies are a major source of error in radiotherapy planning. The integration of 18-fluoride fluorodeoxyglucose positron emission tomography ((18)FDG-PET) and magnetic resonance imaging directly into the radiotherapy planning process has the potential to greatly improve target identification/selection and delineation. This raises a range of new issues surrounding image co-registration, delineation methodology and the use of functional data and treatment adaptation. This overview will discuss the practical aspects of integrating (18)FDG-PET and magnetic resonance imaging into head and neck radiotherapy planning.