Antibiotic resistance pattern and pathological features of avian pathogenic Escherichia coli O78:K80 in chickens

Abstract Avian pathogenic Escherichia coli (APEC) induces colibacillosis, an acute and systemic disease, resulting in substantial economic losses in the poultry sector. This study aimed to investigate the antibiotic resistance pattern associated with frequent virulence gene distribution in APEC O78:K80 that may cause pathological alterations in chickens. The antibiogram profile showed high resistance to erythromycin, chloramphenicol, tetracycline, ampicillin, and co-trimoxazole, followed by intermediate resistance to ciprofloxacin, levofloxacin, enrofloxacin, norfloxacin, nitrofurantoin, and doxycycline hydrochloride, and sensitive to amikacin, streptomycin, gentamicin, and colistin. Virulence gene distribution identifies eight (irp-2, iutA, ompT, iss, iucD, astA, hlyF, iroN) genes through a conventional polymerase chain reaction. APEC O78:K80 caused significantly high liver enzyme concentrations, serum interleukin-6 and tumor necrosis factor-alpha levels in experimental birds. Also, infected birds have hypoproteinemia, hypoalbuminemia, and hyperglobulinemia. Necropsy examination revealed fibrinous perihepatitis and pericarditis, congested lungs, intestinal ecchymotic hemorrhages and necrotizing granulomatosis of the spleen. Histopathological examination depicted hepatocellular degeneration, myocardial necrosis, interstitial nephritis, intestinal hemorrhages and lymphopenia in the spleen. This study is the first evidence to assess the antibiotic resistance profile linked with virulence genes and clinicopathological potential of APEC O78:K80 in chickens in Pakistan, which could be a useful and rapid approach to prevent and control the disease by developing the control strategies.

Acute Toxicity of Hypofractionated and Conventionally Fractionated (Chemo)Radiotherapy Regimens for Bladder Cancer: An Exploratory Analysis from the RAIDER Trial

AIMS

Adding concurrent (chemo)therapy to radiotherapy improves outcomes for muscle-invasive bladder cancer patients. A recent meta-analysis showed superior invasive locoregional disease control for a hypofractionated 55 Gy in 20 fractions schedule compared with 64 Gy in 32 fractions. In the RAIDER clinical trial, patients undergoing 20 or 32 fractions of radical radiotherapy were randomised (1:1:2) to standard radiotherapy or to standard-dose or escalated-dose adaptive radiotherapy. Neoadjuvant chemotherapy and concomitant therapy were permitted. We report exploratory analyses of acute toxicity by concomitant therapy-fractionation schedule combination.

MATERIALS AND METHODS

Participants had unifocal bladder urothelial carcinoma staged T2-T4a N0 M0. Acute toxicity was assessed (Common Terminology Criteria for Adverse Events) weekly during radiotherapy and at 10 weeks after the start of treatment. Within each fractionation cohort, non-randomised comparisons of the proportion of patients reporting treatment emergent grade 2 or worse genitourinary, gastrointestinal or other adverse events at any point in the acute period were carried out using Fisher's exact tests.

RESULTS

Between September 2015 and April 2020, 345 (163 receiving 20 fractions; 182 receiving 32 fractions) patients were recruited from 46 centres. The median age was 73 years; 49% received neoadjuvant chemotherapy; 71% received concomitant therapy, with 5-fluorouracil/mitomycin C most commonly used: 44/114 (39%) receiving 20 fractions; 94/130 (72%) receiving 32 fractions. The acute grade 2+ gastrointestinal toxicity rate was higher in those receiving concomitant therapy compared with radiotherapy alone in the 20-fraction cohort [54/111 (49%) versus 7/49 (14%), P < 0.001] but not in the 32-fraction cohort (P = 0.355). Grade 2+ gastrointestinal toxicity was highest for gemcitabine, with evidence of significant differences across therapies in the 32-fraction cohort (P = 0.006), with a similar pattern but no significant differences in the 20-fraction cohort (P = 0.099). There was no evidence of differences in grade 2+ genitourinary toxicity between concomitant therapies in either the 20- or 32-fraction cohorts.

CONCLUSION

Grade 2+ acute adverse events are common. The toxicity profile varied by type of concomitant therapy; the gastrointestinal toxicity rate seemed to be higher in patients receiving gemcitabine.

Correlation of Clinician- and Patient-Reported Outcomes in the BC2001 Trial

AIMS

To evaluate whether there is sufficient correlation between patient-reported outcomes (PROs) and clinician-reported outcomes (CROs) in bladder cancer follow-up post-radiotherapy to streamline data collection and to reduce trial follow-up burden on patients, clinicians and trial programmes.

MATERIALS AND METHODS

PROs data were collected within the BC2001 trial using the Functional Assessment of Cancer Therapy specific to bladder cancer (FACT-BL) questionnaire. CROs data were collected by clinicians using Late Effects in Normal Tissues Subjective, Objective and Management (LENT/SOM). Data were collected at baseline, post-treatment, at 6 and 12 months post-randomisation and then annually to 5 years. The percentage agreement between CROs and PROs measures was evaluated at 2 and 5 years post-randomisation. Concordance was tested using the weighted Kappa statistic with 95% confidence intervals.

RESULTS

Correlation was evaluated between six categories of the FACT-BL and LENT/SOM scores. At 2 years the percentage agreement across these domains ranged from 45 to 78%, with the weighted Kappa statistic between 0.07 and 0.35. Results were similar in year 5 with 48-83% agreement and kappa statistics between -0.02 and 0.21.

CONCLUSION

The correlation between CROs and PROs in patients treated with radiotherapy for bladder cancer were generally poor. PROs appear to be more sensitive, with higher grade events reported. Further work is needed to evaluate whether PROs alone can be used to evaluate toxicity-related outcomes in randomised controlled trials.

Differences in Quality of Life and Toxicity for Male and Female Patients following Chemo(radiotherapy) for Bladder Cancer

AIMS

BC2001, a randomised trial of treatment for muscle-invasive bladder cancer, demonstrated no difference in health-related quality of life (HRQoL) or late toxicity between patients receiving radical radiotherapy with and without chemotherapy. This secondary analysis explored sex-based differences in HRQoL and toxicity.

MATERIALS AND METHODS

Participants completed the Functional Assessment of Cancer Therapy Bladder (FACT-BL) HRQoL questionnaires at baseline, end of treatment, 6 months and annually until 5 years. Clinicians assessed toxicity with the Radiation Therapy Oncology Group (RTOG) and Late Effects in Normal Tissues Subjective, Objective and Management (LENT/SOM) scoring systems at the same timepoints. The impact of sex on patient-reported HRQoL was evaluated using multivariate analyses of change in FACT-BL subscores from baseline to the timepoints of interest. For clinician-reported toxicity, differences were compared by calculating the proportion of patients with grade 3-4 toxicities occurring over the follow-up period.

RESULTS

For both males and females, all FACT-BL subscores had a reduction in HRQoL at the end of treatment. For males, the mean bladder cancer subscale (BLCS) score remained stable through to year 5. For females, there was a decline in BLCS from baseline at years 2 and 3 with a return to baseline at year 5. At year 3, females had a statistically significant and clinically meaningful worsening of mean BLCS score (-5.18; 95% confidence interval -8.37 to -1.99), which was not seen in males (0.24; -0.76 to 1.23). RTOG toxicity was more frequent in females than males (27% versus 16%, P = 0.027).

CONCLUSION

Results suggest that female patients treated with radiotherapy ± chemotherapy for localised bladder cancer report worse treatment-related toxicity in post-treatment years 2 and 3 than males.

Understanding the Benefit of Magnetic Resonance-guided Adaptive Radiotherapy in Rectal Cancer Patients: a Single-centre Study

AIMS

Neoadjuvant chemoradiotherapy followed by surgery is the mainstay of treatment for patients with rectal cancer. Standard clinical target volume (CTV) to planning target volume (PTV) margins of 10 mm are used to accommodate inter- and intrafraction motion of target. Treating on magnetic resonance-integrated linear accelerators (MR-linacs) allows for online manual recontouring and adaptation (MRgART) enabling the reduction of PTV margins. The aim of this study was to investigate motion of the primary CTV (CTVA; gross tumour volume and macroscopic nodes with 10 mm expansion to cover microscopic disease) in order to develop a simultaneous integrated boost protocol for use on MR-linacs.

MATERIALS AND METHODS

Patients suitable for neoadjuvant chemoradiotherapy were recruited for treatment on MR-linac using a two-phase technique; only the five phase 1 fractions on MR-linac were used for analysis. Intrafraction motion of CTVA was measured between pre-treatment and post-treatment MRI scans. In MRgART, isotropically expanded pre-treatment PTV margins from 1 to 10 mm were rigidly propagated to post-treatment MRI to determine overlap with 95% of CTVA. The PTV margin was considered acceptable if overlap was >95% in 90% of fractions. To understand the benefit of MRgART, the same methodology was repeated using a reference computed tomography planning scan for pre-treatment imaging.

RESULTS

In total, nine patients were recruited between January 2018 and December 2020 with T3a-T4, N0-N2, M0 disease. Forty-five fractions were analysed in total. The median motion across all planes was 0 mm, demonstrating minimal intrafraction motion. A PTV margin of 3 and 5mm was found to be acceptable in 96 and 98% of fractions, respectively. When comparing to the computed tomography reference scan, the analysis found that PTV margins to 5 and 10 mm only acceptably covered 51 and 76% of fractions, respectively.

CONCLUSION

PTV margins can be reduced to 3-5 mm in MRgART for rectal cancer treatment on MR-linac within an simultaneous integrated boost protocol.

Assessing Bladder Radiotherapy Response With Quantitative Diffusion-Weighted Magnetic Resonance Imaging Analysis

AIMS

Radiotherapy with radiosensitisation offers opportunity for cure with organ preservation in muscle-invasive bladder cancer (MIBC). Treatment response assessment and follow-up are reliant on regular endoscopic evaluation of the retained bladder. In this study we aim to determine the role of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) analysis to assess bladder radiotherapy response.

MATERIALS AND METHODS

Patients with T2-T4aN0-3M0 MIBC suitable for radical radiotherapy were recruited prospectively to an ethics approved protocol. Following transurethral resection of the bladder tumour and prior to any treatment, magnetic resonance imaging including DWI was performed on a 1.5T system using b values of 0, 100, 150, 250, 500, 750 s/mm2. DWI was repeated 3 months after completing radiotherapy. Cystoscopy and tumour site biopsy were undertaken following this. The response was dichotomised into response (

RESULTS

Thirty-four patients were evaluated. Response was associated with a significant increase in ΔADC mean compared with poor response at ΔADCall (0.57 × 10-3 mm2/s versus -0.01 × 10-3 mm2/s; P < 0.0001) and ΔADCb100 (0.58 × 10-3 mm2/s versus -0.10 x 10-3 mm2/s; P = 0.007). A 48.50% increase in %ΔADCall mean was seen in response compared with a 1.37% decrease in poor response (P < 0.0001). This corresponded to a %ΔADCb100 mean increase of 50.34% in response versus a 7.36% decrease for poor response (P < 0.0001). Significant area under the curve (AUC) values predictive of radiotherapy response were identified at ΔADC and %ΔADC for ADCall and ADCb100 mean, 10th, 25th, 50th, 75th and 90th percentiles (AUC >0.9, P < 0.01). ΔADCall mean of 0.16 × 10-3 mm2/s and ΔADCb100 mean 0.12 × 10-3 mm2/s predicted radiotherapy response with sensitivity/specificity/positive predictive value/negative predictive value of 92.9%/100.0%/100.0%/75.0% and 89.3%/100.0%/100.0%/66.7%, respectively.

CONCLUSIONS

Quantitative DWI analysis can successfully provide non-invasive assessment of bladder radiotherapy response. Multicentre validation is required before prospective testing to inform MIBC radiotherapy follow-up schedules and decision making.

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Key Words

• Bladder cancer
• Diffusion-weighted MRI
• MRI
• Radiotherapy

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MESH Headings

• Diffusion Magnetic Resonance Imaging/methods
• Humans
• Magnetic Resonance Imaging
• Prospective Studies
• ROC Curve
• Urinary Bladder/diagnostic imaging
• Urinary Bladder Neoplasms/diagnostic imaging
• Urinary Bladder Neoplasms/pathology
• Urinary Bladder Neoplasms/radiotherapy

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Grants

• 28724 Cancer Research UK
• C33589/A19727 Cancer Research UK
• Department of Health
• C33589/A28284 Cancer Research UK

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Affiliation(s)

S Hafeez The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK.
M Koh The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
K Jones The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
A El Ghzal The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
J D'Arcy The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
P Kumar The Royal Marsden NHS Foundation Trust, London, UK
V Khoo The Royal Marsden NHS Foundation Trust, London, UK
S Lalondrelle The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
F McDonald The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK
A Thompson The Royal Marsden NHS Foundation Trust, London, UK
E Scurr The Royal Marsden NHS Foundation Trust, London, UK
A Sohaib The Royal Marsden NHS Foundation Trust, London, UK
R Huddart The Institute of Cancer Research, London, UK; The Royal Marsden NHS Foundation Trust, London, UK

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Mapping Local Failure Following Bladder Radiotherapy According to Dose

AIMS

To determine the relationship between local relapse following radical radiotherapy for muscle-invasive bladder cancer (MIBC) and radiation dose.

MATERIALS AND METHODS

Patients with T2-4N0-3M0 MIBC were recruited to a phase II study assessing the feasibility of intensity-modulated radiotherapy to the bladder and pelvic lymph nodes. Patients were planned to receive 64 Gy/32 fractions to the bladder tumour, 60 Gy/32 fractions to the involved pelvic nodes and 52 Gy/32 fractions to the uninvolved bladder and pelvic nodes. Pre-treatment set-up was informed by cone-beam CT. For patients who experienced local relapse, cystoscopy and imaging (CT/MRI) was used to reconstruct the relapse gross tumour volume (GTVrelapse) on the original planning CT . GTVrelapse D98% and D95% was determined by co-registering the relapse image to the planning CT utilising deformable image registration (DIR) and rigid image registration (RIR). Failure was classified into five types based on spatial and dosimetric criteria as follows: A (central high-dose failure), B (peripheral high-dose failure), C (central elective dose failure), D (peripheral elective dose failure) and E (extraneous dose failure).

RESULTS

Between June 2009 and November 2012, 38 patients were recruited. Following treatment, 18/38 (47%) patients experienced local relapse within the bladder. The median time to local relapse was 9.0 months (95% confidence interval 6.3-11.7). Seventeen of 18 patients were evaluable based on the availability of cross-sectional relapse imaging. A significant difference between DIR and RIR methods was seen. With the DIR approach, the median GTVrelapse D98% and D95% was 97% and 98% of prescribed dose, respectively. Eleven of 17 (65%) patients experienced type A failure and 6/17 (35%) patients type B failure. No patients had type C, D or E failure. MIBC failure occurred in 10/17 (59%) relapsed patients; of those, 7/11 (64%) had type A failure and 3/6 (50%) had type B failure. Non-MIBC failure occurred in 7/17 (41%) patients; 4/11 (36%) with type A failure and 3/6 (50%) with type B failure.

CONCLUSION

Relapse following radiotherapy occurred within close proximity to the original bladder tumour volume and within the planned high-dose region, suggesting possible biological causes for failure. We advise caution when considering margin reduction for future reduced high-dose radiation volume or partial bladder radiotherapy protocols.

Feasibility of tumour-focused adaptive radiotherapy for bladder cancer on the MR-linac

Bladder tumour-focused magnetic resonance image-guided adaptive radiotherapy using a 1.5 Tesla MR-linac is feasible. A full online workflow adapting to anatomy at each fraction is achievable in approximately 30 min. Intra-fraction bladder filling did not compromise target coverage with the class solution employed.

The Development of Therapeutic Radiographers in Imaging and Adaptive Radiotherapy Through Clinical Trial Quality Assurance

AIMS

Adaptive radiotherapy (ART) is an emerging advanced treatment option for bladder cancer patients. Therapeutic radiographers (RTTs) are central to the successful delivery of this treatment. The purpose of this work was to evaluate the image-guided radiotherapy (IGRT) and ART experience of RTTs before participating in the RAIDER trial. A plan of the day (PoD) quality assurance programme was then implemented. Finally, the post-trial experience of RTTs was evaluated, together with the impact of trial quality assurance participation on their routine practice.

MATERIALS AND METHODS

A pre-trial questionnaire to assess the experience of the RTT staff group in IGRT and ART in bladder cancer was sent to each centre. Responses were grouped according to experience. The PoD quality assurance programme was implemented, and the RAIDER trial commenced. During stage 1 of the trial, RTTs reported difficulties in delivering PoD and the quality assurance programme was updated accordingly. A follow-up questionnaire was sent assessing experience in IGRT and ART post-trial. Any changes in routine practice were also recorded.

RESULTS

The experience of RTTs in IGRT and ART pre-trial varied. For centres deemed to have RTTs with more experience, the initial PoD quality assurance programme was streamlined. For RTTs without ART experience, the full quality assurance programme was implemented, of which 508 RTTs completed. The quality assurance programme was updated (as the trial recruited) and it was mandated that at least one representative RTT (regardless of pre-trial experience) participated in the update in real-time. The purpose of the updated quality assurance programme was to provide further support to RTTs in delivering a complex treatment. Engagement with the updated quality assurance programme was high, with RTTs in 24/33 centres participating in the real-time online workshop. All 33 UK centres reported all RTTs reviewed the updated training offline. Post-trial, the RTTs' experience in IGRT and ART was increased.

CONCLUSION

Overall, 508 RTTs undertook the PoD quality assurance programme. There was a high engagement of RTTs in the PoD quality assurance programme and trial. RTTs increased their experience in IGRT and ART and subsequently updated their practice for bladder cancer and other treatment sites.

Image-guided Adaptive Radiotherapy for Bladder Cancer

Technological advancement has facilitated patient-specific radiotherapy in bladder cancer. This has been made possible by developments in image-guided radiotherapy (IGRT). Particularly transformative has been the integration of volumetric imaging into the workflow. The ability to visualise the bladder target using cone beam computed tomography and magnetic resonance imaging initially assisted with determining the magnitude of inter- and intra-fraction target change. It has led to greater confidence in ascertaining true anatomy at each fraction. The increased certainty of dose delivered to the bladder has permitted the safe reduction of planning target volume margins. IGRT has therefore improved target coverage with a reduction in integral dose to the surrounding tissue. Use of IGRT to feed back into plan and dose delivery optimisation according to the anatomy of the day has enabled adaptive radiotherapy bladder solutions. Here we undertake a review of the stepwise developments underpinning IGRT and adaptive radiotherapy strategies for external beam bladder cancer radiotherapy. We present the evidence in accordance with the framework for systematic clinical evaluation of technical innovations in radiation oncology (R-IDEAL).

Feasibility of magnetic resonance guided radiotherapy for the treatment of bladder cancer

Whole bladder magnetic resonance image-guided radiotherapy using the 1.5 Telsa MR-linac is feasible. Full online adaptive planning workflow based on the anatomy seen at each fraction was performed. This was delivered within 45 min. Intra-fraction bladder filling did not compromise target coverage. Patients reported acceptable tolerance of treatment.

The Intensity-Modulated Pelvic Node and Bladder Radiotherapy (IMPART) Trial: A Phase II Single-Centre Prospective Study

AIMS

Node-positive bladder cancer (NPBC) carries a poor prognosis and has traditionally been treated palliatively. However, surgical series suggest that a subset of NPBC patients can achieve long-term control after cystectomy and lymph node dissection. There is little published data regarding the use of radiotherapy to treat NPBC patients. This is in part due to concerns regarding the toxicity of whole-pelvis radiotherapy using conventional techniques. We hypothesised that, using intensity-modulated radiotherapy (IMRT), the pelvic nodes and bladder could be treated within a radical treatment volume with acceptable toxicity profiles.

MATERIALS AND METHODS

The Intensity-modulated Pelvic Node and Bladder Radiotherapy (IMPART) trial was a phase II single-centre prospective study designed to assess the feasibility of delivering IMRT to treat the bladder and pelvic nodes in patients with node-positive or high-risk node-negative bladder cancer (NNBC). The primary end point was meeting predetermined dose constraints. Secondary end points included acute and late toxicity, pelvic relapse-free survival and overall survival.

RESULTS

In total, 38 patients were recruited and treated between June 2009 and November 2012; 22/38 (58%) had NPBC; 31/38 (81.6%) received neoadjuvant chemotherapy; 18/38 (47%) received concurrent chemotherapy; 37/38 (97%) patients had radiotherapy planned as per protocol. Grade 3 gastrointestinal and genitourinary acute toxicity rates were 5.4 and 20.6%, respectively. At 1 year, the grade 3 late toxicity rate was 5%; 1-, 2- and 5-year pelvic relapse-free survival rates were 55, 37 and 26%, respectively. The median overall survival was 1.9 years (95% confidence interval 1.1-3.8) with 1-, 2- and 5-year overall survival rates of 68, 50 and 34%, respectively.

CONCLUSION

Delivering IMRT to the bladder and pelvic nodes in NPBC and high-risk NNBC is feasible, with low toxicity and low pelvic nodal recurrence rates. Long-term control seems to be achievable in a subset of patients. However, relapse patterns suggest that strategies targeting both local recurrence and the development of distant metastases are required to improve patient outcomes.

Magnetic resonance imaging sequence evaluation of an MR Linac system; early clinical experience

OBJECTIVES

To systematically identify the preferred magnetic resonance imaging (MRI) sequences following volunteer imaging on a 1.5 Tesla (T) MR-Linear Accelerator (MR Linac) for future protocol development.

METHODS

Non-patient volunteers were recruited to a Research and Ethics committee approved prospective MR-only imaging study on a 1.5T MR Linac system. Volunteers attended 1-3 imaging sessions that included a combination of mDixon, T1w, T2w sequences using 2-dimensional (2D) and 3-dimensional (3D) acquisitions. Each sequence was acquired over 2-7 minutes and reviewed by a panel of 3 observers to evaluate image quality using a visual grading analysis based on a 4-point Likert scale. Sequences were acquired and modified iteratively until deemed fit for purpose (online image matching or re-planning) and all observers agreed they were suitable in 3 volunteers.

RESULTS

26 volunteers underwent 31 imaging sessions of six general anatomical regions. Images were acquired in one or two of six general anatomical regions: male pelvis (n = 9), female pelvis (n = 4), chestwall/breast (n = 5), lung/oesophagus (n = 5), abdomen (n = 3) and head and neck (n = 5). Images were acquired using a pre-defined exam-card that on average, included six sequences (range 2-10), with a maximum scan time of approximately one hour. The majority of observers preferred T2-weighted sequences. The thorax teams were the only groups to prefer T1-weighted imaging.

CONCLUSIONS

An iterative process identified sequence agreement in all anatomical regions. These sequences will now be evaluated in patient volunteers.

ADVANCES IN KNOWLEDGE

This manuscript is the first publication sharing the results of the first systematic selection of MRI sequences for use in on-board MRI-guided radiotherapy by end-users (therapeutic radiographers and clinical oncologists) in healthy volunteers.

EAU-ESMO consensus statements on the management of advanced and variant bladder cancer-an international collaborative multi-stakeholder effort: under the auspices of the EAU and ESMO Guidelines Committees†

BACKGROUND

Although guidelines exist for advanced and variant bladder cancer management, evidence is limited/conflicting in some areas and the optimal approach remains controversial.

OBJECTIVE

To bring together a large multidisciplinary group of experts to develop consensus statements on controversial topics in bladder cancer management.

DESIGN

A steering committee compiled proposed statements regarding advanced and variant bladder cancer management which were assessed by 113 experts in a Delphi survey. Statements not reaching consensus were reviewed; those prioritised were revised by a panel of 45 experts before voting during a consensus conference.

SETTING

Online Delphi survey and consensus conference.

PARTICIPANTS

The European Association of Urology (EAU), the European Society for Medical Oncology (ESMO), experts in bladder cancer management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Statements were ranked by experts according to their level of agreement: 1-3 (disagree), 4-6 (equivocal), 7-9 (agree). A priori (level 1) consensus was defined as ≥70% agreement and ≤15% disagreement, or vice versa. In the Delphi survey, a second analysis was restricted to stakeholder group(s) considered to have adequate expertise relating to each statement (to achieve level 2 consensus).

RESULTS AND LIMITATIONS

Overall, 116 statements were included in the Delphi survey. Of these, 33 (28%) statements achieved level 1 consensus and 49 (42%) statements achieved level 1 or 2 consensus. At the consensus conference, 22 of 27 (81%) statements achieved consensus. These consensus statements provide further guidance across a broad range of topics, including the management of variant histologies, the role/limitations of prognostic biomarkers in clinical decision making, bladder preservation strategies, modern radiotherapy techniques, the management of oligometastatic disease and the evolving role of checkpoint inhibitor therapy in metastatic disease.

CONCLUSIONS

These consensus statements provide further guidance on controversial topics in advanced and variant bladder cancer management until a time where further evidence is available to guide our approach.

Adaptive Radiotherapy Enabled by MRI Guidance

Adaptive radiotherapy (ART) strategies systematically monitor variations in target and neighbouring structures to inform treatment-plan modification during radiotherapy. This is necessary because a single plan designed before treatment is insufficient to capture the actual dose delivered to the target and adjacent critical structures during the course of radiotherapy. Magnetic resonance imaging (MRI) provides superior soft-tissue image contrast over current standard X-ray-based technologies without additional radiation exposure. With integrated MRI and radiotherapy platforms permitting motion monitoring during treatment delivery, it is possible that adaption can be informed by real-time anatomical imaging. This allows greater treatment accuracy in terms of dose delivered to target with smaller, individualised treatment margins. The use of functional MRI sequences would permit ART to be informed by imaging biomarkers, so allowing both personalised geometric and biological adaption. In this review, we discuss ART solutions enabled by MRI guidance and its potential gains for our patients across tumour types.

Selective organ preservation with neo-adjuvant chemotherapy for the treatment of muscle invasive transitional cell carcinoma of the bladder

BACKGROUND

Radiotherapy for muscle invasive bladder cancer (MIBC) aims to offer organ preservation without oncological compromise. Neo-adjuvant chemotherapy provides survival advantage; response may guide patient selection for bladder preservation and identify those most likely to have favourable result with radiotherapy.

METHODS

Ninety-four successive patients with T2-T4aN0M0 bladder cancer treated between January 2000 and June 2011 were analysed at the Royal Marsden Hospital. Patients received platinum-based chemotherapy following transurethral resection of bladder tumour; repeat cystoscopy (± biopsy) was performed to guide subsequent management. Responders were treated with radiotherapy. Poor responders were recommended radical cystectomy. Progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method; univariate and multivariate analyses were performed using the Cox proportional hazard regression model.

RESULTS

Response assessment was performed in 89 patients. Seventy-eight (88%) demonstrated response; 53 (60%) achieved complete response (CR); 74 responders had radiotherapy; 4 opted for cystectomy. Eleven (12%) demonstrated poor response, 10 received cystectomy. Median survival for CR was 90 months (95% CI 64.7, 115.9) compared with 16 months (95% CI 5.4, 27.4; P < 0.001) poor responders. On multivariate analysis, only response was associated with significantly improved PFS, OS and DSS. After a median follow-up of 39 months (range 4-127 months), 14 patients (16%) required salvage cystectomy (8 for non-muscle invasive disease, 5 for invasive recurrence, 1 for radiotherapy related toxicity). In all, 82% had an intact bladder at last follow-up after radiotherapy; 67% had an intact bladder at last follow-up or death. Our study is limited by its retrospective nature.

CONCLUSIONS

Response to neo-adjuvant chemotherapy is a favourable prognostic indicator and can be used to select patients for radiotherapy allowing bladder preservation in >80% of the selected patients.

Radiographer-led plan selection for bladder cancer radiotherapy: initiating a training programme and maintaining competency

OBJECTIVE

The implementation of plan of the day selection for patients receiving radiotherapy (RT) for bladder cancer requires efficient and confident decision-making. This article describes the development of a training programme and maintenance of competency.

METHODS

Cone beam CT (CBCT) images acquired on patients receiving RT for bladder cancer were assessed to establish baseline competency and training needs. A training programme was implemented, and observers were asked to select planning target volumes (PTVs) on two groups of 20 patients' images. After clinical implementation, the PTVs chosen were reviewed offline, and an audit performed after 3 years.

RESULTS

A mean of 73% (range, 53-93%) concordance rate was achieved prior to training. Subsequent to training, the mean score decreased to 66% (Round 1), then increased to 76% (Round 2). Six radiographers and two clinicians successfully completed the training programme. An independent observer reviewed the images offline after clinical implementation, and a 91% (126/139) concordance rate was achieved. During the audit, 125 CBCT images from 13 patients were reviewed by a single observer and concordance was 92%.

CONCLUSION

Radiographer-led selection of plan of the day was implemented successfully with the use of a training programme and continual assessment. Quality has been maintained over a period of 3 years.

ADVANCES IN KNOWLEDGE

The training programme was successful in achieving and maintaining competency for a plan of the day technique.