Search

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. 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. 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. 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. • Grade 2+ acute toxicity was common and similar for 32- and 20-fraction radiotherapy. • Observed grade 3+ acute toxicity in RAIDER was lower than reported in previous trials. • Acute toxicity following bladder radiotherapy returns to baseline levels by 3 months. • The acute toxicity profile varied by concomitant radiosensitising treatment. • Bowel (but not urinary) toxicity appears higher in those receiving gemcitabine. [ABSTRACT FROM AUTHOR]

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. 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 (0.9, P < 0.01). ΔADC all mean of 0.16 × 10−3 mm2/s and ΔADC b100 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. 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. • Quantitative diffusion-weighted MRI analysis to assess bladder radiotherapy response is feasible. • Significant increase in measured ADC characteristics is seen in those who achieve response compared with poor response. • It provides prognostic information that may help risk-stratify patients and personalise future follow-up. • Multicentre validation to assess reproducibility and repeatability is required before prospective testing. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. • The experience of RTTs in bladder IGRT and adaptive radiotherapy was measured pre- and post-trial. • The experience level of RTTs was mixed and training was tailored accordingly. • RTTs reported difficulties delivering tumour-focused adaptive radiotherapy and training was updated. • Upon completion of the trial and QA the experience of RTTs has improved in bladder IGRT, ART and other tumour sites. • Training programmes are resource-intensive; however, worthwhile as RTTs utilised lessons learned to improve practice for all patients. [ABSTRACT FROM AUTHOR]

Abstract: Aims: With a life expectancy similar to the general population, greater numbers of patients with Down''s syndrome are being diagnosed with testicular cancer. Learning difficulties and medical co-morbidity are common in this patient population and may lead to non-standard oncological treatment. We aimed to identify and discuss management challenges in the treatment of these patients with chemotherapy and radiotherapy and report their clinical outcome. Materials and methods: The Royal Marsden Hospital urology database was searched from 1982 to 2005 to identify all cases of patients with Down''s syndrome and histologically confirmed testicular cancer who were referred for consideration of chemotherapy or radiotherapy. Results: Nine patients were identified, of whom eight received chemotherapy or radiotherapy. Two patients had bilateral tumours and four had crypto-orchidism. At the time of diagnosis, the patients were 21–50 years of age. Of the 11 tumours identified, nine were seminomas and two were malignant teratoma undifferentiated. Five patients presented with stage I disease, of whom three received carboplatin and one received para-aortic radiotherapy as adjuvant treatment. Three patients presented with stage II disease, of whom two were treated with carboplatin and one received combination chemotherapy followed by radiotherapy. One patient with stage IV disease was treated with carboplatin. Five of nine patients relapsed within 30 months, of whom three were successfully salvaged with radiotherapy and one with combination chemotherapy. Conclusion: After standard and non-standard therapy for seminoma, the relapse rate for patients in our cohort was high. Since relapsed disease is much more difficult to manage with combination chemotherapy on account of respiratory, cardiac and renal co-morbidity, adequate initial treatment is advised. Consideration of psycho-social issues and the multiple treatment strategies available is vital in delivering optimal care to patients with Down''s syndrome and testicular cancer. [Copyright &y& Elsevier]

Poster: RTT track: Motion management and adaptive strategies PO-1917: Pre-trial plan selection training - is it sufficient for optimal plan selections online?. [Extracted from the article]

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). [ABSTRACT FROM AUTHOR]

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. 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. 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). 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. • Quality of life (QoL) scores reduce after radiotherapy treatment for bladder cancer. • Male QoL scores then improve and remain stable until 5 years. • Female QoL scores have a further decline at 2 and 3 years. • RTOG toxicity is more frequently reported in females than males. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. • Toxicity data is collected using clinician and patient reported outcomes. • Correlation between clinician and patient reported outcomes are poor. • Patient reported outcomes appear more sensitive, reporting a higher grade of events. • Further work to evaluate if patient reported outcomes can be used alone is needed. [ABSTRACT FROM AUTHOR]

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. 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. 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. PTV margins can be reduced to 3–5 mm in MRgART for rectal cancer treatment on MR-linac within an simultaneous integrated boost protocol. • Adaptive radiotherapy on MRgART for rectal cancer enables adaptation of treatment to anatomy of the day. • Intrafraction motion is minimal between start and end of treatment; however interfraction motion between reference CT planning scan and treatment is large and may not be fully covered with a reduced PTV margin. • Using new RCR guidelines nomenclature, the ICTV absorbs motion effectively, adding a 15 mm PTV margin to the GTV. • The ICTV component can be removed from MR-linac treatment and a direct PTV margin can be applied to the GTV. • Reducing target volumes on MR-linac can lead to trials in dose escalation in order to increase cPR rates. [ABSTRACT FROM AUTHOR]

To determine the relationship between local relapse following radical radiotherapy for muscle-invasive bladder cancer (MIBC) and radiation dose. 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 (GTV relapse) on the original planning CT. GTV relapse 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). 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 GTV relapse 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. 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. • Relapse following radical bladder radiotherapy most often occurs within the bladder. • Local relapse occurs near the original MIBC tumour site and within the planned high dose region. • In this high risk MIBC patient population, muscle invasive relapse was more common than non-muscle invasive relapse. • Tumour dose escalation may be an appropriate future consideration; trial outcome data is awaited. • Margin reduction should be considered with caution for reduced high-dose volume or partial bladder radiotherapy. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. • Radical IMRT to the bladder and pelvic nodes is feasible with low toxicity rates. • A subset of node-positive bladder cancer patients attain disease control with IMRT. • Relapse patterns suggest optimisation of local and systemic treatments is needed. [ABSTRACT FROM AUTHOR]

Abstract 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. [ABSTRACT FROM AUTHOR]