Development and Validation of Consensus Contouring Guidelines for Adjuvant Radiation Therapy for Bladder Cancer After Radical Cystectomy

Bladder Adjuvant Radiation Therapy (BART): Acute and Late Toxicity From a Phase III Multicenter Randomized Controlled Trial

PURPOSE

To report toxicity from the multicenter phase III randomized trial of Bladder Adjuvant Radiation Therapy (BART) after radical cystectomy and chemotherapy in high-risk muscle-invasive bladder cancer (MIBC).

METHODS AND MATERIALS

Patients with nonmetastatic urothelial MIBC with ≥1 high-risk feature after radical cystectomy- pT3-4, pN1-3, nodal yield <10, positive margin, or ≥cT3 downstaged with neoadjuvant chemotherapy- were randomized 1:1 to observation (Obs) or adjuvant radiation therapy (RT) at 4 centers, stratified by pN stage (N0, N+) and chemotherapy (neoadjuvant, adjuvant, none). Stoma-sparing image guided intensity modulated RT 50.4 Gy in 28# was prescribed to the cystectomy bed and pelvic nodes. Acute toxicity (≤3 months of RT/randomization) and late toxicity were assessed per protocol using Common Terminology Criteria for Adverse Event v5.0. Patients progressing within 3 or 6 months of randomization were excluded from acute or late toxicity analysis, respectively.

RESULTS

The BART trial enrolled 153 patients (Obs = 76, RT = 77). About half (49%) had pN+. Nearly 90% received chemotherapy (70% neoadjuvant; most commonly gemcitabine plus cisplatin). In the RT arm, 63/77 completed RT per protocol with no toxicity-related RT termination. Of the 134 patients analyzable for acute toxicity, no difference was observed in grade 3 (Obs 4.2% vs RT 1.6%, P = .34). Grade 2 effects were higher with RT (17.5% vs 1.1%, P < .001), mainly diarrhea/enteritis or proctitis. Late toxicity was analyzable for 104 patients (Obs = 57, RT = 47) with a median follow-up of 27 months. Grades 3 to 4 toxicity were about 10% (Obs 10.5% vs RT 8.4%, P = .62), and cumulative late grade 2+ toxicity was similar in both groups (17.5% vs 23.3%, P = .27).

CONCLUSIONS

In the largest trial of adjuvant RT for high-risk urothelial MIBC, severe acute and late toxicity were low and similar with obervation or radiation therapy. The oncological outcomes are awaited.

Adjuvant Radiotherapy in Bladder Cancers: A Dosimetric Study Focusing on Ileal Conduit Sparing

PURPOSE

To compare ileal conduit (IC) and other organ at risk (OAR) dosimetry between treatment techniques in a prospective cohort of patients planned for adjuvant radiotherapy (RT) after radical cystectomy and IC reconstruction.

METHODS AND MATERIALS

Computed tomography (CT datasets of twenty patients who underwent adjuvant RT were obtained and used prospectively for delineation of target volumes (primary and nodal) and OARs, including IC, uretero-ileal anastomosis and ileal stoma using a specified protocol for simulation including a delayed CT to identify IC. Three RT plans were generated for each patient for a dose of 54 gray (Gy) in 27 fractions (PTV V95% >95%): 3-dimensional conformal radiotherapy (3DCRT) with (3DCRT_S) and without (3DCRT_N) stoma shielding, and volumetric modulated arc therapy (VMAT), with OAR constraints specified for VMAT plans (IC: Dmax<54Gy, V50Gy < 20 cc). Constraints were given for other pelvic OARs (bowel, rectum, femur heads) as per published literature. Plans were evaluated for target coverage as well as OAR doses; in particular, IC and ileal stoma). ANOVA test was used to compare medians of achieved doses, and a p-value <0.05 was statistically significant.

RESULTS

The median IC volume was 63.34 (55.29-82.93) cc. The cranial end of IC was at L5 or L4 vertebral level in 95% of patients and caudal level at S2 or S3 in 80% of patients. In contrast, the ileal stoma spanned from L4 or L5 vertebral level cranially (100%) to L5 level caudally (80%). PTV V95% was similar for 3DCRT_N and VMAT plans while it was significantly lower for 3DCRT_S in areas of ileal stoma shielding (99.95% vs 99.01% vs 96.29%, p < 0.01). Median IC V50Gy was comparable in 3DCRT_N (38.81 cc) and 3DCRT_S (35.62 cc) while it was significantly lower in the VMAT plan (17.05 cc, p < 0.01). IC Dmax did not differ significantly between the three plans. On the other hand, when 3DCRT_N, 3DCRT_S, and VMAT plans were compared for ileal stoma doses, Dmean was comparable (11.93 Gy vs 7.41 Gy vs 9.54 Gy, p = 0.06) while Dmax was significantly higher for 3DCRT_N plan and least for VMAT plan (35.32 Gy vs 27.57 Gy vs 24.22 Gy, p < 0.01). VMAT plans fared significantly better than both 3DCRT plans for uretero-ileal anastomosis, bowel, and rectal dosimetry.

CONCLUSIONS

Ileal stoma shielding in 3DCRT compromises PTV coverage but does not spare IC effectively. Sparing IC with VMAT is feasible without compromising PTV coverage. Dosimetric gains with VMAT are expected to benefit patients needing higher pelvic RT doses and nodal RT by reducing the risk of anastomotic and mucosal complications. Clinical benefits should be evaluated in a prospective protocol.

The Value and Safety of Adjuvant Radiation Therapy After Radical Cystectomy in Locally Advanced Urothelial Bladder Cancer: A Controlled Randomized Study

PURPOSE

Adjuvant radiation therapy (ART) after radical cystectomy in locally advanced bladder cancer was revived after the advancement in precise radiation therapy that decreased the normal pelvic tissue radiation hazards. However, there are still scarce controlled randomized studies addressing this issue.

METHODS AND MATERIALS

One hundred thirty-one cystectomized urothelial bladder cancer patients were enrolled; 122 were randomized to receive ART of 50 Gy/25 fractions 4 weeks after cystectomy or cystectomy alone (CY). Sixty-two were included in the ART arm and 60 in the CY arm. Twenty-four ART and 30 CY patients received neoadjuvant chemotherapy. Eleven patients (9%) had cotenant neobladder diversion, 6 in ART, and 5 in CY arms. All ART patients were treated with intensity modulated radiation therapy with daily verification cone beam computed tomography. The median follow-up was 42.7 months.

RESULTS

The 3-year adjusted locoregional recurrence-free survival rate was higher in the ART arm, measuring 81% (95% CI, 69%-94%) compared with 71% (95% CI, 60%-80%; p = .0457). ART significantly improved the locoregional relapse-free rate in the cystectomy bed and the pelvic side wall (p = .016 and p = .001, respectively). The overall, event-free, and distant metastasis-free survival did not rank to the level of statistical significance in the 2 arms. Even though the acute side effects were slightly higher in ART, the late toxicities were almost equal in the 2 groups.

CONCLUSIONS

ART is safe and quite tolerable after radical cystectomy when using precise radiation techniques. These techniques significantly improved the locoregional recurrence-free survival but had insignificant improvement on the overall survival. ART did not affect the distant metastasis-free survival. Similar studies are performed in different centers around the world to confirm the value of ART in urothelial bladder cancer.

Bladder cancer

Bladder cancer is a global health issue with sex differences in incidence and prognosis. Bladder cancer has distinct molecular subtypes with multiple pathogenic pathways depending on whether the disease is non-muscle invasive or muscle invasive. The mutational burden is higher in muscle-invasive than in non-muscle-invasive disease. Commonly mutated genes include TERT, FGFR3, TP53, PIK3CA, STAG2 and genes involved in chromatin modification. Subtyping of both forms of bladder cancer is likely to change considerably with the advent of single-cell analysis methods. Early detection signifies a better disease prognosis; thus, minimally invasive diagnostic options are needed to improve patient outcomes. Urine-based tests are available for disease diagnosis and surveillance, and analysis of blood-based cell-free DNA is a promising tool for the detection of minimal residual disease and metastatic relapse. Transurethral resection is the cornerstone treatment for non-muscle-invasive bladder cancer and intravesical therapy can further improve oncological outcomes. For muscle-invasive bladder cancer, radical cystectomy with neoadjuvant chemotherapy is the standard of care with evidence supporting trimodality therapy. Immune-checkpoint inhibitors have demonstrated benefit in non-muscle-invasive, muscle-invasive and metastatic bladder cancer. Effective management requires a multidisciplinary approach that considers patient characteristics and molecular disease characteristics.

Study Protocol of the Bladder Adjuvant RadioTherapy (BART) Trial: A Randomised Phase III Trial of Adjuvant Radiotherapy Following Cystectomy in Bladder Cancer

AIMS

To assess the efficacy and safety of adjuvant radiotherapy in patients with high-risk muscle-invasive bladder cancer (MIBC) following radical cystectomy (RC) and chemotherapy.

MATERIALS AND METHODS

The BART (Bladder Adjuvant RadioTherapy) trial is an ongoing multicentric, randomised, phase III trial comparing the efficacy and safety of adjuvant radiotherapy versus observation in patients with high-risk MIBC. The key eligibility criteria include ≥pT3, node-positive (pN+), positive margins and/or nodal yield <10, or, neoadjuvant chemotherapy for cT3/T4/N+ disease. In total, 153 patients will be accrued and randomised, in a 1:1 ratio, to either observation (standard arm) or adjuvant radiotherapy (test arm) following surgery and chemotherapy. Stratification parameters include nodal status (N+ versus N0) and chemotherapy (neoadjuvant chemotherapy versus adjuvant chemotherapy versus no chemotherapy). For patients in the test arm, adjuvant radiotherapy to cystectomy bed and pelvic nodes is planned with intensity-modulated radiotherapy to a dose of 50.4 Gy in 28 fractions using daily image guidance. All patients will follow-up with 3-monthly clinical review and urine cytology for 2 years and subsequently 6 monthly until 5 years, with contrast-enhanced computed tomography abdomen pelvis 6 monthly for 2 years and annually until 5 years. Physician-scored toxicity using Common Terminology Criteria for Adverse Events version 5.0 and patient-reported quality of life using the Functional Assessment of Cancer Therapy - Colorectal questionnaire is recorded pre-treatment and at follow-up.

ENDPOINTS AND STATISTICS

The primary endpoint is 2-year locoregional recurrence-free survival. The sample size calculation was based on the estimated improvement in 2-year locoregional recurrence-free survival from 70% in the standard arm to 85% in the test arm (hazard ratio 0.45) using 80% statistical power and a two-sided alpha error of 0.05. Secondary endpoints include disease-free survival, overall survival, acute and late toxicity, patterns of failure and quality of life.

CONCLUSION

The BART trial aims to evaluate whether contemporary radiotherapy after standard-of-care surgery and chemotherapy reduces pelvic recurrences safely and also potentially affects survival in high-risk MIBC.

Delineating and sparing the ileal conduit in adjuvant radiotherapy for bladder cancer with modulated radiotherapy

PURPOSE

We undertook a prospective planning study to describe the delineation of ileal conduit (IC) loop on radiotherapy planning computed tomography (RTP CT) scan as an organ at risk (OAR) and its sparing using volumetric modulated arc therapy (VMAT) during adjuvant irradiation of bladder malignancies.

MATERIALS AND METHODS

Fifteen patients with bladder malignancy needing adjuvant radiotherapy postoperatively and having normal renal function underwent delayed phase RTP CT from June 2020 to March 2021, with certain modifications (Foley's catheter through stoma, additional delayed scans). We identified the course of ureters, external stoma, IC, and uretero-ileal (right and left) anastomotic sites. VMAT plans were generated.

RESULTS

A step-by-step description is given. Genitourinary OARs include kidneys, ureters, uretero-ileal anastomoses, and IC. The contrast on delayed scan opacifies ureters and IC. IC can be seen three-dimensionally as a structure with two fixed ends (blind proximal end anterior to the right sacroiliac joint and the open distal end over the right anterior abdominal wall in parasagittal location) and a 15-20 cm hanging intraabdominal loop that lies adjacent to the right iliac vessels. For prescription doses (PD) of 50.4 gray and 54 gray, respectively, VMAT plan achieved IC dose maximum to less than PD and V50 lower than 10 cc. Stoma sparing traditionally used as a surrogate for IC sparing is insufficient due to the variable intraabdominal location of IC loop.

CONCLUSIONS

Delineation of IC as an OAR is feasible with slight modifications in the RTP protocols. VMAT (or other forms of intensity modulated radiation therapy) can help IC sparing and should be considered when it lies in close proximity to target volumes and the risk of additional morbidity is considerable.

Challenges and opportunities in the management of non-urothelial bladder cancers

Urothelial carcinoma accounts for approximately 90% of all bladder cancer diagnoses. Localized, muscle-invasive disease is often managed with a multidisciplinary approach including either neoadjuvant chemotherapy (NAC) followed by radical cystectomy or concurrent chemoradiation, whereas multiple immunotherapies and novel antibody drug conjugates have recently joined platinum-based chemotherapy as standard of care therapy for metastatic disease. However, the clinical trials leading to these standards often require majority if not complete urothelial histology for eligibility. As many as one quarter of patients diagnosed with bladder cancer will have either divergent differentiation of their urothelial carcinoma or an alternate epithelial tumor such as squamous cell carcinoma, adenocarcinoma, or small cell carcinoma; even more rare are non-epithelial tumors such as sarcoma. The rarity of these diseases and their general exclusion from treatment within prospective clinical trials has created a challenging situation where treatment plans are often derived from case series or extrapolated from other disease types and outcomes are poor compared to pure urothelial carcinoma. In this review, we summarize the existing data on the diagnosis and treatment of epithelial, non-urothelial bladder cancers including adenocarcinoma, squamous cell carcinoma, and small cell carcinoma in their localized and advances stages. We will also review the current clinical trial landscape investigating novel approaches to these diseases.

Multidisciplinary Management and Radiotherapy Recommendations for Clinically and Pathologically Node-positive Bladder Cancer

There are limited data regarding the optimal management of patients with pelvic node-positive, but non-metastatic, bladder cancer. Increasing data demonstrate that this is a distinct clinical entity with outcomes bridging between bladder-confined muscle-invasive bladder cancer and metastatic advanced bladder cancer. Guidelines and staging systems have formalized the need to incorporate the unique considerations of management of pelvic node-positive bladder cancer. However, there remains an absence of a definite standard of care. Treatment options include systemic therapy alone, neoadjuvant chemotherapy followed by radical cystectomy, or bladder-preserving trimodality therapy. Furthermore, ongoing studies aim to determine the benefit of incorporating immunotherapy into these treatment paradigms. In this review article, we will discuss the key considerations for management of patients with pelvic node-positive bladder cancer.

International Consensus Guidelines for Adjuvant Radiation Therapy for Bladder Cancer After Radical Cystectomy: Update From an IBIS Workgroup

PURPOSE

In 2016, international consensus clinical target volume (CTV) guidelines for adjuvant radiation treatment (ART) after radical cystectomy (RC) in muscle-invasive bladder cancer patients with high risk for locoregional failure (LRF) were published. A subsequent external validation study recommended several CTV optimizations (CTV-OPT). This study aimed to update international consensus guidelines based on new clinical experiences.

METHODS AND MATERIALS

Phase 1 (delineation interobserver variability): 4 observers delineated the CTV of 9 patients post-RC, as in clinical practice. Interobserver agreement in contouring was evaluated using volume- and kappa-statistics. Phase 2 (pattern of failure analysis): Among a prospective cohort of 72 patients treated with ART, 11 developed LRF (10 available for review). LRFs were mapped in predefined pelvic subsites (i.e. common, external and internal iliac, obturator and presacral node regions and cystectomy bed) and their distance to CTV-OPT was measured. The actual delivered dose at each relapse site was calculated. Phase 3 (review CTV): Based on the results of phase 1 and 2, 5 senior radiation-oncologists (XXXX) reviewed the published CTV borders and provided an update when indicated.

RESULTS

Phase 1: The mean overall kappa-value was 0.66 (range: 0.60-0.70), indicating substantial overall agreement per Landis-Koch criteria. Specific kappa-values per area indicated for the common iliac and obturator node regions only slight and moderate variability, respectively. Phase 2: 13 out of 16 LRFs centers were not included in the CTV-OPT. 10 LRF sites received a median dose <45Gy, of which 6 were located in the cystectomy bed that was not included in the CTV because of negative RC margins. Phase 3: Key recommendations by the panel were to include the entire common iliac node region and the cystectomy bed regardless of surgical margin status and re-affirmed to not crop the CTV out of bowel.

CONCLUSION

International consensus guidelines were updated.

Leiomyosarcoma of urinary bladder with unusual recurrence in intestinal mucosa and peritoneum: a case report

BACKGROUND

Leiomyosarcomas of urinary bladder constitute rare malignant sarcomas with very few cases reported in literature.

CASE PRESENTATION

Here, we present a case of bladder leiomyosarcoma in a well-preserved female. She failed to respond to standard chemotherapy and had a rapidly downhill course with unusual metastases in anastomotic site and peritoneum soon after surgery. Despite multimodality management including resection of primary and metastatic site, systemic therapy and pelvic radiotherapy, our patient had dismal prognosis with an overall survival of 1.7 years.

CONCLUSION

Leiomyosarcomas of bladder are aggressive tumors and have a very poor prognosis; thus, future research should focus on optimizing more effective treatment regimes.

Recommendations for planning and delivery of radical radiotherapy for localized urothelial carcinoma of the bladder

PURPOSE

Curative radio-chemotherapy is recognized as a standard treatment option for muscle-invasive bladder cancer (MIBC). Nevertheless, the technical aspects for MIBC radiotherapy are heterogeneous with a lack of practical recommendations.

METHODS AND MATERIALS

In 2018, a workshop identified the need for two cooperative groups to develop consistent, evidence-based guidelines for irradiation technique in the delivery of curative radiotherapy. Two radiation oncologists performed a review of the literature addressing several topics relative to radical bladder radiotherapy: planning computed tomography acquisition, target volume delineation, radiation schedules (total dose and fractionation) and dose delivery (including radiotherapy techniques, image-guided radiotherapy (IGRT) and adaptive treatment modalities). Searches for original and review articles in the PubMed and Google Scholar databases were conducted from January 1990 until March 2020. During a meeting conducted in October 2020, results on 32 topics were presented and discussed with a working group involving 15 radiation oncologists, 3 urologists and one medical oncologist. We applied the American Urological Association guideline development's method to define a consensus strategy.

RESULTS

A consensus was obtained for all 34 except 4 items. The group did not obtain an agreement on CT enhancement added value for planning, PTV margins definition for empty bladder and full bladder protocols, and for pelvic lymph-nodes irradiation. High quality evidence was shown in 6 items; 8 items were considered as low quality of evidence.

CONCLUSION

The current recommendations propose a homogenized modality of treatment both for routine clinical practice and for future clinical trials, following the best evidence to date, analyzed with a robust methodology. The XXX group formulates practical guidelines for the implementation of innovative techniques such as adaptive radiotherapy.

Adjuvant and Neoadjuvant Radiation Therapy for Locally Advanced Bladder Cancer

Local-regional failure for patients with ≥pT3 urothelial carcinoma after radical cystectomy is a significant clinical challenge. Prospective randomised trials have failed to show that chemotherapy reduces the risk of local-regional recurrences. Salvage treatment for local failures is difficult and often unsuccessful. There is promising evidence, particularly from a recent Egyptian National Cancer Institute trial, that radiation therapy plus chemotherapy can significantly reduce local recurrences compared with chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, the National Comprehensive Cancer Network guidelines were revised to include postoperative radiotherapy as an option to consider for patients with ≥pT3 disease. Here we review the problem of local-regional failure after cystectomy, identify patients who would probably benefit from adjuvant radiotherapy, review the patterns of pelvic failure after cystectomy, discuss technical details of radiation treatment and review the modern literature on this topic. Adjuvant radiotherapy should be considered as a treatment option for patients with locally advanced disease, especially those with positive margins or squamous cell carcinoma.

Locoregional recurrence after cystectomy in muscle invasive bladder cancer: Implications for adjuvant radiotherapy

PURPOSE

We report the patterns of locoregional recurrence (LRR) in muscle invasive bladder cancer (MIBC), and propose a risk stratification to predict LRR for optimizing the indication for adjuvant radiotherapy.

MATERIALS AND METHODS

The study included patients of urothelial MIBC who underwent radical cystectomy with standard perioperative chemotherapy between 2013 and 2019. Recurrences were classified into local and/or cystectomy bed, regional, systemic, or mixed. For risk stratification modelling, T stage (T2, T3, T4), N stage (N0, N1/2, N3) and lymphovascular invasion (LVI positive or negative) were given differential weightage for each patient. The cohort was divided into low risk (LR), intermediate risk (IR) and high risk (HR) groups based on the cumulative score.

RESULTS

Of the 317 patients screened, 188 were eligible for the study. Seventy patients (37.2%) received neoadjuvant chemotherapy (NACT) while 128 patients (68.1%) had T3/4 disease and 66 patients (35.1%) had N+ disease. Of the 55 patients (29%) who had a recurrence, 31 (16%) patients had a component of LRR (4% cystectomy bed, 11.5% regional 0.5% locoregional). The median time to LRR was 8.2 (IQR 3.3-18.8) months. The LR, IR and HR groups for LRR based on T, N and LVI had a cumulative incidence of 7.1%, 21.6%, and 35% LRR, respectively. The HR group was defined as T3, N3, LVI positive; T4 N1/2, LVI positive; and T4, N3, any LVI. The odds ratio for LRR was 3.37 (95% CI 1.16-9.73, P = 0.02) and 5.27 (95% CI 1.87-14.84, P = 0.002) for IR and HR respectively, with LR as reference.

CONCLUSION

LRR is a significant problem post radical cystectomy with a cumulative incidence of 35% in the HR group. The proposed risk stratification model in our study can guide in tailoring adjuvant radiotherapy in MIBC.

[Adjuvant radiotherapy after radical cystectomy for muscle-invasive bladder cancer]

OBJECTIVES

Locoregional relapse (LRR) after cystectomy is a common early event associated with poor prognosis. The role of radiotherapy as an adjunct to radical cystectomy is not well-defined. The aim of this critical literature review is to provide an overview of the elements in favor of adjuvant radiation for patients treated for muscle-invasive bladder cancer.

MATERIAL AND METHODS

An exhaustive review of the literature was carried out using the Pubmed search tool with the following keywords: "radiotherapy" [Mesh], "adjuvant" [Mesh], "local recurrence" [Mesh], "Bladder cancer" [Mesh].

RESULTS

Several recent publications have led to the development of a nomogram that predicts the risk of LRR, in order to identify patients for which adjuvant radiotherapy could be beneficial. Several randomized trials seem to suggest a benefit of radiotherapy, in particular when combined with chemotherapy, in terms of reducing LRR, and may even improve overall survival, with good safety profile. However, there are many biases and the interest of adjuvant radiotherapy in urothelial carcinomas remains debated.

CONCLUSION

Prospective trials evaluating adjuvant radiotherapy with current techniques should be undertaken.

Intensity-Modulated Radiotherapy is Superior to Three-Dimensional Conformal Radiotherapy in the Trimodality Management of Muscle-Invasive Bladder Cancer with Daily Cone Beam Computed Tomography Optimization

Objective

Intensity modulated radiation therapy (IMRT) using a volumetric-modulated arc therapy technique may offer dosimetric and clinical benefits compared to the historical standard of care 3D-conformal radiotherapy (3D-CRT) in definitive treatment of bladder cancer. We hypothesized that IMRT with CBCT would reduce dose to the rectum, bowel, and bladder compared to 3D-CRT.

Methods

We reviewed nineteen patients treated with maximal transurethral resection of bladder tumor followed by concurrent chemotherapy with IMRT. All patients received 45 Gy to the entire empty bladder followed by 19.8 Gy tumor boost treated with full bladder. 3D-CRT treatment plans were created for the same prescription. Paired t-test or Wilcoxon matched-pairs signed rank test analyzed dosimetry and bladder volumes.

Results

The rectum and bowel V40, V45, V50, V55, and V60 were reduced by over 50% in the IMRT plans compared to 3D-CRT (p<0.0001). IMRT also reduced volume of bladder irradiated compared to 3D-CRT (p<0.01). After CBCT, patients were likely to undergo clinically significant shifts ≥ 0.5 cm before boost delivery (p=0.001). Bladder volumes were significantly lower during boost treatments compared to pre-treatment simulation (p=0.002). There were 4 (21%) grade 3 genitourinary toxicities and 1 (5%) grade 3 gastrointestinal toxicity.

Conclusion

IMRT is superior to 3D-CRT for bladder cancer and spares dose to bowel, rectum, and bladder with improved acute toxicity compared to published clinical literature. For boost treatment, daily full bladder volume and positioning are not always reproducible, supporting the need for CBCT for optimal localization of the primary bladder tumor.

Effectiveness of postoperative radiotherapy after radical cystectomy for locally advanced bladder cancer

BACKGROUND

Local-regional failure (LF) for locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity/mortality. Postoperative radiotherapy (PORT) can reduce LF and may enhance overall survival (OS) but has no defined role. We hypothesized that the addition of PORT would improve OS in LABC in a large nationwide oncology database.

METHODS

We identified ≥ pT3pN0-3M0 LABC patients in the National Cancer Database diagnosed 2004-2014 who underwent RC ± PORT. OS was calculated using Kaplan-Meier and Cox proportional hazards regression modeling was used to identify predictors of OS. Propensity matching was performed to match RC patients who received PORT vs those who did not.

RESULTS

15,124 RC patients were identified with 512 (3.3%) receiving PORT. Median OS was 20.0 months (95% CI, 18.2-21.8) for PORT vs 20.8 months (95% CI, 20.3-21.3) for no PORT (P = 0.178). In multivariable analysis, PORT was independently associated with improved OS: hazard ratio 0.87 (95% CI, 0.78-0.97); P = 0.008. A one-to-three propensity match yielded 1,858 patients (24.9% receiving PORT and 75.1% without). In the propensity-matched cohort, median OS was 19.8 months (95% CI, 18.0-21.6) for PORT vs 16.9 months (95% CI, 15.6-18.1) for no PORT (P = 0.030). In the propensity-matched cohort of urothelial carcinoma patients (N = 1,460), PORT was associated with improved OS for pT4, pN+, and positive margins (P < 0.01 all).

CONCLUSION

In this observational cohort, PORT was associated with improved OS in LABC. While the data should be interpreted cautiously, these results lend support to the use of PORT in selected patients with LABC, regardless of histology. Prospective trials of PORT are warranted.

Trimodality therapy for bladder cancer: modern management and future directions

PURPOSE OF REVIEW

This review examines both trimodality therapy (TMT) in the definitive management of bladder cancer as well as the use of adjuvant radiotherapy for bladder cancer with a specific focus on publications from the last 2 years.

RECENT FINDINGS

TMT is an effective management strategy for muscle invasive bladder cancer with outcomes similar to radical cystectomy. Effectiveness of this strategy exists in variant histologies and can be personalized with use of biomarkers. There is a role for adjuvant radiotherapy in locally advanced bladder cancer, especially in the age of improved imaging and modern radiotherapy techniques.

SUMMARY

This review should provide the reader data necessary to support use of TMT and adjuvant radiation therapy in their clinic.

National Practice Patterns and Overall Survival After Adjuvant Radiotherapy Following Radical Cystectomy for Urothelial Bladder Cancer in the USA, 2004-2013

BACKGROUND

Adjuvant radiation therapy (ART) after radical cystectomy (RC) for urothelial bladder cancer (UBC) may play a role in the management of muscle-invasive BC, particularly in patients with locally advanced disease and adverse pathologic features (pT3/4 or positive surgical margins [PSMs]). Evidence regarding the effect of ART on overall survival (OS) is lacking.

OBJECTIVE

To evaluate national practice patterns for the use of ART and assess its impact on OS for patients with adverse pathologic features (APF) after RC.

DESIGN, SETTING, AND PARTICIPANTS

Using the National Cancer Data Base, we analyzed all UBC cases with APF after RC from 2004 to 2013. Patients were divided into ART and no-ART groups.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Relationships with oncological outcomes were analyzed using multivariable Cox regression and log-rank analyses.

RESULTS AND LIMITATIONS

Use of ART decreased during the study period from 3.1% in 2004 to 1.7% in 2013 (p=0.03). ART was administered in 1.4%, 4.0% and 5.2% of patients with pT3 UBC, pT4 UBC, and PSMs (any pT stage), respectively. The rate of ART was significantly higher among younger ages, female sex, low-volume hospitals, nonacademic community care centers, higher stages, PSMs, perioperative chemotherapy, and lymph node-positive disease. Predictors of ART receipt were PSMs (odds ratio [OR] 3.4; p<0.0001), pT4 (OR 2.6; p=0.02), community based centers (OR 2.1; p<0.0001), and female sex (OR 1.8; p<0.0001). Risk factors for worse OS included age, higher tumor stage and comorbidities, PSMs, positive nodes, and suboptimal lymph node dissection (<10 nodes removed; all p<0.001). ART was not independently associated with better OS in the full cohort (p=0.54). However, subgroup analyses suggested an OS benefit for patients with PSMs (hazard ratio 0.73; p=0.047). Limitations include the retrospective design and limited details regarding cancer-specific survival.

CONCLUSIONS

Use of ART for APF following RC is not common in the USA and the rate of ART has been decreasing over time. ART may have an OS benefit after RC for patients with PSMs.

PATIENT SUMMARY

In this report we looked at the outcomes for patients with locally advanced bladder cancer receiving adjuvant radiation therapy following cystectomy in a large US population. We found that adding radiation therapy after removing the bladder cancer may have some survival benefits for patients with positive surgical margins.

Standardizing Normal Tissue Contouring for Radiation Therapy Treatment Planning: An ASTRO Consensus Paper

PURPOSE

The comprehensive identification and delineation of organs at risk (OARs) are vital to the quality of radiation therapy treatment planning and the safety of treatment delivery. This guidance aims to improve the consistency of ontouring OARs in external beam radiation therapy treatment planning by providing a single standardized resource for information regarding specific OARs to be contoured for each disease site. The guidance is organized in table format as a quality assurance tool for practices and a training resource for residents and other radiation oncology students (see supplementary materials).

METHODS AND MATERIALS

The Task Force formulated recommendations based on clinical practice and consensus. The draft manuscript was peer reviewed by 16 reviewers, the American Society for Radiation Oncology (ASTRO) legal counsel, and ASTRO's Multidisciplinary Quality Assurance Subcommittee and revised accordingly. The recommendations were posted on the ASTRO website for public comment in June 2018 for a 6-week period. The final document was approved by the ASTRO Board of Directors in August 2018.

RESULTS

Standardization improves patient safety, efficiency, and accuracy in radiation oncology treatment. This consensus guidance represents an ASTRO quality initiative to provide recommendations for the standardization of normal tissue contouring that is performed during external beam treatment planning for each anatomic treatment site. Table 1 defines 2 sets of structures for anatomic sites: Those that are recommended in all adult definitive cases and may assist with organ selection for palliative cases, and those that should be considered on a case-by-case basis depending on the specific clinical scenario. Table 2 outlines some of the resources available to define the parameters of general OAR tissue delineation.

CONCLUSIONS

Using this paper in conjunction with resources that define tissue parameters and published dose constraints will enable practices to develop a consistent approach to normal tissue evaluation and dose documentation.

Radiotherapy with radical cystectomy for bladder cancer: A systematic review and meta-analysis

INTRODUCTION

Muscle-invasive bladder cancer (MIBC) is associated with high recurrence and mortality rates. The role of radiotherapy as an adjunct to radical cystectomy is not well-defined. We sought to evaluate the efficacy and safety of radiotherapy preoperatively or postoperatively for patients with MIBC receiving cystectomy compared to cystectomy alone. The primary outcome was overall survival. The secondary outcome was adverse effects.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched on August 30, 2016 for randomized controlled trials (RCTs) of patients undergoing cystectomy for bladder cancer. A control group receiving cystectomy alone and an intervention group with radiotherapy and cystectomy were required. The Jadad score was used to assess for bias. Fifteen studies representing 10 RCTs met eligibility criteria.

RESULTS

A total of 996 patients were randomized in seven trials included in a meta-analysis of neoadjuvant radiotherapy. Insufficient data were available to complete a pooled analysis for adjuvant radiotherapy. There was a non-statistically significant improvement in overall survival for patients who received neo-adjuvant radiotherapy and cystectomy. At three years and five years, the odds ratios were 1.23 (95% confidence interval [CI] 0.72-2.09) and 1.26 (95% CI 0.76-2.09), respectively, in favour of neoadjuvant radiotherapy. Subgroup analyses including higher doses of radiotherapy showed greater effect on survival.

CONCLUSIONS

These data suggest that radiotherapy prior to cystectomy may improve overall survival. This review was limited by old studies, heterogeneous patient populations, and radiotherapy treatment techniques that may not meet current standards. There is a need for current RCTs to further evaluate this effect.

Early Clinical Outcomes, Patterns of Failure, and Acute Haematologic Toxicity of Image-Guided Volumetric Modulated Arc Therapy (IG-VMAT) in the Definitive Treatment of Locally Advanced Carcinoma Cervix

Purpose:

To evaluate clinical outcomes and failure patterns in patients with locally advanced cervical cancer (LACC) treated definitively using image-guided volumetric-modulated arc therapy (IG-VMAT).

Methods and materials:

This retrospective review included 18 consecutively treated patients with LACC. Treatment consisted of IG-VMAT and concurrent chemotherapy followed by intracavitary radiotherapy. The primary end points were overall survival (OS) and disease-free survival (DFS). Acute haematologic toxicity was evaluated using Radiation Therapy Oncology Group (RTOG) criteria.

Results:

A total of 16 patients were either stage IIB or IIIB and the median follow-up was 30.5 months (interquartile range: 13-36.25 months). The 2-year DFS was 63.3% (95% confidence interval [CI]: 52.8%-72.4%) and 2-year OS was 72.2% (95% CI: 62.1%-80.5%). There were 7 treatment failures, predominantly in-field. Acute haematologic toxicity was low.

Conclusions:

IG-VMAT is associated with favourable outcomes for patients with LACC.

Risk factors for loco-regional recurrence after radical cystectomy of muscle-invasive bladder cancer: A systematic-review and framework for adjuvant radiotherapy

BACKGROUND

Radical cystectomy (RC) associated with pelvic lymph node dissection (PLND) is the most common local therapy in the management of non-metastatic muscle invasive bladder cancer (MIBC). Loco-regional recurrence (LRR), however, remains a common and important therapeutic challenge associated with poor oncologic outcomes. We aimed to systematically review evidence regarding factors associated with LRR and to propose a framework for adjuvant radiotherapy (RT) in patients with MIBC.

METHODS

We performed this systematic review in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We searched the PubMed database for articles related to MIBC and associated treatments, published between January 1980 and June 2015. Articles identified by searching references from candidate articles were also included. We retrieved 1383 publications from PubMed and 34 from other sources. After an initial screening, a review of titles and abstracts, and a final comprehensive full text analysis of papers assessed for eligibility, a final consensus on 32 studies was obtained.

RESULTS

LRR is associated with specific patient-, tumor-, center- or treatment-related variables. LRR varies widely, occurring in as many as 43% of the cases and is strongly related to survival outcomes. While perioperative treatment does not impact on LRR, pathological factors such as pT, pN, positive margins status, extent of PLND, number of lymph nodes removed and/or invaded are correlated with LRR. Patients with pT3-T4a and/or positive lymph-nodes and/or limited pelvic lymph-node dissection and/or positive surgical margins have been distributed in LRR risk groups with accuracy.

CONCLUSIONS

LRR patterns are well-known and for selected patients, adjuvant treatments could target this event. Intrinsic tumor subtype may guide future criteria to define a personalized treatment strategy. Prospective trials evaluating safety and efficacy of adjuvant RT are ongoing in several countries.

The Role of Adjuvant Radiation Therapy in Locally Advanced Bladder Cancer

Background:

The standard of care for locally advanced bladder cancer (LABC) is neoadjuvant chemotherapy followed by cystectomy. However, the role of adjuvant therapy for locally advanced bladder cancer is unclear.

Objective:

The purpose of this study was to evaluate the outcomes of adjuvant radiation therapy (RT) for patients with LABC, and to determine which risk factors best predict for patients who may best benefit from adjuvant RT.

Methods:

The National Cancer Data Base (NCDB) was queried (2004– 2013) for patients with newly-diagnosed pT3-4N0-3M0 urothelial carcinoma of the bladder that received neoadjuvant chemotherapy and cystectomy. Patients were divided into two groups based on the adjuvant therapy they received: RT or observation. Statistics included multivariable logistic regression to determine factors predictive of receiving adjuvant RT, Kaplan-Meier analysis to evaluate overall survival (OS), and Cox proportional hazards modeling to determine variables associated with OS.

Results:

Altogether, 1,646 patients met inclusion criteria; 59 (3.6%) patients received adjuvant RT, while 1,587 (96.4%) were observed. Patients treated with adjuvant RT were more likely to be female, have positive surgical margins, and receive treatment at a non-academic facility. There was no difference in median overall survival (OS) between patients treated with RT when compared to patients observed (17.7 months vs. 23.5 months; p = 0.085). However, an improvement in median OS with the use of adjuvant RT was observed among patients with positive surgical margins (20.3 months vs. 13.1 months; p = 0.032). On multivariate analysis, advancing age, pT4 stage, positive N stage, positive margins, and lower socioeconomic status were associated with worse OS.

Conclusions:

In the largest study to date evaluating efficacy of adjuvant radiotherapy in patients with locally advanced bladder cancer, use of RT was not associated with OS in all patients, while RT was associated with improvemed OS among patients with positive surgical margins. Prospective studies are recommended to confirm these findings.

Adjuvant Sandwich Chemotherapy Plus Radiotherapy vs Adjuvant Chemotherapy Alone for Locally Advanced Bladder Cancer After Radical Cystectomy: A Randomized Phase 2 Trial

Importance

Locoregional failure for patients with locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity and mortality. Adjuvant radiotherapy (RT) can decrease locoregional failure but has not been studied in the chemotherapy era.

Objective

To investigate if adjuvant sequential RT plus chemotherapy can improve locoregional recurrence-free survival (LRFS) compared with adjuvant chemotherapy alone.

Design, Setting, and Participants

A randomized phase 3 trial was opened to compare adjuvant RT vs sequential chemotherapy plus RT after RC for LABC, but a third arm was added later as a randomized phase 2 trial to compare chemotherapy plus RT vs adjuvant chemotherapy alone, an emerging standard. The intent-to-treat phase 2 trial reported herein enrolled patients from December 2002 to July 2008. Data were analyzed from August 3, 2015, to January 6, 2016. Routine follow-up and surveillance pelvic computed tomographic (CT) scans every 6 months during the first 2 years were performed. The setting was an academic center. Patients with bladder cancer 70 years or younger having 1 or more risk factors (≥pT3b, grade 3, or positive nodes) with negative margins after radical cystectomy plus pelvic lymph node dissection were eligible. Patients had Eastern Cooperative Oncology Group performance status of 0 to 2, no evidence of distant metastases on CT scan of the abdomen and pelvis or on chest imaging, and adequate renal, hepatic, and hematologic function. Ninety-one percent (109 of 120) had ≥ pT3 disease.

Interventions

Chemotherapy plus RT included 2 cycles of gemcitabine (1000 mg/m2 intravenously on days 1, 8, and 15) and cisplatin (70 mg/m2 intravenously on day 2) before and after RT to 4500 cGy in 150 cGy twice-daily fractions over 3 weeks using 3-dimensional conformal techniques. Chemotherapy alone included 4 cycles of gemcitabine and cisplatin.

Main Outcome and Measure

Locoregional recurrence-free survival.

Results

The chemotherapy plus RT arm accrued 75 patients, and the chemotherapy-alone arm accrued 45 patients, with a weighted randomization to speed accrual. Fifty-three percent (64 of 120) had urothelial carcinoma, and 46.7% (56 of 120) had squamous cell carcinoma or other. The arms were balanced except for age (median, 52 vs 55 years; P = .04) and tumor size (mean, 4.9 vs 5.8 cm; P < .01), both favoring chemotherapy plus RT. Two-year outcomes and overall adjusted hazard ratios (HRs) for chemotherapy plus RT vs chemotherapy alone were 96% vs 69% (HR, 0.08; 95% CI, 0.02-0.39; P < .01) for LRFS, 68% vs 56% (HR, 0.53; 95% CI, 0.27-1.06; P = .07) for disease-free survival, and 71% vs 60% (HR, 0.61; 95% CI, 0.33-1.11; P = .11) for overall survival (OS). Five patients (7%) had RT-associated late grade 3 gastrointestinal tract adverse effects in the chemotherapy plus RT arm.

Conclusions and Relevance

Adjuvant chemotherapy plus RT was reasonably well tolerated and was associated with significant improvements in LRFS and marginal improvements in disease-free survival vs chemotherapy alone in LABC. The addition of adjuvant RT should be considered for LABC. This regimen warrants further study in phase 3 trials.

Trial Registration

clinicaltrials.gov Identifier: NCT01734798.

Adjuvant treatment following radical cystectomy for muscle-invasive urothelial carcinoma and variant histologies: Is there a role for radiotherapy?

Comprehensive molecular characterisation of muscle-invasive urothelial carcinoma and variant histological subtypes has led to the identification of recurrent driver mutations that are distinct in these aggressive subgroups of bladder cancer. While distant metastasis dominates as a pattern of relapse following radical cystectomy or chemoradiotherapy, loco-regional control rates are also suboptimal with single modality local treatment, and likewise, harbour equivocal implications on the long-term prognosis of patients. The role of adjuvant radiotherapy for optimising disease control within the pelvis is controversial, with limited evidence to support its efficacy. Herein, we present a stepwise review on adjuvant radiotherapy post-cystectomy; first, discussing the evidence to date supporting the concept that adjuvant radiotherapy is effective in targeting occult metastases within the pelvis, and adds to the benefits of adjuvant chemotherapy. Next, we outlined the principles underlying the definition of radiotherapy target volumes. To conclude, we addressed the need for appropriate patient stratification for treatment intensification, based on existing clinical models and novel molecular indices of aggression in muscle-invasive urothelial cancers and variant histological subtypes.

Adjuvant radiotherapy after radical cystectomy for muscle-invasive bladder cancer: A retrospective multicenter study

Objectives

Radical cystectomy (RC) and pelvic lymph-node dissection (LND) is standard treatment for non-metastatic muscle-invasive urothelial bladder cancer (MIBC). However, loco-regional recurrence (LRR) is a common early event associated with poor prognosis. We evaluate 3-year LRR-free (LRRFS), metastasis-free (MFS) and overall survivals (OS) after adjuvant radiotherapy (RT) for pathological high-risk MIBC.

Material and methods

We retrospectively reviewed data from patients in 3 institutions. Inclusion criteria were MIBC, histologically-proven urothelial carcinoma treated by RC and adjuvant RT. Patients with conservative surgery were excluded. Outcomes were evaluated by Kaplan-Meier method. Acute toxicities were recorded according to CTCAE V4.0 scale.

Results

Between 2000 and 2013, 57 patients [median age 66.3 years (45–84)] were included. Post-operative pathological staging was ≤pT2, pT3 and pT4 in 16%, 44%, and 39%, respectively. PLND revealed 28% pN0, 26% pN1 and 42% pN2. Median number of lymph-nodes retrieved was 10 (2–33). Forty-eight patients (84%) received platin-based chemotherapy. For RT, clinical target volume 1 (CTV 1) encompassed pelvic lymph nodes for all patients. CTV 1 also included cystectomy bed for 37 patients (65%). CTV 1 median dose was 45 Gy (4–50). A boost of 16 Gy (5–22), corresponding to CTV 2, was administered for 30 patients, depending on pathological features. One third of patients received intensity-modulated RT. With median follow-up of 40.4 months, 8 patients (14%) had LRR. Three-year LRRFS, MFS and OS were 45% (95%CI 30–60), 37% (95%CI 24–51) and 49% (95%CI 33–63), respectively. Five (9%) patients had acute grade ≥3 toxicities (gastro-intestinal, genito-urinary and biological parameters). One patient died with intestinal fistula in a septic context.

Conclusions

Because of poor prognosis, an effective post-operative standard of care is needed for pathological high-risk MIBC. Adjuvant RT is feasible and may have oncological benefits. Prospective trials evaluating this approach with current RT techniques should be undertaken.

Adjuvant Radiotherapy Use by US Radiation Oncologists After Radical Cystectomy for Muscle-invasive Bladder Cancer

AIMS

Historic trials suggested significant toxicity with adjuvant radiotherapy (ART) after radical cystectomy for muscle-invasive bladder cancer (MIBC). However, recent trials have found improved locoregional control and the 2016 National Comprehensive Cancer Network (NCCN) guidelines recommend ART consideration for select patients at high risk of local recurrence. ART practice patterns among US radiation oncologists are unknown and we carried out a survey to explore current trends.

MATERIALS AND METHODS

We conducted a survey of US radiation oncologists regarding the management of patients with cT2-3N0M0 transitional cell MIBC. Responses were reported using descriptive statistics. Chi-square and univariate logistic regression of clinical and demographic covariates were conducted, followed by multivariable logistic regression analysis to identify factors predicting for ART use.

RESULTS

In total, 277 radiation oncologists completed our survey. Nearly half (46%) have used ART for MIBC at least once in the past. In ART users, indications for ART include gross residual disease (93%), positive margins (92%), pathological nodal involvement (64%), pT3 or T4 disease (46%), lymphovascular invasion (16%) and high-grade disease (13%). On univariate logistic regression, ART use was associated with the number of years in practice (P=0.04), pre-cystectomy radiation oncology consultation (P=0.004), primarily treating MIBC patients fit for cystectomy (P=0.01) and intensity-modulated radiotherapy use (P=0.01). On multivariable logistic regression analysis, routine pre-cystectomy radiation oncology consultation (odds ratio 1.91, 95% confidence interval 1.04-3.51; P=0.04) and intensity-modulated radiotherapy use (odds ratio 2.77, 95% confidence interval 1.48-5.22; P=0.002) remained associated with ART use.

CONCLUSIONS

ART use is controversial in bladder cancer, yet unexpectedly has commonly been used among US radiation oncologists treating patients with MIBC after radical cystectomy. NRG-GU001 was a randomised trial in the US randomizing patients with high-risk pathological findings for observation or ART after cystectomy. However, due to poor accrual it recently closed and thus it will be up to other international trials to clarify the role of ART and identify patients benefiting form this adjuvant therapy.

[Adjuvant radiotherapy for bladder cancer in patients with risk of locoregional recurrence: Who, what and how?]

Radical cystectomy with extended pelvic lymph node dissection remains the standard of care for non-metastatic muscle-invasive bladder cancer. Locoregional control is a key factor in the outcome of patients since it is related to overall survival, metastasis-free survival and specific survival. Locoregional recurrence rate is directly correlated to pathological results and the quality of lymphadenectomy. In addition, while pre- or postoperative chemotherapy improved overall survival, it showed no impact on locoregional recurrence-free survival. Several recent publications have led to the development of a nomogram that predicts the risk of locoregional recurrence, in order to identify patients for which adjuvant radiotherapy could be beneficial. International cooperative groups have then come together to provide the rational for adjuvant radiotherapy, reinforced by recent technical developments limiting toxicity, and to develop prospective studies to reduce the risk of relapse. The aim of this critical literature review is to provide an overview of the elements in favor of adjuvant radiation for patients treated for muscle-invasive bladder cancer.

The Rationale for Post-Operative Radiation in Localized Bladder Cancer

Local-regional recurrence for patients with ≥pT3 disease after radical cystectomy is a significant problem. Chemotherapy has not been shown to reduce the risk of local-regional recurrences in randomized prospective trials, and salvage therapies for local-regional failure are rarely successful. There is promising evidence, particularly from a recent Egyptian NCI trial, that radiation therapy plus chemotherapy can significantly reduce local recurrences compared to chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, the NCCN guidelines were revised in 2016 to include post-operative radiotherapy as an option to consider for patients with ≥pT3 disease. Despite advances in our understanding of the problem of local-regional failure after cystectomy and the potential role of adjuvant radiotherapy, the question of whether adjuvant radiotherapy should have a defined role for patients with locally advanced urothelial carcinoma has not yet been determined. The results of the NRG, European, Indian, and Egyptian trials on adjuvant radiotherapy are eagerly awaited. While none of these trials on their own may provide definitive conclusions, their aggregate outcomes will help clarify whether this treatment should have a role in the management of patients with locally advanced bladder cancer.