Role of FDG-PET CT in the Management of Muscle Invasive Bladder Cancer

Study Overview
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Brief Summary
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Bladder cancer is the seventh cause of cancer mortality in France. Overall survival is poor, between 45 and 50% at 5 years. Optimal staging of lymph nodes and metastasis is crucial for treatment decision of muscle invasive bladder cancer (MIBC). Guidelines do not recommend FDG-Positron Emission Tomography (PET) Computed Tomography (CT), but rather CT for lymph node and metastatic staging, despite its low accuracy. We performed a retrospective analysis of patients undergoing PET CT for localized MIBC in two centers, to help define the utility of PET CT in this setting.

Detailed Description
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Background: Bladder cancer is the second most frequent genito-urinary cancer, and the seventh cause of cancer mortality in France. Overall survival is poor, between 45 and 50% at 5 years. Curative treatment of muscle invasive urothelial carcinoma localized to the bladder includes cisplatin-based neoadjuvant chemotherapy, followed by radical cystectomy with lymph nodes dissection. Nonetheless, surgery indications depend on pre-operative staging regarding nodes and metastatic involvement. Computed Tomography (CT) scan is the reference imaging study for loco-regional and metastatic staging. Lymph node involvement evaluation is based on morphologic criteria only. Its sensitivity lies between 30 and 53% and its specificity between 67 and 91%. Yet, optimal node staging is crucial for therapeutic decision. FDG-Positron Emission Tomography (PET) CT, using both morphologic and functional criteria, could help for node staging in muscle invasive bladder cancer assessment, especially by detecting infracentimetric involved lymph nodes. Moreover, it could be useful for detecting distant metastasis. Objective: To evaluate the accuracy of the PET CT for lymph node staging and to determine the rate of treatment modification according to PET CT results Methods: Retrospective study based on the medical records of every patient undergoing a PET CT at the time of diagnosis of MIBC from 01/2005 to 12/2017 in Bordeaux (Bergonie Institute and University Hospital). PET CT could have been done before any treatment (PET 1) and/or after neo-adjuvant chemotherapy and before surgery (PET 2).

Official Title
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Role of FDG-PET CT in the Management of Muscle Invasive Bladder Cancer

Conditions
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Muscle Invasive Bladder Cancer

Intervention / Treatment
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* Device: PET CT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of Muscle Invasive Urothelial Carcinoma of the bladder (classified at least pT2 on TURB) Diagnosis between January 2005 and December 2017 PET CT done during initial assessment before surgery (at the time of diagnosis and/or after neoadjuvant chemotherapy) Management of cancer at Institut Bergonié or at Bordeaux University Hospital Previous treatment for Non Muscle Invasive Bladder Cancer allowed Exclusion Criteria: Management of cancer outside of Institut Bergonié or Bordeaux University Hospital No PET CT done during initial assessment (before surgery) Rare pathological type of bladder cancer without urothelial carcinoma (epidermoid carcinoma, neuro-endocrine carcinoma, …) Extra-vesical urothelial carcinoma

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: PET CT|Every patient undergoing a PET CT at the time of diagnosis of muscle invasive bladder cancer from January 2005 to December 2017 in Bordeaux (Institut Bergonié and University Hospital).|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of treatment modification according to PET CT results | Description: Assess differences between planned management before knowing the FDG-PET CT results and treatment actually received. | Date of Multidisciplinary Tumor Board following PET CT, up to 16 weeks after inclusion | 
| Evaluation of the accuracy of the PET CT for lymph node staging | Comparison of lymph nodes staging on PET CT (according to EORTC criteria) and lymph nodes staging on pathological report, according to the AJCC TNM Staging System for Bladder Cancer 8th ed., 2017. | Date of pathological results, up to 20 weeks after inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of PET CT and CT scan for lymph node and metastatic staging | Evaluation of the concordance rate between PET CT results (according to EORTC criteria) and CT scan results (according to RECIST 1.1) for lymph node and metastatic staging according to the AJCC TNM Staging System for Bladder Cancer 8th ed., 2017. | Date of the realization of both tests, up to 16 weeks after inclusion | 
| Evaluation of FDG PET-CT results as a predictive factor for Pathological Complete Response | Comparison of PET-CT TNM staging between patients with and patients without a Pathological Complete Response | Date of pathological results, up to 20 weeks after inclusion | 
| Evaluation of Metabolic Response as a predictive factor for Recurrence Free Survival | Comparison of Recurrence Free Survival for patients with and patients without a Complete Metabolic Response (according to EORTC criteria) | From date of inclusion until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 14 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PET CT, Bladder cancer, CT scan, Lymph node staging, TNM staging