title: Whole Versus Partial Bladder Radiation: Use of an Image-guided Hypofractionated IMRT Bladder-preservation Protocol.
abstract: OBJECTIVE
  To report our institutional experience using definitive chemoradiation via whole bladder (WB) and partial bladder (PB) treatment in muscle-invasive bladder cancer. Combining intensity-modulated radiation therapy with image-guidance can improve the therapeutic ratio.
  
  
  METHODS
  Retrospective analysis of 26 patients with clinical stage T2-4 N0-2 M0 urothelial cancer treated in 2009 to 2012; 16 received WB radiation and 10 received PB radiation. PB/tumor boost volume included visibly thickened bladder wall or tumor localized on cystoscopy. WB radiation delivered 45 to 50.4 Gy to bladder/lymph nodes, then sequential 19.8 to 21.6 Gy tumor boost (1.8 Gy/fx). PB radiation was 45 to 50 Gy to lymph nodes (1.8 to 2 Gy/fx) and simultaneous integrated boost to 55 to 62.5 Gy to tumor only (2.2 to 2.5 Gy/fx). The primary endpoint was local control, defined as no muscle-invasive recurrence. Secondary endpoints were overall survival, toxicity, and cost.
  
  
  RESULTS
  Mean age was 77 and median follow-up was 20 months. Freedom from local recurrence was 86% at 2 years (PB 100%, WB 77%). Overall survival was 80% at 1 year (PB 88%, WB 75%), and 55% at 2 years (PB 70%, WB 48%, P=0.38). Failure was predominantly distant. Toxicities were minimal (3 late grade 3 ureteral, 1 acute grade 4 renal), and all resolved. No cystectomies were performed for toxicity. Hypofractionation reduces treatment time and costs by one third.
  
  
  CONCLUSIONS
  Image-guided hypofractionated PB radiation provides local control with similar survival to WB therapy, with minimal toxicity. Hypofractionation also offers time and cost advantages. Our results need to be validated in a larger, multi-institutional cohort.
authors.affiliation: Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA.
authors.forename: Jung J
authors.initials: JJ
authors.lastname: Kang
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steinberg
authors.forename: Patrick
authors.initials: P
authors.lastname: Kupelian
authors.forename: Sherri
authors.initials: S
authors.lastname: Alexander
authors.forename: Christopher R
authors.initials: CR
authors.lastname: King
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D059351:Organ Sparing Treatments / Q000379:methods*; D011379:Prognosis; D000069473:Radiation Dose Hypofractionation; D011832:Radiation Injuries / Q000517:prevention & control; D061089:Radiotherapy, Image-Guided; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States; D001749:Urinary Bladder Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*