Radiation Oncology/Bladder/Technique
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Bladder Cancer RT Technique
Overview
[edit | edit source]Treat with an empty bladder
- Small pelvic fields - includes all bladder, all prostate, lymph nodes adjacent to bladder. Simulate with air contrast in bladder; contrast in rectum. 4 fields. Superior: mid-sacrum (S2-3). Inferior: bottom of obturator foramen. Lateral: PTV 1 cm lateral to bony pelvis. Anterior: PTV 1cm anterior to bladder. Posterior: PTV at least 1.5 cm posterior to bladder. Shield femoral heads.
- Whole bladder fields - PTV 0.5 cm margin around bladder + tumor
- Tumor boost - PTV = GTV + 0.5.
Partial bladder irradiation
[edit | edit source]- Christie Hospital, UK (1993-99) -- whole bladder 52.5/20 vs partial bladder 57.5/20 or 55/16
- Randomized. 149 patients. T2-T3N0M0, unifocal TCC <= 7cm. Randomized to whole bladder conformal RT (52.5/20, 2.63 Gy/fx) or partial bladder RT (CTV + 1.5 cm) in 4 wks (57.5/20, 2.88 Gy/fx) or 3 wks (55 Gy/16, 3.44 Gy/fx). No chemo
- 2004 PMID 15093917 — "Radiotherapy for muscle-invasive carcinoma of the bladder: results of a randomized trial comparing conventional whole bladder with dose-escalated partial bladder radiotherapy." (Cowan RA, Int J Radiat Oncol Biol Phys. 2004 May 1;59(1):197-207.) Median F/U 5.8 years for living patients
- Outcome: 5-year local control WBRT 58% vs PBRT4 59% vs PBRT3 34% (NS), overall 50%. 87% of recurrences within irradiated tumor volume. DM 17% vs 25% vs 22% (NS). 5-year OS 58% (NS)
- Toxicity: Well tolerated. 85% of patients alive at 5 years preserved their bladder
- Conclusion: Comparable outcome between whole bladder RT and partial bladder RT
Accelerated irradiation
[edit | edit source]- Cooperative Urological Oncology Group, UK (1988-1998) -- AHFX 60.8/32 BID vs CF 64/32 QD
- Randomized. 229 patients with T2-T3 N0-N1 bladder cancer. Arm 1) AF split-course 60.8/32 BID (22.8/12 + 19/10 + 19/10) vs. Arm 2) Conventional CF 64/32. Primary endpoint local control
- 2005 PMID 15878099 -- "A randomised trial of accelerated radiotherapy for localised invasive bladder cancer." (Horwich A, Radiother Oncol. 2005 Apr;75(1):34-43. Epub 2004 Nov 25.)
- Outcome: LR AF 32% vs. CF 29% (NS); 3-year OS 47% vs. 54% (NS); 5-year OS 40% vs. 37% (NS)
- Toxicity: Acute AF 44% vs. CF 26% (SS); Late toxicity (if FFR 2 years): Grade 2+ AHFX 44% vs. conventional 38% (NS). 2 treatment-related deaths on AHFX arm
- Conclusion: No benefit for AHFX over conventional fractionation, worse acute GI toxicity