The purpose of this study was to review the magnitude of contribution of chemotherapy(CT) in the local control of muscle invasive bladder carcinoma in the studies where a combined radio-chemotherapy(RCT) was used(how much higher local control rates are obtained with RCT compared to RT alone).Studies on radiotherapy(RT) and combined RCT,neo-adjuvant,concurrent,adjuvant or combinations,reported after 1990 were reviewed.The mean complete response(CR) rates were significantly higher for the RCT studies compared to RT-alone studies:75.9% vs 64.4%(Wilcoxon ranksum test,P = 0.001).Eleven of the included RCT studies involved 2-3 cycles of neo-adjuvant CT,in addition to concurrent RCT.The RCT studies included the onephase type(where a full dose of RCT was given and then assessment of response and cystectomy for nonresponders followed) and the two-phase types(where an assessment of response was undertaken after an initial RCT course,followed 6 wk later by a consolidation RCT for those patients with a CR).CR rates between the two subgroups of RCT studies were 79.6%(one phase) vs 71.6%(two-phase)(P = 0.015).Theaverage achievable tumour control rates,with an acceptable rate of side effects have been around 70%,which may represent a plateau.Further increase in CR response rates demands for new chemotherapeutic agents,targeted therapies,or modified fractionation in various combinations.Quantification of RT and CT contribution to local control using radiobiological modelling in trial designs would enhance the potential for both improved outcomes and the estimation of the potential gain. The purpose of this study was to review the magnitude of contribution of chemotherapy (CT) in the local control of muscle invasive bladder carcinoma in the studies where a combined radio-chemotherapy (RCT) was used (how much higher local control rates are obtained with RCT compared to RT alone). Studies on radiotherapy (RT) and combined RCT, neo-adjuvant, concurrent, adjuvant or combinations, reported after 1990 were. The mean complete response (CR) rates were significantly higher for the RCT studies compared to RT-alone studies: 75.9% vs 64.4% (Wilcoxon ranksum test, P = 0.001). Eleven of the included RCT studies involved 2-3 cycles of neo-adjuvant CT, in addition to concurrent RCT. RCT studies included the onephase type (where a full dose of RCT was given and then assessment of response and cystectomy for nonresponders followed) and the two-phase types (where an assessment of response was responsive after an initial RCT course, followed 6 weeks later by a consolidation RCT for patients w ith a CR) .CR rates between two subgroups of RCT studies were 79.6% (one phase) vs 71.6% (two-phase) (P = 0.015) .Theaverage achievableotumor control rates, with an acceptable rate of side effects have been around 70%, which may represent a plateau. Fuurther increase in CR response rates demands for new chemotherapeutic agents, targeted therapies, or modified fractionation in various combinations. Quantification of RT and CT contribution to local control using radiobiological modeling in trial designs would enhance the potential for both improved outcomes and the estimation of the potential gain.