XXXX . The selection of @entity1 for treatment by full-dose irradiation.

@entity1 @entity137 @entity5 @entity1695 @entity900 @entity150
Cure of muscle-invading @entity150 in 20% to 39% of @entity1 using full-dose external beam irradiation has been reported by many institutions in the last 10 years. Local failure occurs in 50% of @entity1 so treated, however, and successful selection criteria for bladder-sparing radiotherapy are necessary. Prognostic factors which have been identified to be associated with a relatively successful outcome using full-dose irradiation include (1) the clinical stages T2 and T3, (2) the absence of @entity1695 on initial intravenous pyelogram, (3) a visibly "complete" transurethral resection having been achieved, and (4) complete response of the @entity5 to radiation. In addition, @entity5 control appears to be related to total dose administered. Analysis of the results of precystectomy radiation therapy, where @entity5 histology and small @entity5 size yielded improved survival, suggests that these characteristics also may prove to be beneficial in @entity1 selected for full-dose irradiation. The four-field box technique has become accepted as the best method to treat @entity1 using beams from linear accelerators or betatrons. The bladder and pelvic lymph nodes should be treated to 50.4 Gy in 1.8 Gy fractions, 5 days/week. A cone-down boost to the @entity5 volume only then is given for a total dose of 64.8 Gy to 68.4 Gy in 7.5 weeks. The posterior rectosigmoid should receive less than 60 Gy, and the anus and femoral head and neck should be limited to 45 to 50 Gy to avoid @entity137 . Innovative approaches to treatment of muscle-invading @entity150 now are being explored and include the use of intravesical misonidazole combined with fractionated external beam irradiation, and systemic @entity900 administration in combination with radiation. Techniques which have yielded good results in superficial @entity150 include open interstitial implantation, intraoperative single-dose electron beam irradiation, and trans-Foley radium applications. Further prospective evaluations of clinical and histologic @entity5 characteristics, treatment techniques and doses reviewed here will be necessary before definitive selection criteria for treatment with full-dose irradiation are established.
