Previously Untreated Childhood Rhabdomyosarcoma
Table 5. Radiation Therapy (RT) Dose According to Rhabdomyosarcoma Group, Histology, and Site of Disease (Children's Oncology Group [COG]) continued...
Bladder preservation is a major goal of therapy for patients with tumors arising in the bladder and/or prostate. Two important reviews provide information about the historical, current, and future treatment approaches for patients with bladder and prostate rhabdomyosarcomas.[83,84]
In rare cases, the tumor is confined to the dome of the bladder and can be completely resected. Otherwise, to preserve a functional bladder in patients with gross residual disease, chemotherapy and RT have been used to reduce tumor bulk,[85,86] followed, when necessary, by a more limited surgical procedure such as partial cystectomy. Early experience with this approach was disappointing, with only 20% to 40% of patients with bladder/prostate tumors remaining alive and with functional bladders 3 years following diagnosis (3-year OS was 70% in IRS-II).[87,88] The later experience from IRS-III and IRS-IV, which used more intensive chemotherapy and RT, showed 55% of patients alive with functional bladders at 3 years postdiagnosis, with 3-year OS exceeding 80%.[86,89,90] Patients with a primary tumor of the bladder/prostate who present with a large pelvic mass resulting from a distended bladder caused by outlet obstruction at diagnosis receive RT to a volume defined by imaging studies following initial chemotherapy to relieve outlet obstruction. This approach to therapy remains generally accepted, with the belief that more effective chemotherapy and RT will continue to increase the frequency of bladder salvage.
The initial surgical procedure in most patients consists of a biopsy, which often can be performed using ultrasound guidance or cystoscopy, or by a direct-vision transanal route. In selected cases in one series, bladder-conserving surgery plus brachytherapy for boys with prostate or bladder-neck rhabdomyosarcoma led to excellent survival, bladder preservation, and short-term functional results.[Level of evidence: 3iiiB] For patients with biopsy-proven, residual malignant tumor following chemotherapy and RT, appropriate surgical management may include partial cystectomy, prostatectomy, or exenteration (usually approached anteriorly with preservation of the rectum). Very few studies have objective long-term assessments of bladder function, and urodynamic studies are important to obtain accurate evaluation of bladder function.