RESUMO
In the third National Wilms' Tumor Study (NWTS-3), patients with Stage II favorable histologic type (FH) or Stage III FH Wilms' tumor were randomized according to a factorial design for both radiation therapy (RT) and chemotherapy to be given after nephrectomy. Patients with Stage II FH disease were randomized between 2000 cGy and no postoperative RT; patients with Stage III FH disease were randomized between 2000 and 1000 cGy. No significant differences in survival were noticed. Although there were no significant differences in the rate of intraabdominal relapses, those patients with Stage III disease who received 1000 cGy and dactinomycin and vincristine (seven patients) experienced a relapse in the abdomen more frequently than those who received 2000 cGy and dactinomycin and vincristine (three patients), 1000 cGy and dactinomycin, vincristine, and doxorubicin (three patients), or 2000 cGy and dactinomycin, vincristine, and doxorubicin (two patients). This would suggest that doxorubicin might be a good substitute for the second 1000 cGy of RT. Boost doses of RT, although allowed, were rarely given and no assessment of the value of supplemental RT can be made. The dismal prognosis of abdominal relapse after RT is confirmed and delay of initiation of treatment beyond 10 days after surgery was a significant adverse factor as in NWTS-1 and NWTS-2.
Assuntos
Neoplasias Renais/radioterapia , Tumor de Wilms/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Dactinomicina/administração & dosagem , Doxorrubicina/administração & dosagem , Humanos , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Dosagem Radioterapêutica , Vincristina/administração & dosagem , Tumor de Wilms/patologia , Tumor de Wilms/terapiaRESUMO
The NSD (nominal standard dose) concept has been useful in therapy for comparing various radiation treatment schedules. More recently, TDF (time, dose, and fractionation) factors were introduced. By incorporating treatment schedules (time and fractionation) with isodose summations, TDFs can be determined throughout the patient contour, including tissue in and outside the tumor volume. For this purpose an isodose summation program was modified to generate iso-TDF maps based on the treatment schedule. For schedules in which all fields are not treated every day, recovery is not inhibited throughout the total treatment volume. It was necessary to reevaluate the concept of "recovery time" for tissues outside the tumor volume and to introduce a "threshold to inhibit recovery" model. Clinical examples assuming this recovery model are presented.