<qa>  What is the best dose of topotecan?This phase I trial is studying the side effects and best way to give radiation therapy when given together with topotecan and cisplatin in treating patients with locally advanced cervical cancer. This trial is also studying the best dose of topotecan when given in this regimen. Radiation therapy uses high-energy x-rays to damage tumor cells. Drugs used in chemotherapy, such as topotecan and cisplatin, use different ways to stop tumor cells from dividing so they stop growing or die. Combining radiation therapy with chemotherapy may kill more tumor cells. 