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Adaptive planning, with selection of a plan of the day, can help to overcome this problem. An overview of the current literature addressing these issues will be presented. Conclusion The implementation of modern radiotherapy techniques in a bladder preserving strategy could induce a paradigm shift towards a more widespread use of bladder- conserving treatment. To obtain this goal, research on proper patient selection, modern imaging to improve target volume delineation, defining the optimal treatment schedule (dose per day, total treatment duration) and technique as well as correct positioning is mandatory. SP-0022 When should we give radiotherapy following cystectomy and how? P. Sargos 1 1 Institut Bergonié, radiotherapie, BORDEAUX CEDEX, France Abstract text Local-regional recurrence after radical cystectomy is a significant problem for a subset of patients. Chemotherapy has not been shown to reduce the risk of local-regional recurrences in randomized prospective trials, and salvage therapies for local-regional failure are rarely successful. There is promising evidence that radiation therapy plus chemotherapy can significantly reduce local recurrences compared to chemotherapy alone, and that this improvement in local-regional control may translate to meaningful improvements in disease-free and overall survival with acceptable toxicity. In light of the high rates of local failure following cystectomy for locally advanced disease and the progress that has been made in identifying patients at high risk of failure and the patterns of failure in the pelvis, post-operative radiotherapy could be an option to consider for patients with ≥pT3 disease. Despite advances in our understanding of the problem of local-regional failure after cystectomy and the potential role of adjuvant radiotherapy, the question of whether adjuvant radiotherapy should have a defined role for patients with locally advanced urothelial carcinoma has not yet been determined. The results of the NRG, European, Indian, and Egyptian trials on adjuvant radiotherapy are eagerly awaited. While none of these trials on their own may provide definitive conclusions, their aggregate outcomes will help clarify whether this treatment should have a role in the management of patients with locally advanced bladder cancer. SP-0023 No, not necessary, the Danish experience G. Ørtoft 1 1 Rigshospitalet, Department of Gynecology- Copenhagen University Hospital, Copenhagen, Denmark Abstract text In Denmark postoperative radiotherapy was omitted in 1986 for low-risk stage I endometrial cancer, in 1998 for intermediate-risk stage I and for high-risk stage I in 2010. Instead pelvic lymph node resection was introduced in 2010 for intermediate- and high-risk patients to tailor the postoperative therapy after lymph node status. Since 2010 almost no Danish patients have received postoperative radiotherapy. Only postoperative chemotherapy has been offered to patients with disseminated disease. The Danish endometrial cancer group (DEMCA) has published two prospective nationwide Symposium: Do we need adjuvant vaginal BT in endometrial cancer?

studies and demonstrated that postoperative radiotherapy (RT) could be omitted in low- and intermediate-risk stage I patients without loss of survival when evaluated after 5 years. The group also demonstrated that omitting radiotherapy seems to increase the rate of local recurrence in the intermediate group, but not in the low-risk stage I group. The explanation for the survival results was that local vaginal recurrences could be treated with radiotherapy at time of recurrences. Since then all Danish patients have been registered in the Danish Gynecological Cancer Database (DGCD) and data from 2005-2012 have now been evaluated. I will demonstrate recurrence rate, location of recurrences (vaginal, pelvic, abdominal and distant) for low-, intermediate- and high-risk stage I patients not given postoperative radiotherapy and give an estimate of number needed to treat if vaginal recurrences should be prevented by brachytherapy. SP-0024 Yes, in selected patients. - The US experience M. Harkenrider 1 1 Loyola University Chicago, Department of Radiation Oncology, Maywood, USA Abstract text The primary management of endometrial cancer is TH- BSO with or without pelvic and paraaortic lymph node dissection. Adjuvant radiation therapy for endometrial cancer may be recommended based upon presence of known adverse risk factors. Adjuvant radiotherapy can be performed with either external beam radiotherapy (EBRT) or vaginal brachytherapy (VBT) with choice of adjuvant therapy based on risk factors and risk of failure in the pelvis or vagina. Recurrent disease, even in the vagina, has a high rate of second recurrence even after definitive radiation, and the intensive therapy required to treat recurrent disease has significant associated toxicity. Therefore, the ability to prevent disease recurrence is highly beneficial for patients. PORTEC-2 randomized high-intermediate risk patients to pelvic EBRT or VBT. Five-year vaginal recurrence was 1.8% with VBT and 1.6% with EBRT (p=0.74). Pelvic recurrence rates were higher in the group treated with VBT compared to EBRT (3.8% vs. 0.5%, p=0.02). H-I risk patients fall along a spectrum of risk for recurrence, and it is important to consider these risk factors to estimate risks of recurrence in the both the pelvis and vagina when offering adjuvant radiotherapy. Our group has previously published risks of recurrence using the previously mentioned risk factors to help guide referral to the radiation oncologist and decision making for radiation oncologists and patients. GOG 249 recently reported outcomes of high- intermediate and high risk (stage I-II) endometrial cancer patients comparing adjuvant EBRT to VBT with chemotherapy. They showed no difference in distant metastases, relapse-free survival, or overall survival between these two regimens. They reported greater rate of pelvic and paraaortic recurrences in patients treated with VBT and chemotherapy vs. EBRT (9% vs. 4%, HR 0.47), and EBRT was also better tolerated. It remains unclear if there is a subset of early stage endometrioid patients who may benefit from adjuvant systemic therapy, and molecular subtyping of endometrial cancers may be useful in this regard. We performed a multi-institutional study of Stage II endometrioid-type endometrial cancer patients under- going VBT without EBRT. Among patients treated with VBT alone, the vaginal and pelvic recurrence rates were low at 2.6% and 4.2% at 5 years, respectively. However, distant recurrences were higher at 7.2% by 5 years. Overall, these outcomes are quite favorable for this group of patients. The majority (~90%) of patients in this cohort had grade 1 or 2 disease. Additionally, nearly all patients had microscopic cervical stroma invasion, so