Abstract Book

ESTRO 37

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that were not covered by the CTV included (para-aortic,) common-iliac, pre-sacral, obturatoric, para-rectal, para- vesical and pre-acetabular locations. With a Pearson correlation we additionally evaluated whether the Gleason score, the PSA value or the risk according to the Roach formula correlates with a higher chance of LNs being outside of the CTV in uncommon LN locations. None of the three parameters did show a significant Over half of our patients had at least one lymph node detected by 68 Ga-PSMA-PET-imaging that was not inside the standard CTV possibly leading to an insufficient dose and inadequate therapy. 68 Ga-PSMA-PET-imaging seems to be a valuable diagnostic tool in the primary setting for a high-risk PC population. correlation. Conclusion PO-0831 Modified Glasgow prognostic score can predict survival in elderly patients with bladder cancer K. Kikuchi 1 , R. Nakamura 1 , T. Segawa 1 , H. Kakuhara 1 , H. Oikawa 1 , H. Ariga 1 1 Iwate Medical University, Radiation Oncology, Morioka, Japan Purpose or Objective Elderly patients with muscle invasive bladder cancer (MIBC) frequently undergo radiotherapy as a definitive therapy being unsuitable or unwilling to radical cystectomy or multimodal bladder-sparing protocols, with a compensation of relatively poor prognosis. Prognostic predictors other than age are required to select elderly patients potentially benefit from treatment enhancement. The modified Glasgow prognostic score (mGPS), an inflammation-based score, has predicted prognosis of patients with various cancer undergoing anti- tumour therapy. The aim of this study was to assess whether pre-treatment mGPS has prognostic value in elderly patients with MIBC undergoing radiotherapy. Material and Methods A retrospective analysis was done using patients aged ≥70 years and treated by three-dimensional conformal radiotherapy with a dose of 60-66Gy in 1.8-2.0Gy QD fractions from January 2011 to December 2016 in our institute. In addition to characteristics of patients and tumors, patients were classified as mGPS 0, 1, and 2 based on the values of albumin and serum C-reactive protein (CRP) prior to treatment such as CRP <0.5 mg/dl and albumin ≥3.5g/dl, CRP ≥0.5 mg/dl or albumin <3.5 g/dl, and CRP ≥0.5 mg/dl and albumin <3.5 g/dl, respectively. Overall survival (OS) rates were compared between subgroups divided by the values of these backgrounds using Kaplan-Meier estimates with log-rank test verification. Results Backgrounds of 86 patients included in this study were as follows: a median 81 (range, 70-95) years old; Male/Female: 64/22; ECOG Performance Status of 0/1/2/3: 35/32/17/2; urothelial cancer/ others: 80/6; Stage II/III/IV (UICC 7th): 27/50/9; mGPS 0/1/2: 36/32/18. Concurrent chemotherapy was combined with radiotherapy in 12 patients (14%). The median follow-up for all patients was 16 months (range, 2-79). The 3-year OS rate for all patients was 44.8%. The 3-year OS rate with mGPS of 0, 1, and 2 were 58.1%, 44.6%, and 11.4%, respectively (Fig. 1). Patients with mGPS 0 had a significantly better OS rate than those with mGPS 2 (P = 0.046). There was no difference in OS rates by dichotomization of any other backgrounds. Poster: Clinical track: Urology-non-prostate

Conclusion Pre-treatment mGPS may be a novel biomarker which can predict survival in elderly patients with MIBC undergoing radiotherapy. PO-0832 Long-term outcomes following organ preservation treatment for muscle invasive bladder cancer D. Büchser 1 , A. Zapatero 1 , J. Rogado 2 , M. Talaya 1 , C. Martin de Vidales 1 , R. Arellano 3 , G. Bocardo 3 , A. Cruz Conde 1 , L. Fernandez 1 , L. Perez 1 , M. Murillo 1 1 Hospital Universitario La Princesa, Radiation Oncology, Madrid, Spain 2 Hospital Universitario La Princesa, Clinical Oncology, Madrid, Spain 3 Hospital Universitario La Princesa, Urology, Madrid, Spain Purpose or Objective To report long-term results on long-term survival, toxicity and patterns of failure of a 20 years experience with three organ sparing strategies for patients with muscle invasive bladder cancer (MIBC). Material and Methods This is a prospective analysis of three consecutive bladder-sparing protocols combining maximal trans- urethral resection (mTUR), radiotherapy (RT) and chemotherapy (QT). Protocol 1(1990-1999) consisted on mTUR and 3 cycles of neoadjuvant methotrexate, cisplatin, and vinblastine (MCV) followed by endoscopic re-evaluation with randomized biopsies and consolidative normo-fractionated RT 60 Gy in complete responders. Protocol 2 (2000-2010) included induction treatment with altered-fractionation RT 40.8 Gy and concurrent weekly cisplatin (40 mg/m2 iv weekly) prior to re-evaluation, followed by endoscopic re-evaluation after a 3-week break. Complete responders proceeded to consolidative chemo-radiotherapy (CRT) (24 Gy to bladder tumour). Finally, protocol 3 (2010-2015) consisted on full course CRT prior to re-evaluation (normofractionated RT 64.8 Gy with concomitant 40 mg/m2 iv weekly cisplatin). Non- responders underwent radical cystectomy RC. The analysis cut-off was set on March 2017. Primary endpoints were overall survival (OS), cancer specific survival (CSS) and metastasis free survival (MFS). Organ preservation, pattern of failure analysis and late toxicity evaluation were secondary endpoints. Probabilities for OS, CSS and MFS were calculated using Kaplan-Meier product limited estimates. A Cox-regression multivariate analysis (MVA) was performed to detect potential risk factors for OS, CSS and MFS. The P < 0.05 significance level was considered for all statistical tests. Results From 1990 to 2016 90 patients were enrolled in all three protocols, 42 in protocol 1, 38 in protocol 2 and 10 in protocol 3. The 5 and 10-year bladder preservationn rate was 79%. Twenty (22%) patients died from bladder