The pretreatment nodal SUV in patients with locally advanced HNSCC is prognostic for DMFS. However, according to our results primary tumor SUV and nodal SUV were not significantly related to OS, DFS or LRC. Patients presenting KPS < 80% had worse OS, DFS, CSS and LRC.

590 Background: Polymorphisms in cytochrome P450 2D6 gene affect the plasma concentration of tamoxifen active metabolites (endoxifen). Some drugs are known to be CYP2D6 inhibitors. We aim to determine the relationship between CYP2D6*4 polymorphisms, concomitant CYP2D6 inhibitors use and clinical outcomes of breast cancer patients receiving adjuvant tamoxifen (TAM). Patients and Methods: CYP2D6*4 (1934 G>A+1) genotype was determinated from DNA of blood samples using PCR-RFLP technique and Taqman Allelic Discrimination Assay in a series of 84 breast cancer patients receiving adjuvant TAM. CYP2D6 inhibitors were recorded. Chi-square test and logistic regression models were used to determinate association between genotype, use of concomitant CYP2D6 inhibitors and disease relapse rate. Results: In our 84 patients series mean age was 51.5y. (33–71). 14.8% were stage I, 58.0% stage II and 27.2% stage III. 61.4% were nodes positive and 98.7% tumors had positive hormonal receptors. We observed disease recurrence in 36.9% of cases. The mean following-up was 5.5 y. Genotype frequency was: wt/wt (57.1%), wt/*4 (40.5%) and *4/*4 (2.4%). 50% (18 of 36) of patients with the wt/*4 + *4/*4 genotypes had disease relapse compared with 27% (13 of 48) with wt/wt genotype (P= 0.041). Only 6 patients received concomitants CYP2D6 inhibitors, mainly antidepressants, all of them with the wt/*4 genotype. 50% presented disease relapse. Clinical pathological variables were evaluated and significant relation was found between stage and disease relapse by univariate analysis (P= 0.001). We investigated whether CYP2D6*4 genotype and stage to diagnosis could influence in disease relapse. For these analyses we use as reference group the genotype wt/wt. We observed that combined genotype wt/*4 + *4/*4 was more strongly associated with disease recurrence than wt/wt genotype (adjusted hazard ratio [HR], 2.82, 95% confidence interval [CI] 1.0- 7.9) P= 0.049. Conclusions: Breast cancer patients with the CYP2D6 *4/*4 or wt/*4 genotype could have lower benefit of TAM adjuvant treatment and tend to have a higher risk of disease relapse. Pre-treatment CYP2D6 genotype determination from blood sample could predicts TAM clinical outcomes and help to oncologist in treatment decision. No significant financial relationships to disclose.

A verification protocol (3-mm action level) provided by EPIDs improves the set-up accuracy. Intrafractional error is not negligible and contributes to create a larger CTV-PTV margin. The appropriate CTV-PTV margin for our institute is between 3 and 4.5 mm considering both inter- and intrafractional errors.

Objective:The primary objective of this study was to assess clinical outcomes in patients with oligometastatic prostate cancer recurrence after single or repeated salvage radiation treatment.Methods: Forty-nine consecutive prostate cancer patients diagnosed with oligometastatic recurrence on Ch-PET have been prospectively treated. Seven (23%) patients had castrate-resistant disease. Clinical outcomes were assessed using the Kaplan-Meier method. Potential prognostic factors were examined using univariate proportional hazards regression. Results:The treatments administered to the initial oligorecurrence sites were intensity-modulated radiotherapy (IMRT) ± ADT (26 patients; 53%) and stereotactic ablative radiotherapy (SABR) ± ADT (23 patients; 47%). With a median follow-up of 24 months (range 6-39), 24 patients developed a biochemical failure. Twenty out of the 24 relapsed patients underwent a second Ch-PET/CT. Seven patients presented poly-metastatic relapse and 10 oligometastatic diseases. Six of 10 patients with a second oligorecurrence were treated again with SABR. Overall, 102 lesions were treated. Local control was detected in 45 (91.8%) patients. No relevant (grade ≥ 2) toxicity was reported, and there was no grade 3 toxicity. On univariate analysis, none of the variables were significantly predicted for clinical disease-free survival. At last follow-up visit, 24 patients (40%) were free from biochemical failure and 37 (71%) patients were free from clinical disease. The 2-year OS and PCSS were 91.8% and 95.9% respectively. Conclusion: Salvage IMRT or SBRT of oligometastatic prostate cancer recurrence is associated with a prolonged cDFS. This may result in a longer time to develop castrate-resistant disease and a longer time without systemic therapies.