34 research outputs found

    Design of Adaptive Structures under Random Impact Conditions

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    Survival benefits for non-small cell lung cancer patients treated with adaptive radiotherapy

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    Introduction Tumor match and adaptive radiotherapy based on on-treatment imaging increases the precision of RT. This allows a reduction of treatment volume and, consequently, of the dose to organs at risk. We investigate the clinical benefits of tumor match and adaptive radiotherapy for a cohort of non-small cell lung cancer patients (NSCLC). Methods In 2013, tumor match and adaptive radiotherapy based on daily cone-beam CT scans was introduced to ensure adaption of the radiotherapy treatment plan for all patients with significant anatomical changes during radiotherapy. Before 2013, the daily cone-beam CT scans were matched on the vertebra and anatomical changes were not evaluated systematically. To estimate the effect of tumor match and adaptive radiotherapy, 439 consecutive NSCLC patients treated with definitive chemo-radiotherapy (50-66 Gy/25-33 fractions, 2010-2018) were investigated retrospectively. They were split in two groups, pre-ART (before tumor match and adaptive radiotherapy, 184 patients), and ART (after tumor match and adaptive radiotherapy, 255 patients) and compared with respect to clinical, treatment-specific and dosimetric variables (χ2 tests, Mann Whitney U tests), progression, survival and radiation pneumonits (CTCAEv3). Progression-free and overall survival as well as radiation pneumonitis were compared with log-rank tests. Hazard ratios were estimated from Cox proportional hazard regression. Results No significant differences in stage (p=0.36), histology (p=0.35), PS (p=0.12) and GTV volumes (p=0.24) were observed. Concomitant chemotherapy was administered more frequently in the ART group (78%) compared to preART (64%), p<0.001. Median[range] PTV volumes decreased from 456 [71;1262] cm3 (preART) to 270 [31;1166] cm3 (ART), p<0.001, thereby significantly reducing mean doses to lungs (median, preART 16.4 [1.9;24.7] Gy, ART 12.1 [1.7;19.4] Gy, p<0.001) and heart (median, preART 8.0 [0.1;32.1] Gy, ART 4.4 [0.1;33.9] Gy, p<0.001). The incidence of RP at nine months decreased significantly with ART (50% to 20% for symptomatic RP (≥G2), 21% to 7% for severe RP (≥G3), 6% to 0.4% for lethal RP (G5), all p<0.001). The two-year progression free survival increased from 22% (preART) to 30% (ART), while the overall survival increased from 43% (preART) to 56% (ART). The median overall survival time increased from 20 (preART) to 28 months (ART). Conclusion Tumor match and adaptive radiotherapy significantly decreased radiation pneumonitis, while maintaining loco-regional control. Further, we observed a significantly improved progression-free and overall survival

    Results from three municipal hospitals regarding radical cystectomy on elderly patients

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    OBJECTIVE: Radical cystectomy is the standard treatment for invasive bladder carcinoma in elderly patients at major surgical centers. As yet no data are available as to the question whether radical surgery on the genitourinary tract of patients over 75 can also be carried out at municipal hospitals with comparable intra and postoperative morbidity, and respective mortality. MATERIALS AND METHODS: 452 radical cystectomies and urinary diversions as ileum conduits or ileum neobladders due to transitional cell carcinoma were carried out at three municipal hospitals between 1992 and 2004. At the time of the surgery, 44 patients (9.7%) were > 75 (75-84) (Group-1), by comparison 408 patients were younger than 75 (35-74) (Group-2). Comparisons are to be made between the groups for 30 day mortality, 30 day reoperation rate, early complication rate (< 3 months), late complication rate (> 3 months), progression-free survival, and overall survival. The results are to be discussed in view of the international literature. Mean follow-up was 49 months (median: 38 months). RESULTS: The perioperative mortality in Group-1 was 2.3% compared to 2.5% in Group-2 (p = 0.942). There was no significant difference in the perioperative mortality with regard to the different case load of the evaluated hospital. There were no significant group differences regarding the 30 day reoperation rate, early and late complications. Progression-free and overall survival of all patients after 5 years was 56.1% and 53.6% respectively; here again the differences between the age groups was not significant (p = 0.384 and p = 0.210). Our results for patients > 75 do not differ from the published data of large clinics with a high cystectomy frequency. CONCLUSIONS: Our data confirm that radical cystectomy on elderly patients can also be carried out in municipal hospitals with acceptable mortality and morbidity rates. Of prime importance is a careful patient selection based on comorbidity scores and possibly geriatric assessment
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