Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Comparative Study
Additional PET/CT in week 5-6 of radiotherapy for patients with stage III non-small cell lung cancer as a means of dose escalation planning?
Loco-regional failure after radiotherapy with total doses of 60-70 Gy for non-small cell lung cancer (NSCLC) remains a major clinical problem. Escalation of radiation dose is often limited because of exceeding normal tissue constraints. The present study was designed to test the hypothesis that a reduction in disease volume during radiotherapy detected by FDG PET/CT would facilitate radiation dose escalation, whilst remaining within normal tissue constraints. ⋯ Our data suggest that despite tumour shrinkage determined by subsequent FDG PET/CT during treatment the tested adaptive targeting strategy would result only in a modest improvement in the context of dose escalation. Further studies on the optimal use of FDG PET/CT and other approaches for dose escalation in loco-regionally advanced NSCLC are warranted.
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Three-dimensional conformal radiation therapy (3D-CRT) represents an advance in the better delineation of the target contours and more accurate dose distributions. The purpose of this study was to identify local control prognostic factors in patients with locally advanced non-small cell lung cancer (LA-NSCLC) treated with 3D-CRT. ⋯ This study shows that local control was independently related to PTV-1 size. The great majority of local recurrences were located in the high-dose region. Dosimetric parameters may contribute to improving radiotherapy results in multidisciplinary treatment for LA-NSCLC.
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To evaluate the efficacy of dose-individualized stereotactic body radiotherapy (SBRT) and adjuvant chemotherapy in stage T1-3N0M0 non-small cell lung cancer (NSCLC). ⋯ Patients treated with the dose-individualization strategy of SBRT showed excellent local control and improved survival. Adjuvant chemotherapy may reduce the frequency of relapse and increase overall survival in stage at T1-3N0M0 NSCLC patients.
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Outcome after radiochemotherapy (RCHT) with temozolomide (TMZ) versus radiotherapy (RT) for WHO grade III astrocytic tumors was evaluated. No significant difference in overall survival or progression-free survival between both groups was calculated. RCHT seems not to result in an improved outcome. Further randomized studies are needed to support these results.
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The two main modalities to deliver high dose to the prostate and prevent high doses to neighboring organs are intensity modulated radiotherapy (IMRT) or external beam radiotherapy combined with brachytherapy. Because of the different biological effectiveness the physical dose distributions were converted to 3-dimensional linear quadratic dose at 2 Gy per fraction (EQD(2)). From the latter, cumulative EQD(2)-volume histograms were determined for comparison of the modalities. ⋯ Because of the high doses within an implant, the dose in 50% of the prostate volume is much higher with the brachytherapy modalities than IMRT-only which may have clinical consequences. With brachytherapy the doses to the OAR are lower or similar to IMRT-only. Dose escalation for prostate tumors is more easily achieved with brachytherapy than with IMRT alone. Therefore, brachytherapy might be the preferred modality to achieve further dose escalation.