Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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Multicenter Study Comparative Study
Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: a 'Big Brother' evaluation.
To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. ⋯ With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between observers concerning the delineation style were large. This study led to recommendations on how to improve delineation accuracy by adapting the delineation protocol (guidelines for L/W use) and delineation software (double window with lung and mediastinum L/W settings at the same time, enforced use of coronal and sagittal views) and including FDG-PET information (lymph nodes and atelectasis).
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Randomized Controlled Trial Multicenter Study
Delayed rectal and urinary symptomatology in patients treated for prostate cancer by radiotherapy with or without short term neo-adjuvant androgen deprivation.
To identify contributing factors to delayed rectal and urinary symptoms in a randomised trial comparing different durations of maximal androgen deprivation (MAD), given prior to radiotherapy, for locally advanced prostate cancer. ⋯ Prevalence data provide more clinically meaningful estimates of risk of delayed effects in normal tissues where assessment relies substantially on reported symptom levels. In these tissues consideration of the impact of baseline symptom levels and pathologies, and greatest acute symptom levels in analyses of delayed effects appears mandatory. Obstructive lower urinary symptoms improve over several years in the majority of patients treated for locally advanced prostate cancer by radiotherapy. Future research could address whether rectal toxicity is affected by initial haemoglobin levels and declines in it due to MAD.
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Comparative Study
Normal tissue complication probability modeling for acute esophagitis in patients treated with conformal radiation therapy for non-small cell lung cancer.
To evaluate the ability of a well-known normal tissue complication probability (NTCP) model to predict radiation esophagitis by determining updated model parameters and then comparing these results with the predictive value of other dosimetric parameters. ⋯ New values of TD50, n and m offer a good description of the esophagitis distribution in our population. Compared to the use of this model with previously published parameters (associated with late toxicity) predictions of the model for acute esophagitis using the new parameters would indicate that, for a population of patients, the distribution of events as a function of uniform dose would occur with a lower mean uniform dose value (smaller TD50), over a wider range of uniform doses (larger m), while also exhibiting a bigger volume effect (larger n). These new parameter values are supported in essence by the correlations found for the dose/volume threshold parameters.
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To investigate the feasibility and the advantages of using Intensity-Modulated Radiotherapy (IMRT) for the treatment of head-and-neck cancer. Comparing different methods to deliver IMRT in this clinical setting. ⋯ With the Varian planning and delivery system, Step-and-shoot approximations of inversely optimised fluences in head-neck IMRT compare well with SW delivery, even with only five intensity levels. With a number of intensity level of 10 or more, no differences can be appreciated in PTV coverage/OAR sparing with respect to SW.
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To investigate the association between the mean salivary gland and oral cavity dose, with patient-rated moderate and severe xerostomia and sticky saliva. ⋯ Both MD(par) and MD(subm) influence the risk of xerostomia in irradiated patients at 6 months. This probability as a function of the mean parotid dose significantly depended on the mean dose in the submandibular glands. Sticky saliva mainly depends on MD(subm).