Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
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To assess the feasibility, and potential implications, of using intra-prostatic fiducial markers, rather than bony landmarks, for the co-registration of computed tomography (CT) and magnetic resonance (MR) images in the radiation treatment planning of localized prostate cancer. ⋯ Prostate contouring on MR is associated with less inter-observer variation than on CT. In addition, we have demonstrated the feasibility of using intra-prostatic fiducial markers, rather than bony landmarks, for the co-registration of CT and MR images in the radiation treatment planning of localized prostate cancer. This technique, together with on-line correction of treatment set-up according to the fiducial marker position on electronic portal imaging, may enable a reduction in the planning target volume (PTV) margin needed to account for inter-observer error in target delineation, and for prostate motion.
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To evaluate the impact on biochemical control (bNED), acute and late gastro-intestinal (GI) and urological (GU) morbidity of initial and locally advanced prostate cancer treated with fractionated transrectal ultrasound-guided (TRUS) high dose rate after loading brachytherapy (HDR-B) as a boost to conventional external beam radiation therapy (EBRT). ⋯ There are many advantages in HDR-B, but the most important ones are the capability of on-line dosimetry, quality control and the procedure being very conformal. There is a low incidence of GU and GI acute and late morbidity with acceptable bNED when treating initial and locally advanced prostate cancer with HDR-B as a boost to EBRT, but we still need to wait for results of phase III open trials that analyze HDR-B and conformal therapy.
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Clinical Trial
Predictive factors of acute urinary morbidity after iodine-125 brachytherapy for localised prostate cancer: a phase 2 study.
To analyse predictive factors of acute urinary morbidity after transperineal permanent prostate brachytherapy. ⋯ Our short-term data suggest that both pre-implant prostate volume value and post-implant V.U. 150 value might be predictors for urinary morbidity after prostate brachytherapy.
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Appropriate planning target volume (PTV) definition is critical for local disease eradication in the treatment of non-small cell lung cancer (NSCLC). When margins are added to the gross tumour volume (GTV) in the standard way, the PTV formed may be too large to facilitate dose escalation due to normal tissue tolerance. To increase the feasibility of dose escalation with 3-dimensional conformal radiotherapy (3DCRT), this study examines an alternative method for the formation of the PTV in NSCLC. This strategy is based on the reduced probability of tumour cells from the GTV outwards and on the associated lower dose requirements to eradicate such subclinical disease. ⋯ Using this strategy with standard 3DCRT, all PTVs were irradiated to the required dose with this approach, but none of the corresponding Rind volumes had an acceptable dose distribution. The addition of dual volume planning or the use of intensity modulated radiation therapy may achieve an appropriate dose distribution in the Rind volume while not increasing the dose to the organs at risk and may thereby facilitate dose escalation.
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To investigate patient set-up, tumor movement and shrinkage during 3D conformal radiotherapy for non-small cell lung cancer. ⋯ The application of the correction protocol resulted in a significant improvement in the set-up accuracy. There was wide variation in the observed tumor motion with more movement of lower lobe lesions. Tumor shrinkage was observed. The position of the tumor on the planning CT scan did not always coincide with the average position as measured during treatment.