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[en] Many years ago, surgery was the only satisfactory treatment modality for hepatocellular carcinoma (HCC), but it was limited only to selected cases. The main limiting factor for resection is liver function. Diagnostic methods have improved to an extent that small HCC less than 1 cm can be detected. More and more alternative approaches have been administered in the treatment for localized HCC, as radiofrequency ablation (RFA), percutaneous ethanol injection (PEI), radiotherapy and trans arterial chemo embolization (TACE), radioisotopes treatment. Radiotherapy underwent major technological improvements during the last decades, including new radiotherapy techniques: three dimensional conformal radiotherapy (3D CRT), intensity-modulated radiotherapy (IMRT), image guided radiotherapy (IGRT), stereotactic body radiosurgery. All these technological advances allow to treat liver tumours much more precisely, to deliver increased dose for smaller tumour size. Radiotherapy has gained increased consideration for treatment of HCC. (author)
[en] To date, no great interest has been shown in the clinical implementation of recent Image-guided radiation therapy (IGRT) modalities in rectal cancer since only a few studies have been published on this issue. This may be explained by the fact that with current treatment modalities locoregional recurrences are already very low (around 10%). However, there is still room for improvement in treatment of high risk patients (cT3 CRM+, cT4, N+). In these patients better results may be obtained improving radiation technique from 2D to 3D, which showed to be more reliable in terms of target coverage. Also, when higher doses are delivered, Intensity Modulated Radiation Therapy (IMRT) may be used to spare small bowel. But before employing 3D irradiation or IMRT, a proper definition of our clinical target volume (CTV) and planning target volume (PTV) is needed. The CTV should encompass the tumour site, the mesorectum and the lateral nodes, recognized as the most likely sites of local recurrence, with different incidence according to tumour stage. Recent studies discussed the correct delineation of these target volumes in respect of tumour site and stage. From the preliminary results of a study conducted in Rome Univ. 2D planning seemed insufficient to cover the different target volumes especially in T4 patients compared to 3D planning. Also an appropriate PTV margin is necessary in order to manage set-up errors and organ motion. Particularly in these patients, the knowledge of mesorectal movement is required to avoid target missing. Large mesorectal displacements were observed in a study carried out in Leuven Univ. in collaboration with Rome Univ.. A systematic review of the literature together with the data from these first experiences led to the awareness that IGRT could help us to follow the target volume and organs at risk during the treatment, allowing adjustments to improve accuracy in dose delivery, especially when dose escalation studies are planned in the treatment of rectal cancer
[en] The aim is to review technology and indications of stereotactic body radiotherapy (SBRT). SBRT has been developed in the last few years and allows the hypo fractionated treatment of extracranial tumours, using either single or limited number of dose fractions, resulting in the delivery of biologically high effective dose with low toxicity. Efficiency of SBRT is based on high level of accuracy of tumour localisation, dose distribution conformity, setup verification and compensation of breathing motions. Due to high dose per fraction, clinicians must pay attention to new healthy tissues dose limits and new radiobiological models are required. Currently, SBRT is considered safe and effective treatment of tumours otherwise untreatable by the means of conventional radiotherapy or surgery. Early lung cancer has become standard indication in inoperable patients. SBRT seems to be effective in many other indications like liver tumours, pancreatic cancer, bone metastases, prostate cancer and in head and neck and pelvic reirradiation. (author)
[en] In modern day radiotherapy, the emphasis on reduction on volume exposed to high radiotherapy doses, improving treatment precision as well as reducing radiation-related normal tissue toxicity has increased, and thus there is greater importance given to accurate position verification and correction before delivering radiotherapy. At present, several techniques that accomplish these goals impeccably have been developed, though all of them have their limitations. There is no single method available that eliminates treatment-related uncertainties without considerably adding to the cost. However, delivering “high precision radiotherapy” without periodic image guidance would do more harm than treating large volumes to compensate for setup errors. In the present review, we discuss the concept of image guidance in radiotherapy, the current techniques available, and their expected benefits and pitfalls
[en] The term of biological therapy is not exactly defined, but from this group of therapeutics are currently in the treatment of malignant lymphomas used conjugated and unconjugated monoclonal antibodies and to lesser extent interferon-alpha. Introduction of rituximab into treatment protocols of the patients with B-cell lymphomas has been the most important step in clinical practice during previous decade. There is currently ongoing substantial number of clinical trials studying different drugs belonging to the designation biological therapy. Some of them can become standard part of our treatment schemes in the near future. (author)
[en] The urinary bladder shows considerable individual variation in shape and position during a course of radiotherapy (RT). In this study we have developed and compared three different adaptive RT (ART) strategies for bladder cancer involving daily cone beam CT (CBCT) imaging and plan selection. Material and methods. Ten patients treated for bladder cancer had daily CBCTs acquired that were registered online using bony anatomy registration. Seven patients received intensity modulated RT (IMRT) with a simultaneous integrated boost (SIB) technique to the bladder and pelvic lymph nodes. Three patients received treatment to the bladder only. Retrospectively, we compared three ART strategies that were all based on daily selection of the most suitable plan from a library consisting of three IMRT-plans corresponding to a small, medium and large target volume. ART method A utilised population-based margins while methods B and C used the bladder as seen on CBCT-scans from the first week of treatment; method B without delineation of the bladder on CBCT and method C with delineation of the bladder. Total dose distributions were calculated using the planning CT. For each patient, we calculated ratios of the dose volume histograms (DVHs) for the three ART strategies relative to non-adaptive therapy. Results. The inter-patient variation was large for all three ART strategies. The mean ratios of the volumes receiving 57 Gy or more (corresponding to 95% of prescribed dose) for methods A, B and C were 0.66 (SD: 0.11), 0.67 (SD: 0.13) and 0.67 (SD: 0.16) respectively when compared to the non-adaptive plan. Conclusion. When using any of the ART strategies, it is possible to reduce significantly the volumes receiving high doses compared to the use of a standard non-adaptive plan. The differences in dose volume parameters between the three methods were small compared with the differences from the standard plan.
[en] Purpose. To investigate the impact of prone versus supine patient set-up and use of various image-guidance protocols on residual set-up error for radiation therapy of pelvic malignancies. We aim to identify an optimal frequency and protocol for image-guidance. Materials. Using daily online image-guidance mega-voltage CT data from 30 patients (829 MVCT; 299 prone set-up on belly board, 530 supine set-up), we retrospectively assessed the impact of various image-guidance protocols on residual set-up error. We compared daily image-guidance with three different No Action Level protocols (NAL), alternate day image-guidance with running mean and weekly image-guidance. Results. Of 5 IGRT protocols analyzed, the protocol with the highest imaging frequency, alternate day imaging with a running mean (50% imaging frequency), provided the best set-up error reduction. This protocol would have reduced the average length of 3D corrective vector shifts derived from daily image-guidance from 15.2 and 13.5 mm for prone and supine set-up, to 5 and 5.4 mm, respectively. A NAL protocol, averaging shifts of the first 3 fractions (NAL3), would have reduced the respective set-up variability to 6.3 (prone), and 7.5 mm (supine). An extended NAL (eNAL) protocol, averaging shifts of the first 3 fractions plus weekly imaging, would have reduced the daily positioning variability to 6 mm for both prone and supine set-ups. Daily image-guidance yielded set-up corrections >10 mm in 64.3% for prone and 70.3% for supine position. Use of the NAL3 protocol would have reduced the respective frequency to 14.4%, and 21.2% for prone, and supine positioning. In comparison, the alternate day running mean protocol would have reduced the frequency of shifts >10 mm to 5.5% (prone), and 8.3% (supine), respectively. Discussion. In this comparison, high frequency image-guidance provided the highest benefit with respect to residual set-up errors. However, both NAL and eNAL protocols provided significant set-up error reduction with lowered imaging frequency. While the mean 3D vector of corrective shifts was longer for prone set-up compared to the supine set-up, using any image-guidance protocol would have reduced shifts for prone set-up to a greater extent than for the supine set-up. This indicates a greater risk for systematic set-up errors in prone set-up, and larger random errors using a supine patient set-up
[en] The recent wave of enthusiasm for image guidance in radiation therapy is largely due to the advent of on-line imaging devices. The current narrow definition of image-guided radiotherapy (IGRT), in fact, essentially connotes the use of near real-time imaging during treatment delivery to reduce uncertainties in target position and should therefore be termed IGRT-D. However, a broader (and more appropriate) context of image-guidance should include: (1) detection and diagnosis, (2) delineation of target and organs at risk, (3) determining biological attributes, (4) dose distribution design, (5) dose delivery assurance and (6) deciphering treatment response through imaging i.e. the 6 D's of IGRT. Strategies to advance these areas will be discussed
[en] The tomotherapy treatment unit has exclusive and specific modalities of intensity modulated radiotherapy (IMRT) owing to its design. The increasing implantation of these kind of devices, has motivated to resume the work, initiated in the framework of the task group on IMRT of the Medical Physics Spanish Society, to provide a set of recommended procedures for the quality assurance of IMRT in tomotherapy. The tests described in this document come mainly from those proposed by the manufacturer (later compiled in the report of the American Association of Medical Physics AAPM TG-148), others are based on publications of other users, and some have been contributed by the authors themselves. In any case, for each test, one or more methodologies (including the analysis) are described in detail, indicating the required equipment (preferably the one supplied with the treatment unit), the recommended periodicity and tolerance, as well as the time and minimum staff needed.
[es]La unidad de tratamiento de tomoterapia dispone de modalidades de radioterapia de intensidad modulada (IMRT) exclusivas y específicas debidas a su diseño. La creciente implantación de esta clase de equipos, ha motivado retomar la labor, iniciada en el marco del grupo de trabajo de la Sociedad Española de Física Médica sobre IMRT, para proporcionar un conjunto de procedimientos recomendados para el control de calidad de IMRT en tomoterapia. Las pruebas descritas en este documento proceden principalmente de las propuestas por el fabricante (posteriormente recopiladas en el informe de la Asociación Americana de Física Médica AAPM TG-148), otras se basan en publicaciones de otros usuarios, y algunas han sido aportadas por los propios autores. En cualquier caso, para cada prueba se describe de forma detallada una o varias metodologías (incluyendo el análisis), indicando el equipamiento requerido (preferentemente el suministrado con la unidad de tratamiento), la periodicidad y tolerancia recomendadas, así como el tiempo y personal mínimos necesarios