38 research outputs found

    Targeted high-precision radiotherapy for prostate cancer.

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    Contains fulltext : 51415.pdf (publisher's version ) (Open Access)RU Radboud Universiteit Nijmegen, 29 november 2006Promotor : Leer, J.W.H. Co-promotor : Visser, A.G.180 p

    Application of anorectal sparing devices in prostate radiotherapy

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    Impact of late anorectal dysfunction on quality of life after pelvic radiotherapy

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    Item does not contain fulltextPURPOSE: Anorectal dysfunction is common after pelvic radiotherapy. This study aims to explore the relationship of subjective and objective anorectal function with quality of life (QoL) and their relative impact in patients irradiated for prostate cancer. METHODS: Patients underwent anal manometry, rectal barostat measurement, and completed validated questionnaires, at least 1 year after prostate radiotherapy (range 1-7 years). QoL was measured by the Fecal Incontinence Quality of Life scale (FIQL) and the Expanded Prostate Cancer Index Composite Bowel domain (EPICB)-bother subscale. Severity of symptoms was rated by the EPICB function subscale. RESULTS: Anorectal function was evaluated in 85 men. Sixty-three percent suffered from one or more anorectal symptoms. Correlations of individual symptoms ranged from r = 0.23 to r = 0.53 with FIQL domains and from r = 0.36 to r = 0.73 with EPICB bother scores. They were strongest for fecal incontinence and urgency. Correlations of anal sphincter pressures, rectal capacity, and sensory thresholds ranged from r = 0.00 to r = 0.42 with FIQL domains and from r = 0.15 to r = 0.31 with EPICB bother scores. Anal resting pressure correlated most strongly. Standardized regression coefficients for QoL outcomes were largest for incontinence, urgency, and anal resting pressure. Regression models with subjective parameters explained a larger amount (range 26-92 %) of variation in QoL outcome than objective parameters (range 10-22 %). CONCLUSIONS: Fecal incontinence and rectal urgency are the symptoms with the largest influence on QoL. Impaired anal resting pressure is the objective function parameter with the largest influence. Therefore, sparing the structures responsible for an adequate fecal continence is important in radiotherapy planning

    Increased rectal wall stiffness after prostate radiotherapy: relation with fecal urgency.

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    Item does not contain fulltextBACKGROUND: Late anorectal toxicity is a frequent adverse event of external beam radiotherapy (EBRT) for prostate cancer. The pathophysiology of anorectal toxicity remains unknown, but we speculate that rectal distensibility is impaired due to fibrosis. Our goal was to determine whether EBRT induces changes of rectal distensibility as measured by an electronic barostat and to explore whether anorectal complaints are related to specific changes of anorectal function. METHODS: Thirty-two men, irradiated for localized prostate carcinoma, underwent barostat measurements, anorectal manometry, and completed a questionnaire prior to and 1 year after radiotherapy. The primary outcome measure was rectal distensibility in response to stepwise isobaric distensions. In addition, we assessed sensory thresholds, anal pressures, and anorectal complaints. KEY RESULTS: External beam radiotherapy reduced maximal rectal capacity (227 +/- 14 mL vs 277 +/- 15 mL; P < 0.001), area under the pressure-volume curve (3212 +/- 352 mL mmHg vs 3969 +/- 413 mL mmHg; P < 0.005), and rectal compliance (15.7 +/- 1.2 mL mmHg(-1) vs 17.6 +/- 0.9 mL mmHg(-1) ; P = 0.12). Sensory pressure thresholds did not significantly change. Sixteen of the 32 patients (50%) had one or more anorectal complaints. Patients with urgency (n = 10) had a more reduced anal squeeze and maximum pressure (decrease 29 +/- 11 mmHg vs 1 +/- 7 mmHg; P < 0.05 and 31 +/- 12 mmHg vs 2 +/- 8 mmHg; P < 0.05 respectively) compared with patients without complaints, indicating a deteriorated external anal sphincter function. CONCLUSIONS & INFERENCES: Irradiation for prostate cancer leads to reduced rectal distensibility. In patients with urgency symptoms, anal sphincter function was also impaired.1 april 201

    Rectal wall sparing effect of three different endorectal balloons in 3D conformal and IMRT prostate radiotherapy.

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    Contains fulltext : 47427.pdf (publisher's version ) (Closed access)PURPOSE: To investigate the dosimetric consequences and rectal wall (Rwall) sparing effect of three different endorectal balloons (ERBs) for three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) for prostate cancer. METHODS AND MATERIALS: In 20 patients, 4 planning computed tomography scans were made: 1 without ERB and 3 with ERB1, ERB2, or ERB3 inserted. Two different planning target volumes were defined: prostate only, and prostate plus seminal vesicles. The 3D-CRT and IMRT planning techniques were used, and the prescription dose was 78 Gy. In 284 treatment plans, the Rwall mean dose, the Rwall normal tissue complication probability, and the absolute Rwall volumes exposed to > or =50 Gy (V(50)) and > or =70 Gy (V(70)) were calculated. For spatial dose distribution analysis, inner rectal wall dose maps and dose surface histograms were generated. RESULTS: Each ERB was tolerated well. In the case of 3D-CRT, each ERB showed a statistically significant reduction of all the measured parameters. ERB2 and ERB3 performed better than ERB1. In IMRT, a statistically significant reduction in the Rwall dose parameters could not be demonstrated for any of the ERBs. For 3D-CRT and IMRT, as a result of the rectal dilation, ranging from 8 to 20 cm in circumference, the ERBs resulted in a reduction of the relative inner Rwall surface exposed to intermediate and high doses. CONCLUSIONS: In 3D-CRT, any ERB showed a significant rectal wall sparing effect. ERB2 and ERB3 were superior to ERB1. For both 3D-CRT and IMRT, a reduction of the relative inner Rwall surface exposed to intermediate and high doses was found, which may lead to reduced late rectal toxicity. Development of user- and patient-friendly ERBs is warranted to increase their acceptability

    Bladder filling variation during radiation treatment of prostate cancer: can the use of a bladder ultrasound scanner and biofeedback optimize bladder filling?

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    Contains fulltext : 50927.pdf (publisher's version ) (Closed access)PURPOSE: To investigate the use of a bladder ultrasound scanner in achieving a better reproducible bladder filling during irradiation of pelvic tumors, specifically prostate cancer. METHODS AND MATERIALS: First, the accuracy of the bladder ultrasound scanner relative to computed tomography was validated in a group of 26 patients. Next, daily bladder volume variation was evaluated in a group of 18 patients. Another 16 patients participated in a biofeedback protocol, aiming at a more constant bladder volume. The last objective was to study correlations between prostate motion and bladder filling, by using electronic portal imaging device data on implanted gold markers. RESULTS: A strong correlation between bladder scanner volume and computed tomography volume (r = 0.95) was found. Daily bladder volume variation was very high (1 SD = 47.2%). Bladder filling and daily variation did not significantly differ between the control and the feedback group (47.2% and 40.1%, respectively). Furthermore, no linear correlations between bladder volume variation and prostate motion were found. CONCLUSIONS: This study shows large variations in daily bladder volume. The use of a biofeedback protocol yields little reduction in bladder volume variation. Even so, the bladder scanner is an easy to use and accurate tool to register these variations

    Set-up improvement in head and neck radiotherapy using a 3D off-line EPID-based correction protocol and a customised head and neck support.

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    Item does not contain fulltextPURPOSE: First, to investigate the set-up improvement resulting from the introduction of a customised head and neck (HN) support system in combination with a technologist-driven off-line correction protocol in HN radiotherapy. Second, to define margins for planning target volume definition, accounting for systematic and random set-up uncertainties. METHODS AND MATERIALS: In 63 patients 498 treatment fractions were evaluated to develop and implement a 3D shrinking action level correction protocol. In the comparative study two different HN-supports were compared: a flexible 'standard HN-support' and a 'customised HN-support". For all three directions (x, y and z) random and systematic set-up deviations (1 S.D.) were measured. RESULTS: The customised HN-support improves the patient positioning compared to the standard HN-support. The 1D systematic errors in the x, y and z directions were reduced from 2.2-2.3 mm to 1.2-2.0 mm (1 S.D.). The 1D random errors for the y and z directions were reduced from 1.6 and 1.6 mm to 1.1 and 1.0 mm (1S.D.). The correction protocol reduced the 1D systematic errors further to 0.8-1.1 mm (1 S.D.) and all deviations in any direction were within 5 mm. Treatment time per measured fraction was increased from 10 to 13 min. The total time required per patient, for the complete correction procedure, was approximately 40 min. CONCLUSIONS: Portal imaging is a powerful tool in the evaluation of the department specific patient positioning procedures. The introduction of a comfortable customised HN-support, in combination with an electronic portal imaging device-based correction protocol, executed by technologists, led to an improvement of overall patient set-up. As a result, application of proposed recipes for CTV-PTV margins indicates that these can be reduced to 3-4 mm

    Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy.

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    Item does not contain fulltextPURPOSE: To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). METHODS AND MATERIALS: In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated. RESULTS: The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: </= 30 Gy to the IAS; </= 10 Gy to the EAS; </= 50 Gy to the PRM; and </= 40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles. CONCLUSIONS: Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are excluded

    Ung i Sollentuna : drive-in-fotboll, ett lokalt utvecklingsprojekt

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    I denna rapport redovisas ett uppdrag FoU-NordvÀst fÄtt frÄn Sollentuna kommun. Uppdraget har dels bestÄtt i en kartlÀggning av hur situationen för ungdomar i Sollentuna upplevs av olika aktörer och dÄ inte minst ungdomarna sjÀlva. Den andra delen Àr en utvÀrdering av projektet drive-in-fotboll som startade i Sollentuna hösten 2013. Insamlingen av data har till största delen skett genom intervjuer med ungdomar och andra aktörer. Intervjuerna har gjorts vid tvÄ olika tidpunkter, dels innan drive-in-fotbollen startade dels nÀr den avslutats. I rapportens resultatdel presenteras först olika aktörers upplevelser av hur situationen gestaltar sig för ungdomarna i Sollentuna. Ungdomarnas egna röster fÄr hÀr stor plats. Efter detta beskrivs upplevelser och tankar kring drive-in-fotbollsprojektet. Intervjuer har gjorts med olika kommunala tjÀnstemÀn, med nÀrpolisen, med representant för den lokala fotbollsföreningen samt med deltagande ungdomar och ledare. Rapporten avslutas med en sammanfattande analys
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