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Background and Purpose: Previous studies confirmed that implantable rectum spacers (IRS) decreased acute gastro-intestinal (GI) toxicity in a significant percentage of prostate cancer patients undergoing intensity modulated radiation therapy (IMRT). We developed decision rules based on clinical risk factors (CRFs) to select those patients who are expected to benefit most from IRS implantation., Materials and Methods: For 26 patients dose distributions with (IMRT+IRS) and without (IMRT-IRS) IRS were calculated. Validated nomograms based on CRFs and dosimetric criteria (anorectal V 40Gy and V 75Gy ) were used to predict probabilities for grade 2-3 (G2-3) acute GI toxicity, G2-3 late rectal bleeding (LRB), G3 LRB, and G2-3 faecal incontinence (FI) for IMRT+IRS and IMRT-IRS. All permutations of CRFs were generated to identify most benefit scenarios (MBS) in which a predicted toxicity reduction of ⩾5% points in ⩾25% of the cohort was present due to IRS implantation., Results: IMRT+IRS revealed a significant reduction in V 40Gy (p=0.0357) and V 75Gy (p<0.0001) relative to IMRT-IRS. For G2-3 acute GI toxicity and G2-3 LRB, the predicted toxicity rates decreased in 17/26 (65%) and 20/26 (77%) patients, and decision rules were derived for 22/32 (69%) and 12/64 (19%) MBS, respectively. From the decision rules, it follows that diabetes status has no impact on G2-3 acute toxicity, and in absence of pre-RT abdominal surgery, the implantation of an IRS is predicted to show no clinically relevant benefit for G2-3 LRB., Conclusions: Prostate cancer patients who are expected to benefit most from IRS implantation can be identified prior to IMRT based on their CRFs profile., (Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)

Background and Purpose: To compare the cost-effectiveness of treating prostate cancer patients with intensity-modulated radiation therapy and a spacer (IMRT+S) versus IMRT-only without a spacer (IMRT-O)., Materials and Methods: A decision-analytic Markov model was constructed to examine the effect of late rectal toxicity and compare the costs and quality-adjusted Life Years (QALYs) of IMRT-O and IMRT+S. The main assumption of this modeling study was that disease progression, genito-urinary toxicity and survival were equal for both comparators., Results: For all patients, IMRT+S revealed a lower toxicity than IMRT-O. Treatment follow-up and toxicity costs for IMRT-O and IMRT+S amounted to €1604 and €1444, respectively, thus saving €160 on the complication costs at an extra charge of €1700 for the spacer in IMRT+S. The QALYs yielded for IMRT-O and IMRT+S were 3.542 and 3.570, respectively. This results in an incremental cost-effectiveness ratio (ICER) of €55,880 per QALY gained. For a ceiling ratio of €80,000, IMRT+S had a 77% probability of being cost-effective., Conclusion: IMRT+S is cost-effective compared to IMRT-O based on its potential to reduce radiotherapy-related toxicity., (Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)

Purpose: To investigate the pattern of lymph node spread on magnetic resonance lymphography (MRL) in prostate cancer patients and compare this pattern to the clinical target volume for elective pelvis irradiation as defined by the radiation therapy oncology group (RTOG-CTV)., Methods and Materials: The charts of 60 intermediate and high risk prostate cancer patients with non-enlarged positive lymph nodes on MRL were reviewed. Positive lymph nodes were assigned to a lymph node region according to the guidelines for delineation of the RTOG-CTV. Five lymph node regions outside this RTOG-CTV were defined: the para-aortal, proximal common iliac, pararectal, paravesical and inguinal region., Results: Fifty-three percent of the patients had an MRL-positive lymph node in a lymph node region outside the RTOG-CTV. The most frequently involved aberrant sites were the proximal common iliac, the pararectal and para-aortal region, which were affected in 30%, 25% and 18% respectively., Conclusion: More than half of the patients had an MRL-positive lymph node outside the RTOG-CTV. To reduce geographical miss while minimizing the toxicity of radiotherapy, image based definition of an individual target volume seems to be necessary., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: To investigate the effect of an endorectal balloon (ERB) on anal wall (Awall) and rectal wall (Rwall) doses in high-dose post-prostatectomy intensity-modulated radiotherapy (IMRT)., Materials and Methods: For 20 patients, referred for salvage IMRT after prostatectomy for prostate cancer, two planning CT-scans were performed: one with and one without an air-filled ERB. A planning target volume (PTV) was defined, using international guidelines. Furthermore, the Awall and Rwall were delineated. In both the scans, IMRT plans were generated with a prescribed dose of 70 Gy. The mean dose (D(mean)), maximum dose, minimum dose, and volumes exposed to doses ranging from ≥ 20 to ≥ 70 Gy (V(20)-V(70)) to the Awall and Rwall were calculated. Finally, inner Rwall surface areas exposed to doses ranging from ≥ 20 to ≥ 70 Gy (A(20)-A(70)) were calculated. Dose-parameters were compared between plans with and without ERB., Results: All Awall parameters, except V(70), were significantly reduced by the ERB with an overall D(mean) reduction of 6 Gy. Absolute reductions in dose-volume parameters varied from 5% to 11%. Significantly reduced Rwall V(30), V(40), and A(40) were observed with ERB, irrespective of the target volume size., Conclusion: ERB application significantly reduces Awall and to a lesser degree Rwall doses in high-dose post-prostatectomy IMRT., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: We studied whether hormonal therapy, (neo)adjuvant to radiotherapy for localized prostate cancer, is related to an increase in depression and whether this is caused by the hormonal therapy itself or by the relatively poor prognosis of patients who get (neo)adjuvant hormonal therapy., Methods: Between 2002 and 2005, 288 patients, irradiated for prostate cancer (T1-3N0M0), were studied prospectively in two clinics. In one clinic almost all patients received (neo)adjuvant androgen deprivation (Bicalutamide+Gosereline). In a second clinic hormonal therapy was prescribed mainly for high risk patients. This allowed us to separate the effects of hormonal therapy and the patient's prognosis., Results: During the course of hormonal therapy, depression was significantly heightened by both hormone use (p<0.001) and poor prognosis (p<0.01). After completion of hormonal therapy, poor prognosis continued to affect the depression score (p<0.01). The increase was, however, small., Conclusions: Depression was mildly increased in patients receiving hormonal therapy. The increase appeared to be related to both the hormone therapy itself and the high risk status of patients. High risk status, with the associated poor prognosis, had a more sustained effect on depression. The rise was statistically significant, but was too small, however, to bear clinical significance., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: Goals of this study are to report the outcomes and tolerance of salvage radiotherapy (SRT) after prostatectomy, to identify risk factors for failure after SRT and to evaluate how these results compare with published results of immediate post-operative adjuvant radiotherapy (ART)., Material and Methods: Men receiving SRT for elevated PSA levels after radical prostatectomy (RP) were included. Biochemical progression-free survival (bPFS), overall survival (OS) and disease-specific survival (DSS) were estimated. Risk factors for biochemical failure and death were evaluated. Late toxicity and quality of life were evaluated. Secondary bPFS (defined as bPFS from prostatectomy until progression after radiotherapy) was calculated for high-risk patients (pT3 and/or positive surgical margins) in order to compare SRT outcomes with ART., Results: 197 Men were included. Five-year bPFS after SRT was 59% (95% CI 49-69%). Five-year OS and DSS were 90% (85-96%) and 97% (93-100%), respectively. Capsular perforation (pT≥T3), negative surgical margins and serum PSA>1 ng/ml at the start of RT were significant predictors of lower bPFS. Patients without any negative factors had a 5-year bPFS of 89%. No severe late toxicity was reported. Five-year secondary bPFS for SRT in high-risk patients was 78% and comparable with published results for ART., Conclusions: Salvage radiotherapy for patients with organ-confined prostate cancer was effective and well tolerated. SRT outcomes were comparable with published ART results for high-risk patients. Initially monitoring serum PSA and considering early SRT for these patients are not harmful and might be a valuable alternative for immediate ART., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: Endorectal balloons (ERBs) are being used in prostate radiotherapy for prostate immobilization and rectal wall (Rwall) sparing. Some of their aspects, however, have been questioned, like patient's tolerance and their value in modern high-precision radiotherapy. This paper gives an overview of published data concerning ERB application in prostate radiotherapy., Materials and Methods: Systematic literature review based on PubMed/MEDLINE database searches., Results: Overall, ERBs are tolerated well, although patients with pre-existing anorectal disease have an increased risk of developing ERB-related toxicity. Planning studies show reduced Rwall and anal wall (Awall) doses with ERB application. Clinical data, however, are scarce, as only one study shows reduced late rectal damage. There is no consensus about the immobilizing properties of ERBs and it is recommended to use additional set-up and correction protocols, especially because there are potential pitfalls., Conclusion: ERBs seem well-tolerated and in planning studies reduce anorectal wall doses. This may lead to reduced anorectal toxicity, although clinical studies are warranted to confirm this hypothesis and to further investigate the immobilizing properties of ERBs, preferably in combination with advanced techniques for position verification., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Background and Purpose: To investigate the anal wall (Awall) sparing effect of an endorectal balloon (ERB) in 3D conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) for prostate cancer., Materials and Methods: In 24 patients with localized prostate carcinoma, two planning CT-scans were performed: with and without ERB. A prostate planning target volume (PTV) was defined, and the Awall was delineated, using two different methods. Three-field and 4-field 3D-CRT plans, and IMRT plans were generated with a prescription dose of 78Gy. In 144 treatment plans, the minimum dose (D(min)), maximum dose (D(max)), and mean dose (D(mean)) to the Awall were calculated, as well as the Awall volumes exposed to doses ranging from >or=20Gy to >or=70Gy (V(20)-V(70), respectively)., Results: In the 3D-CRT plans, an ERB significantly reduced D(mean), D(max), and V(30)-V(70). For IMRT all investigated dose parameters were significantly reduced by the ERB. The absolute reduction of D(mean) was 12Gy in 3D-CRT and was 7.5Gy in IMRT for both methods of Awall delineation., Conclusions: Application of an ERB showed a significant Awall sparing effect in both 3D-CRT and IMRT. This may lead to reduced late anal toxicity in prostate radiotherapy.

Purpose: To evaluate the efficiency of combining on-line and off-line corrections for the positioning of patients receiving external beam radiotherapy for prostate cancer., Materials and Methods: Daily portal images were acquired during the treatment of 102 patients to verify and correct the position of the prostatic gland using implanted gold markers. In addition to an existing off-line procedure, on-line corrections were applied in the anterior-posterior (AP) direction only, to limit the increase in daily workload. The possible increase in workload of the combined correction procedure for on-line corrections in either two or three directions was further investigated by simulating the required position corrections for 500 treatments., Results: The combined correction procedure in AP-direction resulted in a systematic dispersion and random variation of 0.3mm (1 SD) and 1.0mm (1 SD), respectively. Application of off-line corrections during pre-treatment setup reduced the number of required on-line corrections from 22+/-4 (1 SD) to 17+/-4 (1 SD), at the cost of 1.4+/-1.0 (1 SD) off-line corrections. For on-line corrections in two or three directions, application of a combined on-line/off-line procedure did not noticeably reduce the number of setup corrections., Conclusions: The on-line procedure is feasible and significantly improves both systematic and random errors to below 1 mm with a limited impact on the workload and treatment time. The application of off-line setup corrections during pre-treatment patient positioning only marginally reduces the number of on-line setup corrections.

Purpose: 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.