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ABSTRACT: BACKGROUND AND PURPOSE: The aim was to evaluate the spacer dimensions and prostate position variability during the course of radiotherapy for prostate cancer. MATERIALS AND METHODS: CT scans were performed in a group of 15 patients (G1) after the 10ml injection of a hydrogel spacer (SpaceOAR™) and 30 patients without a spacer (G2) before the beginning of treatment (CT1) and in the last treatment week, 10-12weeks following spacer implantation (CT2). Spacer dimensions and displacements were determined and prostate displacements compared. RESULTS: Mean volume of the hydrogel increased slightly (17%; p<0.01), in 4 of 15 patients >2cm(3). The average displacement of the hydrogel center of mass was 0.6mm (87%⩽2.2mm), -0.6mm (100%⩽2.2mm) and 1.4mm (87%⩽4.3mm) in the x-, y- and z-axes (not significant). The average distance between prostate and anterior rectal wall before/at the end of radiotherapy was 1.6cm/1.5cm, 1.2cm/1.3cm and 1.0cm/1.1cm at the level of the base, middle and apex (G1). Prostate position variations were similar comparing G1 and G2, but significant systematic posterior displacements were only found in G2. CONCLUSIONS: A stable distance between the prostate and anterior rectal wall results during the radiotherapy course after injection of the spacer before treatment planning. Larger posterior prostate displacements could be reduced.
Radiotherapy and Oncology 01/2013; · 5.58 Impact Factor
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ABSTRACT: BACKGROUND: The outcome of patients after radiotherapy (RT) for localized prostate cancer in case of prostate-specific antigen (PSA) progression during primary hormonal therapy (HT) is not well known. METHODS: A group of 27 patients presenting with PSA progression during primary HT for local prostate cancer RT was identified among patients who were treated in the years 2000--2004 either using external-beam RT (EBRT; 70.2Gy; n=261) or Ir-192 brachytherapy as a boost to EBRT (HDR-BT; 18Gy + 50.4Gy; n=71). The median follow-up period after RT was 68 months. RESULTS: Median biochemical recurrence free (BRFS), disease specific (DSS) and overall survival (OS) for patients with PSA progression during primary HT was found to be only 21, 54 and 53 months, respectively, with a 6-year BRFS, DSS and OS of 19%, 41% and 26%. There were no significant differences between different RT concepts (6-year OS of 27% after EBRT and 20% after EBRT with HDR-BT).Considering all 332 patients in multivariate Cox regression analysis, PSA progression during initial HT, Gleason score>6 and patient age were found to be predictive for lower OS (p<0.001). The highest hazard ratio resulted for PSA progression during initial HT (7.2 in comparison to patients without PSA progression during primary HT). PSA progression and a nadir >0.5ng/ml during initial HT were both significant risk factors for biochemical recurrence. CONCLUSIONS: An unfavourable prognosis after PSA progression during initial HT needs to be considered in the decision process before local prostate radiotherapy. Results from other centres are needed to validate our findings.
Radiation Oncology 12/2012; 7(1):209. · 2.32 Impact Factor
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ABSTRACT: The impact of the dose to the urethra and sources placed close to the urethra on urinary morbidity after permanent prostate brachytherapy (PPB) is not well known.
Fifty-nine patients were surveyed prospectively before treatment (A), 1 month after (B) and > 1 year after PPB (C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Computed tomography (CT) postimplant scans were performed at days 1 (Foley catheter in situ) and 30 after PPB and sources within 5mm of the urethra at day 1 were identified.
As opposed to the urethral dose-volume histogram, a larger number of sources within 5mm of the urethra at day 1 predicted significantly larger urinary bother score changes at times B and C - with an impact on incontinence and frequency (e.g. moderate/big problem with leaking urine in 25% vs. 3%, p = 0.02; moderate/big problem with frequent urination in 33% vs. 7%, p < 0.01, at time C with vs. without ≥ 3 sources in a single strand placed close to the urethra).
Placement of sources with a minimum distance of a few mm to the urethra should be a major aim to avoid urinary morbidity irrespective of the urethral dose-volume histogram.
Radiotherapy and Oncology 01/2012; 103(2):247-51. · 5.58 Impact Factor
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Michael Pinkawa,
Marc D Piroth,
Richard Holy, Jens Klotz,
Victoria Djukic,
Nuria Escobar Corral,
Mariana Caffaro,
Oliver H Winz,
Thomas Krohn,
Felix M Mottaghy,
Michael J Eble
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ABSTRACT: In comparison to the conventional whole-prostate dose escalation, an integrated boost to the macroscopic malignant lesion might potentially improve tumor control rates without increasing toxicity. Quality of life after radiotherapy (RT) with vs. without (18)F-choline PET-CT detected simultaneous integrated boost (SIB) was prospectively evaluated in this study.
Whole body image acquisition in supine patient position followed 1 h after injection of 178-355MBq (18)F-choline. SIB was defined by a tumor-to-background uptake value ratio > 2 (GTV(PET)). A dose of 76Gy was prescribed to the prostate (PTV(prostate)) in 2Gy fractions, with or without SIB up to 80Gy. Patients treated with (n = 46) vs. without (n = 21) SIB were surveyed prospectively before (A), at the last day of RT (B) and a median time of two (C) and 19 month (D) after RT to compare QoL changes applying a validated questionnaire (EPIC - expanded prostate cancer index composite).
With a median cut-off standard uptake value (SUV) of 3, a median GTV(PET) of 4.0 cm(3) and PTV(boost) (GTV(PET) with margins) of 17.3 cm(3) was defined. No significant differences were found for patients treated with vs. without SIB regarding urinary and bowel QoL changes at times B, C and D (mean differences ≤3 points for all comparisons). Significantly decreasing acute urinary and bowel score changes (mean changes > 5 points in comparison to baseline level at time A) were found for patients with and without SIB. However, long-term urinary and bowel QoL (time D) did not differ relative to baseline levels - with mean urinary and bowel function score changes < 3 points in both groups (median changes = 0 points). Only sexual function scores decreased significantly (> 5 points) at time D.
Treatment planning with (18)F-choline PET-CT allows a dose escalation to a macroscopic intraprostatic lesion without significantly increasing toxicity.
Radiation Oncology 01/2012; 7:14. · 2.32 Impact Factor
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ABSTRACT: Comparison of health-related quality of life after whole pelvic (WPRT) and prostate-only (PORT) external beam radiotherapy for prostate cancer.
A group of 120 patients (60 in each group) was surveyed prospectively before radiation therapy (RT) (time A), at the last day of RT (time B), at a median time of 2 months (time C) and >1 year after RT (time D) using a validated questionnaire (Expanded Prostate Cancer Index Composite). All patients were treated with 1.8- to 2.0-Gy fractions up to 70.2 to 72.0 Gy with or without WPRT up to 45 to 46 Gy. Pairs were matched according to the following criteria: age±5 years, planning target volume±10 cc (considering planning target volume without pelvic nodes for WPRT patients), urinary/bowel/sexual function score before RT±10, and use of antiandrogens.
With the exception of prognostic risk factors, both groups were well balanced with respect to baseline characteristics. No significant differences were found with regard to urinary and sexual score changes. Mean bladder function scores reached baseline levels in both patient subgroups after RT. However, bowel function scores decreased significantly more for patients after WPRT than in those receiving PORT at all times (p<0.01, respectively). Significant differences were found for most items in the bowel domain in the acute phase. At time D, patients after WPRT reported rectal urgency (>once a day in 15% vs. 3%; p=0.03), bloody stools (≥half the time in 7% vs. 0%; p=0.04) and frequent bowel movements (>two on a typical day in 32% vs. 7%; p<0.01) more often than did patients after PORT.
In comparison to PORT, WPRT (larger bladder and rectum volumes in medium dose levels, but similar volumes in high dose levels) was associated with decreased bowel quality of life in the acute and chronic phases after treatment but remained without adverse long-term urinary effects.
International journal of radiation oncology, biology, physics 09/2011; 81(1):23-8. · 4.59 Impact Factor
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ABSTRACT: The aim was to evaluate treatment-related morbidity after intensity-modulated (IMRT) and image-guided (IGRT) radiotherapy with a total dose of 76 Gy in comparison to conventional conformal radiotherapy (3DCRT) up to 70.2-72 Gy for patients with prostate cancer.
All patients were prospectively surveyed prior to, on the last day, as well as after a median time of 2 and 16 months after RT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Criteria for the 78 matched pairs after IMRT vs. 3DCRT were patient age, use of antiandrogens, treatment volume (± whole pelvis), prognostic risk group, and urinary/bowel/sexual quality of life (QoL) before treatment.
QoL changes after dose-escalated IMRT were found to be similar to QoL changes after 3DCRT in all domains. Only sexual function scores more than 1 year after RT decreased slightly more after 3DCRT in comparison to IMRT (mean 9 vs. 6 points; p = 0.04), with erections firm enough for intercourse in 14% vs. 30% (p = 0.03). Painful bowel movements were reported more frequently after 3DCRT vs. IMRT 2 months after treatment (≥ once a day in 10% vs. 1%; p = 0.03), but a tendency for higher rectal bleeding rates was found after IMRT vs. 3DCRT more than 1 year after RT (≥ rarely in 20% vs. 9%; p = 0.06).
Combination of dose escalation with technological advances (IMRT and IGRT) is not associated with increased morbidity for patients with prostate cancer.
Strahlentherapie und Onkologie 08/2011; 187(8):479-84. · 3.56 Impact Factor
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ABSTRACT: Early detection of treatment response in glioma patients after radiochemotherapy (RCX) is uncertain because treatment-related contrast enhancement in magnetic resonance imaging can mimic tumor progression. Positron emission tomography (PET) using the amino acid tracer [(18)F]fluoroethyltyrosine (FET) seems to be a promising tool for treatment monitoring. The aim of this prospective study was to evaluate the prognostic value of early changes of FET uptake after postoperative RCX in glioblastomas.
Twenty-two patients with glioblastoma were treated by surgery and subsequent RCX (whole dose 60-72 Gy). The FET-PET studies were performed before RCX, 7-10 days and 6-8 weeks after completion of RCX. Early treatment response in PET was defined as a decrease of the maximal tumor-to-brain ratio (TBR(max)) of FET uptake after RCX of more than 10%. The prognostic value of early changes of FET uptake after RCX was evaluated using Kaplan-Maier estimates for median disease-free survival and overall survival.
The median overall and disease-free survival of the patients was 14.8 and 7.8 months. There were 16 early responders in FET-PET (72.7%) and 6 nonresponders (27.3%). Early PET responders had a significantly longer median disease-free survival (10.3 vs. 5.8 months; p < 0.01) and overall survival ("not reached" vs. 9.3 months; p < 0.001). No statistically significant differences between the patient subgroups were found concerning the defined prognostic parameters.
FET-PET is a sensitive tool to predict treatment response in patients with glioblastomas at an early stage after RCX.
International journal of radiation oncology, biology, physics 05/2011; 80(1):176-84. · 4.59 Impact Factor
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ABSTRACT: To report the own experience with 66 patients who received 18F-choline PET-CT (positron emission tomography-computed tomography) for treatment planning.
Image acquisition followed 1 h after injection of 178-355 MBq (18)F-choline. An intraprostatic lesion (GTV(PET) [gross tumor volume]) was defined by a tumor-to-background SUV (standard uptake value) ratio > 2. A dose of 76 Gy was prescribed to the prostate in 2-Gy fractions, with a simultaneous integrated boost up to 80 Gy.
A boost volume could not be defined for a single patient. One, two and three or more lesions were found for 36 (55%), 22 (33%) and seven patients (11%). The lobe(s) with a positive biopsy correlated with a GTV(PET) in the same lobe in 63 cases (97%). GTV(PET) was additionally defined in 33 of 41 prostate lobes (80%) with only negative biopsies. GTV(PET), SUV(mean) and SUV(max) were found to be dependent on well-known prognostic risk factors, particularly T-stage and Gleason Score. In multivariate analysis, Gleason Score > 7 resulted as an independent factor for GTV(PET) > 8 cm(3) (hazard ratio 5.5; p = 0.02) and SUV(max) > 5 (hazard ratio 4.4; p = 0.04). Neoadjuvant hormonal treatment (NHT) did not affect SUV levels. The mean EUDs (equivalent uniform doses) to the rectum and bladder (55.9 Gy and 54.8 Gy) were comparable to patients (n = 18) who were treated in the same period without a boost (54.3 Gy and 55.6 Gy).
Treatment planning with (18)F-choline PET-CT allows the definition of an integrated boost in nearly all prostate cancer patients - including patients after NHT - without considerably affecting EUDs for the organs at risk. GTV(PET) and SUV levels were found to be dependent on prognostic risk factors, particularly Gleason Score.
Strahlentherapie und Onkologie 09/2010; 186(11):600-6. · 3.56 Impact Factor
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ABSTRACT: To evaluate the impact of the clinical target volume (CTV) and fraction dose on quality of life (QoL) after external-beam radiotherapy (EBRT) for prostate cancer.
A group of 283 patients has been surveyed prospectively before, at the last day, at a median time of 2 months and 15 months after EBRT (70.2-72 Gy) using a validated questionnaire (Expanded Prostate Cancer Index Composite). EBRT of prostate alone (P, n = 70) versus prostate with seminal vesicles (PS, n = 213) was compared. Differences of fraction doses (1.8 Gy, n = 80, vs. 2.0 Gy, n = 69) have been evaluated in the patient group receiving a total dose of 72 Gy.
Significantly higher bladder and rectum volumes were found at all dose levels for the patients with PS versus P within the CTV (p < 0.001). Similar volumes resulted in the groups with different fraction doses. Paradoxically, bowel function scores decreased significantly less 2 and 15 months after EBRT of PS versus P. 2 months after EBRT, patients with a fraction dose of 2.0 Gy versus 1.8 Gy reported pain with urination (> or = once a day in 12% vs. 3%; p = 0.04) and painful bowel movements (> or = rarely in 46% vs. 29%; p = 0.05) more frequently. No long-term differences were found.
The risk of adverse QoL changes after EBRT for prostate cancer cannot be derived from the dose-volume histogram alone. Seminal vesicles can be included in the CTV up to a moderate total dose without adverse effects on QoL. Apart from a longer recovery period, higher fraction doses were not associated with higher toxicity.
Strahlentherapie und Onkologie 11/2009; 185(11):724-30. · 3.56 Impact Factor
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ABSTRACT: The aim of the study was to evaluate bowel quality-of-life changes after prostate brachytherapy and the impact of Day 1 vs. Day 30 postimplant dosimetry.
In 61 patients, computed tomography (CT) scans were performed at Days 1 and 30 after (125)I brachytherapy. The patients have been surveyed prospectively before (time A), 1 month (time B), and >1 year after treatment (time C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Different parameters were tested for their predictive value on bowel quality-of-life changes (bowel bother score decrease >20 points at time B=BB20; bowel bother score decrease >10 points at time C=BC10), including seed displacements.
Mean bowel function/bother score decreased 13/13 points at time B (p<0.01) and 1/4 points at time C (change not significant). BB20 and BC10 were found in 25% and 20% of patients, respectively. Bowel bother score declines at time B correlated well with declines at time C (r=0.53; p<0.01). Prostate volume before implantation and the number of seeds per cubic centimeters were found to be predictive for BB20 and BC10. Smaller rectal wall volumes covered by the 60-100% isodoses at Day 1 were (paradoxically) found to be significantly predictive for BC10. Larger posterior seed displacements between Days 1 and 30 were significantly associated with BB20.
Quality-of-life scores have not been found to change significantly >1 year after brachytherapy. Larger rectal wall volumes within higher isodoses at Day 1 or 30 were not found to be predisposing for adverse quality-of-life changes.
Brachytherapy 10/2009; 9(1):1-7. · 1.47 Impact Factor
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ABSTRACT: The aim of the study was to evaluate self-assessed bowel toxicity after radiotherapy (RT) for prostate cancer. In contrast to rectal bleeding, information concerning irritative symptoms (rectal urgency, pain) and incontinence after RT has not been adequately documented and reported in the past.
Patients (n = 286) have been surveyed prospectively before (A), at the last day (70.2-72.0 Gy; B), a median time of two (C) and 16 months after RT (D) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Bowel domain score changes were analyzed and patient-/dose-volume-related factors tested for a predictive value on three separate factors (subscales): irritative symptoms, incontinence and rectal bleeding.
Irritative symptoms were most strongly affected in the acute phase, but the scores of all subscales remained slightly lower at time D in comparison to baseline scores. Good correlations (correlation indices >0.4; p < 0.001 for all) were found between irritative and incontinence function/bother scores at times B-D, suggesting the presence of an urge incontinence for the majority of patients who reported uncontrolled leakage of stool. Planning target volume (PTV), haemorrhoids and stroke in past history were found to be independent predictive factors for rectal bleeding at time D. Chronic renal failure predisposed for lower irritative scores at time D. Paradoxically, patients with greater rectum volumes inside higher isodose levels presented with higher quality of life scores in the irritative and incontinence subscales.
PTV and specific comorbidities are important predictive factors on adverse bowel quality of life changes after RT for prostate cancer. However, greater rectum volumes inside high isodose levels have not been found to be associated with lower quality of life scores.
Radiation Oncology 09/2009; 4:36. · 2.32 Impact Factor
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ABSTRACT: Interpretation of comparative health-related quality of life (HRQOL) studies following different prostate cancer treatments is often difficult due to differing patient ages. Furthermore, age-related changes can hardly be discriminated from therapy-related changes. The evaluation of age-and comorbidity-related changes was in focus of this study.
HRQOL of 528 prostate cancer patients was analysed using a validated questionnaire (Expanded Prostate Cancer Index Composite) before a curative treatment. Patients were divided into age groups <or=65, 6670, 7175 and >75 years. The impact of specific comorbidities and the Charlson Comorbidity Index (CCI) were evaluated. The questionnaire comprises 50 items concerning the urinary, bowel, sexual and hormonal domains for function and bother. For assessment of sexual and hormonal domains, only patients without prior hormonal treatment were included (n = 336).
Urinary incontinence was observed increasingly with higher age (mean function scores of 92/88/85/87 for patients <or=65, 6670, 7175 and >75 years) complete urinary control in 78%/72%/64%/58% (p < 0.01). Sexual function scores decreased particularly (48/43/35/30), with erections sufficient for intercourse in 68%/50%/36%/32% (p < 0.01) a decrease of more than a third comparing patients <or=65 vs. 6670 (36%) and 6670 vs. 7175 years (39%). The percentage of patients with comorbidities was lowest in the youngest group (48% vs. 66%/68%/63% for ages 6670/7175/>75 years; p < 0.05). A multivariate analysis revealed an independent influence of both age and comorbidities on urinary incontinence, specifically diabetes on urinary bother, and both age and diabetes on sexual function/bother. Rectal domain scores were not significantly influenced by age or comorbidities. A CCI>5 particularly predisposed for lower urinary and sexual HRQOL scores.
Urinary continence and sexual function are the crucial HRQOL domains with age-related and independently comorbidity-related decreasing scores. The results need to be considered for the interpretation of comparative studies or longitudinal changes after a curative treatment.
BMC Cancer 08/2009; 9:296. · 3.01 Impact Factor
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ABSTRACT: The aim of the study was to evaluate the impact of a dose escalation to an (18)F-choline PET-CT defined simultaneous integrated boost (IB) on the dose distribution and changes of the equivalent uniform dose (EUD).
PET-CT was performed in 12 consecutive patients for treatment planning. An intraprostatic lesion was defined by a tumour-to-background uptake value ratio >2 (GTV(PET)). Dose escalation was focused only on the intraprostatic lesion. Two comparisons were evaluated: whole prostate irradiation to 76 Gy+/-boost to 80 Gy (C1) and whole prostate irradiation to 66.6 Gy+/-boost to 83.25 Gy (C2).
PTV/GTV(PET)+margins were covered by a mean EUD of 75.9/76.1 Gy vs. 77.1/80.1 Gy (C1) and 66.5/66.2 Gy vs. 71.1/82.9 Gy (C2) (p<0.01, respectively). Concerning the organs at risk, EUD increased slightly with an additional boost (mean EUD for bladder: C1 53.2 Gy vs. 53.8 Gy; C2 43.0 Gy vs. 45.1 Gy; for rectum: C1 52.0 Gy vs. 52.6 Gy; C2 43.0 Gy vs. 45.4 Gy; p<0.01, respectively). The distance to the organs at risk had a significant impact on the respective maximum doses in the treatment plans with IB.
Treatment planning with IB allows an individually adapted dose escalation. The therapeutic ratio can be improved by a considerable dose escalation to the macroscopic tumour, but only minor EUD changes to the bladder and rectum.
Radiotherapy and Oncology 08/2009; 93(2):213-9. · 5.58 Impact Factor
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ABSTRACT: To evaluate inter- and intrafraction organ motion with an ultrasound-based prostate localization system (BAT) for patients treated with intensity-modulated radiotherapy for prostate cancer.
After set-up to external skin marks, 260/219 ultrasound-based alignments were performed before/after irradiation in 32 consecutive patients. Image quality was classified as good, satisfactory or poor. Patient- and imaging-related parameters were analyzed to identify predictors for poor image quality. Shifts in relation to the treatment planning computed tomography (CT) were recorded before/after irradiation in the superior-inferior (SI), anterior-posterior (AP) and right-left (RL) directions to determine inter-/intrafraction prostate motion.
The thickness of tissue anterior to the bladder and bladder volume during the ultrasound localization as well as an inferior prostate position relative to public symphysis (determined in treatment planning CT) were found to be independent predictors of a poor image quality. Interfraction shifts (mean+/-standard deviation: -0.2+/-4.8 [SI], 2.4+/-6.6 [AP] and 1.9+/-4.6 [RL]) varied much stronger than intrafraction shifts (0.0+/-2.0 [SI], 0.6+/-2.2 [AP] and 0.2+/-1.9 [RL]). A larger pressure of the ultrasound probe (determined as a larger reduction of the distance abdominal skin to prostate between the planning CT and the ultrasound) was applied in case of poor image quality, associated with larger systematic posterior prostate displacements.
Intrafraction prostate shifts are considerably smaller in comparison to interfraction shifts. Bladder filling and a small pressure on the ultrasound probe are crucial to achieve an adequate image quality without systematic prostate displacements.
Strahlentherapie und Onkologie 01/2009; 184(12):679-85. · 3.56 Impact Factor
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ABSTRACT: The aim of the study was to compare intra-operative and postplanning at different intervals with special focus on sources placed close to the rectal wall.
In 61 consecutive patients, CT scans were performed on day 1 and day 30 after an I-125 implant with stranded seeds. The number of sources < or =7 mm to the rectal wall was determined, and displacements were analyzed. The angulation of strands relative to rectal wall was compared between intra-operative transrectal ultrasound (TRUS) and both postplanning CT scans.
Sources close to the rectum on day 1 (n=204) have been the most apical in a strand in 98.5% (n=201). By comparing day 1 and day 30 data, significant inferior source displacements (mean 3.6 mm; p=0.02) relative to pelvic bones and a decreasing distance to the rectal wall (mean 1.2 mm; p<0.01)--consequentially increasing rectal dose--were determined only for sources initially > or =3 mm to the rectum. In contrast to an almost parallel arrangement of the needle track and the rectal wall in TRUS, strands and rectal wall converged towards the apex in the postplanning CT scans (mean >30 degrees).
Posterior preplanning margins around the prostate should be particularly limited at the level of the prostate apex.
Radiotherapy and Oncology 12/2008; 91(2):207-12. · 5.58 Impact Factor
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ABSTRACT: PurposeTo evaluate inter- and intrafraction organ motion with an ultrasound-based prostate localization system (BAT®) for patients
treated with intensity-modulated radiotherapy for prostate cancer.
Patients and MethodsAfter set-up to external skin marks, 260/219 ultrasound-based alignments were performed before/after irradiation in 32 consecutive
patients. Image quality was classified as good, satisfactory or poor. Patient- and imaging-related parameters were analyzed
to identify predictors for poor image quality. Shifts in relation to the treatment planning computed tomography (CT) were
recorded before/after irradiation in the superior-inferior (SI), anterior-posterior (AP) and right-left (RL) directions to
determine inter-/intrafraction prostate motion.
ResultsThe thickness of tissue anterior to the bladder and bladder volume during the ultrasound localization as well as an inferior
prostate position relative to public symphysis (determined in treatment planning CT) were found to be independent predictors
of a poor image quality. Interfraction shifts (mean ± standard deviation: −0.2 ± 4.8 [SI], 2.4 ± 6.6 [AP] and 1.9 ± 4.6 [RL])
varied much stronger than intrafraction shifts (0.0 ± 2.0 [SI], 0.6 ± 2.2 [AP] and 0.2 ± 1.9 [RL]). A larger pressure of the
ultrasound probe (determined as a larger reduction of the distance abdominal skin to prostate between the planning CT and
the ultrasound) was applied in case of poor image quality, associated with larger systematic posterior prostate displacements.
ConclusionIntrafraction prostate shifts are considerably smaller in comparison to interfraction shifts. Bladder filling and a small
pressure on the ultrasound probe are crucial to achieve an adequate image quality without systematic prostate displacements.
ZielBestimmung der inter- und intrafraktionellen Organbewegung mit einem ultraschallbasierten Lokalisationssystem der Prostata
(BAT®) bei mit intensitätsmodulierter Radiotherapie behandelten Patienten mit Prostatakarzinom.
Patienten und MethodikNach Lagerung entsprechend der externen Hautmarkierung wurden 260/219 ultraschallbasierte Positionierungen vor/nach Bestrahlung
bei 32 konsekutiven Patienten durchgeführt. Die Bildqualität wurde als gut, zufriedenstellend oder schlecht bewertet. Patienten-
und bildgebungsabhängige Parameter wurden zur Identifikation von Prädiktoren für schlechte Bildqualität analysiert. Verschiebungen
im Verhältnis zur Bestrahlungsplanungs-Computertomographie(-CT) wurden in der superior-inferioren (SI), anterior-posterioren
(AP) und Rechts-links-(RL-)Achse vor/nach Bestrahlung dokumentiert, um inter-/intrafraktionelle Prostatabewegungen zu bestimmen.
ErgebnisseSowohl die Dicke des Gewebes ventral der Blase und das Blasenvolumen während der Ultraschalllokalisation als auch eine inferiore
Prostatalage relativ zur Symphyse (bestimmt im Bestrahlungsplanungs-CT) fanden sich als unabhängige Prädiktoren einer schlechten
Bildqualität. Interfraktionelle Verschiebungen (Mittelwert ± Standardabweichung: −0,2 ± 4,8 [SI], 2,4 ± 6,6 [AP] und 1,9 ±
4,6 [RL]) variierten viel stärker als intrafraktionelle Verschiebungen (0,0 ± 2,0 [SI], 0,6 ± 2,2 [AP] und 0,2 ± 1,9 [RL]).
Ein stärkerer Druck auf die Ultraschallsonde (als eine größere Reduktion des Abstandes Bauchhaut zu Prostata zwischen dem
Planungs-CT und dem Ultraschall bestimmt) wurde vor allem bei schlechter Bildqualität ausgeübt, verbunden mit größeren systematischen
dorsalen Prostataverschiebungen.
SchlussfolgerungIntrafraktionelle Prostataverschiebungen sind deutlich geringer als interfraktionelle Verschiebungen. Blasenfüllung und ein
geringer Druck auf die Ultraschallsonde sind zum Erzielen einer adäquaten Bildqualität ohne systematische Prostataverschiebungen
entscheidend.
Strahlentherapie und Onkologie 11/2008; 184(12):679-685. · 3.56 Impact Factor
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ABSTRACT: To evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels.
In 61 patients, postimplant CT scans were performed 1 day and 1 month after an implant with stranded seeds. Seed and prostate surface displacements were determined relative to pelvic bones. Four groups of seed locations were selected: seeds at the base (n = 305; B), at the apex (n = 305; A), close to the urethra (n = 306; U), and close to the rectal wall (n = 204; R). The length of two strands (always containing four seeds) per patient was measured in all CT scans and compared.
The largest inferior seed displacements were found at the base: mean 5.3 mm (B), 2.2 mm (A), 2.7 mm (U), 3.3 mm (R; p < 0.001). Posterior displacements predominated both at the base and the central region: mean 2.2 mm (B), 2.0 mm (U), 0.8 mm (A), -0.6 mm (R; p < 0.001). With a decreasing edema between day 1 and 30 (mean prostate volume of 51 cm(3) vs. 41 cm(3); p < 0.001), a mean caudal prostate base displacement of 3.9 mm was found, whereas the mean inward displacement ranged from 1.2 to 1.6 mm at the remaining borders (lateral, anterior, posterior, apical). The analysis of the strand lengths revealed an implant compression between day 1 and 30 (mean 1.7 mm; p < 0.001).
The largest prostate tissue and seed displacements were observed at the prostate base, associated with an implant compression. Predominantly inferior and posterior displacements implicate consequential smaller preplanning margins at the apex and the posterior prostate.
Strahlentherapie und Onkologie 10/2008; 184(10):520-5. · 3.56 Impact Factor
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ABSTRACT: There is a lack of prospective studies focusing on the sexual quality of life of prostate cancer patients after conformal radiotherapy (RT).
To evaluate the incidence, progression, and predictive factors for erectile dysfunction (ED).
Patients who responded to the sexual domain of the Expanded Prostate Cancer Index Composite (EPIC) questionnaire before and more than 1 yr after RT and never received an antiandrogen treatment were included (n=123).
RT dose was 70.2-72 Gy. Eleven patients used a phosphodiesterase-5 (PDE-5) inhibitor.
Patients responded to the EPIC questionnaire before (time A), at the last day (B), a median time of 2 mo after (C), and 16 mo after (D) RT. In a multivariate analysis, risk factors (patient age, prostate volume, planning target volume, use of PDE-5 inhibitor, comorbidities) were tested for their independent effects on ED before and after RT.
Sexual function and bother scores had already decreased by the end of RT (median function and bother scores at times A/B/C/D: 41/30/32/24 and 75/50/50/50). Initial function scores correlated well with late function scores (r=0.7; p<0.001). The ability to have an erection was reported by 81%/72%/74%/60% (preserved erectile ability in 70% at time D), erections firm enough for sexual intercourse by 44%/33%/35%/27% (preserved erections sufficient for intercourse in 53% at time D) of patients. A higher patient age and diabetes were predictive of both a pre-existing ED and a post-RT acquired ED. Nightly erections before treatment proved prognostically favourable (at least weekly vs. < weekly-hazard ratio of 5.9 for preserved erections sufficient for intercourse; p=0.01). Higher rates of ED can be expected with longer follow-up.
The incidence of ED progressively increases after RT. Patient age and diabetes are risk factors for both pre-treatment and RT-associated ED. Nightly erections before RT proved prognostically favourable.
European urology 04/2008; 55(1):227-34. · 7.67 Impact Factor
