Impact of age and comorbidities on health-related quality of life for patients with prostate cancer: evaluation before a curative treatment.

BACKGROUND: 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. METHODS: 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 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). RESULTS: Urinary incontinence was observed increasingly with higher age (mean function scores of 92/88/85/87 for patients 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 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. CONCLUSION: 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.

Neoadjuvant hormonal therapy and external-beam radiotherapy versus external-beam irradiation alone for prostate cancer. A quality-of-life analysis.

PURPOSE: To evaluate the impact of neoadjuvant hormonal therapy (NHT) on quality of life after external-beam radiotherapy (EBRT) for prostate cancer. PATIENTS AND METHODS: A group of 170 patients (85 with and 85 without NHT) has been surveyed prospectively before EBRT (70.2-72 Gy), at the last day of EBRT, a median time of 2 months and 15 months after EBRT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs with and without NHT (median treatment time of 3.5 months before EBRT) were matched according to the respective planning target volume and prostate volume. RESULTS: Before EBRT, significantly lower urinary function/bother, sexual function and hormonal function/bother scores were found for patients with NHT. More than 1 year after EBRT, only sexual function scores remained lower. In a multivariate analysis, NHT and adjuvant hormonal therapy (HT) versus NHT only (hazard ratio 14; 95% confidence interval 2.7-183; p = 0.02) and luteinizing hormone-releasing hormone (LHRH) agonists versus antiandrogens (hazard ratio 3.6; 95% confidence interval 1.1-12; p = 0.04) proved to be independent risk factors for long-term erectile dysfunction (no or very poor ability to have an erection). CONCLUSION: With the exception of sexual function (additional adjuvant HT and application of LHRH analog independently adverse), short-term NHT was not found to decrease quality of life after EBRT for prostate cancer.

Rectal dosimetry following prostate brachytherapy with stranded seeds--comparison of transrectal ultrasound intra-operative planning (day 0) and computed tomography-postplanning (day 1 vs. day 30) with special focus on sources placed close to the rectal wall.

BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: Posterior preplanning margins around the prostate should be particularly limited at the level of the prostate apex.

Erectile dysfunction after external beam radiotherapy for prostate cancer.

BACKGROUND: There is a lack of prospective studies focusing on the sexual quality of life of prostate cancer patients after conformal radiotherapy (RT). OBJECTIVE: To evaluate the incidence, progression, and predictive factors for erectile dysfunction (ED). DESIGN, SETTING AND PARTICIPANTS: 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). INTERVENTION: RT dose was 70.2-72 Gy. Eleven patients used a phosphodiesterase-5 (PDE-5) inhibitor. MEASUREMENTS: 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. RESULTS AND LIMITATIONS: 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. CONCLUSIONS: 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.

Health-related quality of life after permanent I-125 brachytherapy and conformal external beam radiotherapy for prostate cancer--a matched-pair comparison.

BACKGROUND AND PURPOSE: The aim of the study was to compare quality of life after permanent I-125 brachytherapy (BT) and external beam radiotherapy (EBRT) for prostate cancer. MATERIALS AND METHODS: A group of 104 patients (52 in each group) have been surveyed prospectively before EBRT/BT (time A), at the last day of EBRT (70.2-72.0 Gy) or one month after BT (time B), and a median time of 16 months after EBRT/BT (time C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs were matched according to the following criteria: age +/-5 years, prostate volume +/-10 cc, use of antiandrogens, and erectile function. RESULTS: Urinary function/bother scores decreased significantly more after BT both at time B and time C. Bowel function/bother scores tended to be higher after BT, with a lower percentage of patients with painful bowel movements (BT: 12%/27%/15%; EBRT: 19%/52%/35% at time A/B/C; p<0.05 for differences at times B/C) and rectal bleeding (BT: 12%/12%/12%; EBRT: 8%/14%/17%). No difference concerning erectile dysfunction was found (67% vs. 61% with preserved erections firm enough for intercourse after BT vs. EBRT at time C). CONCLUSIONS: BT was associated with higher urinary, but lower rectal toxicity. The risk of treatment-associated erectile dysfunction did not differ between these methods.

Image-guided radiotherapy for prostate cancer. Implementation of ultrasound-based prostate localization for the analysis of inter- and intrafraction organ motion.

PURPOSE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Seed displacements after permanent brachytherapy for prostate cancer in dependence on the prostate level.

PURPOSE: To evaluate seed displacements after permanent prostate brachytherapy considering different prostate levels. PATIENTS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Sequencing chemotherapy and radiotherapy in locoregional advanced breast cancer patients after mastectomy - a retrospective analysis.

BACKGROUND: Combined chemo- and radiotherapy are established in breast cancer treatment. Chemotherapy is recommended prior to radiotherapy but decisive data on the optimal sequence are rare. This retrospective analysis aimed to assess the role of sequencing in patients after mastectomy because of advanced locoregional disease. METHODS: A total of 212 eligible patients had a stage III breast cancer and had adjuvant chemotherapy and radiotherapy after mastectomy and axillary dissection between 1996 and 2004. According to concerted multi-modality treatment strategies 86 patients were treated sequentially (chemotherapy followed by radiotherapy) (SEQgroup), 70 patients had a sandwich treatment (SW-group) and 56 patients had simultaneous chemoradiation (SIM-group) during that time period. Radiotherapy comprised the thoracic wall and/or regional lymph nodes. The total dose was 45-50.4 Gray. As simultaneous chemoradiation CMF was given in 95.4% of patients while in sequential or sandwich application in 86% and 87.1% of patients an anthracycline-based chemotherapy was given. RESULTS: Concerning the parameters nodal involvement, lymphovascular invasion, extracapsular spread and extension of the irradiated region the three treatment groups were significantly imbalanced. The other parameters, e.g. age, pathological tumor stage, grading and receptor status were homogeneously distributed. Looking on those two groups with an equally effective chemotherapy (EC, FEC), the SEQ- and SW-group, the sole imbalance was the extension of LVI (57.1 vs. 25.6%, p < 0.0001).5-year overall- and disease free survival were 53.2%/56%, 38.1%/32% and 64.2%/50%, for the sequential, sandwich and simultaneous regime, respectively, which differed significantly in the univariate analysis (p = 0.04 and p = 0.03, log-rank test). Also the 5-year locoregional or distant recurrence free survival showed no significant differences according to the sequence of chemo- and radiotherapy. In the multivariate analyses the sequence had no independent impact on overall survival (p = 0.2) or disease free survival (p = 0.4). The toxicity, whether acute nor late, showed no significant differences in the three groups. The grade III/IV acute side effects were 3.6%, 0% and 3.5% for the SIM-, SW- and SEQ-group. By tendency the SIM regime had more late side effects. CONCLUSION: No clear advantage can be stated for any radio- and chemotherapy sequence in breast cancer therapy so far. This could be confirmed in our retrospective analysis in high-risk patients after mastectomy. The sequential approach is recommended according to current guidelines considering a lower toxicity.

Health-related quality of life after adjuvant and salvage postoperative radiotherapy for prostate cancer - a prospective analysis.

BACKGROUND AND PURPOSE: The aim of the study was to analyze health-related quality of life changes after postoperative radiotherapy (RT) for prostate cancer. MATERIALS AND METHODS: A group of 101 patients has been surveyed prospectively before (time A), at the last day (B), two months after (C) and >1 year after (D) RT using a validated questionnaire (Expanded Prostate Cancer Index Composite) with urinary, bowel, sexual and hormonal domains. The prostatic fossa was treated with a four-field box technique up to a total dose of 66.6 Gy. RESULTS: While median urinary scores reached baseline levels already two months after radiotherapy (function/bother scores at time A-B-C-D: 94/89-89/75-94/89-94/89; A vs. B: p<0.01), bowel problems needed a longer time to recover (function/bother scores at time A-B-C-D: 96/100-85/89-88/93-96/100; A vs. B/C: p<0.01). Greater bladder volumes inside specific isodoses were associated with temporary significantly lower urinary bother scores and chronically lower urinary incontinence scores. Only 7% of patients reported of erections firm enough for intercourse before RT, so that RT-associated sexual toxicity played a minor role. CONCLUSIONS: In contrast to bowel symptoms, acute urinary problems recover very soon after the end of postoperative RT. After >1 year, only minor HRQOL changes occurred in comparison to baseline scores.

Toxicity profile with a large prostate volume after external beam radiotherapy for localized prostate cancer.

PURPOSE: To assess the impact of prostate volume on health-related quality of life (HRQOL) before and at different intervals after radiotherapy for prostate cancer. METHODS AND MATERIALS: A group of 204 patients was surveyed prospectively before (Time A), at the last day (Time B), 2 months after (Time C), and 16 months (median) after (Time D) radiotherapy, with a validated questionnaire (Expanded Prostate Cancer Index Composite). The group was divided into subgroups with a small (11-43 cm(3)) and a large (44-151 cm(3)) prostate volume. RESULTS: Patients with large prostates presented with lower urinary bother scores (median 79 vs. 89; p = 0.01) before treatment. Urinary function/bother scores for patients with large prostates decreased significantly compared to patients with small prostates due to irritative/obstructive symptoms only at Time B (pain with urination more than once daily in 48% vs. 18%; p < 0.01). Health-related quality of life did not differ significantly between both patient groups at Times C and D. In contrast to a large prostate, a small initial bladder volume (with associated higher dose-volume load) was predictive for lower urinary bother scores both in the acute and late phase; at Time B it predisposed for pollakiuria but not for pain. Patients with neoadjuvant hormonal therapy reached significantly lower HRQOL scores in several domains (affecting only incontinence in the urinary domain), despite a smaller prostate volume (34 cm(3) vs. 47 cm(3); p < 0.01). CONCLUSIONS: Patients with a large prostate volume have a great risk of irritative/obstructive symptoms (particularly dysuria) in the acute radiotherapy phase. These symptoms recover rapidly and do not influence long-term HRQOL.

Postoperative radiotherapy of glioblastoma multiforme: analysis and critical assessment of different treatment strategies and predictive factors.

BACKGROUND AND PURPOSE: Different factors influence glioblastoma patients' prognosis. The aim of this retrospective, explorative analysis was to define the role of recent treatment strategies and to examine the value of different prognostic factors. PATIENTS AND METHODS: A total of 110 patients was analyzed. Complete resection, partial resection, and biopsy was accomplished in 69, 22, and 19 patients, respectively. 56 patients received conventionally fractionated radiotherapy with a median total dose of 60 Gy, 2 Gy daily. 54 patients received hyperfractionated accelerated radiotherapy with a median total dose of 54 Gy, 2 x 1.8 Gy daily. 20 patients had concomitant temozolomide (50-75 mg/m2/d), and 20 patients concomitant topotecan (0.5 mg/m2 as continuous venous infusion over 21 days). 37 patients received temozolomide as salvage therapy. RESULTS: Median overall (OS) and disease-free survival (DFS) were 8.7 and 4.8 months. After complete resection, partial resection, and biopsy, OS was 9.5, 8.5, and 5.5 months, respectively. OS was 8.5, 13.8, and 8.2 months for radiotherapy alone, concomitant temozolomide, and concomitant topotecan, respectively. Hazard ratio was 0.29 (OS; p = 0.002) and 0.32 (DFS; p = 0.003) for concomitant temozolomide compared to radiotherapy alone. Topotecan led to an increased toxicity. With 9.7 months for conventionally fractionated radiotherapy and 8.1 months for hyperfractionated radiotherapy, OS differed significantly (p = 0.003, log-rank test). OS in patients with RPA (recursive partitioning analysis) score III, IV, V, and VI was 14.1, 10, 9.5, and 5.8 months (p = 0.003, log-rank test). In the univariate (p = 0.0001, log-rank test) and multivariate analysis (p = 0.002, Cox regression), salvage temozolomide led to a statistically significant survival benefit (10.6 vs. 7.7 months). CONCLUSION: Concomitant topotecan or the use of hyperfractionated radiotherapy did not show to be superior in outcome in this retrospective analysis. Topotecan led to an increased toxicity. An attempt at complete resection is justified. Temozolomide should be integrated in therapy initially. As salvage therapy, temozolomide is also effective.

Evaluation of source displacement and dose--volume changes after permanent prostate brachytherapy with stranded seeds.

BACKGROUND AND PURPOSE: The aim of the study was to analyze source displacements and dose-volume changes in the first month after a permanent implant. MATERIALS AND METHODS: In 51 consecutive patients, CT scans were performed at the postoperative day (day 1) and one month (day 30) after an (125)I implant with stranded seeds. Seed positions were determined relative to pelvic bones for five seeds at the base and five seeds at the apex for each patient (n=510) and compared. To verify these results, treatment margins (TM=distance of prescription isodose to prostate) and displacements of the prostate surface (anterior/posterior/right/left/superior/inferior) relative to pelvic bones were measured. RESULTS: Seed positions have moved significantly between day 1 and 30 in the posterior (mean 1.0mm; p<0.001) and inferior (mean 3.8mm; p<0.001) directions. TM increased particularly at the posterior (mean 2.2mm; p<0.001) and apical (median 3.0mm; p<0.001) prostate contour with decreasing oedema. With a stable apex position and a mean inward posterior surface displacement of 1.1mm (p<0.001) relative to pelvic bones, seed displacements could be well correlated with prescription isodose displacements (Pearson correlation coefficients >or=0.81; p<0.001). CONCLUSIONS: Both changes of prostate volume and seed displacements need to be considered to explain dosimetric changes after permanent prostate brachytherapy.

Sequential (gemcitabine/vinorelbine) and concurrent (gemcitabine) radiochemotherapy with FDG-PET-based target volume definition in locally advanced non-small cell lung cancer: first results of a phase I/II study.

BACKGROUND: The aim of the study was to determine the maximal tolerated dose (MTD) of gemcitabine every two weeks concurrent to radiotherapy, administered during an aggressive program of sequential and simultaneous radiochemotherapy for locally advanced, unresectable non-small cell lung cancer (NSCLC) and to evaluate the efficacy of this regime in a phase II study. METHODS: 33 patients with histologically confirmed NSCLC were enrolled in a combined radiochemotherapy protocol. 29 patients were assessable for evaluation of toxicity and tumor response. Treatment included two cycles of induction chemotherapy with gemcitabine (1200 mg/m2) and vinorelbine (30 mg/m2) at day 1, 8 and 22, 29 followed by concurrent radiotherapy (2.0 Gy/d; total dose 66.0 Gy) and chemotherapy with gemcitabine every two weeks at day 43, 57 and 71. Radiotherapy planning included [18F] fluorodeoxyglucose positron emission tomography (FDG PET) based target volume definition. 10 patients were included in the phase I study with an initial gemcitabine dose of 300 mg/m2. The dose of gemcitabine was increased in steps of 100 mg/m2 until the MTD was realized. RESULTS: MTD was defined for the patient group receiving gemcitabine 500 mg/m2 due to grade 2 (next to grade 3) esophagitis in all patients resulting in a mean body weight loss of 5 kg (SD = 1.4 kg), representing 8% of the initial weight. These patients showed persisting dysphagia 3 to 4 weeks after completing radiotherapy. In accordance with expected complications as esophagitis, dysphagia and odynophagia, we defined the MTD at this dose level, although no dose limiting toxicity (DLT) grade 3 was reached. In the phase I/II median follow-up was 15.7 months (4.1 to 42.6 months). The overall response rate after completion of therapy was 64%. The median overall survival was 19.9 (95% CI: [10.1; 29.7]) months for all eligible patients. The median disease-free survival for all patients was 8.7 (95% CI: [2.7; 14.6]) months. CONCLUSION: After induction chemotherapy, the maximum tolerated dose and frequency of gemcitabine was defined at 500 mg/m2 every two weeks in three cycles during a maximum of 7 weeks of thoracic radiotherapy for the phase II study. This regimen represents an effective and tolerable therapy in the treatment of NSCLC.

pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

BACKGROUND: The present study was conducted to analyze the value of ([18F] fluoromisonidazole (FMISO) and [18F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO2 histography) was used for comparing the different non invasive measurements. METHODS: Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO2 was measured using a pO2-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO2 readings, with values < or = 2.5, < or = 5.0 and < or = 10.0 mmHg, as well as mean and median pO2 were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISOT/M) and tumor to blood ratios (FMISOT/B) were calculated. FDG PET of the lymph node metastases was performed 71 +/- 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue--defining velocity (v) and color area--defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = vmean x Amean. RESULTS: In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO2 polarography (pO2 readings with values < or = 2.5, < or = 5.0 and < or = 10.0 mmHg, as well as median pO2), CPD and FMISOT/M. Only a slight correlation between TP and the fraction of pO2 values < or = 10.0 mmHg, median and mean pO2 could be detected. After exclusion of four outliers the absolute values of the Pearson correlation coefficients increased clearly. There was no relevant association between mean or maximum FDG uptake and the different polarographic- as well as the CDS parameters. CONCLUSION: CDS and FMISO PET represent different approaches for estimation of therapy relevant tumor hypoxia. Each of these approaches is methodologically limited, making evaluation of clinical potential in prospective studies necessary.

Bladder extension variability during pelvic external beam radiotherapy with a full or empty bladder.

BACKGROUND AND PURPOSE: Varying bladder fillings during radiotherapy lead to a changing dose-volume load to the bladder and adjacent structures. The aim of the study was to compare the extent of bladder wall movements during parallel series with full bladder (FB) and empty bladder (EB). MATERIALS AND METHODS: Three hundred and forty serial computed tomography (CT) scans were performed in 50 patients scheduled for primary and postoperative radiotherapy for prostate cancer. Each patient underwent two CT scans (with FB and EB) before and 2-3 times during radiotherapy. Displacements of the bladder wall were compared and correlated with changing bladder fillings. RESULTS: The variability of FB was larger compared to EB volume (standard deviation of 124 cc and 56 cc; p<0.01), but significant bladder wall displacement variabilities were only found at the anterior and superior borders. Within a bladder volume range between -100 and +200 ml relative to the FB planning scan, the mean bladder wall displacement remained < 5 mm at the inferior, lateral, and posterior borders - as opposed to 15 and 21 mm at the anterior and superior borders. CONCLUSIONS: Treating the pelvis with EB compared to FB, bladder wall displacement can be only reduced at the superior and anterior borders. FB wall displacements are comparable with EB displacements at all other borders.

Active breathing control (ABC): determination and reduction of breathing-induced organ motion in the chest.

PURPOSE: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. METHODS AND MATERIALS: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. RESULTS: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. CONCLUSIONS: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

Postoperative radiotherapy for prostate cancer : evaluation of target motion and treatment techniques (intensity-modulated versus conformal radiotherapy).

PURPOSE: To determine the extent of target motion in postprostatectomy radiotherapy (RT) and the value of intensity-modulated radiotherapy (IMRT) compared to three-dimensional conformal radiotherapy (3D-CRT). PATIENTS AND METHODS: 20 patients underwent CT scans in supine position with both a full bladder (FB) and an empty bladder (EB) before RT and at three dates during the RT series. Displacements of the CTV (clinical target volume) center of mass and the posterior border were determined. 3D-CRT and IMRT treatment plans were compared regarding homogeneity, conformity, and dose to organs at risk. RESULTS: In the superior-inferior direction, larger displacements were found for EB compared to FB scans; anterior-posterior and right-left displacements were similar. With an initial rectum volume of < 115 cm(3), 90% of displacements at the posterior border were within a margin of 6 mm. The non-target volume irradiated in the high-dose area doubled in 3D-CRT versus IMRT plans (80 cm(3) vs. 38 cm(3) encompassed by the 95% isodose). Bladder dose was significantly lower with IMRT, but no advantage was found for the integral rectal dose. An adequate bladder filling was paramount to reduce the dose to the bladder. CONCLUSION: Postprostatectomy RT can be recommended with FB due to an improved CTV position consistency and a lower dose to the bladder. With improved non-target tissue and bladder volume sparing, IMRT is an option for dose escalation. However, this analysis did not find an advantage concerning the integral rectal dose with IMRT versus 3D-CRT.

Influence of the initial rectal distension on posterior margins in primary and postoperative radiotherapy for prostate cancer.

BACKGROUND AND PURPOSE: The aim of the study was to define the effect of different rectum fillings in the planning CT study on the posterior clinical target volume (CTV) displacements (PD) in primary and postoperative radiotherapy (RT) for prostate cancer. MATERIALS AND METHODS: Fifty patients underwent CT scans in supine position with a full bladder and an empty bladder before RT and at several points in time during the treatment. PD were determined depending on the initial rectum volume (RV), average cross-sectional rectal area (CSA), and the rectal diameter at the level of the bladder neck (RD). RESULTS: Posterior CTV motion was not found to be minimal with a particularly small initial rectum filling. Steeply increasing PD resulted for patients with RV>120cm(3), CSA>12cm(2), and RD>4.5cm. While below these critical values a posterior margin of 6mm/9mm allowed to cover 80%/90% of displacements, 18mm/24mm were needed for patients with larger rectum fillings. No correlation of increasing rectum distension with increasing PD was found at the apex level. PD could not be reduced by voiding the bladder. CONCLUSIONS: Defining the posterior margin in prostate RT, the initial rectum distension and the superior-inferior CTV level has to be considered. Patients with large initial rectum fillings have preferentially the need for repeated planning CT scans or image-guided RT.