Standard spin-echo images of the posterior cranial fossa are usually impaired by pulsation artifa... more Standard spin-echo images of the posterior cranial fossa are usually impaired by pulsation artifacts. We evaluated a heavily Tt weighted MPRAGE sequence (TR/TE/ar/TI = 10/4/10-15"/200-350) for detection of intracerebral lesions in the posterior fossa in 11 patients. Overall quality of the MPRAGE images was superior due to the lack of pulsation artifacts, high S/N and excellent gray-white matter contrast. Lesion detection was better in one pa-
Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized ... more Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized in mitochondria. Because expression of MnSOD plays a major role in maintaining cellular redox status and reactive oxygen species are known to play a role in signal transduction and carcinogenesis, we investigated the role of MnSOD in the development of cancer using a two-stage [7,12-dimethylbenz(a)-anthracene plus 12-Otetradecanoylphorbol-13-acetate (TPA)] skin carcinogenesis model. Female transgenic mice expressing the human MnSOD gene in the skin and their nontransgenic counterparts were used in this study. Pathological examination demonstrated significant reduction of papilloma formation in transgenic mice. Quantitative analysis of 4-hydroxy-2-nonenal-modified proteins showed greater accumulation of oxidative damage products in nontransgenic compared with transgenic mice, and this oxidative damage was demonstrated to be present in both mitochondria and nucleus. TPA increased activator protein-1 (AP-1) binding activity within6hi nnontransgenic mice, but increased AP-1 binding activity was delayed in the transgenic mice. Electrophoretic mobility shift assay, transcription of the target genes, and Western analysis studies indicated that the increased AP-1 binding activity was attributable to induction of the Jun but not the Fos protein families. Overexpression of MnSOD selectively inhibited the TPA-induced activation of protein kinase C⑀ and prevented subsequent activation of c-Jun NH 2 -terminal kinase in response to TPA. Overall, these results indicate that MnSOD regulates both cellular redox status and selectively modulates PKC⑀ signaling, thereby delaying AP-1 activation and inhibiting tumor promotion, resulting in reduction of tumors in MnSOD transgenic mice.
Purpose/Objective(s): To determine the efficacy and safety of preoperative capecitabine (Xeloda) ... more Purpose/Objective(s): To determine the efficacy and safety of preoperative capecitabine (Xeloda) and radiation therapy (RT) for patients with locally advanced rectal cancer. Materials/Methods: Patients with adenocarcinoma of the rectum Stage $T3 or $N1, aged between 18-80, ECOG #2, adequate bone marrow reserve, and normal renal and hepatic functions were included. Pretreatment staging was performed with magnetic resonance or endorectal ultrasound. Patients were treated with oral capecitabine 825 mg/m 2 /12 h days 1 to 42 continuously, and 50 Gy RT in 2 Gy fractions. Three-dimensional planning and conformal techniques were used in all patients. Results: Thirty patients were enrolled (M/F 22/8), median age 63.3 years (33-80) and ECOG = 0: 85.1%. Tumor was located within the 5 distal cm in 21 patients (70%) and between 6 and 15 cm from the anal verge in 9 patients (30%). Fifteen patients (50%) were T3N0M0, 12 (40%) T3N1-2M0 and 3 (10%) T2N1-2. Twenty-seven patients (90%) completed combined modality therapy, 3 patients completed RT but not chemotherapy. The most frequent treatment-related Grade I/II toxicities were diarrhea (40%), frequency/dysuria (16%), proctitis (26%), hand-foot syndrome (6%), and leucopenia (4.5%). Grade III toxicities were limited to diarrhea (2 patients) and hand-foot syndrome (1 patient). An anterior resection was performed on 17 patients (56%), an abdominal-perineal resection in 10 (33%), and a transanal resection in 3 patients (10%). There were no major postoperative complications. Nine patients (30%) had pathologic complete response, 14 (46%) had partial response and 7 (23%) had stable disease. Conclusions: The combination of preoperative capecitabine and RT in patients with locally advanced rectal cancer has significant antitumor activity, with a high proportion of complete pathological responses and tumor downstaging. The sphincter preservation rate was high, and the toxicity profile was acceptable in these patients.
Cancer cells generally generate higher amounts of reactive oxygen species than normal cells. On t... more Cancer cells generally generate higher amounts of reactive oxygen species than normal cells. On the basis of this difference, prodrugs have been developed (e.g., hydroxyferrocifen), which remain inactive in normal cells, but become activated in cancer cells. In this work we describe novel aminoferrocene-based prodrugs, which, in contrast to hydroxyferrocifen, after activation form not only quinone methides (QMs), but also catalysts (iron or ferrocenium ions). The released products act in a concerted fashion. In particular, QMs alkylate glutathione, thereby inhibiting the antioxidative system of the cell, whereas the iron species induce catalytic generation of hydroxyl radicals. Since the catalysts are formed as products of the activation reaction, it proceeds autocatalytically. The most potent prodrug described here is toxic toward cancer cells (human promyelocytic leukemia (HL-60), IC(50) = 9 μM, and human glioblastoma-astrocytoma (U373), IC(50) = 25 μM), but not toxic (up to 100 μM) toward representative nonmalignant cells (fibroblasts).
ABSTRACT The irradiation with intensity-modulated fields is possible with static as well as dynam... more ABSTRACT The irradiation with intensity-modulated fields is possible with static as well as dynamic methods. In our university hospital, the intensity-modulated radiotherapy (IMRT) with compensators was prepared and used for the first time for patient irradiation in July 2001. The compensators consist of a mixture of tin granulate and wax, which is filled in a milled negative mould. The treatment planning is performed with Helax-TMS (MDS Nordion). An additional software is used for editing the modulation matrix („Modifix“). Before irradiation of the first patient, extensive measurements have been carried out in terms of quality assurance of treatment planning and production of compensators. The results of the verification measurements have shown that IMRT with compensators possesses high spatial and dosimetric exactness. The calculated dose distributions are applied correctly. The accuracy of the calculated monitor units is normally better than 3%; in small volumes, further dosimetric inaccuracies between calculated and measured dose distributions are mostly less than 3%. Therefore, the compensators contribute to the achievement of high-level IMRT even when apparatuses without MLC are used. This paper describes the use of the IMRT with compensators, presents the limits of this technology, and discusses the first practical experiences.
Background: We investigated the influence of age on short-term complications in women undergoing ... more Background: We investigated the influence of age on short-term complications in women undergoing intraoperative radiotherapy (IORT) for early breast cancer. Patients and Methods: We retrospectively analyzed data of 188 women who underwent IORT during breast-conserving surgery (BCS). The study group consisted of 54 patients aged 70 years or older. One hundred and thirty four patients aged less than 70 years served as the control group. Results: In both collectives, the acute toxicity was low. There were no significant differences regarding type and duration of surgery, and type of radiation treatment, comparing both collectives. The most frequent postoperative side-effects were haematoma/suggillation (13/54, 24.1% vs. 28/134, 20.9%; p=0.633). There was a significantly higher incidence of postoperative axillary haematoma in the study group (10/54, 18.5% vs. 10/134, 7.5%; p=0.026). Conclusion: Acute toxicity after BCS with IORT in women aged 70 years and older does not seem to be higher compared to younger patients.
Background The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intra... more Background The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the fi rst analysis of overall survival.
Radiation therapy is a treatment option for curative management of localized and locally advanced... more Radiation therapy is a treatment option for curative management of localized and locally advanced prostate cancer. Depending on tumor stage and constellation of risk factors (PSA level, findings on digital rectal examination, and Gleason score), various forms of radiotherapy are applied. In addition to the sole use of external beam radiotherapy, brachytherapy with radioactive seeds is also employed as stand-alone treatment in patients with low risk factors and in early clinical stages. Increasing risk of recurrence requires more intensive therapies which can be accomplished by adding hormone deprivation therapy and/or intensifying radiation therapy (dose escalation). Combined approaches using brachytherapy and percutaneous radiotherapy are also initiated in these cases. If hormone ablation therapy is administered, this should occur over a course of 3-36 months as neoadjuvant, concommitant and/or adjuvant treatment, depending on the risk of recurrence.
Purpose/Objectives: To determine the degree to which dosimetric quality of multi-catheter partial... more Purpose/Objectives: To determine the degree to which dosimetric quality of multi-catheter partial breast irradiation plans are impacted by individual practitioner and overall single institution experience. Also, to assess whether multi-catheter implantation, in the absence of CT-guidance, can achieve high quality dosimetry. women with Stage 0, I, II invasive breast cancers were treated with lumpectomy followed by accelerated partial breast irradiation (APBI) utilizing multi-catheter interstitial high dose rate brachytherapy (HDR) at the University of Washington Medical Center. Eligibility criteria included node negative breast cancer, pathologically negative margins, absence of extensive intraductal component, and age $45 years. Radiation dose was 34 Gy delivered in 10 twice-daily fractions over five-seven days, 6-8 weeks following surgery. GTV was defined as the residual lumpectomy cavity; PTV as GTV plus 2 cm margin. Dosimetric performance was evaluated by V100, D90, dose homogeneity index (DHI), conformal index (COIN) and maximum dose to lung and skin. Dosimetric quality of first five implants at our institution was compared with quality of 20 most recent implants. As well, dosimetric quality of first five plans of the two main practitioners at our institution was compared with the remaining implants. Two sided t test was used to compare performance. Catheter insertion was performed with template utilizing mammogram guidance. Results: For all patients treated, mean of 98.9% of GTV and 91.6% of PTV received at least 100% of prescribed dose. D90 for GTV was 128% and for PTV was 108%. DHI was 0.76 and COIN was 0.70. Mean maximum lung dose was 35% of prescribed dose and mean maximum skin dose was 75% of prescribed dose. There was no difference in tumor volume coverage between first five plans performed at our institution and most recent 20 plans (PTV V100 = 90.4% vs 89.9%). There also was no significant difference in dose homogeneity or normal tissue dose, but conformality of initial plans was not as good as subsequent plans (COIN = 0.59 vs 0.72, p\0.01). Comparison of the first five plans of both practitioner and the remaining plans also did not identify difference in tumor volume coverage (V100 91% vs 91%) or homogeneity (DHI = 0.75 vs 0.77), but conformality improved in later plans (COIN 0.61 vs 0.72, p \ 0.01). There was a trend to using a higher number of catheters in initial implants compared to later plans. Conclusions: Use of template guidance for catheter insertion allows for high quality dosimetric plans, with excellent tumor volume coverage, dose homogeneity and conformality. Achieving high quality multi-catheter implants does not necessarily require extensive institutional or individual practitioner experience, although plan conformality improves with experience.
Conclusions: Baseline post-surgery, pre-radiotherapy cosmesis is an important determinant of over... more Conclusions: Baseline post-surgery, pre-radiotherapy cosmesis is an important determinant of overall cosmesis at 2 years after radiotherapy. An important component of breast induration and shrinkage is actually due to surgery rather than radiotherapy. Larger breast volume, baseline surgical cosmesis, post-operative infection and smoking influence late radiotherapy toxicity. Modification of preventable risk factors such as post-operative infection and smoking may limit the development of late toxicity.
Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brai... more Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.
ABSTRACT Brachytherapy (BT) is an established treatment option for low risk prostate cancer. The ... more ABSTRACT Brachytherapy (BT) is an established treatment option for low risk prostate cancer. The aim of this study was to determine the long-term complications and side effects of the procedure in an up to 13 year long single center follow-up analysis. A total of 505 patients were treated by BT for prostate cancer between May 1991 and August 2005. Cohort I (n=412; May 1991 to November 2003) was evaluated by written questionnaire (modified ICS male) and patient chart evaluation in terms of side effects and secondary interventions. In cohort II (n=148; January 2002 to August 2005) perioperative complications were investigated. The mean follow-up was 5.5 years. Perioperative complications were present in 5.4% of patients. Transurethral resection of the prostate was a common secondary intervention, performed in 7% of cases. The rate of incontinence was 6.3% in the long-term follow-up, the rate of potency was 43.5% in those patients who were potent before BT and no hormonal manipulation was performed at any time. BT is a minimally invasive procedure for the treatment of localised "low risk" prostate cancer. Perioperative complications are rare, secondary intervention may be necessary and the patient has to be informed of possible impotence, incontinence and lack of ejaculation.
Ziel: Darstellung der Strukturqualität (Personal, Beschleuniger, Patienten) der strahlentherapeut... more Ziel: Darstellung der Strukturqualität (Personal, Beschleuniger, Patienten) der strahlentherapeutischen Abteilungen am Beispiel Baden-Württemberg, basierend auf Vor-Ort-Audits und der Unterbreitung von Verbesserungsvorschlägen durch die Gutachter der Ärztlichen Stelle (ÄS). Material und Methodik: Auf der Grundlage der Richtlinie und des bundeseinheitlichen Bewertungssystems für ÄS wurden die strahlentherapeutischen Abteilungen in Baden-Württemberg bewertet. Gemäß der Richtlinie besteht die Kommission aus mindestens zwei Fachärzten, einem Medizinphysikexperten (MPE) und einem organisatorischen Mitglied der ÄS. Ergebnisse: Im Zeitraum 2005-2007 wurden 24 strahlentherapeutische Einheiten mit 60 Linearbeschleunigern bezogen auf eine Bevölkerung von ungefähr 10,7 Mio. Einwohnern überprüft (178 000 Einwohner/Beschleuniger). An diesen 60 Linearbeschleunigern wurden im Jahr 2007 28 210 Patienten (Behandlungsfälle) mit bösartigen Tumoren bestrahlt. Insgesamt arbeiten 127 Fachärzte, 83 MPE und 235 medizinisch-technische Radiologieassistenten (MTRA) in diesen Zentren. Bezogen auf das Personal und Jahr bedeutet dies ein durchschnittliches Zahlenverhältnis von 222 behandelten Patienten pro Facharzt (Spannweite 85-400 Patienten), 339 Patienten pro MPE (Spannweite 170-538 Patienten) und 120 Patienten pro MTRA (Spannweite 48-189 Patienten)
Standard spin-echo images of the posterior cranial fossa are usually impaired by pulsation artifa... more Standard spin-echo images of the posterior cranial fossa are usually impaired by pulsation artifacts. We evaluated a heavily Tt weighted MPRAGE sequence (TR/TE/ar/TI = 10/4/10-15"/200-350) for detection of intracerebral lesions in the posterior fossa in 11 patients. Overall quality of the MPRAGE images was superior due to the lack of pulsation artifacts, high S/N and excellent gray-white matter contrast. Lesion detection was better in one pa-
Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized ... more Manganese superoxide dismutase (MnSOD) is a nuclear encoded primary antioxidant enzyme localized in mitochondria. Because expression of MnSOD plays a major role in maintaining cellular redox status and reactive oxygen species are known to play a role in signal transduction and carcinogenesis, we investigated the role of MnSOD in the development of cancer using a two-stage [7,12-dimethylbenz(a)-anthracene plus 12-Otetradecanoylphorbol-13-acetate (TPA)] skin carcinogenesis model. Female transgenic mice expressing the human MnSOD gene in the skin and their nontransgenic counterparts were used in this study. Pathological examination demonstrated significant reduction of papilloma formation in transgenic mice. Quantitative analysis of 4-hydroxy-2-nonenal-modified proteins showed greater accumulation of oxidative damage products in nontransgenic compared with transgenic mice, and this oxidative damage was demonstrated to be present in both mitochondria and nucleus. TPA increased activator protein-1 (AP-1) binding activity within6hi nnontransgenic mice, but increased AP-1 binding activity was delayed in the transgenic mice. Electrophoretic mobility shift assay, transcription of the target genes, and Western analysis studies indicated that the increased AP-1 binding activity was attributable to induction of the Jun but not the Fos protein families. Overexpression of MnSOD selectively inhibited the TPA-induced activation of protein kinase C⑀ and prevented subsequent activation of c-Jun NH 2 -terminal kinase in response to TPA. Overall, these results indicate that MnSOD regulates both cellular redox status and selectively modulates PKC⑀ signaling, thereby delaying AP-1 activation and inhibiting tumor promotion, resulting in reduction of tumors in MnSOD transgenic mice.
Purpose/Objective(s): To determine the efficacy and safety of preoperative capecitabine (Xeloda) ... more Purpose/Objective(s): To determine the efficacy and safety of preoperative capecitabine (Xeloda) and radiation therapy (RT) for patients with locally advanced rectal cancer. Materials/Methods: Patients with adenocarcinoma of the rectum Stage $T3 or $N1, aged between 18-80, ECOG #2, adequate bone marrow reserve, and normal renal and hepatic functions were included. Pretreatment staging was performed with magnetic resonance or endorectal ultrasound. Patients were treated with oral capecitabine 825 mg/m 2 /12 h days 1 to 42 continuously, and 50 Gy RT in 2 Gy fractions. Three-dimensional planning and conformal techniques were used in all patients. Results: Thirty patients were enrolled (M/F 22/8), median age 63.3 years (33-80) and ECOG = 0: 85.1%. Tumor was located within the 5 distal cm in 21 patients (70%) and between 6 and 15 cm from the anal verge in 9 patients (30%). Fifteen patients (50%) were T3N0M0, 12 (40%) T3N1-2M0 and 3 (10%) T2N1-2. Twenty-seven patients (90%) completed combined modality therapy, 3 patients completed RT but not chemotherapy. The most frequent treatment-related Grade I/II toxicities were diarrhea (40%), frequency/dysuria (16%), proctitis (26%), hand-foot syndrome (6%), and leucopenia (4.5%). Grade III toxicities were limited to diarrhea (2 patients) and hand-foot syndrome (1 patient). An anterior resection was performed on 17 patients (56%), an abdominal-perineal resection in 10 (33%), and a transanal resection in 3 patients (10%). There were no major postoperative complications. Nine patients (30%) had pathologic complete response, 14 (46%) had partial response and 7 (23%) had stable disease. Conclusions: The combination of preoperative capecitabine and RT in patients with locally advanced rectal cancer has significant antitumor activity, with a high proportion of complete pathological responses and tumor downstaging. The sphincter preservation rate was high, and the toxicity profile was acceptable in these patients.
Cancer cells generally generate higher amounts of reactive oxygen species than normal cells. On t... more Cancer cells generally generate higher amounts of reactive oxygen species than normal cells. On the basis of this difference, prodrugs have been developed (e.g., hydroxyferrocifen), which remain inactive in normal cells, but become activated in cancer cells. In this work we describe novel aminoferrocene-based prodrugs, which, in contrast to hydroxyferrocifen, after activation form not only quinone methides (QMs), but also catalysts (iron or ferrocenium ions). The released products act in a concerted fashion. In particular, QMs alkylate glutathione, thereby inhibiting the antioxidative system of the cell, whereas the iron species induce catalytic generation of hydroxyl radicals. Since the catalysts are formed as products of the activation reaction, it proceeds autocatalytically. The most potent prodrug described here is toxic toward cancer cells (human promyelocytic leukemia (HL-60), IC(50) = 9 μM, and human glioblastoma-astrocytoma (U373), IC(50) = 25 μM), but not toxic (up to 100 μM) toward representative nonmalignant cells (fibroblasts).
ABSTRACT The irradiation with intensity-modulated fields is possible with static as well as dynam... more ABSTRACT The irradiation with intensity-modulated fields is possible with static as well as dynamic methods. In our university hospital, the intensity-modulated radiotherapy (IMRT) with compensators was prepared and used for the first time for patient irradiation in July 2001. The compensators consist of a mixture of tin granulate and wax, which is filled in a milled negative mould. The treatment planning is performed with Helax-TMS (MDS Nordion). An additional software is used for editing the modulation matrix („Modifix“). Before irradiation of the first patient, extensive measurements have been carried out in terms of quality assurance of treatment planning and production of compensators. The results of the verification measurements have shown that IMRT with compensators possesses high spatial and dosimetric exactness. The calculated dose distributions are applied correctly. The accuracy of the calculated monitor units is normally better than 3%; in small volumes, further dosimetric inaccuracies between calculated and measured dose distributions are mostly less than 3%. Therefore, the compensators contribute to the achievement of high-level IMRT even when apparatuses without MLC are used. This paper describes the use of the IMRT with compensators, presents the limits of this technology, and discusses the first practical experiences.
Background: We investigated the influence of age on short-term complications in women undergoing ... more Background: We investigated the influence of age on short-term complications in women undergoing intraoperative radiotherapy (IORT) for early breast cancer. Patients and Methods: We retrospectively analyzed data of 188 women who underwent IORT during breast-conserving surgery (BCS). The study group consisted of 54 patients aged 70 years or older. One hundred and thirty four patients aged less than 70 years served as the control group. Results: In both collectives, the acute toxicity was low. There were no significant differences regarding type and duration of surgery, and type of radiation treatment, comparing both collectives. The most frequent postoperative side-effects were haematoma/suggillation (13/54, 24.1% vs. 28/134, 20.9%; p=0.633). There was a significantly higher incidence of postoperative axillary haematoma in the study group (10/54, 18.5% vs. 10/134, 7.5%; p=0.026). Conclusion: Acute toxicity after BCS with IORT in women aged 70 years and older does not seem to be higher compared to younger patients.
Background The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intra... more Background The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the fi rst analysis of overall survival.
Radiation therapy is a treatment option for curative management of localized and locally advanced... more Radiation therapy is a treatment option for curative management of localized and locally advanced prostate cancer. Depending on tumor stage and constellation of risk factors (PSA level, findings on digital rectal examination, and Gleason score), various forms of radiotherapy are applied. In addition to the sole use of external beam radiotherapy, brachytherapy with radioactive seeds is also employed as stand-alone treatment in patients with low risk factors and in early clinical stages. Increasing risk of recurrence requires more intensive therapies which can be accomplished by adding hormone deprivation therapy and/or intensifying radiation therapy (dose escalation). Combined approaches using brachytherapy and percutaneous radiotherapy are also initiated in these cases. If hormone ablation therapy is administered, this should occur over a course of 3-36 months as neoadjuvant, concommitant and/or adjuvant treatment, depending on the risk of recurrence.
Purpose/Objectives: To determine the degree to which dosimetric quality of multi-catheter partial... more Purpose/Objectives: To determine the degree to which dosimetric quality of multi-catheter partial breast irradiation plans are impacted by individual practitioner and overall single institution experience. Also, to assess whether multi-catheter implantation, in the absence of CT-guidance, can achieve high quality dosimetry. women with Stage 0, I, II invasive breast cancers were treated with lumpectomy followed by accelerated partial breast irradiation (APBI) utilizing multi-catheter interstitial high dose rate brachytherapy (HDR) at the University of Washington Medical Center. Eligibility criteria included node negative breast cancer, pathologically negative margins, absence of extensive intraductal component, and age $45 years. Radiation dose was 34 Gy delivered in 10 twice-daily fractions over five-seven days, 6-8 weeks following surgery. GTV was defined as the residual lumpectomy cavity; PTV as GTV plus 2 cm margin. Dosimetric performance was evaluated by V100, D90, dose homogeneity index (DHI), conformal index (COIN) and maximum dose to lung and skin. Dosimetric quality of first five implants at our institution was compared with quality of 20 most recent implants. As well, dosimetric quality of first five plans of the two main practitioners at our institution was compared with the remaining implants. Two sided t test was used to compare performance. Catheter insertion was performed with template utilizing mammogram guidance. Results: For all patients treated, mean of 98.9% of GTV and 91.6% of PTV received at least 100% of prescribed dose. D90 for GTV was 128% and for PTV was 108%. DHI was 0.76 and COIN was 0.70. Mean maximum lung dose was 35% of prescribed dose and mean maximum skin dose was 75% of prescribed dose. There was no difference in tumor volume coverage between first five plans performed at our institution and most recent 20 plans (PTV V100 = 90.4% vs 89.9%). There also was no significant difference in dose homogeneity or normal tissue dose, but conformality of initial plans was not as good as subsequent plans (COIN = 0.59 vs 0.72, p\0.01). Comparison of the first five plans of both practitioner and the remaining plans also did not identify difference in tumor volume coverage (V100 91% vs 91%) or homogeneity (DHI = 0.75 vs 0.77), but conformality improved in later plans (COIN 0.61 vs 0.72, p \ 0.01). There was a trend to using a higher number of catheters in initial implants compared to later plans. Conclusions: Use of template guidance for catheter insertion allows for high quality dosimetric plans, with excellent tumor volume coverage, dose homogeneity and conformality. Achieving high quality multi-catheter implants does not necessarily require extensive institutional or individual practitioner experience, although plan conformality improves with experience.
Conclusions: Baseline post-surgery, pre-radiotherapy cosmesis is an important determinant of over... more Conclusions: Baseline post-surgery, pre-radiotherapy cosmesis is an important determinant of overall cosmesis at 2 years after radiotherapy. An important component of breast induration and shrinkage is actually due to surgery rather than radiotherapy. Larger breast volume, baseline surgical cosmesis, post-operative infection and smoking influence late radiotherapy toxicity. Modification of preventable risk factors such as post-operative infection and smoking may limit the development of late toxicity.
Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brai... more Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.
ABSTRACT Brachytherapy (BT) is an established treatment option for low risk prostate cancer. The ... more ABSTRACT Brachytherapy (BT) is an established treatment option for low risk prostate cancer. The aim of this study was to determine the long-term complications and side effects of the procedure in an up to 13 year long single center follow-up analysis. A total of 505 patients were treated by BT for prostate cancer between May 1991 and August 2005. Cohort I (n=412; May 1991 to November 2003) was evaluated by written questionnaire (modified ICS male) and patient chart evaluation in terms of side effects and secondary interventions. In cohort II (n=148; January 2002 to August 2005) perioperative complications were investigated. The mean follow-up was 5.5 years. Perioperative complications were present in 5.4% of patients. Transurethral resection of the prostate was a common secondary intervention, performed in 7% of cases. The rate of incontinence was 6.3% in the long-term follow-up, the rate of potency was 43.5% in those patients who were potent before BT and no hormonal manipulation was performed at any time. BT is a minimally invasive procedure for the treatment of localised "low risk" prostate cancer. Perioperative complications are rare, secondary intervention may be necessary and the patient has to be informed of possible impotence, incontinence and lack of ejaculation.
Ziel: Darstellung der Strukturqualität (Personal, Beschleuniger, Patienten) der strahlentherapeut... more Ziel: Darstellung der Strukturqualität (Personal, Beschleuniger, Patienten) der strahlentherapeutischen Abteilungen am Beispiel Baden-Württemberg, basierend auf Vor-Ort-Audits und der Unterbreitung von Verbesserungsvorschlägen durch die Gutachter der Ärztlichen Stelle (ÄS). Material und Methodik: Auf der Grundlage der Richtlinie und des bundeseinheitlichen Bewertungssystems für ÄS wurden die strahlentherapeutischen Abteilungen in Baden-Württemberg bewertet. Gemäß der Richtlinie besteht die Kommission aus mindestens zwei Fachärzten, einem Medizinphysikexperten (MPE) und einem organisatorischen Mitglied der ÄS. Ergebnisse: Im Zeitraum 2005-2007 wurden 24 strahlentherapeutische Einheiten mit 60 Linearbeschleunigern bezogen auf eine Bevölkerung von ungefähr 10,7 Mio. Einwohnern überprüft (178 000 Einwohner/Beschleuniger). An diesen 60 Linearbeschleunigern wurden im Jahr 2007 28 210 Patienten (Behandlungsfälle) mit bösartigen Tumoren bestrahlt. Insgesamt arbeiten 127 Fachärzte, 83 MPE und 235 medizinisch-technische Radiologieassistenten (MTRA) in diesen Zentren. Bezogen auf das Personal und Jahr bedeutet dies ein durchschnittliches Zahlenverhältnis von 222 behandelten Patienten pro Facharzt (Spannweite 85-400 Patienten), 339 Patienten pro MPE (Spannweite 170-538 Patienten) und 120 Patienten pro MTRA (Spannweite 48-189 Patienten)
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Papers by Frederik Wenz