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Biomedical subjects

M Flentje

Publications and source records attributed to M Flentje.

At least 19 recordsLinked to original sources
PubMed2004

Normal expression of DNA repair proteins, hMre11, Rad50 and Rad51 but protracted formation of Rad50 containing foci in X-irradiated skin fibroblasts from radiosensitive cancer patients.

About 5% of oncology patients treated by radiation therapy develop acute or late radiotoxic effects whose molecular mechanisms remain poorly understood. In this study, we evaluated the potential role of DNA repair proteins in the hypersensitivity of cancer patients to radiation therapy. The expression levels and focal nuclear distribution of DNA repair proteins, hMre11, Rad50 and Rad51 were investigated in skin fibroblasts strains derived from cancer patients with adverse early skin reaction to radiotherapy using Western blot and foci immunofluorescence techniques, respectively. Cells from cancer patients with normal reaction to radiotherapy as well as cells from apparently healthy subjects served as controls. Cellular radiosensitivity after in vitro irradiation was assessed by the clonogenic survival assay. The clonogenic survival assay and Western blot analysis of the DNA repair proteins did not reveal any abnormalities in cellular radiosensitivity in vitro and in protein expression levels or their migration patterns in the fibroblasts derived from cancer patients with hypersensitive reaction to radiotherapy. In contrast, in vitro irradiated cells from radiosensitive patients exhibited a significantly higher number of nuclei with focally concentrated Rad50 protein than in both control groups. The observed alteration of the distribution of radiation-induced Rad50 foci in cells derived from cancer patients with acute side reactions to radiotherapy might contribute to their radiation therapy outcome. These data suggest the usefulness of the Rad50 foci analysis for predicting clinical response of cancer patients to radiotherapy.

Acid Anhydride Hydrolases↗
PubMed2003

Radiation-induced suppression of the Bmp2 signal transduction pathway in the pluripotent mesenchymal cell line C2C12: an in vitro model for prevention of heterotopic ossification by radiotherapy.

Heterotopic ossification is a common complication after total hip replacement. Clinical studies showed the effectiveness of radiation for prevention of heterotopic ossification. The mechanism of radiotherapy responsible for the reduction of heterotopic ossification is unclear. The purpose of this study was to study an analogue model showing a time- and dose-dependent effect of radiation. Using cells of the defined embryonic mouse cell line C2C12, the influence of ionizing radiation on the Bmp-induced signal cascade leading to osteogenic differentiation was analyzed. Binding of iodinated Bmp2 to the receptors, Smad1 activation, and alkaline phosphatase (ALP) activity were determined in cells with or without irradiation. The cytotoxic effect of radiotherapy was evaluated using viability tests. Radiotherapy reduced formation of the Bmp2/Bmp receptor complex. This effect was dependent on dose. The phosphorylation (activation) of Smad1 decreased after irradiation in a time-dependent manner, whereas the level of total Smads was not influenced by radiotherapy. The ALP activity decreased after radiotherapy. A dose of 7 Gy delivered 6 h before or after incubation with Bmp resulted in about a 30% decrease in ALP activity. No signs of cytotoxic effects were observed within the time window studied using doses of 0 to 20 Gy. The time- and dose-dependent effect of radiotherapy for prevention of heterotopic ossification known from the results of clinical studies has an analogue in the C2C12 cell model. The primary mechanism of radiotherapy seems to be an influence on cellular responsiveness to the Bmp2-induced osteoblastic differentiation. The results suggest a down-regulation of the Bmp2/receptor complex.

Alkaline Phosphatase↗
PubMed2002

In vitro radiosensitivity measured in lymphocytes and fibroblasts by colony formation and comet assay: comparison with clinical acute reactions to radiotherapy in breast cancer patients.

PURPOSE: To compare colony-forming and comet assays on fibroblasts and lymphocytes of 32 breast cancer patients irradiated after breast-conserving operations and to correlate the results with acute clinical radiation reactions in the skin. MATERIAL AND METHODS: Skin fibroblasts were isolated and cultivated before radiotherapy and lymphocytes were drawn prior to the first and directly after the final external irradiation. The colony-forming assay was performed with fibroblasts and the comet assay with lymphocytes and fibroblasts of breast cancer patients according to standard protocols. The clinical radiation reactions of the patients were graded according to the RTOG system. RESULTS: No significant correlation (p =0.09) was detected between clinical acute skin reactions and the in vitro clonogenic data in fibroblasts. Results of the comet assay in lymphocytes, however, showed a significant correlation (p <0.05) with the clinical data when patients were divided into two groups with average and elevated acute reactions. Apart from initial damage, fibroblasts did not show significant differences between the two patient groups. Repeated comet assays in lymphocytes of the same patient drawn before treatment and before and after external radiotherapy demonstrated good reproducibility of the test and no significant impact of preceding radiation treatment. There was a good correlation (r =0.65) between the comet assay results in fibroblasts and lymphocytes of the same individual. CONCLUSIONS: In this cohort of patients, a significant correlation between the in vitro results of the comet assay in lymphocytes and clinical acute reactions was detected. The results of the comet assay and of fibroblast colony formation did not correlate with in vitro radiosensitivity.

Breast Neoplasms↗
PubMed2001

Light scatter and DNA accessibility to propidium iodide of ataxia telangiectasia and fanconi anemia cells.

Cells from individuals with genetic diseases ataxia telangiectasia (AT) and Fanconi anemia (FA) exhibit hypersensitivity to ionizing radiation (AT) or DNA cross-linking agents (FA) which may be caused by multiple factors including defects in chromatin structure and DNA repair. In this study, a combination of cytometric techniques was employed to study the chromatin conformation of AT and FA cells. Nuclei of peripheral blood mononuclear cells (PBMCs) and of skin fibroblasts established from AT and FA patients were analyzed by light scattering and fluorimetric titration with the DNA-intercalating dye propidium iodide. The light scatter measurements revealed the presence of small-sized nuclei with reduced granularity in PBMCs and fibroblasts from both AT and FA patients. The fluorometric titration data could be interpreted by assuming two classes of propidium iodide binding sites with different affinities. The number of high-affinity sites in AT and FA fibroblasts was significantly larger (by 20%) than in control cells. Our findings show the applicability of cytometric techniques for the rapid assessment of chromatin conformation and also suggest the possibility to identify AT and FA carriers.

Ataxia Telangiectasia↗
PubMed2001

Intensified hyperfractionated accelerated radiotherapy limits the additional benefit of simultaneous chemotherapy--results of a multicentric randomized German trial in advanced head-and-neck cancer.

PURPOSE: To demonstrate the efficacy of radiochemotherapy (RCT) as the first choice of treatment for advanced unresectable head-and-neck cancer. To prove an expected benefit of simultaneously given chemotherapy, a two-arm randomized study with hyperfractionated accelerated radiochemotherapy (HF-ACC-RCT) vs. hyperfractionated accelerated radiotherapy (HF-ACC-RT) was initiated. The primary endpoint was 1-year survival with local control (SLC). METHODS AND MATERIALS: Patients with Stage III and IV (UICC) unresectable oro- and hypopharyngeal carcinomas were randomized for HF-ACC-RCT with 2 cycles of 5-FU (600 mg/m(2)/day)/carboplatinum (70 mg/m(2)) on days 1--5 and 29--33 (arm A) or HF-ACC-RT alone (arm B). In both arms, there was a second randomization for testing the effect of prophylactically given G-CSF (263 microg, days 15--19) on mucosal toxicity. Total RT dose in both arms was 69.9 Gy in 38 days, with a concomitant boost regimen (weeks 1--3: 1.8 Gy/day, weeks 4 and 5: b.i.d. RT with 1.8 Gy/1.5 Gy). Between July 1995 and May 1999, 263 patients were randomized (median age 56 years; 96% Stage IV tumors, 4% Stage III tumors). RESULTS: This analysis is based on 240 patients: 113 patients with RCT and 127 patients with RT, qualified for protocol and starting treatment. There were 178 oropharyngeal and 62 hypopharyngeal carcinomas. Treatment was tolerable in both arms, with a higher mucosal toxicity after RCT. Restaging showed comparable nonsignificant different CR + PR rates of 92.4% after RCT and 87.9% after RT (p = 0.29). After a median observed time of 22.3 months, l- and 2-year local-regional control (LRC) rates were 69% and 51% after RCT and 58% and 45% after RT (p = 0.14). There was a significantly better 1-year SLC after RCT (58%) compared with RT (44%, p = 0.05). Patients with oropharyngeal carcinomas showed significantly better SLC after RCT (60%) vs. RT (40%, p = 0.01); the smaller group of hypopharyngeal carcinomas had no statistical benefit of RCT (p = 0.84). For both tumor locations, prophylactically given G-CSF was a poor prognostic factor (Cox regression), and resulted in reduced LRC (log-rank test: +/- G-CSF, p = 0.0072). CONCLUSION: With accelerated radiotherapy, the efficiency of simultaneously given chemotherapy may be not as high as expected when compared to standard fractionated RT. Oropharyngeal carcinomas showed better LRC after HF-ACC-RCT vs. HF-ACC-RT; hypopharyngeal carcinomas did not. Prophylactic G-CSF resulted in an unexpected reduced local control and should be given in radiotherapy regimen only with strong hematologic indication.

Adult↗
PubMed2001

p53 and Ki-67 as predictive markers for radiosensitivity in squamous cell carcinoma of the oral cavity? an immunohistochemical and clinicopathologic study.

PURPOSE: Previously published data relating the expression of p53 and Ki-67 to radiation response in head and neck cancer are conflicting. This may be due to differences in patient selection and treatment modalities. In this study of a homogenous population of patients with oral cavity cancer, Ki-67 and p53 indices were correlated with histopathologically assessed tumor regression after preoperative radiochemotherapy and longterm outcome. METHODS AND MATERIALS: Eighty-eight patients with squamous cell carcinoma of the oral cavity and treated between September 1985 and November 1995 by preoperative radiochemotherapy and definitive surgery were included in this analysis. By immunohistochemistry (IHC) the pre-irradiation expression of p53 and of Ki-67 were analyzed and correlated with the histopathologically proven tumor regression, overall survival and local control. RESULTS: The overall 2- and 5-year survival rates were 76.5% and 63%, the locoregional control rates were 84% and 79%, respectively. After preoperative radiochemotherapy 29 patients (33%) showed complete tumor regression (ypT(0) classification). Survival and local control rates were significantly higher for patients showing ypT(0) classification than ypT(1-4) classification (p < 0.01). This effect was independent of pretreatment tumor classification in multivariate analysis. Pre-irradiation p53 status and Ki-67 index had no influence on tumor regression and clinical outcome in these patients. CONCLUSION: Complete tumor regression after preoperative treatment is related to an improved outcome in combined modality treatment of oral cavity cancer. The presented study could not demonstrate an influence of p53 and Ki-67 status as detected by immunohistochemical staining on survival, local control, or tumor regression after radiochemotherapy.

Adult↗
PubMed2001

Stereotactic radiotherapy of targets in the lung and liver.

BACKGROUND: Stereotactic irradiation of extracranial targets offers a non-invasive treatment modality for patients with localized tumors, which are not amenable for surgery or other invasive approaches because of age or impaired medical condition. The purpose of the study was the evaluation of the method to achieve local control of irradiated targets in relation to treatment toxicity. PATIENTS AND METHODS: Irradiation was performed as hypofractionated treatment in three fractions of 10 Gy each, normalized to the PTV enclosing 65% isodose with patient fixation in a stereotactic body frame. The isocenter was localized by stereotactic coordinates. Targets were circumscribed tumors in the lung (n = 27) and liver (n = 24) not amenable for other treatment modalities: primary lung cancer (n = 12), local recurrences of lung cancer (n = 4), lung metastases (n = 11), liver metastases (n = 23) and one cholangiocellular carcinoma. Median CTV/PTV for targets in the lung was 57/113 cm3 (min/max 5-277 cm3/17-343 cm3) and for targets in the liver 50/102 cm3 (min/max 9-516 cm3/42-772 cm3). Median follow-up for targets in the lung was 8 months (2-33) and 9 months (2-28) for liver targets. Local control was defined as complete or partial remission and stable disease, measured by repeated CT scans after 6 weeks and in 3 months intervals. Treatment toxicity was evaluated according to the WHO score. RESULTS: Crude local control was 85% for pulmonary targets and 83% for hepatic targets. Actuarial local control after 1 and 2 years was 76% and 76% for lung tumors and 76% and 61% for liver tumors. Actuarial overall patient survival was 48% after 1 year and 21% after 2 years for targets in the lung and 71% and 43% for targets in the liver. No acute grade 3-5 side effects were observed. Serious late toxicity occurred in two patients: a chronic ulceration of the esophagus at a target close to the mediastinum after 3 months (grade 3) and fatal bleeding from the pulmonary artery after 9 months (grade 5) in a previously irradiated patient. It remained unclear, whether the bleeding was a side effect of irradiation or due to tumor infiltration. CONCLUSION: Hypofractionated stereotactic irradiation of targets in the lung and liver is a locally effective treatment with actuarial local control rates of 76% after 1 year and 61-76% after 2 years without relevant acute toxicity. Severe late toxicity did not occur, if targets close to the mediastinum were avoided.

Adenocarcinoma↗
PubMed2001

Intracavitary afterloading boost in anal canal carcinoma. Results, function and quality of life.

BACKGROUND: First clinical data on a new intracavitary afterloading boost method for anal canal carcinoma is reported. PATIENTS AND METHODS: 20 consecutive patients (T1 5%, T2 70%, T3 20%, T4 5%; N0 75%, N1 10%, N2 15%; all M0) treated with external beam pelvic radiotherapy (median dose 56 Gy, range 46-64 Gy), simultaneous 5-FU and mitomycin (in 75%) and an intracavitary afterloading boost (one or two fractions of 5 Gy at 5 mm depth) were analyzed after a mean +/- SD follow-up for living patients of 4.4 +/- 2.1 years. Quality of Life (QoL) and anorectal manometry parameters were assessed in ten colostomy-free survivors. RESULTS: Overall, recurrence-free and colostomy-free survival at 5 years were 84%, 79% and 69%, respectively. No death was tumor-related. The only local failure was successfully salvaged by local excision. All three colostomies were performed for toxicity. Resting pressure and maximum squeeze pressure of the anal sphincter were reduced by 51% and 71%, as compared with control subjects, but quality of life was similar compared to healthy volunteers. CONCLUSION: The described regimen is highly effective but associated with increased toxicity.

Aged↗
PubMed2001

Soft X-ray therapy of recurrent pterygium--an alternative to 90Sr eye applicators.

BACKGROUND: Analysis of effectiveness of perioperative 20 kV soft X-ray irradiation in recurrent pterygium as an alternative to postoperative 90Sr beta irradiation. PATIENTS AND METHODS: Between 1987 and 2000 a total of 65 patients with 81 pterygia were treated with 20 kV X-ray therapy in the course of surgical treatment of recurrent pterygium. Until 1995 simple excision (bare sclera technique) followed by postoperative irradiation (generally four fractions of 5 Gy) was applied, with radiation starting on mean 4 days following surgery (34 cases, mean follow-up 52 months). Since 1995 we have changed our policy to a perioperative regimen starting with a single dose of 7 Gy prior to microsurgical excision with conjunctival autograft and proceeding within 24 hours with 5 Gy single dose to the surgical bed and then every other day to a total dose of 27 Gy (47 cases, mean follow-up 31 months). Recurrence rate was calculated by Kaplan Meier method. A multivariate Cox regression analysis of prognostic factors for recurrence was performed. RESULTS: A total of 19 recurrences were observed, 15 in the historical postoperative group and four in the perioperative group. Actuarial 2- and 5-year recurrence rate is 9% in the "new treatment group" compared to 34% and 56% in the historical group (p = 0.001). Only one of the four recurrences among the pre- and postoperatively irradiated group required a new surgical procedure. In this case radiation had been terminated at 17 Gy. Actuarial rate of surgical reintervention was only 2% at 2 and 5 years compared to 28% and 36% in the historical group. In multivariate Cox regression analysis only the new treatment strategy was found to influence control rate significantly. Until now no case of severe side effects like scleral necrosis or thinning, symble-pharon, radiation-induced cataract or glaucoma were observed in both groups. CONCLUSION: The combination of pre- and postoperative 20 kV X-ray therapy and microsurgical excision combined with conjunctival autograft is a highly effective treatment to prevent recurrence in the high-risk group of recurrent pterygia and can be recommended as an alternative to postoperative 90Sr beta irradiation.

Actuarial Analysis↗
PubMed2001

Radiation-induced reduction of BMP-induced proteoglycan synthesis in an embryonal mesenchymal tissue equivalent using the chicken "limb bud" test.

PURPOSE: Heterotopic ossification (HO) is a common complication following total hip replacement. Clinical studies showed the effectiveness of irradiation for prevention of heterotopic ossification. The mechanism of radiotherapy responsible for the reduction of heterotopic ossification is unclear. The purpose of this study was to find a suitable cell system, which can reproduce in-vitro data resulting from clinical in-vivo studies. The establishment of such a cell model allows detailed analyses of the mechanism of radiotherapy. METHOD: The chicken limb bud test was used as an in-vitro model. The cells acquired by the limb bud test were irradiated with different doses (0 Gy, 3 Gy, 7 Gy, 10 Gy, 20 Gy). Irradiation was set either 1 hour before, or 1 or 3 days after BMP-2 incubation. The synthesis of proteoglycans (PGS) upon treatment with bone morphogenetic protein (BMP)-2 was measured in cells incubated with BMP-2 for 4 days followed by 35SO4(2-) labeling for 6 hours. Labeled proteoglycans were precipitated using Alcian blue and measured in a raytest radio-TLC analyzer. The incubation with BMP-2 was defined to correlate the in-vivo stimulus meaning the operation. RESULTS: The proteoglycan synthesis was significantly reduced by irradiation 1 hour before or 1 day after BMP-2 incubation, if the dosage was at least 7 Gy. Higher doses than 7 Gy did not lead to lower proteoglycan levels. There was only a trend for a reduction of proteoglycan synthesis by 3 Gy irradiation, but no significant difference compared to the non-irradiated control. An irradiation 3 days after BMP-2 incubation had no effect on proteoglycan. CONCLUSION: A dose and time dependent effect of radiation on BMP-2-induced proteoglycan synthesis was observed. Therefore the results of clinical in-vivo studies were reproduced exactly by the limb bud test. We established an in-vitro cell model to analyze the mechanism of the prevention of heterotopic ossification by radiotherapy on cellular or sub-cellular level.

Animals↗
PubMed2001

Sequential chemo- and radiochemotherapy with weekly paclitaxel (Taxol) and 3D-conformal radiotherapy of stage III inoperable non-small cell lung cancer. Results of a dose escalation study.

The purpose of this study was the determination of the maximum tolerable dose (MTD) of weekly paclitaxel (PX) in combination with 3D-conformal radiotherapy in non-small cell lung cancer (NSCLC) and the evaluation of side effects, patient outcome and tumor response. Thirty-eight patients with inoperable NSCLC, UICC-stage IIIA (n=14)/IIIB (n=24) received two cycles of induction chemotherapy with PX/carboplatin followed by combined radiochemotherapy (60 Gy/6 weeks) with weekly PX which was escalated in cohorts of four patients until dose limiting toxicity (DLT) was reached. Starting level was 40 mg/m(2). 3D-conformal radiotherapy was applied in all patients. Toxicity was determined by WHO criteria. Patients were followed-up 3-monthly. Thirty eight patients have entered the study, 34 patients are evaluable. DLT was esophagitis III degrees, requiring interruption of radiotherapy and was reached at the PX 70 mg/m(2). Two hypersensitivity reactions (50 mg/m(2)) and one leucopenia III degrees (60 mg/m(2)) were observed. Only one patient (60 mg/m(2), 50 Gy) completely aborted treatment. The pneumonitis rate was between 21 and 36% but showed no clear correlation with PX dose. Tumor response (PR and CR) defined by CT-scan 6 weeks following radiotherapy was 88% (30/34). The 1- and 2-year survival rate is 73% and 34%. We conclude that the MTD of weekly PX with 60 Gy normofractionated radiotherapy is 60 mg/m(2). The DLT is esophagitis. Response and survival data of this sequential/combined approach are promising. A minor increase of pulmonary toxicity of irradiation is suspected.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Sequential chemo-radiotherapy in non-small cell lung cancer.

Locally advanced non-small cell lung cancer (NSCLC) stage IIIA/IIIB represents approximately 30% of NSCLC and still has a poor prognosis. In this article we give a short review on several randomized phase III trials that showed a slight but significant survival benefit for sequential chemo-radiotherapy in the treatment of locally advanced NSCLC.

Carcinoma, Non-Small-Cell Lung↗
PubMed2001

Response to X-irradiation of Fanconi anemia homozygous and heterozygous cells assessed by the single-cell gel electrophoresis (comet) assay.

Fanconi anemia (FA) is an autosomal recessive disorder characterized by bone marrow failure and cancer susceptibility. Patient cells are sensitive to a variety of clastogens, most prominently cross-linking agents. Although there is the long-standing clinical impression of radiosensitivity, in vitro studies have yielded conflicting results. We exposed peripheral blood mononuclear cells from FA patients and carriers to x-rays and determined their DNA damage and repair profiles using the alkaline single-cell gel electrophoresis (comet) assay. Studies were carried out in two independent series of experiments by two laboratories using different protocols. The cells of both FA patients and carriers showed uniformly high initial DNA damage rates as assessed by the total initial tail moment. In addition, the average residual tail moment at 30 to 50 minutes and the repair half-time parameters were significantly elevated. These findings suggest an increased release of fragmented DNA following x-ray exposure in cells that carry one or two mutations in one of the FA genes. The comet assay may be a useful adjunct for heterozygote detection in families of FA patients.

Adult↗
PubMed2001

The in vitro colony assay: a predictor of clinical outcome.

PURPOSE: To determine the predictive power of an in vitro colony assay on the clinical normal-tissue complication rate. MATERIAL AND METHODS: Primary skin fibroblasts from 88 individuals were generated from the skin biopsies of patients who received a standardized radiotherapy. Tissue was cultured for three to six passages, irradiated with doses between 1 and 8 Gy under defined conditions, seeded and finally the colonies were stained and counted after 10-14 days. The survival curves were fitted by the L-Q model and the SF2, alpha/beta and plating efficiency were calculated. RESULTS: The parameters SF2 and plating efficiency were stable throughout the 4-year test period. Intra-individual differences between repeated experiments were significantly lower than inter-individual test results. For the observed acute skin and late normal-tissue reactions other than skin the in vitro parameter SF2 correlated significantly (p<0.005). For late skin reactions this correlation was not found. DISCUSSION: In contrast to other publications, a clear correlation was found between the in vitro test results and clinically observed early reactions. The lack of correlation for late skin reactions suggests that the combination of intrinsic radiation sensitivity and exogenous factors may alter the clinically observed reaction of certain tissues to a different extent.

Breast Neoplasms↗
PubMed2000

The influence of the radicality of resection and dose of postoperative radiation therapy on local control and survival in carcinomas of the upper aerodigestive tract.

PURPOSE: To evaluate dose concepts in postoperative irradiation of carcinomas of the upper aerodigestive tract according to the radicality of resection. PATIENTS AND METHODS: In a retrospective analysis, the charts of 257 patients with histologically-proven carcinoma of the upper aerodigestive tract (40 T1, 80 T2, 53 T3, 84 T4 tumors, with nodal involvement in 181 cases) were reviewed according to the radicality of resection and dose of irradiation administered. Sixty-four patients had tumor-free resection margins (> 3 mm), 66 patients had close resection margins (< 3 mm), and 101 patients had R1 resections, and 26 patients had R2 resections. A median dose of 56 Gy was applied to the primary tumor bed and the cervical lymphatics (2 Gy/fraction, 5 fractions/week). In cases of R1 or R2 resection, or of close margins (< 3 mm), the tumor bed or, respectively, tumor residuals were boosted with doses up to a median of 66 Gy. Locoregional tumor control and survival was investigated by uni- and multivariate analyses according to T-, N-stage, grade of resection, total dose of radiation, and presence or absence of extracapsular tumor spread and lymphangiosis carcinomatosa. RESULTS: An overall 3- and 5-year survival rate of 60% and 45%, respectively, was achieved. Rates for freedom from locoregional recurrence were 77% and 72% at 3 and 5 years, respectively. The survival rates according to the grade of resection at 5 years were 67% for patients resected with tumor-free margins, 59% for patients resected with close margins, 26% for patients with R1 resection, and 27% for patients with R2 resection. Within a median follow-up period of 4.7 years for living patients, a total of 67 recurrences (26%) were observed (in 9% of patients resected with tumor-free margins, in 27% with close margins, in 37% of R1 resected, and in 19% of R2 resected patients). Freedom from locoregional recurrence at 3 years was achieved in 100% of the patients resected with tumor-free margins, in 92% of patients resected with close surgical margins, in 87% of R1 and 69% of R2 resected patients. In multivariate Cox-regression analysis, the variables grade of resection (p = 0.00031) and total dose of irradiation (p = 0.0046) were found as factors influencing locoregional control. Variables influencing survival according to multivariate analysis are T-stage (p = 0.0057), N-stage (p = 0.024), grade of resection (p = 0.000015), total dose of irradiation (p < 0. 000000). Extracapsular tumor spread and lymphangiosis carcinomatosa are factors of borderline significance (p = 0.055, p = 0.066). CONCLUSION: In postoperative radiotherapy of head and neck carcinomas, doses adapted to the risk of locoregional recurrent disease should be applied. Patients with R1 and R2 resections should be treated with doses of more than 68 Gy (2 Gy/fraction, 5 fractions/week) (with close margins [< 3 mm] more than 66 Gy) to achieve an improvement in locoregional control and survival.

Adult↗
PubMed2000

Transcranial sonography: integration into target volume definition for glioblastoma multiforme.

PURPOSE: Recent studies indicate that transcranial sonography (TCS) reliably displays the extension of malignant brain tumors. The effect of integrating TCS into radiotherapy planning for glioblastoma multiforme (GBM) was investigated herein. METHODS AND MATERIALS: Thirteen patients subtotally resected for GBM underwent TCS during radiotherapy planning and were conventionally treated (54 to 60 Gy). Gross tumor volumes (GTVs) and stereotactic boost planning target volumes (PTVs, 3-mm margin) were created, based on contrast enhancement on computed tomography (CT) only (PTV(CT)) or the combined CT and TCS information (PTV(CT+TCS)). Noncoplonar conformal treatment plans for both PTVs were compared. Tumor progression patterns and preoperative magnetic resonance imaging (MRI) were related to both PTVs. RESULTS: A sufficient temporal bone window for TCS was present in 11 of 13 patients. GTVs as defined by TCS were considerably larger than the respective CT volumes: Of the composite GTV(CT+TCS) (median volume 42 ml), 23%, 13%, and 66% (medians) were covered by the overlap of both methods, CT only and TCS only, respectively. Median sizes of PTV(CT) and PTV(CT+TCS) were 34 and 74 ml, respectively. Addition of TCS to CT information led to a median increase of the volume irradiated within the 80% isodose by 32 ml (median factor 1.51). PTV(CT+TCS) volume was at median 24% of a "conventional" MRI(T2)-based PTV. Of eight progressions analyzed, three and six occurred inside the 80% isodose of the plans for PTV(CT) and for PTV(CT+TCS), respectively. CONCLUSION: Addition of TCS tumor volume to the contrast-enhancing CT volume in postoperative radiotherapy planning for GBM increases the treated volume by a median factor of 1.5. Since a high frequency of marginal recurrences is reported from dose-escalation trials of this disease, TCS may complement established methods in PTV definition.

Adult↗