Search

Previous studies have shown that the dual phosphatidylinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) inhibitor NVP-BEZ235 radiosensitizes tumor cells if added shortly before ionizing radiation (IR) and kept in culture medium thereafter. The present study explores the impact of inhibitor and IR schedule on the radiosensitizing ability of NVP-BEZ235 in four human glioblastoma cell lines. Two different drug-IR treatment schedules were compared. In schedule I, cells were treated with NVP-BEZ235 for 24 hours before IR and the drug was removed before IR. In schedule II, the cells were exposed to NVP-BEZ235 1 hour before, during, and up to 48 hours after IR. The cellular response was analyzed by colony counts, expression of marker proteins of the PI3K/AKT/mTOR pathway, cell cycle, and DNA damage. We found that under schedule I, NVP-BEZ235 did not radiosensitize cells, which were mostly arrested in G1phase during IR exposure. In addition, the drug-pretreated and irradiated cells exhibited less DNA damage but increased expressions of phospho-AKT and phospho-mTOR, compared to controls. In contrast, NVP-BEZ235 strongly enhanced the radiosensitivity of cells treated according to schedule II. Possible reasons of radiosensitization by NVP-BEZ235 under schedule II might be the protracted DNA repair, prolonged G2/M arrest, and, to some extent, apoptosis. In addition, the PI3K pathway was downregulated by the NVP-BEZ235 at the time of irradiation under schedule II, as contrasted with its activation in schedule I. We found that, depending on the drug-IR schedule, the NVP-BEZ235 can act either as a strong radiosensitizer or as a cytostatic agent in glioblastoma cells.

Targeting heat shock protein 90 (Hsp90) provides a promising therapeutic approach to enhance the sensitivity of tumor cells to ionizing radiation (IR). To explore the impact of scheduling drug-IR administration, in the present study, we analyzed the response of lung carcinoma A549 and glioblastoma SNB19 cells to simultaneous drug-IR treatment followed by a long-term drug administration. Cellular response was evaluated at different time intervals after IR-alone, drug-alone, or combined drug-IR treatments by colony counts and expression profiles of Hsp90 and its clients, along with several apoptotic markers and cell cycle-related proteins, as well as by IR-drug-induced cell cycle arrest, DNA damage, and repair. A short 30-minute exposure to either Hsp90 inhibitor did not affect the radiosensitivity of both tumor cell lines. Increasing the duration of post-IR-drug treatment progressively enhanced the sensitivity of SNB19 cells to IR. In contrast, the response of A549 cells to drug-IR combination was largely determined by the cytotoxic effects of both drugs without radiosensitization. Combined drug-IR treatment induced more severe DNA damage in both tumor cell lines than each treatment alone and also protracted the kinetics of DNA damage repair in SNB19 cells. In addition to large cell cycle disturbances, drug-IR treatment also caused depletion of the antiapoptotic proteins Akt and Raf-1 in both cell lines, along with a decrease of survivin in A549 cells in case of NVP-AUY922. The data show that simultaneous Hsp90 inhibition and irradiation may induce cell type-specific radiosensitization as well as cytotoxicity against tumor cells.

NVP-AUY922, a novel inhibitor of Hsp90, was shown to enhance the effect of ionizing radiation (IR) on tumor cells under normoxic conditions. Since low oxygen tension is a common feature of solid tumors, we explore in the present study the impact of hypoxia on the combined treatment of lung carcinoma A549 and glioblastoma SNB19 cell lines with NVP-AUY922 and IR. Cellular analysis included the colony-forming ability, expression of CAIX, Hsp90, Hsp70, Raf-1, Akt, cell cycle progression and associated proteins, as well as DNA damage measured by histone γH2AX. The clonogenic assay revealed that in both cell lines NVP-AUY922 enhanced the radiotoxicity under hypoxic exposure to a level similar to that observed under oxic conditions. Irrespective of oxygen supply during drug treatment, NVP-AUY922 also reduced the expression of anti-apoptotic proteins Raf-1 and Akt. As judged by the levels of histone γH2AX, drug-treated hypoxic cells exhibited a lower repair rate of DNA double-strand breaks than normoxic cells. The drug-IR mediated changes in the cell cycle, i.e., S-phase depletion and G2/M arrest, developed not directly during hypoxic exposure but first upon 24 h reoxygenation. Under both oxygen tensions, Hsp90 inhibition downregulated the cell cycle-associated proteins, Cdk1, Cdk4 and pRb.The finding that NVP-AUY922 can enhance the in vitro radiosensitivity of hypoxic tumor cells may have implications for the combined modality treatment of solid tumors.

Hypoxia is a crucial factor in tumour aggressiveness and its treatment resistance, particularly in human brain cancer. Tumour resistance against radiation- and chemo- therapy is facilitated by oxygenation reduction at tumour areas. HIF-1 regulated genes are mostly responsible for this type of resistance. Among these genes, carbonic anhydrase isoform 9 (CA9) is highly overexpressed in many types of cancer especially in high grade brain cancer like GBM. CA IX contributes to tumour environment acidification by catalyzing the carbon dioxide hydration to bicarbonate and protons, leading to the acquisition of metastasic phenotypes and chemoresistance to weakly basic anticancer drugs and therefore to inadequate application of radio-therapeutic or chemotherapeutic anti-cancer treatment strategies. Inhibition of this enzymatic activity by application of specific chemical CA9 inhibitors (sulphonamide derivative compounds) or indirect inhibitors like HIF-1 inhibitors (chetomin) or molecular inhibitors like CA9-siRNA leads to reversion of these processes, leading to the CA9 functional role inhibition during tumourigenesis. Hypoxia significantly influences the tumour microenvironment behaviour via activation of genes involved in the adaptation to the hypoxic stress. It also represents an important cancer prognosis indicator and is associated with aggressive growth, malignant progression, metastasis and poor treatment response. The main objective in malignant GBM therapy is either to eradicate the tumour or to convert it into a controlled, quiescent chronic disease. Sulfonamide derivative compounds with CA9 inhibitory characteristics represent one of the optimal treatment options beside other CA9 inhibitory agents or chemical inhibitory compounds against its main regulating transcription factor which is the hypoxia induced HIF-1 when applied against human cancers with hypoxic regions like GBM, bearing potential for an effective role in human brain tumour therapeutic strategies. Glycolytic inhibitors, when added in controlled doses under hypoxia, lead to a reduced accumulation of HIF-1 and can function as indirect hypoxia regulated genes inhibitors like CA9. These may be used as alternative or in conjunction with other direct inhibitors like the sulphonamide derivate compounds, chetomin or specific siRNAs, or other different chemical compounds possessing similar functionality making them as optimal tools for optimized therapy development in cancer treatment, especially against human brain cancer. Further experimental analysis towards the tumour stage specific inhibitory CA9 characteristics determination are necessary to find the optimal therapeutic solutions among the different available modalities; whether they are direct or indirect chemical, molecular or natural inhibitors to be able to set up successful treatment approaches against the different human tumour diseases.

In order to enhance the cytotoxicity of radiation, camptothecin (CPT), an inhibitor of DNA topoisomerase I, was added to the cultured glioma cell lines before irradiation (IR). Radiation responses of five glioblastoma cell lines (U87-MG, U373-MG, GHE, GaMG and SNB-19) treated with CPT were analyzed in terms of cell and colony counts, cell cycle progression, expression of histone γH2AX, DNA repair protein Rad50, survivin, cleaved caspase 3, p53 and of topoisomerase I. CPT enhanced the radiotoxicity in U87-MG and SNB-19 cell lines if cell and colony counts were used as the end-points. In contrast, pre-treatment with CPT of U373-MG, GHE and GaMG cell lines did not enhance cytotoxicity of IR in terms of cell and colony counts but accelerated DNA damage repair assessed by Rad50 foci. CPT treated glioma cells revealed at least two subpopulations with respect to the expression of histone γH2AX, a marker of DNA double-strand breaks. The cell lines tested also differed in the expression of survivin, cleaved caspase 3, p53 and of topoisomerase I. The failure of CPT to enhance the radiotoxicity of glioma U373-MG, GHE and GaMG cell lines in terms of cell and colony counts was found to correlate with accelerated DNA damage repair, and with low expression of topoisomerase I, a target of CPT.

Purpose:: To evaluate the delineation of either the rectal volume (RV) or the rectal wall (RW) in intensity-modulated radiotherapy (IMRT) for prostate cancer: influence on dose distribution to the targets and organs at risk (OARs) was investigated.Material and Methods:: For ten patients with localized prostate cancer IMRT treatment plans were generated with the RV, wall including the filling, and the RW without the lumen as OAR (plan-RVandplan-RW), respectively. Two different IMRT treatment- planning systems (TPS) were utilized. The influence on target coverage and sparing of OARs was investigated.Results:: No influence was seen on target coverage and sparing of the bladder and femoral heads. Doses to the RV were significantly reduced inplan-RVfor all evaluated dose levels: maximum 26% and 17%, respectively, in both TPS. The dose distribution to the RW was not significantly different betweenplan-RVandplan-RW.Conclusion:: The different delineation of the OAR rectum significantly affected the inverse IMRT treatment-planning process. The use of the RV as OAR resulted in improved dose distributions to the RV. Therefore, it is suggested using the RV as OAR in IMRT treatment planning of the prostate.

Nijmegen breakage syndrome (NBS) patients and carriers are predisposed to malignancy and are often treated with X‐irradiation. In the present study, the single‐cell gel electrophoresis (Comet) assay was used to examine radiation‐induced DNA damage and repair in peripheral blood mononuclear cells from NBS patients (n= 13) and carriers (n= 36) of six unrelated families. Cells from apparently healthy donors (n= 10) and from breast cancer patients with normal clinical radiosensitivity (n= 10) served as controls. Cells were irradiated with 5 Gy of X‐rays and assayed for initial DNA damage and for residual DNA damage after 40 min of repair; the kinetics of DNA repair also was estimated. In addition, the nuclear area of unirradiated cells was extracted from the Comet data. The initial radiation‐induced DNA fragmentation indicated that cells from members of two out of six NBS families were significantly more sensitive to X‐irradiation than cells from the controls. Cells from four NBS families had longer DNA repair half‐time values, while cells from five NBS families had significantly increased residual DNA damage following repair. The mean nuclear area of unirradiated cells processed in the Comet assay was 1.3‐fold higher in cells from all NBS families than in the controls (P< 0.05). Notably, the Comet assay parameters (initial and residual DNA damage and the repair kinetics) of irradiated NBS cells predicted the carrier status of the majority (86%) of blindly tested individuals. The prediction of NBS status was higher if the nuclear area of unirradiated cells was used as the endpoint. The results of this study suggest that the impaired radiation response of NBS cells should be taken into account if radiotherapy of NBS patients and carriers is required. Environ. Mol. Mutagen, 2006. © 2006 Wiley‐Liss, Inc.

Background and Purpose: A technical modification for radiotherapy of prostate cancer is presented to smooth the scalloped dose pattern that occurs at treatment field edge, when a multileaf collimator (MLC) has been used. Material and Methods: Ten patients with prostate cancer receiving postoperative, adjuvant irradiation were studied prospectively. By a three-dimensional planning system (TMS, Helax 6.1B) the irradiation was planned for an 18-MV linear accelerator (Primus 1, Siemens). The volumes of interest (VOI) were the planning target volume (PTV; the region of the prostate including the seminal vesicles), the volume of rectum (V rectum) and urinary bladder (V bladder). Two four-field techniques (0°, 90°, 180°, 270°) were planned using “beam’s eye view” for setting the leaf position of the MLC. For technique A the MLC was adapted to the PTV using a 0° collimator angle for the lateral fields. For technique B the collimator angle of the lateral fields was optimized to compensate the cascade field shape. Dose-volume histograms of PTV, V rectum and V bladder were analyzed. The dose was prescribed for the reference point according to ICRU 50. Film dosimetry was used to show the dose pattern at the field edge produced by the two techniques. Results: Dose to PTV did not differ between technique A and B. Median dose to V rectum was 82.6% for technique A and 77.3% for technique B (p < 0.001). Technique A irradiates a larger V rectum than technique B being significant for all isodose levels tested. Median dose to V bladder did not differ for technique A and B (p > 0.05). Conclusion: The presented technical modification is an effective method to blur the staggered dose distribution that results, when the MLC is conventionally stepped to adapt to the dorsal, irregular PTV border in irradiation of prostate. Especially for irradiation to escalated dose levels, this modification may reduce the dose to the rectum and thus the rectal side effects in comparison to the conventional MLC fields.

Purpose: The influence of two different calculation algorithms (“pencil beam” [PB] versus “collapsed cone” [CC]) on dose distribution, as well as the dose-volume histograms (DVHs) of the planning target volume (PTV) and the organs at risk was analyzed for irradiation of lung cancer. Material and Methods: Between 10/2001 and 02/2002 three-dimensional treatment planning was done in ten patients with lung cancer (Helax, TMS ®, V.6.01). The PTV, the ipsilateral lung (IL) and the contralateral lung (CL) were defined in each axial CT slice (slice thickness 1 cm). Dose distributions for three-dimensional multiple-field technique were calculated using a PB and a CC algorithm, respectively. Normalization was in accordance with ICRU 50. The DVHs were analyzed relating the minimum, maximum, median and mean dose to the volumes of interest (VOI). Results: Median PTV amounted to 774 cm 3. Minimum dose within the PTV was 67.4% for CC and 75.6% for PB algorithm (p = 0.04). Using the CC algorithm, only 76.5% of the PTV was included by the 95% isodose, whereas 90.1% was included when the PB algorithm (p = 0.01) was used. Median volume of IL amounted to 1 953 cm 3. Mean dose to IL was 43.0% for CC and 44.0% for PB algorithm (p = 0.02). Median volume of IL within the 80% isodose was 19.6% for CC and 24.1% for PB algorithm (p < 0.01). Median volume of CL amounted to 1 847 cm 3. Mean dose to CL was 17.4% for CC and 18.1% for PB algorithm (p < 0.01). Volume of CL within the 80% isodose was 3.3% for CC and 4.1% for PB algorithm (p = 0.03). Conclusion: The CC and PB calculation algorithms result in different dose distributions in case of lung tumors. Particularly the minimum dose to the PTV, which may be relevant for tumor control, is significantly lower for CC. Since it is generally accepted that the CC algorithm describes secondary particle transport more exactly than PB models, the use of the latter should be critically evaluated in the treatment planning of lung cancer.

Background: Fanconi anemia (FA) is an autosomal recessive chromosome instability disorder characterized by progressive pancytopenia and cancer susceptibility. The risks of radiation therapy in FA patients who have cancer remain to be investigated. Recently, Marcou et al. (2001) reported a case of severe clinical radiosensitivity in a female FA patient with a tonsillar squamous cell carcinoma treated by radiotherapy. By contrast, her in vitro irradiated skin fibroblasts revealed nearly normal radiosensitivity as determined by the colony survival assay. Material and Methods: In view of this discrepancy, the radiation response of this particular FA fibroblast strain (designated 425BR) was further analyzed in the present study by means of the alkaline single-cell gel electrophoresis (Comet) assay, and also by the cytochalasin-blocked micronuclei (MN) test. In addition, the expression levels of DNA repair proteins, hMre11, Rad50, and Rad51, were investigated using Western blot and foci immunofluorescence staining. Results: The Comet assay revealed that the initial DNA fragmentation in irradiated FA cells was two times higher and the DNA rejoining process was three times slower than that in control (1BR3) fibroblasts. Moreover, although the baseline level of MNs was lower in FA cells than in controls, the FA fibroblasts were more prone (about two times) to MN production than control cells when irradiated with 2–4 Gy. Western blot analysis of the DNA repair proteins (hMre11, Rad50, and Rad51) did not reveal any abnormalities in protein expression levels or their migration patterns in the fibroblasts derived from an FA patient either before or after irradiation. At the same time, in vitro irradiated cells from the FA patient exhibited a significantly reduced number of nuclei with focally concentrated DNA repair Rad51 protein than in control cells. Conclusion: The increased DNA damage and MN induction in irradiated FA fibroblasts, and the reduction of the formation of DNA repair foci containing Rad51 suggest a possible link to the profound clinical radiosensitivity reported earlier for this FA patient. The findings on this particular FA cell strain presented in the study point toward the difficulties involved in the prediction of the radiation response of cell lines and tumors based solely on the colony survival test.

Background: Recent developments in imaging technology and tumor biology have led to new techniques to detect hypoxia and related alterations of the metabolic microenvironment in tumors. However, whether these new methods can predict radiobiological hypoxia and outcome after fractionated radiotherapy still awaits experimental evaluation. Material and Methods: The present article will introduce a multiinstitutional research project addressing the impact of hypoxia and the metabolic microenvironment on radiotherapy of solid tumors. The four laboratories involved are situated at the universities of Dresden, Mainz, Munich and Würzburg, Germany. Results: The joint scientific project started to collect data obtained on a set of ten different human tumor xenografts growing in nude mice by applying various imaging techniques to detect tumor hypoxia and related parameters of the metabolic microenvironment. These techniques include magnetic resonance imaging and spectroscopy, metabolic mapping with quantitative bioluminescence and single-photon imaging, histological multiparameter analysis of biochemical hypoxia, perfusion and vasculature, and immunohistochemistry of factors related to angiogenesis, invasion and metastasis. To evaluate the different methods, baseline functional radiobiological data including radiobiological hypoxic fraction and outcome after fractionated irradiation will be determined. Conclusion: Besides increasing our understanding of tumor biology, the project will focus on new, clinically applicable strategies for microenvironment profiling and will help to identify those patients that might benefit from targeted interventions to improve tumor oxygenation.

Purpose: Evaluation of the inter- and intraindividual applicator variability of multiple high-dose-rate (HDR) brachytherapy applications for primary treatment of cancer of the uterine cervix. Material and Methods: Retrospective analysis of 460 pairs of orthogonal X-ray films for conventional treatment in 92 patients with five intrauterine applications using an HDR tandem applicator. Measurement of the position of the applicator origin relative to a bony reference system in three dimensions. Evaluation of the differences of the applicator position in all 460 applications (interindividual variability), of the five applications in a single patient (intraindividual variability) and of the intraindividual variability relative to the applicator position at the first application. Results: The position of the applicator origin in the pelvis ranged from 23 mm cranial and 55 mm caudal to the top of femoral heads, 23 mm right and 27 mm left to the pelvic midline, and 6–53 mm dorsal to the mid of the femoral heads. Standard deviation (SD) of interindividual applicator variability was 12.9 mm (minimum/maximum –55/+23 mm, mean –13.6 mm) in longitudinal, 5.1 mm (–27/+23 mm, mean 1.6 mm) in lateral, and 7.6 mm (6/53 mm, mean 26 mm) in anterior-posterior [AP] direction. SD of intraindividual variability was 5.5 mm (–21/+23 mm, mean 0 mm) in longitudinal, 2.5 mm (–17/+19 mm, mean 0 mm) in lateral, and 4.2 mm (–15/+18 mm, mean 0 mm) in AP direction compared to intraindividual variability relative to the first insertion with an SD of 8.9 mm (–23/+36 mm, mean 2.8 mm) in longitudinal, 4.0 mm (–11/+23 mm, mean 0 mm) in lateral, and 6.8 mm (–27/+17 mm, mean –0.8 mm) in AP direction. Conclusion: Intraindividual applicator variability is significantly smaller than interindividual variability. Applicator-related procedures such as midline shielding or dose matching of tele- and brachytherapy should be performed with information on at least one individual applicator position.

Background: A population-based registry (PBR) in Lower Frankonia in southern Germany was conducted to evaluate the changes of incidence and prognosis of thyroid carcinoma (TC) in this area. Methods: The study comprised 476 patients with differentiated thyroid carcinoma (DTC) from Lower Franconia (1.3×106inhabitants) registered between 1981 and 1995 at the Regional Tumor Center. The incidence was assessed with respect to gender, age, histology, tumor stage, lymph node involvement and distant metastases in 5-year intervals (1981-1985, 1986-1990, and 1991-1995). Results: An increasing rate of papillary thyroid carcinoma PTC and a decreasing rate of follicular thyroid carcinoma (FTC) were observed over the three time periods (1981-1985, 1986-1990, and 1991-1995). The overall incidence revealed no significant change with time for both females from 3.22 to 3.25 and 3.73 and males (1.07 to 1.54 and 1.69) between the three time periods. There was a significant improvement in outcome of patients with DTC with respect to life expectancy. Conclusions: Iodine prophylaxis does influence the distribution of the histologic types of thyroid cancer and leads to an increase in the ratio of papillary versus follicular carcinoma. Our study supports the hypothesis that the benefits of correcting iodine deficency outweigh the risks of iodine supplementation.

Background and Purpose: Recommendations for radiation ports in adjuvant radiation therapy for rectal cancer are mainly based on analysis of recurrence patterns. To evaluate whether changes in surgical technique have influenced this pattern of recurrence, a multicenter retrospective analysis was carried out on a patient population treated recently. Patients and Methods: 123 patients were evaluated with the help of a CT-based self-developed 3-D data file system and an extensive questionnaire. Major inclusion criteria (one sufficient) for eligibility were: histological confirmation, clear bone destruction, and a positive PET scan, or at least three minor criteria: progressive soft tissue mass, invasion of adjacent organs on follow-up CT or MRI, rising tumor markers, and typical appearance in cross-sectional imaging. Clinical or serologic signs of inflammation were exclusion criteria. Results: Initially, 54% of the evaluated patients were N0; in the remainder, N1 and N2 were distributed evenly. Initial T-category was T1 in 2%, T2 in 24%, T3 in 60%, and T4 in 13%, the male-to-female ratio was 2 : 1. Recurrent tumors were mainly situated in the posterior part of the bony pelvis as displayed in the figures. When abdominoperineal resection was compared to low anterior resection as primary operation, there was a significant difference in extension of recurrent tumors in the inferior parts of the pelvis (p < 0.025 in all statistical tests applied), whereas no significant difference was found in the superior parts of the pelvis. Conclusion: Based on these results, a modest field size reduction in adjuvant radiotherapy for rectal cancer seems feasible, offering the perspective of a reduction in acute and late side effects.

Background and Purpose: Radiochemotherapy (RChT) as adjuvant treatment for rectal cancer UICC stage II/III has been recommended by the National Cancer Institute (NCI) since 1991 and in Germany since 1994. Quality and results of postoperative treatment in day-to-day clinical practice in a complete region are evaluated retrospectively in a multi-institutional approach. Patients and Methods: 534 patients from six institutions treated between 1993 and 1998 were evaluated. The institutions covered a complete region with radiotherapeutic care. Patients were staged as follows: UICC I 1%, II 28%, III 69%, and IV 2%. 92% received RChT, 8% radiotherapy (RT) alone. Median follow-up of patients was 47 months (17–91 months). Results: Only about 37% of expected patients were referred for postoperative treatment. The 5-year actuarial rate was as follows: local control 75% (63–84%), freedom from distant metastases 56% (44–63%), disease-free survival (DFS) 53% (42–59%), and overall survival (OS) 53% (45–64%). In multivariate analysis, local control was significantly influenced by T- and N-category, tumor grading, and RChT instead of RT alone. 6% (2–11%) of patients showed involved resection margins, in 33% of patients categorized pN0 less than the required twelve lymph nodes were examined, both leading to a significant decrease of local control. Conclusion: While the quality of adjuvant treatment followed consensus guidelines, the number of referred patients which was lower as expected and the inferior treatment results as compared to randomized studies indicate that the consensus recommendations for adjuvant treatment have not been fully accepted. Instead of patient referral according to UICC stage, patient selection by the surgeons has been performed according to individual risk factors. Efforts have to be made not only to improve treatment results in randomized studies but also to transfer and control these standards in daily practice.

Es sollte eine Tischplatte für die Anwendung in der Strahlentherapie konstruiert und gefertigt werden, die gleichermaßen für ein im Bestrahlungsraum integriertes CT geeignet ist. Kleinräumig war die maximale Verfälschung der Dosisverteilung durch den Tisch auf 4 % zu limitieren, die mittlere Reduktion über das gesamte Zielvolumen auf 2 %. Das CT sollte nur geringe Artefakte aufweisen, um eine Relokalisation des Zielvolumens im Bestrahlungsraum zu ermöglichen.

Background: The effectiveness of pre- or postoperative radiotherapy for prevention of heterotopic ossification (HO) following total hip replacement (THR) has already been demonstrated in the past. Thereby, in most studies using preoperative radiotherapy patients were irradiated < 6 h before surgery. The purpose of this prospective study was to analyze the effectiveness of preoperative irradiation on the evening before surgery and to identify risk factors for HO in a homogeneous collective of patients. Patients and Methods: From July 1997 to July 2001, 416 patients (462 hips; 235 males, 227 females) received preoperative radiotherapy of the hip on the evening before surgery with a 7-Gy single fraction. The patients’ median age was 67.1 years. The most frequent indication for radiotherapy was hypertrophic osteoarthritis (383 hips, 82.9%). Treatment results were assessed by comparison of pre- and postoperative hip X-rays (immediately and 6 months after surgery). The analysis of radiographs was performed according to the Brooker score. Results: The overall incidence of HO was 18.1% (n = 84), Brooker score 1 12.3% (n = 57), score 2 3.9% (n = 18), score 3 1.5% (n = 7), and score 4 0.4% (n = 2). Sex, body height, hypertrophic osteoarthritis of higher degree, size of the femoral component of the prosthesis, previous ipsi- or contralateral HO, and short course of nonsteroidal anti-inflammatory drug (diclofenac) therapy significantly influenced the HO rate in univariate analysis. In multivariate analysis, an interdependence of prosthesis size, sex and patient’s height was found. From these three variables, only prosthesis size was statistically significant in multivariate analysis. The cumulative dose of diclofenac (= 300 mg or > 300 mg) within the first 7 postoperative days and previous ipsi- or contralateral HO influenced the incidence of HO in multivariate analysis. Conclusion: Preoperative radiotherapy on the evening before surgery is an effective treatment modality to reduce overall (Brooker 1–4) and clinically relevant, severe HOs (Brooker 3–4), and includes several advantages compared to postoperative irradiation. Previous ipsi- and contralateral HOs were identified as high risk factors for HO in this study. In patients with these risk factors, the incidence of HO increased.

Purpose: To determine whether a little dose to a large normal lung volume or a high dose to a small lung volume is more critical for induction of clinical pneumonitis. The second question is if dose-volume histogram (DVH) parameters are more reliable, if the lungs are analyzed as separate organs or as a whole organ. Patients and Methods: We analyzed the clinical and DVH data from 49 patients treated for a thoracic malignancy using 3-D conformal treatment plans. 18 patients had developed a clinical pneumonitis (CTC II or III). The majority of patients (n = 48) received radiochemotherapy for non-small-cell lung cancer (NSCLC) with a combination of paclitaxel and carboplatin. Patients were generally treated 5 fx/week, single dose 2 Gy, using a two-series approach (shrinking field) up to a total dose of 60–70 Gy. For every individual patient, the overall dose distribution was recalculated in the Helax-TMS by means of adding dose plans according to the total dose applied in each series. The lungs were defined both as separate organs and as a whole organ. Low-dose volume (= 10 Gy, V low), moderate-dose volume (> 10–40 Gy, V mod) and high-dose volume (> 40 Gy, V high), as well as V10–V40 and mean lung dose (MLD) were defined from the cumulative DVH. Dose-effect relationships were fitted with a logistic regression model. Results: Manifestation of clinical pneumonitis was within 3 months from termination of irradiation in all cases. For the ipsilateral lung, the incidence of pneumonitis was closely correlated to V high. The pneumonitis rate increased from 13% up to 60%. By contrast, with increasing V low the pneumonitis rate dropped to < 10%. A similar but less pronounced effect was seen for the total lung. The lung volumes V low, V mod and V high of the ipsilateral, contralateral and whole lung were significantly correlated to the corresponding MLD. The incidence of pneumonitis increased with increasing MLD for the ipsilateral lung with a D 50 of 32 Gy and a ? 50 of 0.98. For the whole lung, the observed increase was less steep. MLD showed a close correlation to NTCP calculated by the Kutcher model. However, NTCP calculation overestimated the pneumonitis risk for the ipsilateral lung and underestimated the risk for the whole lung due to the steeper gradient. The logistic regression curve for the DVH parameters V10–V40 showed an increase of steepness toward higher doses. From the logistic regression curves, a DVH template indicating critical borders of V10–V40 was generated for the ipsilateral as well as for the total lung. Conclusion: Our data indicate that it is reasonable to disperse the dose outside the target volume over large areas in order to reduce the volumes of lung receiving > 40 Gy. Reducing the high-dose volume reduces the pneumonitis rate more than a corresponding reduction in the low-dose regions of the DVH. Landmarks for DVH optimization as defined in this analysis may serve as a basis for DVH constraints in IMRT planning. Separate organ analysis produced more reliable results and should be preferred to whole-organ analysis, if techniques mainly involving one side of the lung are applied. Further validation of these constraints is necessary prior to general recommendation.

Ziel: Übersicht über die Entwicklung kombinierter Behandlungsstrategien beim Nasopharynxkarzinom. Ergebnisse: Die Strahlentherapie ist akzeptierte Standardtherapie bei der Behandlung des Nasopharynxkarzinoms. Es herrscht jedoch keineswegs Einigkeit über das optimale Therapieregime bezüglich Dosierung, Fraktionierung, Technik oder gar Einsatz von systemischer Chemotherapie. Die vergleichende Beurteilung neuerer Studien wird durch unterschiedliche Stagingsysteme und das Auftreten biologisch differenter Karzinome in der westlichen Hemisphäre und in Ostasien erschwert. Schlussfolgerungen aus älteren Publikationen, die vorwiegend retrospektive Analysen darstellen, sind aufgrund der Weiterentwicklung in Diagnostik und Therapie eingeschränkt bewertbar. Der gültige Standard bei lymphknotenpositiven Tumoren ist eine simultane Radiochemotherapie. Schlussfolgerungen: Um die Bedeutung der beiden Komponenten Strahlentherapie und Chemotherapie in der Behandlung der Nasopharynxkarzinome zu klären, müssen Patienten mit unterschiedlichen histologischen Subtypen nach einheitlichen Schemata behandelt werden. Nur so wird es möglich sein, stadiengerechte Behandlungskonzepte, die zudem die Tumorbiologie berücksichtigen, festzulegen. Aim: Review of the evolution of combined treatment strategies in nasopharyngeal carcinoma. Results: Radiotherapy is accepted standard for treatment of nasopharyngeal cancer. Nevertheless, there is no uniform opinion with regard to doses, fractionation, technique or use of systemic chemotherapy. It is hardly possible to compare the results of recent and historical trials because of different staging systems and because nasopharyngeal cancer occurring in the Oceano-Asian region are biologically different to those in Western countries. Conclusions drawn from former, mostly retrospective analyses are not applicable to newer standards regarding the developments in diagnostics and therapy. Presently simultaneous chemoradiotherapy is standard for lymphnode positive nasopharyngeal cancer. Conclusions: It will be necessary to treat patients with different histologic subtypes with an uniform treatment schedule to define the place of combined modality treatment. This will probably be the only way to develop treatment concepts for distinct stages and biological entities.

Abstract 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 boose (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. Zusammenfassung Hintergrund: Erste klinische Ergebnisse einer neuen Methode zur intrakavitären Afterloading-Boost-Bestrahlung des Analkanalkarzinoms werden vorgestellt. Patienten und Methoden: 20 in Folge behandelte Patienten (T1 5%, T2 70%, T3 20%, T4 5%, N0 75%, N1 10%; N2 15%; alle M0) erhielten eine perkutane Bestrahlung (mediane Dosis 56 Gy, 46-64 Gy), simultan 5-FU und Mitomycin (75%) und einen intrakavitären Afterloading-Boost (eine oder zwei Fraktionen mit je 5 Gy in 5 mm Tiefe). Der mittlere Nachbeobachtungszeitraum lebender Patienten betrug 4,4±2,1 Jahre. Zehn kolostomiefrei Üerlebende wurden bezüglich Lebensqualität und anorektaler Manometriewerte untersucht. Ergebnisse: Gesamtüberleben, rezidivfreies und kolostomiefreies Überleben nach 5 Jahren betrugen 84%, 79% und 60%. Kein Todesfall war tumorassoziiert. Das einzige Lokalrezidiv konnte durch lokale Exzision kontrolliert werden. Alle drei Kolostomien waren toxizitätsbedingt. Der mediane Ruhedruck und Willkürdruck waren gegenüber einem Normalkollektiv um 51% bzw. 71% reduziert, die Lebensqualität jedoch vergleichbar mit der von gesunden Probanden. Schlussfolgerung: Das beschriebene Behandlungsschema ist sehr effektiv, aber mit erhöhter Toxizität verbunden.

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.

Ziel: Untersuchung einer für Anlagen mit asymmetrisch einstellbaren Blenden vorteilhaften Bestrahlungstechnik mit einer Kombination von kraniokaudal aneinander grenzenden Feldern und Feldern über die gesamte Zielvolumenlänge hinsichtlich des Feldanschlusses sowie der Schonung von Normalgewebe und Risikoorganen. Patient und Methode: Für ein in kraniokaudaler Richtung stark variierendes Zielvolumen im Beckenbereich wurde eine Füf-Felder-Technik mit individuell gewichteten und ausgeblockten Feldern geplant. Dabei grenzten drei Felder in kraniokaudaler Richtung aneinander, zwei weitere Felder erfassten das gesamte Zielvolumen. Der Feldanschluss wurde gemessen sowie im Bestrahlungsplanungssystem Helax TMS^© überprüft. Des Weiteren wurden eine Vier-Felder-Box sowie eine Gegenfeldtechnik geplant. Die-Dosis-Volumen-Histogramme für Zielvolumen, Blase, Darm und Weichteilgewebe wurden exportiert und die Normalgewebekomplikationswahrscheinlichkeiten (NTCP) bzw. Tumorkontrollwahrscheinlichkeiten (TCP) für die einzelnen Techniken verglichen. Ergebnisse: Im Bereich des Feldanschlusses ergaben sich durch Summation der gemessenen, in Feldmitte normierten Kurven relative Dosisüberhöhungen von 6,0% im kaudalen Bereich bzw. 4,5% im kranialen Bereich. Die Maxima im Bereich des Feldanschlusses werden durch Felder über die gesamte Zielvolumenlänge auf 2,0% (kaudal) bzw. 1,8% (kranial) verringert. Für die im Helax TMS^© berechneten Dosisprofile konnten Überhöhungen nicht festgestellt werden. Die Fünf-Felder-Technik mit aneinander grenzenden Feldern zeigt eine deutliche Schonung der Risikoorgane im Vergleich zu den anderen Techniken bei gleicher Tumorkontrolle. Schlussfolgerungen: In ausgewählten Fällen ist eine Technik mit kraniokaudaler aneinander grenzenden Feldern hinsichtlich der Schonung von Normalgewebe und Risikoorganen zu empfehlen. Aim: A treatment technique favorable for linacs with asymmetric jaws, which combined cranio-caudal matching fields with fields enclosing the whole target volume, is investigated with respect to field matching and sparing of normal tissue and organs at risk. Patient and Methods: For a pelvic target volume rapidly varying in cranio-caudal direction a 5-field technique was planned with individually weighted and blocked fields. Three fields adjoining in cranio-caudal direction were completed by 2 fields enclosing the whole target volume. The matching line was measured and calculated with Helax TMS^©. Furthermore a 4-field box and opposing fields were planned. The dose-volume histograms for target, bladder, intestine and soft tissue were exported. Normal tissue complication probability and tumor control probability, respectively, were calculated for all techniques. Results: In the region of the matching line the summation of the measured normalized curves resulted in relative dose maxima of 6.0% (caudal) and 4.5% (cranial), respectively. For fields enclosing the whole target volume the dose maxima in the region of the matching line decreased to 2.0% (caudal) and 1.8% (cranial), respectively. For the dose profiles calculated with Helax TMS^© no overdose was found. The 5-field technique with adjoining fields results in a better sparing of the organs at risk compared to the other techniques, whereas the tumor control remains the same. Conclusions: In specific cases a technique with cranio-caudal adjoining fields can be recommended with respect to sparing of normal tissue and organs at risk.

Background: The use of modern irradiation techniques requires better verification films for determining set-up deviations and patient movements during the course of radiation treatment. This is an investigation of the image quality and time requirement of a new verification film system compared to a conventional portal film system. Material and Methods: For conventional verifications we used Agfa Curix HT 1000 and 381 Kodak EC-L portal films of different tumor sites (prostate, rectum, head and neck) were visually judged on a light box by 2 experienced physicians. Subjective judgement of image quality, masking of films and time requirement were checked. Results: In this investigation 68% of 175 Kodak EC-L ap/pa-films were judged ",good", only 18% were classified "moderate" or "poor" 14%, but only 22% of 173 conventional ap/pa verification films (Agfa Curix HT 1000) were judged to be "good". Conclusions: The image quality, detail perception and time required for film inspection of the new Kodak EC-L film system were significantly improved when compared with standard portal films. They could be read more accurately and the detection of set-up deviation was facilitated. Hintergrund: Vergleich von Bildqualität, Bildbetrachtungszeit und Anzahl der Kontrollaufnahmen bei Verifikationsaufnahmen mit einem herkömmlichen (Agfa Curix HT 1000) und einem neuen Film-Folien-System (Kodak EC-L). Material und Methode: Bei den Bestrahlungsserien von drei unterschiedlichen Tumorlokalisationen (Prostata, Rektum und Kopf/Hals) wurden die Verifikationskontrollen zweier Film-Folien-Systeme verglichen. 344 Agfa-Curix-HT-1000- und 381 Kodak-EC-L-Filme wurden dabei ausgewertet. Die Bildqualität beider Film-Folien-Systeme wurde mit einem subjektiven Fragebogen erfragt, Einblendungsbedarf und die Bildbetrachtungszeit wurden erfasst. Ergebnisse: Bei der Auswertung der ap/pa angefertigten Verifikationsaufnahmen wurden 68% der 175 Aufnahmen der Kodak-EC-L-Filme, aber nur 22% der 173 herkömmlichen Agfa-Curix-HT-Filme als gut klassifiziert. Schlussfolgerung: Die Bildqualität der neuen Kodak-EC-L-Filme war signifikant besser und erleichterte die Auswertung der Verifikationsaufnahmen. So wurden relevante Abweichungen seit der Umstellung auf das neue Film-Folien-System besser erkannt.

IMPORTANCE: Total neoadjuvant therapy has been increasingly adopted for multimodal rectal cancer treatment. The optimal sequence of chemoradiotherapy (CRT) and chemotherapy needs to be established. OBJECTIVE: To report the long-term results of the secondary end points prespecified in the Randomized Phase 2 Trial of Chemoradiotherapy Plus Induction or Consolidation Chemotherapy as Total Neoadjuvant Therapy (CAO/ARO/AIO-12 trial) for Locally Advanced Rectal Cancer. DESIGN, SETTING, AND PARTICIPANTS: This secondary analysis of a randomized clinical trial included 311 patients who were recruited from the accrued CAO/ARO/AIO-12 trial population from June 15, 2015, to January 31, 2018, from 18 centers in Germany. Patients with cT3-4 and/or node-positive rectal adenocarcinoma were included in the analysis. Data were analyzed from June 15, 2015, to January 31, 2018. The follow-up analysis was conducted between January 31, 2018, and November 30, 2020. INTERVENTIONS: Patients were randomly assigned to group A for 3 cycles of fluorouracil, leucovorin, and oxaliplatin before fluorouracil/oxaliplatin CRT (50.4 Gy), or to group B for CRT before chemotherapy. Total mesorectal excision was scheduled on day 123 after the start of total neoadjuvant therapy in both groups. MAIN OUTCOMES AND MEASURES: The end points assessed in this secondary analysis included long-term oncologic outcomes, chronic toxicity, patient-reported outcome measures for global health status (GHS) and quality of life (QoL), and the Wexner stool incontinence score. RESULTS: Of the 311 patients enrolled, 306 were evaluable, including 156 in group A (mean [SD] age, 60 [11] years; 106 men [68%]) and 150 in group B (mean [SD] age, 62 [10] years; 100 men [67%]). After a median follow-up of 43 months (range, 35-60 months), the 3-year disease-free survival was 73% in both groups (hazard ratio, 0.95; 95% CI, 0.63-1.45, P = .82); the 3-year cumulative incidence of locoregional recurrence (6% vs 5%, P = .67) and distant metastases (18% vs 16%, P = .52) were not significantly different. Chronic toxicity grade 3 to 4 occurred in 10 of 85 patients (11.8%) in group A and 8 of 66 patients (9.9%) in group B at 3 years. The GHS/QoL score decreased after total mesorectal excision but returned to pretreatment levels 1 year after randomization with no difference between the groups. Stool incontinence deteriorated 1 year after randomization in both groups and only improved slightly at 3 years, but never reached baseline levels. CONCLUSIONS AND RELEVANCE: This secondary analysis of a randomized clinical trial showed that CRT followed by chemotherapy resulted in higher pathological complete response without compromising disease-free survival, toxicity, QoL, or stool incontinence and is thus proposed as the preferred total neoadjuvant therapy sequence if organ preservation is a priority. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02363374

Abstract: Background: It was the aim of the quality control program of the randomized trial HIT ’91 (intensive chemotherapy before irradiation versus maintenance chemotherapy after irradiation) to assess prospectively the quality of neuroaxis irradiation with respect to the protocol guidelines and to evaluate acute toxicity with respect to treatment arm. Patients, Materials and Methods: Data of 134 patients undergoing irradiation of the craniospinal axis were available. Positioning aids, shielding techniques, treatment machines, choice of energy, total dose and fractionation were evaluated. A total of 651 simulation and verification films were analyzed to assess the coverage of the clinical target volume (whole brain, posterior fossa, sacral nerve roots) and deviations of field alignment between simulation and verification of first treatment. Field matching between whole brain and adjacent cranial spinal fields was analyzed with respect to site and width of junction. Acute maximal side effects were evaluated according to a modified WHO score for neurotoxicity, infections, skin, mucosa and myelotoxicity. Results: In 91.3% of patients contemporary positioning aids and individualized shielding techniques were used to assure a reproducible treatment. In 98 patients (73.1%) linear accelerators and in 36 patients (26.8%) 60Cobalt machines were used. Single and total dose were administered according to the protocol guidelines in more than 90% of patients. In 20.2% of patients the cribriform plate, in 1.4% the middle cranial fossa and in 21.1% the posterior fossa and in 4.5% the 2nd sacral segment were incompletely encompassed by the treatment portals. Ninety-five percent of deviations of field alignment were less than 13.0 mm (whole brain) and 12 mm (cranial spinal field) with a random error between 4.9 and 7.6 mm (whole brain) and 6.9 mm and 9.9 mm (spinal canal), respectively. In 77.5% of patients the junctions between whole brain and cranial spinal fields were placed without a gap. A gap between 5 and 10 mm was left in 15 patients (18.7%), exceeding 10 mm in 3 patients. Acute neurotoxicity and skin reactions were mild, the rate of infections was low in both treatment arms. However, myelotoxicity resulted in interruptions of radiotherapy in 31.9% after intensive chemotherapy as compared to 20.0% without preceding chemotherapy. Conclusions: In the HIT ’91 trial a precise radiotherapy of craniospinal axis has been performed in the majority of patients. Our findings indicate that the high quality is possibly an important contributing factor for the therapeutic outcome. However, preceding intensive chemotherapy caused marked toxicity of subsequent irradiation leading to a high rate of interruptions. Our database is subject to a future analysis of recurrences.

Zusammenfassung: Hintergrund: In den letzten Jahren hat sich die kombinierte Radiochemotherapie mit platinhaltigen Substanzen zur Standardtherapie des inoperablen nichtkleinzelIigen Bronchialkarzinoms entwickelt. Neueren Substanzen, allen voran Taxol, wird ein noch höheres Wirkungspotential zugeschrieben. Bestrahlung: Trotz ermutigender Ergebnisse bleiben der lokal progrediente Tumor und die systemische Fernmetastasierung Hauptprobleme dieser Erkrankung. Die lokale Kontrolle kann durch Erhöhung der Gesamtdosis der Bestrahlung, durch die Verkürzung der Behandlungszeit in akzelerierten Fraktionierungsschemata und durch die Gabe radiosensibilisierender Substanzen verbessert werden. Die 3D-konforme Bestrahlungsplanung, zum Teil mit intensitätsmodulierten Feldern, kombiniert mit biologischen Berechnungsmodellen, ermöglicht eine risikoadaptierte Intensivierung der Bestrahlung. Taxol: Taxol wird ein strahlenwirkungsverstarkender Effekt aufgrund eines Zellzyklusarrests in der G2/M-Phase zugeschrieben. Strahlenbiologische Arbeiten fanden diesbezüglich widersprüchliche Ergebnisse. Der Wirkmechanismus der „Radiosensibilisierung” bleibt unklar und ist wohl nicht ausschließlich auf einen G2/M-Block zurückzuführen. Für die simultane Radiochemotherapie mit wochentlichen Taxol-Gaben wurde bei einer Gesamtdosis von 60 bis 66 Gy (normfraktioniert) in mehreren Dosisfindungsstudien eine Taxol-Dosis von 60 mg/m2 übereinstimmend als maximal tolerable Dosis festgestellt. Änderungen der Taxol-Gaben (zum Beispiel täglich, zweimal wöchentlich oder zweiwöchentlich) oder der Fraktionierung und Gesamtdosis der Strahlentherapie führen zu einer entsprechenden Dosisanpassung des Taxols. Die dosislimitierende Toxizität der kombinierten Radiochemotherapie mit Taxol ist in den meisten Studien die (reversible) Ösophagitis. Die zusätzliche sequentielle Kombinationschemotherapie (beispielsweise Taxol 200 mg/m2 plus Carboplat AUC 6) ist bei der hohen Fernmetastasierungsrate grundsätzlich empfehlenswert.

Background: In clinical radiotherapy most patients tolerate the applied dosage with no or moderate side effects. However, 5 to 10% of all individuals show increased acute and/or late reactions. In-vitro test systems are investigated for their suitability for predictive purposes. This paper attempts a correlation between the induction and repair of DNA damage measured in the comet assay and the clinical observed reaction in order to evaluate the suitability of the comet assay for prediction of radiation sensitivity. Patients and Methods: Skin fibroblasts of 30 patients with average tissue reactions or acute and/or late increased side effects and cell lines of 4 individuals carrying the heritable disease ataxia telangiectasia (AT) were irradiated in vitro. The induction and repair of DNA damage was measured at different time points after irradiation in the comet assay (single cell gel electrophoresis). These results were compared to the acute and late clinical reactions classified according to the RTOG grading system. Results: The radiation induced DNA damage decreased over time reflecting DNA repair. Cells of the AT individuals showed an elevated damage induction and a reduced repair capacity compared to patients with average tissue reactions. Fibroblasts of patients with increased acute and late side effects exhibited slower DNA repair. In addition to the known lack of cell cycle control, our results indicate that AT cells show reduced DNA repair capacity. Conclusions: The comet assay seems to be able to detect some types of increased individual radiation sensitivity. In contrast to other predictive in-vitro tests, the comet assay needs less time and fewer cells, which would be useful in a clinical setting. Hintergrund: Eine strahlentherapeutische Behandlung wird von der Mehrzahl der Patienten mit keinen oder nur geringen Nebenwirkungen überstanden. Bei 5 bis 10% der Behandelten zeigen sich jedoch stärkere Akut- und/oder Spätnebenwirkungen. Verschiedene In-vitro-Tests werden untersucht, um die individuelle Strahlensensibilität schon prätherapeutisch zu bestimmen. In dieser Arbeit wird der mit dem Comet Assay gemessene induzierte und reparierte DNS-Schaden in in vitro bestrahlten Patientenfibroblasten mit den klinisch beobachteten Nebenwirkungen korreliert und somit seine Eignung als prädiktiver Test für Strahlensensibilität überprüft. Patienten und Methodik: Die Hautfibroblasten von insgesamt 30 Patienten mit durchschnittlichen Strahlenreaktionen oder mit erhöhten Früh- und/oder Spätnebenwirkungen sowie von vier Patienten mit Ataxia teleangiectatica wurden in vitro bestrahlt. Indukion und Reparatur des DNS-Schadens wurden zu verschiedenen Zeitpunkten nach Bestrahlung mit dem Comet Assay gemessen. Die Ergebnisse wurden mit den klinischen Akut- und Spätnebenwirkungen (klassifiziert nach der RTOG-Graduierung) dieser Patienten verglichen. Ergebnisse: Der strahleninduzierte DNS-Schaden nahm im Laufe der Zeit durch DNS-Reparatur wieder ab. Die Zellen der homozygoten AT-Träger zeigten im Vergleich zu den übrigen Patienten eine erhöhte Schadensinduktion und eine verminderte Reparaturkapazität. Zusätzlich zum Verlust der Zellzykluskontrolle scheinen AT-Zellen eine verminderte DNS-Reparaturkapazität zu haben. Die Fibroblasten der Patienten mit überdurchschnittlichen Akut- und/oder Spätnebenwirkungen zeigten im Vergleich zu den Patienten mit durchschnittlicher Strahlenreaktion eine langsamere DNS-Reparatur. Schlußfolgerungen: Mit Hilfe des Comet Assay scheint sich die individuelle Strahlensensibilität bestimmen zu lassen. Im Gegensatz zu anderen prädiktiven Tests braucht diese Methode weniger Zeit und Zellen und erleichtert somit den klinischen Einsatz.

Background and purpose: The existence of hereditary factors influencing the cellular response to ionising radiation, has led to the hypothesis that the inter-patient variability of clinical radiation reactions may, at least in part, be attributable to an individual, or intrinsic, radiosensitivity. Considerable effort has been spent in the development of test systems that would determine individual radiosensitivity before or early during radiotherapy to possibly predict treatment outcome, but the results are still conflicting. The present explorative study was therefore aimed at the detection of associations between acute and late radiation effects, tumour control and in vitro radiosensitivity of primary normal tissue fibroblasts.

For patients with advanced-stage or poor-prognosis malignant lymphoma, high-dose therapy with peripheral blood progenitor cell (PBPC) support may become a first-line treatment. The duration of severe cytopenia in this setting is inversely related to the number of PBPCs autografted. In a retrospective analysis, we therefore looked for factors influencing the yield of PBPCs in 61 patients (16 with high-grade and 29 with low-/intermediate-grade non-Hodgkin's lymphoma [NHL], and 16 with Hodgkin's disease) who received cytotoxic chemotherapy and filgrastim (R-metHuG-CSF, 300 μg/d; median, 4.2 μg/kg/d; range, 2.7 to 6.6 μg/ kg/d; subcutaneously). Sixteen patients had active disease, while 45 were in partial remission (PR) or complete remission (CR) after conventional therapy. A median of three leukaphereses (range, one to 10) resulted in a median of 5.7 × 106CD34+cells/kg (range, 0.03 to 31.1 × 106). Previous cytotoxic chemotherapy and irradiation adversely affected the yield of CD34+cells. Each cycle of chemotherapy is associated with an average decrease of 0.2 × 106CD34+cells/kg per leukapheresis in nonirradiated patients, while large-field radiotherapy reduces the collection efficiency by an average of 1.8 × 106/kg CD34+ cells. The collection efficiency was also significantly lower in patients with Hodgkin's disease. However, except for one, all had been previously irradiated. In contrast, age, sex, disease status, bone marrow involvement during mobilization, and the time since the last chemotherapy or radiotherapy were not significantly related to the collection efficiency. Following high-dose conditioning therapy, 42 patients were autografted with filgrastim-mobilized PBPCs. Hematological recovery (neutrophils ≥0.5 × 109/L and an unsupported platelet count ≥20 × 109/L) within 2 weeks was observed in patients autografted with ≥2.5 × 106CD34+cells/kg. In seven patients, the quantity of CD34+cells reinfused was below this threshold. They required a median of 17 days (range, 11 to 34) and 31 days (range, 13 to 141) for neutrophil and platelet recovery, respectively. K autografting with PBPCs in malignant lymphoma with poor prognosis is being considered, mobilization and harvesting should be planned early after initial diagnosis to avoid exhaustion of hematopoiesis by cumulative toxicity.

The ability of amphotericin B (AmB) to potentiate the cytotoxicity of several different anticancer agents against two murine tumor models was examined. A spleen colony assay was used to quantitate the cytotoxicity of BCNU, CCNU, and l-PAM, either alone or in combination with AmB against the MOPC-315 plasmacytoma. A high level of potentiation of the effects of CCNU and l-PAM by AmB occurred, but AmB did not increase the cytotoxicity of BCNU. Tumor growth curves and calculation of cell survival demonstrated significant potentiation of the cytotoxicity of CCNU by AmB against SC Lewis lung carcinoma.

Zusammenfassung: Ziel: Die brusterhaltende Therapie des Mammakarzinoms mit konservativer Operation und konsekutiver Bestrahlung wird im Rahmen dieser retrospektiven Studie in Hinblick auf lokale Tumorkontrolle, Überleben und kosmetische Ergebnisse überprüft. Patienten und Methode: Alle Mammakarzinom-Patientinnen der Heidelberger Strahlenklinik mit brusterhaltender Therapie aus den Jahren 1984 bis 1992 wurden befragt und einbestellt. Mittels Fragebogen wurde die persönliche Einschätzung des kosmetischen Ergebnisses der Behandlung erfaßt. Kosmetik, Umfänge und Temperaturen verschiedener Brustregionen wurden vom Untersucher beurteilt und gemessen. Nebenwirkungen und Spätfolgen der Bestrahlung wurden nach dem EORTC/RTOG-Score bewertet. Ergebnisse: 192 Patientinnen der Stadien pT1 (71,9%) und pT2 (28,1%) konnten durchschnittlich 4,5 Jahre (Median: vier Jahre) nachbeobachtet werden. Nodal positiv waren 26,6% der Patientinnen. Lymphknotenbefall korrelierte mit schlechtem Grading des Tumors (p=0,0001). Zehnmal traten Fernmetastasen auf, davon einmal bei Lokalrezidiv. Acht Patientinnen hatten Lokalrezidive, drei davon traten vor Bestrahlung (Salvage) auf. Insgesamt traten nach Bestrahlung füf Lokalrezidive auf (=2,6%), davon waren drei Frauen prä-, zwei postmenopausal. Drei der betroffenen Patientinnen sind verstorben, einmal traten Fernmetastasen auf. 17 der 192 Patientinnen verstarben, drei davon wiesen ein Lokalrezidiv, acht Fernmetastasen auf. 64 Patientinnen wurden im Hinblick auf das kosmetische Ergebnis untersucht. Es war zweimal schlecht, 13mal mäßig, 34mal gut, 15mal sehr gut bei signifikant besserer Selbsteinschätzung als durch den Untersucher. Das Ergebnis der späten Strahlenreaktion: einmal trat eine drittgradige Spätfolge auf, elfmal zweitgradige, 38mal erstgradige und 14mal keine sichtbare. Bei Bestrahlung mit Keilfilter zeigte sich ein tendenziell besseres Langzeit- und kosmetisches Ergebnis (p=0,06). Weder die Operationsmethode (Quadranten-, Segmentresektion, Tumorexzision) noch die Breite des Bestrahlungsfeldes, die Strahlenqualität (Co60 oder 6 MVX) oder die Applikation eines Boosts auf das ehemalige Tumorbett hatten Einfluß auf die Kosmetik. Kein signifikanter Unterschied fand sich bei den Armumfängen der befallenen und unbefallenen Seite. Bei Temperaturmessungen korrespondierender Areale der erkrankten und der kontralateralen Brust fanden sich keine signifikanten Differenzen. Mit zunehmendem zeitlichen Abstand zur Primärbehandlung verschlechterten sich die kosmetischen Ergebnisse. Schlußfolgerung: Die brusterhaltende Therapie des Mammakarzinoms erbringt bei wirksamer lokaler Tumorkontrolle gute bis sehr gute kosmetische Resultate mit akzeptablen Nebenwirkungen. Die geringfügige Verschlechterung der kosmetischen Ergebnisse im längeren zeitlichen Verlauf ist biologisch interessant und bedarf weiterer Klärung.

In vitro colony formation and chemosensitivity were analyzed in 65 human solid tumors and compared to proliferation parameters simultaneously obtained by DNA flow cytometry of the same tumor specimens.

Comparative in vitro drug testing was performed in 72 of 183 surgically removed human colorectal cancer specimens (34 primary lesions, 38 metastases). In 10 of these tumors, comparative dose-response curves were obtained. Given a =70% ICF (inhibition of colony formation) as threshold for in vitro sensitivity, 5-FU was active in 16/62 specimens, and FUDR in 14/62. significantly discordant sensitivity results were observed in 8/62 tests, 5-FU being the more active agent in 5 of these cases. These data are supported by the finding of 3 considerably differing dose-response curves in 10 additional comparative studies of human primary tumors.

Cancer fatalities result from metastatic dissemination and therapy resistance, both processes that depend on signals from the tumor microenvironment. To identify how invasion and resistance programs cooperate, we used intravital microscopy of orthotopic sarcoma and melanoma xenografts. We demonstrate that these tumors invade collectively and that, specifically, cells within the invasion zone acquire increased resistance to radiotherapy, rapidly normalize DNA damage, and preferentially survive. Using a candidate-based approach to identify effectors of invasion-associated resistance, we targeted β1 and αVβ3/β5 integrins, essential extracellular matrix receptors in mesenchymal tumors, which mediate cancer progression and resistance. Combining radiotherapy with β1 or αV integrin monotargeting in invading tumors led to relapse and metastasis in 40–60% of the cohort, in line with recently failed clinical trials individually targeting integrins. However, when combined, anti-β1/αV integrin dual targeting achieved relapse-free radiosensitization and prevented metastatic escape. Collectively, invading cancer cells thus withstand radiotherapy and DNA damage by β1/αVβ3/β5 integrin cross-talk, but efficient radiosensitization can be achieved by multiple integrin targeting.

Knop: Takeda: Consultancy. Einsele:Celgene: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Speakers Bureau. Mielke:MSD: Consultancy, Other: Travel grants; Gilead: Other: Travel grants; Novartis: Consultancy; Celgene: Other: Travel grants, Speakers Bureau; JAZZ Pharma: Speakers Bureau.