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Purpose: Histone deacetylase inhibitors (HDACIs) can enhance the sensitivity of cells to photon radiation treatment (XRT) by altering numerous molecular pathways. We investigated the effect of pan-HDACIs such as suberoylanilide hydroxamic acid (SAHA) on radiation response in two osteosarcoma (OS) and two rhabdomyosarcoma (RMS) cell lines., Methods and Materials: Clonogenic survival, cell cycle analysis, and apoptosis were examined in OS (KHOS-24OS, SAOS2) and RMS (A-204, RD) cell lines treated with HDACI and HDACI plus XRT, respectively. Protein expression was investigated via immunoblot analysis, and cell cycle analysis and measurement of apoptosis were performed using flow cytometry., Results: SAHA induced an inhibition of cell proliferation and clonogenic survival in OS and RMS cell lines and led to a significant radiosensitization of all tumor cell lines. Other HDACI such as M344 and valproate showed similar effects as investigated in one OS cell line. Furthermore, SAHA significantly increased radiation-induced apoptosis in the OS cell lines, whereas in the RMS cell lines radiation-induced apoptosis was insignificant with and without SAHA. In all investigated sarcoma cell lines, SAHA attenuated radiation-induced DNA repair protein expression (Rad51, Ku80)., Conclusion: Our results show that HDACIs enhance radiation action in OS and RMS cell lines. Inhibition of DNA repair, as well as increased apoptosis induction after exposure to HDACIs, can be mechanisms of radiosensitization by HDACIs., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Purpose: We analyzed our experience with intraoperative electron radiotherapy (IOERT) followed by moderate doses of external beam radiotherapy (EBRT) after organ-sparing surgery in patients with primary or recurrent aggressive fibromatosis., Methods and Materials: Indication for IOERT and postoperative EBRT as an individual treatment approach to avoid mutilating surgical procedures was seen when complete surgical removal seemed to be unlikely or impossible. A total of 31 lesions in 30 patients were treated by surgery and IOERT with a median dose of 12 Gy. Median age was 31 years (range, 13-59 years). Resection status was close margin in six lesions, microscopically positive in 13, and macroscopically positive in 12. Median tumor size was 9 cm. In all, 25 patients received additional EBRT, with a median dose of 45 Gy (range, 36-54 Gy)., Results: After a median follow-up of 32 months (range, 3-139 months), no disease-related deaths occurred. A total of five local recurrences were seen, resulting in actuarial 3-year local control rates of 82% overall and 91% inside the IOERT areas. Trends to improved local control were seen for older age (>31 years) and negative margins, but none of these factors reached significance. Perioperative complications were found in six patients, in particular as wound healing disturbances in five patients and venous thrombosis in one patient. Late toxicity was seen in five patients., Conclusion: Introduction of IOERT into a multimodal treatment approach in patients with aggressive fibromatosis is feasible with low toxicity and yielded good local control rates even in patients with microscopical or gross residual disease., (Copyright 2010 Elsevier Inc. All rights reserved.)

Purpose: To evaluate toxicity and outcomes in patients with primary glioblastoma (GB) treated with postoperative radiochemotherapy (RCHT) with temozolomide (TMZ) comparing two dose regimens., Methods and Materials: A total of 160 patients with histologically confirmed GB were treated with postoperative RCHT with TMZ. Of the patients, 66 were female and 94 were male, with a median age of 60 years. After the primary diagnosis, a biopsy had been performed in 42 patients; a subtotal and total resection was conducted in 66 and 52 patients. Postoperative radiotherapy was applied with a median dose of 60 Gy with a median fractionation of 5 x 2Gy/week. Concomitant TMZ was prescribed at 50 mg/m(2) in 123 patients (Group A) and at 75 mg/m(2) in 37 patients (Group B). Patients were followed in 3-months intervals, with a median follow-up of 13 months., Results: Overall survival (OS) rates in Group A vs. Group B were 67% and 79% at 1 year and 43% vs. 49% at 2 years, respectively (p = 0.69). Progression-free survival was 49% vs. 54% at 1 year and 22% vs. 29% at 2 years (p = 0.31). Hematologic toxicity was not statistically significant over the 6-week RCHT period except for a significant decrease in platelets during Week 6 (p = 0.01) in Group B., Conclusions: Overall survival seems to be comparable in both groups, although longer follow-up and a larger group of patients are needed to corroborate these results. Lower dosing of TMZ also is associated with a more beneficial toxicity profile.

Purpose: To assess the outcome of 57 patients with localized ependymomas treated with radiotherapy (RT)., Methods and Materials: Fifty-seven patients with localized ependymomas were treated with RT. Histology was myxopapillary ependymoma (n = 4), ependymoma (n = 23), and anaplastic ependymoma (n = 30). In 16 patients, irradiation of the craniospinal axis (CSI) was performed with a median dose of 20 Gy. Forty-one patients were treated with local RT, with a local dose of 45 Gy to the posterior fossa, including a boost to the tumor bed of 9 Gy. In 19 patients, the tumor bed was irradiated with a median dose of 54 Gy., Results: Overall survival after primary diagnosis was 83% and 71% at 3 and 5 years. Five-year overall survival was 80% in low-grade and 79% in high-grade tumors. Survival from RT was 79% at 3 and 64% at 5 years. We could not show a significant difference in overall survival between CSI and local RT only. Freedom of local failure was 67% at 5 years in patients treated with CSI and 60% at 5 years after local RT. A rate of 83% for distant failure-free survival could be observed in the CSI group as opposed to 93% in the group receiving local RT only., Conclusion: Local RT in patients with localized tumors is equieffective to CSI. The radiation oncologist must keep in mind that patients with localized ependymomas benefit from local doses > or =45 Gy.

Purpose: To evaluate efficacy and toxicity in elderly patients with glioblastoma multiforme (GBM) treated with postoperative radiochemotherapy with temozolomide (TMZ)., Patients and Methods: Forty-three patients aged 65 years or older were treated with postoperative with radiochemotherapy using TMZ for primary GBM. Median age at primary diagnosis was 67 years; 14 patients were female, 29 were male. A complete surgical resection was performed in 12 patients, subtotal resection in 17 patients, and biopsy only in 14 patients. Radiotherapy was applied with a median dose of 60 Gy, in a median fractionation of 5x2 Gy/wk. Thirty-five patients received concomitant TMZ at 50 mg/m2, and in 8 patients 75 mg/m2 of TMZ was applied. Adjuvant cycles of TMZ were prescribed in 5 patients only., Results: Median overall survival was 11 months in all patients; the actuarial overall survival rate was 48% at 1 year and 8% at 2 years. Median overall survival was 18 months after complete resection, 16 months after subtotal resection, and 6 months after biopsy only. Median progression-free survival was 4 months; the actuarial progression-free survival rate was 41% at 6 months and 18% at 12 months. Radiochemotherapy was well tolerated in most patients and could be completed without interruption in 38 of 43 patients. Four patients developed hematologic side effects greater than Common Terminology Criteria Grade 2, which led to early discontinuation of TMZ in 1 patient., Conclusions: Radiochemotherapy is safe and effective in a subgroup of elderly patients with GBM and should be considered in patients without major comorbidities.

Purpose: The aim of this study is to implement augmented reality in real-time image-guided interstitial brachytherapy to allow an intuitive real-time intraoperative orientation., Methods and Materials: The developed system consists of a common video projector, two high-resolution charge coupled device cameras, and an off-the-shelf notebook. The projector was used as a scanning device by projecting coded-light patterns to register the patient and superimpose the operating field with planning data and additional information in arbitrary colors. Subsequent movements of the nonfixed patient were detected by means of stereoscopically tracking passive markers attached to the patient., Results: In a first clinical study, we evaluated the whole process chain from image acquisition to data projection and determined overall accuracy with 10 patients undergoing implantation. The described method enabled the surgeon to visualize planning data on top of any preoperatively segmented and triangulated surface (skin) with direct line of sight during the operation. Furthermore, the tracking system allowed dynamic adjustment of the data to the patient's current position and therefore eliminated the need for rigid fixation. Because of soft-part displacement, we obtained an average deviation of 1.1 mm by moving the patient, whereas changing the projector's position resulted in an average deviation of 0.9 mm. Mean deviation of all needles of an implant was 1.4 mm (range, 0.3-2.7 mm)., Conclusions: The developed low-cost augmented-reality system proved to be accurate and feasible in interstitial brachytherapy. The system meets clinical demands and enables intuitive real-time intraoperative orientation and monitoring of needle implantation.

Purpose: To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition., Methods and Materials: We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.4 Gy), and in 88% simultaneous chemotherapy was applied. Median follow-up was 59 months., Results: Local failure was observed in 17 patients (7%), resulting in a 5-year local control rate of 92%. Only complete resection and absence of nodal involvement correlated positively with local control. Considering IOERT fields, seven infield recurrences were seen in the presacral space, resulting in a 5-year local control rate of 97%. The remaining local relapses were located as follows: retrovesical/retroprostatic (5), anastomotic site (2), promontorium (1), ileocecal (1), and perineal (1)., Conclusion: Intraoperative electron beam radiotherapy as part of a multimodal treatment approach including TME is a highly effective regimen to prevent local failure. The presacral space remains the site of highest risk for local failure, but IOERT can decrease the percentage of relapses in this area.

Purpose: Salvage radiotherapy (RT) is used to treat patients with biochemical failure after radical prostatectomy (RP). Although retrospective series have demonstrated that salvage RT will result in biochemical response in approximately 75% of patients, long-term response is much lower (20-40%). The purpose of this study was to determine prognostic factors related to the prostate-specific antigen (PSA) outcome after salvage RT., Methods and Materials: Between 1991 and 2004, 171 patients received salvage RT at the University of Heidelberg. Patient age, margin status, Gleason score, tumor grading, pathologic tumor stage, pre-RP and pre-RT PSA levels, and time from RP to rise of PSA were analyzed., Results: Median follow-up time was 39 months. The 5-year overall and clinical relapse-free survival were 93.8% and 80.8%, respectively. After RT serum PSA decreased in 141 patients (82.5%). The 5-year biochemical relapse-free survival was 35.1%. Univariate analysis showed following statistically significant predictors of PSA recurrence after RT: preoperative PSA level (p = 0.035), pathologic tumor classification (p = 0.001), Gleason score (p < 0.001), tumor grading (p = 0.004), and pre-RT PSA level (p = 0.031). On multivariate analysis, only Gleason score (p = 0.047) and pre-RT PSA level (p = 0.049) were found to be independently predictive of PSA recurrence., Conclusions: This study represents one of the largest retrospective studies analyzing the outcome of patients treated with salvage RT at a single institution. Our findings suggest that patients with Gleason score <7 and low pre-RT PSA levels are the best candidates for salvage RT, whereas patients with high-grade lesions should be considered for additional treatment (e.g., hormonal therapy).

Background: We analyzed the long-term results of patients with locally advanced rectal cancer using a multimodal approach consisting of total mesorectal excision (TME), intraoperative electron-beam radiation therapy (IOERT), and pre- or postoperative chemoradiation (CRT)., Patients and Methods: Between 1991 and 2003, 210 patients with locally advanced rectal cancer (65 International Union Against Cancer [UICC] Stage II, 116 UICC Stage III, and 29 UICC Stage IV cancers) were treated with TME, IOERT, and preoperative or postoperative CHT. A total of 122 patients were treated postoperatively; 88 patients preoperatively. Preoperative or postoperative fluoropyrimidine-based CRT was applied in 93% of these patients., Results: Median age was 61 years (range, 26-81). Median follow-up was 61 months. The 5-year actuarial overall survival (OS), disease-free survival (DFS), local control rate (LC), and distant relapse free survival (DRS) of all patients was 69%, 66%, 93%, and 67%, respectively. Multivariate analysis revealed that UICC stage and resection status were the most important independent prognostic factors for OS, DFS, and DRS. The resection status was the only significant factor for local control. T-stage, tumor localization, type of resection, and type of chemotherapy had no significant impact on OS, DFS, DRS, and LC. Acute and late complications > or =Grade 3 were seen in 17% and 13% of patients, respectively., Conclusion: Multimodality treatment with TME and IOERT boost in combination with moderate dose pre- or postoperative CRT is feasible and results in excellent long-term local control rates in patients with intermediate to high-risk locally advanced rectal cancer.

Purpose: This is the first preclinical report evaluating a trimodal therapy consisting of irradiation, chemotherapy, and antiangiogenesis in the context of a multimodal anticancer strategy. The combination of the folate antimetabolite pemetrexed, SU5416, a receptor tyrosine kinase inhibitor of VEGFR2, and irradiation was investigated in human endothelial cells and tumor cell lines., Methods and Materials: Primary isolated human umbilical vein endothelial cells (HUVEC), human dermal microvascular endothelial cells (HDMEC), and human glioblastoma (U87) and prostate cancer cells (PC3) were exposed to pemetrexed (2 h) alone and in combination with SU5416 (2 h). When combined with irradiation up to 8 Gy, fixed concentrations of pemetrexed (1.06 muM) and SU5416 (1.0 muM) were used. Proliferation and clonogenic assays were conducted with endothelial and tumor cells. The migration/invasion ability of endothelial cells and the ability to produce tubular structures were tested in Matrigel and tube formation assays. Apoptosis was measured by sub-G1 DNA and caspase-3 flow cytometry. To investigate underlying cell signaling, immunocytochemistry was used to detect Akt survival signaling involvement., Results: Triple combination using only a low-toxicity drug exposure of pemetrexed and SU5416 results in greater response than each treatment alone or than each combination of two modalities in all tested endothelial and tumor cell models. Triple combination substantially inhibits proliferation, migration/invasion, tube formation, and clonogenic survival. Triple combination also induced the highest rate of apoptosis in HDMEC and HUVEC as indicated by sub-1 G1 and caspase-3 assessment. Interestingly, triple combination therapy also reduces proliferation and clonogenic survival significantly in U87 and PC3 tumor cell lines. SU5416 potently inhibited Akt phosphorylation which could be induced by radiation and radiochemotherapy in human endothelial cells., Conclusions: Our findings demonstrate the high antiendothelial/antitumoral efficacy of the concurrent administration of irradiation, chemotherapy, and angiogenesis inhibition in vitro. A potential explanation for the favorable combination would be that VEGF signaling inhibition downregulates Akt survival signaling upon activation by radiation and/or chemotherapy. The data also suggest that endothelial cell apoptosis may have an important role in the benefits of the presented therapy.

Purpose: The novel folate antimetabolite Alimta (pemetrexed disodium, LY231514) exhibits antitumor activity in a broad array of human malignancies and was recently found to enhance radiation-induced cell killing in vitro. In the present study, a possible cell cycle phase-specific radiosensitization by pemetrexed was assessed., Methods and Materials: Widr human colon carcinoma cells were synchronized by serum withdrawal/stimulation that yielded about 80% cells with G1 DNA content 6 h after replating and more than 60% S-phase cells after 22 h, as assessed by flow cytometry. The respective cultures were irradiated with doses up to 12 Gy in combination with a subtoxic pemetrexed exposure (1.06 microM for 2 h: about 80% survival), or after mock treatment. Survival curves were generated by the clonogenic assay; apoptosis was measured by sub-G1 DNA flow cytometry., Results: The combination treatment of the G1 cells and of the more radioresistant S-phase cell preparations yielded survival rates that were lower than expected for independent cell killing. Radiosensitization, calculated as the ratio of the mean inactivation doses without or with drug exposure (enhancement ratio), was not significantly different for the two cell preparations (enhancement ratio of 2.1 and 2.3, respectively) and was similar to the previously reported value for log-phase cells. Pemetrexed exposure was unable to stimulate an apoptotic response of these cells to radiation., Conclusions: Radiosensitization by pemetrexed is not cell cycle phase-specific, and the relative radioresistance of S-phase cells is retained. Apoptosis seems to have no influence on radiosensitization in this cell line.

Purpose: Pemetrexed disodium (Alimta, multitargeted antifolate, LY231514; Eli Lilly and Co., Indianapolis, Indiana) ("pemetrexed") is a new folate antimetabolite with significant antitumor activity. Different from classic antifolates, pemetrexed inhibits several key enzymes of thymidylate and purine synthesis, but a radiosensitizing potential may also be presumed. Therefore, the interaction of pemetrexed and ionizing radiation was studied for in vitro clonogenic survival of different human tumor cell lines., Methods and Materials: Human colon (Widr), breast (MCF-7), cervix (Hela), and lung (LXI) carcinoma cells from log-phase cultures were exposed to pemetrexed (2 h) in combination with different radiation doses given 1 h before pemetrexed washout (all cell lines) or at different points of time before or after pemetrexed addition (Widr). Survival curves were analyzed according to the linear-quadratic (LQ) model, and mean inactivation doses (MID) and radiation enhancement ratios were calculated from the survival curve parameters. Cell-cycle progression of serum-stimulated and pemetrexed- or mock-treated Widr cells was monitored by flow cytometry., Results: Radiosensitization was found for all cell lines at moderately toxic pemetrexed exposures (0.05-0.3 microg/ml [106-636 nM]), but this was cell-type dependent and was most pronounced at roughly isotoxic concentrations, for the least pemetrexed-sensitive Widr cells. Enhancement ratios ranged from about 1.2 (MCF-7 and Hela) to 1.8 (Widr), with a tendency to increase with pemetrexed concentration. Little, if any, change of radiosensitization was observed (Widr) when the time of irradiation was varied from 4 h before to 10 h after the beginning of pemetrexed treatment. Cell-cycle progression of serum-stimulated Widr cells was only marginally affected by pemetrexed., Conclusions: Pemetrexed enhances radiation-induced cell inactivation at moderately toxic exposures and over many hours after drug removal. This effect is not due to disturbed cell-cycle progression, but likely involves an interaction of pemetrexed with long-lived (>4 h) cellular radiation damage and needs to be considered when introducing a combined clinical application.