@article{WilbertGuckenbergerPolatetal.2010, author = {Wilbert, Juergen and Guckenberger, Matthias and Polat, Buelent and Sauer, Otto and Vogele, Michael and Flentje, Michael and Sweeney, Reinhart A.}, title = {Semi-robotic 6 degree of freedom positioning for intracranial high precision radiotherapy; first phantom and clinical results}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68613}, year = {2010}, abstract = {Background: To introduce a novel method of patient positioning for high precision intracranial radiotherapy. Methods: An infrared(IR)-array, reproducibly attached to the patient via a vacuum-mouthpiece(vMP) and connected to the table via a 6 degree-of-freedom(DoF) mechanical arm serves as positioning and fixation system. After IR-based manual prepositioning to rough treatment position and fixation of the mechanical arm, a cone-beam CT(CBCT) is performed. A robotic 6 DoF treatment couch (HexaPOD™) then automatically corrects all remaining translations and rotations. This absolute position of infrared markers at the first fraction acts as reference for the following fractions where patients are manually prepositioned to within ± 2 mm and ± 2° of this IR reference position prior to final HexaPOD-based correction; consequently CBCT imaging is only required once at the first treatment fraction. The preclinical feasibility and attainable repositioning accuracy of this method was evaluated on a phantom and human volunteers as was the clinical efficacy on 7 pilot study patients. Results: Phantom and volunteer manual IR-based prepositioning to within ± 2 mm and ± 2° in 6DoF was possible within a mean(± SD) of 90 ± 31 and 56 ± 22 seconds respectively. Mean phantom translational and rotational precision after 6 DoF corrections by the HexaPOD was 0.2 ± 0.2 mm and 0.7 ± 0.8° respectively. For the actual patient collective, the mean 3D vector for inter-treatment repositioning accuracy (n = 102) was 1.6 ± 0.8 mm while intra-fraction movement (n = 110) was 0.6 ± 0.4 mm. Conclusions: This novel semi-automatic 6DoF IR-based system has been shown to compare favourably with existing non-invasive intracranial repeat fixation systems with respect to handling, reproducibility and, more importantly, intrafraction rigidity. Some advantages are full cranial positioning flexibility for single and fractionated IGRT treatments and possibly increased patient comfort.}, subject = {Strahlentherapie}, language = {en} } @article{MantelFlentjeGuckenberger2013, author = {Mantel, Frederick and Flentje, Michael and Guckenberger, Matthias}, title = {Stereotactic body radiation therapy in the re-irradiation situation - a review}, series = {Radiation Oncology}, journal = {Radiation Oncology}, doi = {10.1186/1748-717X-8-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96346}, year = {2013}, abstract = {Although locoregional relapse is frequent after definitive radiotherapy (RT) or multimodal treatments, re-irradiation is only performed in few patients even in palliative settings like e.g. vertebral metastasis. This is most due to concern about potentially severe complications, especially when large volumes are exposed to re-irradiation. With technological advancements in treatment planning the interest in re-irradiation as a local treatment approach has been reinforced. Recently, several studies reported re-irradiation for spinal metastases using SBRT with promising local and symptom control rates and simultaneously low rates of toxicity. These early data consistently indicate that SBRT is a safe and effective treatment modality in this clinical situation, where other treatment alternatives are rare. Similarly, good results have been shown for SBRT in the re-irradiation of head and neck tumors. Despite severe late adverse effects were reported in several studies, especially after single fraction doses >10 Gy, they appear less frequently compared to conventional radiotherapy. Few studies with small patient numbers have been published on SBRT re-irradiation for non-small cell lung cancer (NSCLC). Overall survival (OS) is limited by systemic progression and seems to depend particularly on patient selection. SBRT re-irradiation after primary SBRT should not be practiced in centrally located tumors due to high risk of severe toxicity. Only limited data is available for SBRT re-irradiation of pelvic tumors: feasibility and acceptable toxicity has been described, suggesting SBRT as a complementary treatment modality for local symptom control.}, language = {en} } @article{GuckenbergerAlexandrowFlentje2012, author = {Guckenberger, Matthias and Alexandrow, Nikolaus and Flentje, Michael}, title = {Radiotherapy alone for stage I-III low grade follicular lymphoma: long-term outcome and comparison of extended field and total nodal irradiation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75702}, year = {2012}, abstract = {Background: To analyze long-term results of radiotherapy alone for stage I-III low grade follicular lymphoma and to compare outcome after extended field irradiation (EFI) and total nodal irradiation (TNI). Methods and materials: Between 1982 and 2007, 107 patients were treated with radiotherapy alone for low grade follicular lymphoma at Ann Arbor stage I (n = 50), II (n = 36) and III (n = 21); 48 and 59 patients were treated with EFI and TNI, respectively. The median total dose in the first treatment series of the diaphragmatic side with larger lymphoma burden was 38 Gy (25 Gy - 50 Gy) and after an interval of median 30 days, a total dose of 28 Gy (12.6 Gy - 45 Gy) was given in the second treatment series completing TNI. Results: After a median follow-up of 14 years for living patients, 10-years and 15-years overall survival (OS) were 64\% and 50\%, respectively. Survival was not significantly different between stages I, II and III. TNI and EFI resulted in 15-years OS of 65\% and 34\% but patients treated with TNI were younger, had better performance status and higher stage of disease compared to patients treated with EFI. In multivariate analysis, only age at diagnosis (p<0.001, relative risk [RR] 1.06) and Karnofsky performance status (p = 0.04, RR = 0.96) were significantly correlated with OS. Freedom from progression (FFP) was 58\% and 56\% after 10-years and 15-years, respectively. Recurrences outside the irradiated volume were significantly reduced after TNI compared to EFI; however, increased rates of in-field recurrences and extra-nodal out-of-field recurrence counterbalanced this effect resulting in no significant difference in FFP between TNI and EFI. In univariate analysis, FFP was significantly improved in stage I compared to stage II but no differences were observed between stages I/II and stage III. In multivariate analysis no patient or treatment parameter was correlated with FFP. Acute toxicity was significantly increased after TNI compared to EFI with a trend to increased late toxicity as well. Conclusions: Radiotherapy alone for stage I and II follicular lymphoma resulted in long-term OS with high rates of disease control; no benefit of TNI over EFI was observed. For stage III follicular lymphoma, TNI achieved promising OS and FFP and should be considered as a potentially curative treatment option.}, subject = {Medizin}, language = {en} } @article{GuckenbergerRoeschBaieretal.2012, author = {Guckenberger, Matthias and Roesch, Johannes and Baier, Kurt and Sweeney, Reinhart A. and Flentje, Michael}, title = {Dosimetric consequences of translational and rotational errors in frame-less image-guided radiosurgery}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75669}, year = {2012}, abstract = {Background: To investigate geometric and dosimetric accuracy of frame-less image-guided radiosurgery (IG-RS) for brain metastases. Methods and materials: Single fraction IG-RS was practiced in 72 patients with 98 brain metastases. Patient positioning and immobilization used either double- (n = 71) or single-layer (n = 27) thermoplastic masks. Pre-treatment set-up errors (n = 98) were evaluated with cone-beam CT (CBCT) based image-guidance (IG) and were corrected in six degrees of freedom without an action level. CBCT imaging after treatment measured intra-fractional errors (n = 64). Pre- and posttreatment errors were simulated in the treatment planning system and target coverage and dose conformity were evaluated. Three scenarios of 0 mm, 1 mm and 2 mm GTV-to-PTV (gross tumor volume, planning target volume) safety margins (SM) were simulated. Results: Errors prior to IG were 3.9 mm± 1.7 mm (3D vector) and the maximum rotational error was 1.7° ± 0.8° on average. The post-treatment 3D error was 0.9 mm± 0.6 mm. No differences between double- and single-layer masks were observed. Intra-fractional errors were significantly correlated with the total treatment time with 0.7mm±0.5mm and 1.2mm±0.7mm for treatment times ≤23 minutes and >23 minutes (p<0.01), respectively. Simulation of RS without image-guidance reduced target coverage and conformity to 75\% ± 19\% and 60\% ± 25\% of planned values. Each 3D set-up error of 1 mm decreased target coverage and dose conformity by 6\% and 10\% on average, respectively, with a large inter-patient variability. Pre-treatment correction of translations only but not rotations did not affect target coverage and conformity. Post-treatment errors reduced target coverage by >5\% in 14\% of the patients. A 1 mm safety margin fully compensated intra-fractional patient motion. Conclusions: IG-RS with online correction of translational errors achieves high geometric and dosimetric accuracy. Intra-fractional errors decrease target coverage and conformity unless compensated with appropriate safety margins.}, subject = {Medizin}, language = {en} } @article{GuckenbergerHawkinsFlentjeetal.2012, author = {Guckenberger, Matthias and Hawkins, Maria and Flentje, Michael and Sweeney, Reinhart A.}, title = {Fractionated radiosurgery for painful spinal metastases: DOSIS - a phase II trial}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75853}, year = {2012}, abstract = {Background One third of all cancer patients will develop bone metastases and the vertebral column is involved in approximately 70 \% of these patients. Conventional radiotherapy with of 1-10 fractions and total doses of 8-30 Gy is the current standard for painful vertebral metastases; however, the median pain response is short with 3-6 months and local tumor control is limited with these rather low irradiation doses. Recent advances in radiotherapy technology - intensity modulated radiotherapy for generation of highly conformal dose distributions and image-guidance for precise treatment delivery - have made dose-escalated radiosurgery of spinal metastases possible and early results of pain and local tumor control are promising. The current study will investigate efficacy and safety of radiosurgery for painful vertebral metastases and three characteristics will distinguish this study. 1) A prognostic score for overall survival will be used for selection of patients with longer life expectancy to allow for analysis of long-term efficacy and safety. 2) Fractionated radiosurgery will be performed with the number of treatment fractions adjusted to either good (10 fractions) or intermediate (5 fractions) life expectancy. Fractionation will allow inclusion of tumors immediately abutting the spinal cord due to higher biological effective doses at the tumor - spinal cord interface compared to single fraction treatment. 3) Dose intensification will be performed in the involved parts of the vertebrae only, while uninvolved parts are treated with conventional doses using the simultaneous integrated boost concept. Methods / Design It is the study hypothesis that hypo-fractionated image-guided radiosurgery significantly improves pain relief compared to historic data of conventionally fractionated radiotherapy. Primary endpoint is pain response 3 months after radiosurgery, which is defined as pain reduction of ≥2 points at the treated vertebral site on the 0 to 10 Visual Analogue Scale. 60 patients will be included into this two-centre phase II trial. Conclusions Results of this study will refine the methods of patient selection, target volume definition, treatment planning and delivery as well as quality assurance for radiosurgery. It is the intention of this study to form the basis for a future randomized controlled trial comparing conventional radiotherapy with fractionated radiosurgery for palliation of painful vertebral metastases. Trial registration ClinicalTrials.gov Identifier: NCT01594892}, subject = {Medizin}, language = {en} } @article{TamihardjaSchortmannLawrenzetal.2021, author = {Tamihardja, J{\"o}rg and Schortmann, Max and Lawrenz, Ingulf and Weick, Stefan and Bratengeier, Klaus and Flentje, Michael and Guckenberger, Matthias and Polat, B{\"u}lent}, title = {Moderately hypofractionated radiotherapy for localized prostate cancer: updated long-term outcome and toxicity analysis}, series = {Strahlentherapie und Onkologie}, volume = {197}, journal = {Strahlentherapie und Onkologie}, issn = {0179-7158}, doi = {10.1007/s00066-020-01678-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232509}, pages = {124-132}, year = {2021}, abstract = {Purpose Evaluation of long-term outcome and toxicity of moderately hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost treatment planning and cone beam CT-based image guidance for localized prostate cancer. Methods Between 2005 and 2015, 346 consecutive patients with localized prostate cancer received primary radiotherapy using cone beam CT-based image-guided intensity-modulated radiotherapy (IG-IMRT) and volumetric modulated arc therapy (IG-VMAT) with a simultaneous integrated boost (SIB). Total doses of 73.9 Gy (n = 44) and 76.2 Gy (n = 302) to the high-dose PTV were delivered in 32 and 33 fractions, respectively. The low-dose PTV received a dose (D95) of 60.06 Gy in single doses of 1.82 Gy. The pelvic lymph nodes were treated in 91 high-risk patients to 45.5 Gy (D95). Results Median follow-up was 61.8 months. The 5‑year biochemical relapse-free survival (bRFS) was 85.4\% for all patients and 93.3, 87.4, and 79.4\% for low-, intermediate-, and high-risk disease, respectively. The 5‑year prostate cancer-specific survival (PSS) was 94.8\% for all patients and 98.7, 98.9, 89.3\% for low-, intermediate-, and high-risk disease, respectively. The 5‑year and 10-year overall survival rates were 83.8 and 66.3\% and the 5‑year and 10-year freedom from distant metastasis rates were 92.2 and 88.0\%, respectively. Cumulative 5‑year late GU toxicity and late GI toxicity grade ≥2 was observed in 26.3 and 12.1\% of the patients, respectively. Cumulative 5‑year late grade 3 GU/GI toxicity occurred in 4.0/1.2\%. Conclusion Moderately hypofractionated radiotherapy using SIB treatment planning and cone beam CT image guidance resulted in high biochemical control and survival with low rates of late toxicity.}, language = {en} } @article{TamihardjaLawrenzLutyjetal.2022, author = {Tamihardja, J{\"o}rg and Lawrenz, Ingulf and Lutyj, Paul and Weick, Stefan and Guckenberger, Matthias and Polat, B{\"u}lent and Flentje, Michael}, title = {Propensity score-matched analysis comparing dose-escalated intensity-modulated radiation therapy versus external beam radiation therapy plus high-dose-rate brachytherapy for localized prostate cancer}, series = {Strahlentherapie und Onkologie}, volume = {198}, journal = {Strahlentherapie und Onkologie}, number = {8}, doi = {10.1007/s00066-022-01953-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325055}, pages = {735-743}, year = {2022}, abstract = {Purpose Dose-escalated external beam radiation therapy (EBRT) and EBRT + high-dose-rate brachytherapy (HDR-BT) boost are guideline-recommended treatment options for localized prostate cancer. The purpose of this study was to compare long-term outcome and toxicity of dose-escalated EBRT versus EBRT + HDR-BT boost. Methods From 2002 to 2019, 744 consecutive patients received either EBRT or EBRT + HDR-BT boost, of whom 516 patients were propensity score matched. Median follow-up was 95.3 months. Cone beam CT image-guided EBRT consisted of 33 fractions of intensity-modulated radiation therapy with simultaneous integrated boost up to 76.23 Gy (D\(_{Mean}\)). Combined treatment was delivered as 46 Gy (D\(_{Mean}\)) EBRT, followed by two fractions HDR-BT boost with 9 Gy (D\(_{90\\%}\)). Propensity score matching was applied before analysis of the primary endpoint, estimated 10-year biochemical relapse-free survival (bRFS), and the secondary endpoints metastasis-free survival (MFS) and overall survival (OS). Prognostic parameters were analyzed by Cox proportional hazard modelling. Genitourinary (GU)/gastrointestinal (GI) toxicity evaluation used the Common Toxicity Criteria for Adverse Events (v5.0). Results The estimated 10-year bRFS was 82.0\% vs. 76.4\% (p = 0.075) for EBRT alone versus combined treatment, respectively. The estimated 10-year MFS was 82.9\% vs. 87.0\% (p = 0.195) and the 10-year OS was 65.7\% vs. 68.9\% (p = 0.303), respectively. Cumulative 5‑year late GU ≥ grade 2 toxicities were seen in 23.6\% vs. 19.2\% (p = 0.086) and 5‑year late GI ≥ grade 2 toxicities in 11.1\% vs. 5.0\% of the patients (p = 0.002); cumulative 5‑year late grade 3 GU toxicity occurred in 4.2\% vs. 3.6\% (p = 0.401) and GI toxicity in 1.0\% vs. 0.3\% (p = 0.249), respectively. Conclusion Both treatment groups showed excellent long-term outcomes with low rates of severe toxicity.}, language = {en} }