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Dive into the research topics where Christhardt Koehler is active.

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Featured researches published by Christhardt Koehler.


Radiation Oncology | 2015

Which technique for radiation is most beneficial for patients with locally advanced cervical cancer? Intensity modulated proton therapy versus intensity modulated photon treatment, helical tomotherapy and volumetric arc therapy for primary radiation – an intraindividual comparison

Simone Marnitz; Waldemar Wlodarczyk; Oliver Neumann; Christhardt Koehler; Mirko Weihrauch; Volker Budach; Luca Cozzi

BackgroundTo compare highly sophisticated intensity-modulated radiotherapy (IMRT) delivered by either helical tomotherapy (HT), RapidArc (RA), IMRT with protons (IMPT) in patients with locally advanced cervical cancer.Methods and materialsTwenty cervical cancer patients were irradiated using either conventional IMRT, VMAT or HT; ten received pelvic (PEL) and ten extended field irradiation (EFRT). The dose to the planning-target volume A (PTV_A: cervix, uterus, pelvic ± para-aortic lymph nodes) was 1.8/50.4 Gy. The SIB dose for the parametrium (PTV_B), was 2.12/59.36 Gy. MRI-guided brachytherapy was administered with 5 fractions up to 25 Gy. For EBRT, the lower target constraints were 95% of the prescribed dose in 95% of the target volume. The irradiated small bowel (SB) volumes were kept as low as possible. For every patient, target parameters as well as doses to the organs at risk (SB, bladder, rectum) were evaluated intra-individually for IMRT, HT, VMAT and IMPT.ResultsAll techniques provided excellent target volume coverage, homogeneity, conformity. With IMPT, there was a significant reduction of the mean dose (Dmean) of the SB from 30.2 ± 4.0 Gy (IMRT); 27.6 ± 5.6 Gy (HT); 34.1 ± 7.0 (RA) to 18.6 ± 5.9 Gy (IMPT) for pelvic radiation and 26.3 ± 3.2 Gy (IMRT); 24.0 ± 4.1 (HT); 25.3 ± 3.7 (RA) to 13.8 ± 2.8 Gy (IMPT) for patients with EFRT, which corresponds to a reduction of 38-52% for the Dmean (SB). Futhermore, the low dose bath (V10Gy) to the small bowel was reduced by 50% with IMPT in comparison to all photon techniques. Furthermore, Dmean to the bladder and rectum was decresed by 7-9 Gy with IMPT in patents with pelvic radiation and EFRT.ConclusionAll modern techniques (were proved to be dosimetrically adequate regarding coverage, conformity and homogeneity of the target. Protons offered the best sparing of small bowel and rectum and therefore could contribute to a significant reduction of acute and late toxicity in cervical cancer treatment.


Journal of Perinatal Medicine | 2012

Neonatal outcome in infants of patients with radical vaginal trachelectomy

Mandy Mangler; Dorothee Speiser; Bich Doan Nguyen; Malte Cremer; Christhardt Koehler; Achim Schneider; Malgorzata Lanowska

Abstract Objective: Radical vaginal trachelectomy (RVT) as a fertility-preserving surgery in patients with early-stage cervical cancer is proven to be oncologically safe. After RVT, pregnancy rates vary between 40% and 80%. Outcome of infants is complicated by a preterm delivery rate of 30–50%. We investigated pregnancy and neonatal outcome after RVT. Methods: A total of 154 patients with cervical cancer underwent RVT between March 1995 and February 2008. Desire to conceive, pregnancy data, and neonatal outcome were prospectively recorded. Infants’ data were pair-matched to data of a control group according to weeks of gestation. Bayley scales of infant development scores were recorded in the group of preterm-delivered infants. Results: Fifty-five women who underwent RVT gave birth to 58 children. Twenty-five (43%) pregnancies were complicated by preterm rupture of membranes. Thirty infants (52%) were born preterm, of with 17 (29%) were <32 gestational weeks (GW) and seven (12%) were <28 GW. There were significantly more premature rupture of membranes in pregnancies after RVT. Despite a higher occurrence of postnatal infections in newborns of mothers who underwent RVT, long-term outcomes are not affected negatively. Regarding overall morbidity, a trend to fewer postnatal complications, compared with the control group, was found. Conclusion: Postnatal morbidity in infants of women who underwent RVT, based on trend, is decreased compared with controls. Intense medical observation and treatment during pregnancy, birth, and neonatal period may explain this finding. Neonates in the RVT group have a non-significantly elevated risk for postnatal infections. They do not show an additional risk due to the maternal operation. Their long-term postnatal outcome is not affected negatively.


Jsls-journal of The Society of Laparoendoscopic Surgeons | 2011

Vaginal-Assisted Laparoscopic Radical Hysterectomy: Rationale, Technique, Results

Elisabeth Gottschalk; Malgorzata Lanowska; Vito Chiantera; Simone Marnitz; Achim Schneider; Verena Brink-Spalink; Kati Hasenbein; Christhardt Koehler

The authors conclude that vaginal-assisted laparoscopic radical hysterectomy is an oncologic viable alternative to abdominal radical hysterectomy, laparoscopic-assisted radical vaginal hysterectomy, totally laparoscopic radical hysterectomy, and robotic radical hysterectomy.


Journal of Perinatal Medicine | 2006

Sonographic monitoring of systemic and local methotrexate (MTX) therapy in patients with intact interstitial pregnancies

Petra Klemm; Christhardt Koehler; Karl-Heinz Eichhorn; Peter Hillemanns; Achim Schneider

Abstract Objective: After the confirmation of an intact interstitial pregnancy through sonographic diagnosis and laparoscopy, systemic and local methotrexate therapy is a well established conservative treatment to preserve the uterus. The parameters of successful treatment are the course of serum hCG value and sonographic changes. In this case series we describe sonographic monitoring under methotrexate (MTX) application and the residual sonographic findings after completing therapy. Methods: Three consecutive patients (two singleton and one twin pregnancy) with intact interstitial pregnancies were diagnosed and treated with MTX between 2000 and 2004. During the treatment we recorded the hCG values, maximum size of the interstitial lesion, vitality of the pregnancy, and vascularization. Results: In all patients the sonographic diagnosis of an interstitial pregnancy was confirmed by laparoscopy. Following systemic MTX therapy, the hCG values normalised within 8 weeks in the singleton pregnancies and in 10 weeks in the twin pregnancy. During conservative therapy vascularization in the lesion withered continuously. The size of the primary myometrial lesion decreased at a slow rate and part of the lesion persisted in all three patients. Conclusion: Despite decreasing hCG levels, residual sonographic patterns of an interstitial ectopic pregnancy persist in the uterine wall.


Journal of Minimally Invasive Gynecology | 2005

Laparoscopy versus laparotomy in endometrial cancer: First analysis of survival of a randomized prospective study

Roberto Tozzi; Sabine Malur; Christhardt Koehler; Achim Schneider


Gynecologic Oncology | 2005

Analysis of morbidity in patients with endometrial cancer: is there a commitment to offer laparoscopy?

Roberto Tozzi; Sabine Malur; Christhardt Koehler; Achim Schneider


Journal of Perinatal Medicine | 2005

Laparoscopic and vaginal repair of uterine scar dehiscence following cesarean section as detected by ultrasound.

Petra Klemm; Christhardt Koehler; Mandy Mangler; Uwe Schneider; Achim Schneider


Fertility and Sterility | 2011

Pregnancy after lymphadenectomy and neoadjuvant chemotherapy followed by radical vaginal trachelectomy in FIGO stage IB1 cervical cancer

Elisabeth Gottschalk; Mandy Mangler; Achim Schneider; Christhardt Koehler; Malgorzata Lanowska


Gynecological Surgery | 2007

Temporary clipping of the uterine artery during laparoscopic myomectomy—a new technique and the results of first cases

Martin Voss; Christhardt Koehler; Florian Elger; Susanne Kruppa; Achim Schneider


Radiation Oncology | 2013

Optimizing image guidance frequency and implications on margins for gynecologic malignancies

Carmen Stromberger; Arne Gruen; Waldemar Wlodarczyk; Volker Budach; Christhardt Koehler; Simone Marnitz

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Roberto Tozzi

The Royal Marsden NHS Foundation Trust

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