Daniel Koehler

Dr. Daniel Koehler

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 May 2021 in Cancers
Verified
Journal Article
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TFThorben Fründt
Thorben Fründt
LKLinda Krause
Linda Krause
EHElaine Hussey
Elaine Hussey
BSBettina Steinbach
Bettina Steinbach
DKDaniel Koehler
Daniel Koehler
HSHeidi Schwarzenbach
Heidi Schwarzenbach
We aimed to identify a specific microRNA (miRNA) pattern to determine diagnostic and prognostic value in plasma exosomes of hepatocellular carcinoma (HCC) patients. A two-stage study was carried out: exosomal miRNAs were quantified in plasma of HCC patients and healthy individuals by PCR-based microarray cards containing 45 different miRNAs (training cohort). Then, four deregulated miRNAs (miR-16, miR-146a, miR-192, and miR-221) were quantified in the validation analysis using exosomes derived from 85 HCC patients, 50 liver cirrhosis patients, and 20 healthy individuals. Exosomal miR-146a (p = 0.0001), miR-192 (p = 0.002) and miR-221 (p = 0.032) were upregulated only in HCC patients. Repeated 10-fold cross validation showed that miR-146a differentiated HCC from liver cirrhosis patients with AUC of 0.80 ± 0.14 (sensitivity: 81 ± 13%, specificity: 58 ± 22%) in a logistic regression model. High miR-192 presence is associated with poor overall survival (OS) in all HCC patients (p = 0.027) and was predictor of OS in HCC patients in an uni- and multivariate Cox regression model. Moreover, decreased miR-16 levels correlated with OS in liver cirrhosis patients (p = 0.034). Our results emphasized that exosomes secreted into the plasma carry differentially expressed miRNAs of which in particular, miR-192, miR-146, and miR-16 are promising diagnostic and prognostic markers for both HCC and liver cirrhosis patients.

14 July 2022 in Journal of Nuclear Medicine
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Journal Article
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DKDaniel Koehler
Daniel Koehler
MSMarkus Sauer
Markus Sauer
SKSusanne Klutmann
Susanne Klutmann
IAIvayla Apostolova
Ivayla Apostolova
WLWencke Lehnert
Wencke Lehnert
TMTobias Maurer
Tobias Maurer
This case series evaluated the feasibility of prostate-specific membrane antigen (PSMA) radioguided surgery (RGS) with 99mTc-MIP-1404 in recurrent prostate cancer. Methods: 9 patients with PSMA-positive lesions on PET/CT received 99mTc-MIP-1404 (median 747 MBq, interquartile range (IQR) 710 – 764) 17.2 hours (IQR 16.9 – 17.5) before SPECT/CT and 22.3 hours (IQR 20.8 – 24.0) before RGS. Results: 17 PSMA-positive lesions were detected on PET/CT (median short axis diameter 4 mm, IQR 3 – 6; median SUVmax 8.9, IQR 5.2 – 12.6). 9/17 (52.9%) were visible on SPECT/CT (median SUVmax 13.8, IQR 8.0 – 17.9). Except for 2 foci, all PET/CT-positive findings demonstrated intraoperative count rates above the background (median counts 31, IQR 17 – 89) and were lymph node metastases. Moreover, PSMA-RGS identified 2 additional metastases compared to PET/CT. Prostate-specific antigen values decreased after RGS in 6/9 (67%) patients. Conclusion: PSMA-RGS with 99mTc-MIP-1404 identified lymph node metastases in all patients including two additional lesions compared to PET/CT.

9 October 2022 in EJNMMI Research
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Journal Article
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DKDaniel Koehler
Daniel Koehler
MSMarkus Sauer
Markus Sauer
AKAmir Karimzadeh
Amir Karimzadeh
IAIvayla Apostolova
Ivayla Apostolova
SKSusanne Klutmann
Susanne Klutmann
CBChristoph Berliner
Christoph Berliner
Background: PSMA PET/CT is the recommended imaging test in cases with prostate-specific antigen (PSA) recurrence after primary therapy of prostate cancer (PCa). However, imaging protocols remain a topic of active research. The aim of the presented study was to examine the impact of additional late scans of the pelvis in [68 Ga]Ga-PSMA-I&T PET/CT of patients with rising PSA after prostatectomy. Methods: A total of 297 patients (median PSA 0.35 ng/ml, interquartile range (IQR) 0.2–0.8) who underwent early whole-body [68 Ga]Ga-PSMA-I&T PET/CT (median dose 141 MBq, IQR 120–163; median 86 min, IQR 56–107) and additional late scans of the pelvis (median 180 min, IQR 170–191) were investigated retrospectively. Early and late images were staged separately according to the PROMISE criteria and compared with a final consensus of both. Standardized uptake values were analyzed for early and late scans. Results: One hundred and thirty-four (45.1%) [68 Ga]Ga-PSMA-I&T PET/CT showed evidence of recurrent PCa (114/38.4% early, 131/44.1% late). Of 195 lesions, 144 (73.8%) were identified correctly on early scans. 191 (97.9%) lesions were detected on late imaging. The lesion SUVmax (median 3.4, IQR 0.4–6.5 vs. median 3.9, IQR 2.6–8.2) as well as the SUVmax to background ratio (median 9.4, IQR 1.7–19.1 vs. median 15.5, IQR 9.6–34.1) increased significantly between the imaging time points (p < 0.01, respectively). Compared to the final consensus, the miTNM-staging of early scans changed in 58 (19.5%) cases. Of these, 31 patients (10.4%) with negative early scans (T0 N0 M0) were upstaged. Twenty-seven (9.1%) patients with PCa characteristic lesions on early imaging (> T0 N0 M0) were up- and/or downstaged. In 4 (1.3%) cases, PCa-related lesions were only detectable on early PET/CT leading to upstagings of late imaging. Conclusions: Additional late scans of the pelvis in [68 Ga]Ga-PSMA-I&T PET/CT detected more lesions and an increasing contrast compared to early imaging. This influenced the final miTNM-staging substantially.

16 October 2023 in Cancers
Verified
Journal Article
Open access
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FFFabian Falkenbach
Fabian Falkenbach
FAFrancesca Ambrosini
Francesca Ambrosini
PTPierre Tennstedt
Pierre Tennstedt
MEMatthias Eiber
Matthias Eiber
MHMatthias M. Heck
Matthias M. Heck
TMTobias Maurer
Tobias Maurer
Objective: To assess the influence of biochemical recurrence (BCR) risk groups and PSA kinetics on the outcomes of radioguided surgery against prostate-specific membrane antigen (PSMA-RGS). Currently, neither BCR risk group nor PSA doubling time (PSA-DT), or PSA velocity (PSA-V) are actively assigned or relevant for counseling prior to PSMA-RGS. Methods: We retrospectively analyzed PSMA-RGS cases for oligorecurrent prostate cancer between 2014 and 2023. BCR risk groups, PSA-DT, and PSA-V were analyzed as predictors for complete biochemical response (cBR, PSA < 0.2 ng/mL), BCR-free, and therapy-free survival (BCRFS, TFS). Results: Of 374 included patients, only 21/374 (6%) and 201/374 (54%) were classified as low- and high-risk BCR (no group assignment possible in 152/374, 41%). A total of 13/21 (62%) patients with low- and 120/201 (60%) with high-risk BCR achieved cBR (p = 1.0). BCR classification was no predictor for BCRFS (HR:1.61, CI: 0.70–3.71, p = 0.3) or subsequent TFS (HR:1.07, CI: 0.46–2.47, p = 0.9). A total of 47/76 (62%) patients with PSA-DT ≤ 6 mo and 50/84 (60%) with PSA-DT > 6 mo achieved cBR (p = 0.4). PSA-DT was not associated with cBR (OR: 0.99, CI: 0.95–1.03, p = 0.5), BCRFS (HR: 1.00, CI: 0.97–1.03, p = 0.9), or TFS (HR: 1.02, CI: 0.99–1.04, p = 0.2). Consistent negative findings were recorded for PSA-V. Conclusions: The BCR risk groups and PSA kinetics do not predict the oncological success of PSMA-RGS performed at low absolute PSA values. Indolent low-risk BCR is rarely treated by PSMA-RGS.

29 February 2024 in Cancers
Verified
Journal Article
Open access
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IRInka Ristow
Inka Ristow
LWLennart Well
Lennart Well
NWNis Jesper Wiese
Nis Jesper Wiese
MWMalte Warncke
Malte Warncke
JTJoseph Tintelnot
Joseph Tintelnot
MSMarkus Sauer
Markus Sauer
Objectives: To compare the feasibility and reliability of manual versus software-assisted assessments of computed tomography scans according to iRECIST in patients undergoing immune-based cancer treatment. Methods: Computed tomography scans of 30 tumor patients undergoing cancer treatment were evaluated by four independent radiologists at baseline (BL) and two follow-ups (FU), resulting in a total of 360 tumor assessments (120 each at BL/FU1/FU2). After image interpretation, tumor burden and response status were either calculated manually or semi-automatically as defined by software, respectively. The reading time, calculated sum of longest diameter (SLD), and tumor response (e.g., “iStable Disease”) were determined for each assessment. After complete data collection, a consensus reading among the four readers was performed to establish a reference standard for the correct response assignments. The reading times, error rates, and inter-reader agreement on SLDs were statistically compared between the manual versus software-assisted approaches. Results: The reading time was significantly longer for the manual versus software-assisted assessments at both follow-ups (median [interquartile range] FU1: 4.00 min [2.17 min] vs. 2.50 min [1.00 min]; FU2: 3.75 min [1.88 min] vs. 2.00 min [1.50 min]; both p < 0.001). Regarding reliability, 2.5% of all the response assessments were incorrect at FU1 (3.3% manual; 0% software-assisted), which increased to 5.8% at FU2 (10% manual; 1.7% software-assisted), demonstrating higher error rates for manual readings. Quantitative SLD inter-reader agreement was inferior for the manual compared to the software-assisted assessments at both FUs (FU1: ICC = 0.91 vs. 0.93; FU2: ICC = 0.75 vs. 0.86). Conclusions: Software-assisted assessments may facilitate the iRECIST response evaluation of cancer patients in clinical routine by decreasing the reading time and reducing response misclassifications.

31 December 2024 in Cancers
Verified
Journal Article
Open access
PDF file
GMGiovanni Mazzucato
Giovanni Mazzucato
FFFabian Falkenbach
Fabian Falkenbach
MSMarie-Lena Schmalhofer
Marie-Lena Schmalhofer
FSFarzad Shenas
Farzad Shenas
MCMaria Angela Cerruto
Maria Angela Cerruto
TMTobias Maurer
Tobias Maurer
Background: To examine the feasibility and safety of the SENSEI® drop-in gamma probe for robot-assisted, prostate-specific membrane antigen (PSMA)-radioguided salvage surgery (RGS) in lymph node or local oligorecurrent prostate cancer (PCa), detected via PSMA positron emission tomography/computed tomography (PET/CT). Methods: The first thirteen patients with pelvic oligorecurrent PCa who underwent [99mTc]Tc-PSMA-I&S RGS using the SENSEI® drop-in gamma probe at the Martini-Klinik (February–June 2024) were retrospectively analyzed. Radioactivity measurements in counts per second (CPS) as absolute values or ratios (CPS of tumor specimens/mean CPS from the patients’ benign tissues) were correlated with preoperative imaging and pathological findings (benign/malignant, lesion size). Postoperative complete biochemical response (cBR) was defined as prostate-specific antigen (PSA) levels of <0.2 ng/mL. Results: Fifty-four specimens were removed from 13 patients, with nineteen (35%) containing PCa. All patients had one PSMA PET/CT-positive lesion, which were all detected intraoperatively. These lesions showed higher ex vivo CPS, CPS ratios, and larger cancer diameters than PSMA PET/CT-negative lesions (all p < 0.05). Cancer-containing specimens exhibited higher CPS and CPS ratios than benign tissues (median values of 45 vs. 3, and 9.9 vs. 1.0, both p < 0.001). In total, 12/13 (92%) patients achieved cBR. Conclusions: This device yielded excellent detection rates with good correlation to preoperative imaging and histological results without adverse events.