scholarly journals Isotropic Expansion of the Intraprostatic Gross Tumor Volume of Primary Prostate Cancer Patients Defined in MRI—A Correlation Study With Whole Mount Histopathological Information as Reference

2020 ◽  
Vol 10 ◽  
Author(s):  
Maria Kramer ◽  
Simon K. B. Spohn ◽  
Selina Kiefer ◽  
Lara Ceci ◽  
August Sigle ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Ex Vivo ◽  
Standard Of Care ◽  
Volumetric Analysis ◽  
Correlation Study ◽  
Lesion Detection ◽  
Coverage Ratio ◽  
Primary Prostate Cancer

IntroductionAn accurate delineation of the intraprostatic gross tumor volume (GTV) is of importance for focal treatment in patients with primary prostate cancer (PCa). Multiparametric MRI (mpMRI) is the standard of care for lesion detection but has been shown to underestimate GTV. This study investigated how far the GTV has to be expanded in MRI in order to reach concordance with the histopathological reference and whether this strategy is practicable in clinical routine.Patients and MethodsTwenty-two patients with planned prostatectomy and preceded 3 Tesla mpMRI were prospectively examined. After surgery, PCa contours delineated on histopathological slides (GTV-Histo) were superimposed on MRI using ex-vivo imaging as support for co-registration. According to the PI-RADSv2 classification, GTV was manually delineated in MRI (GTV-MRI) by two experts in consensus. For volumetric analysis, we compared GTV-MRI and GTV-Histo. Subsequently, we isotropically enlarged GTV-MRI in 1 mm increments within the prostate and also compared those with GTV-Histo regarding the absolute volumes. For evaluating the spatial accuracy, we considered the coverage ratio of GTV-Histo, the Sørensen–Dice coefficient (DSC), as well as the contact with the urethra.ResultsIn 19 of 22 patients MRI underestimated the intraprostatic tumor volume compared to histopathological reference: median GTV-Histo (4.7 cm3, IQR: 2.5–18.8) was significantly (p<0.001) lager than median GTV-MRI (2.6 cm3, IQR: 1.2–6.9). A median expansion of 1 mm (range: 0–4 mm) adjusted the initial GTV-MRI to at least the volume of GTV-Histo (GTVexp-MRI). Original GTV-MRI and expansion with 1, 2, 3, and 4 mm covered in median 39% (IQR: 2%–78%), 62% (10%–91%), 70% (15%–95%), 80% (21–100), 87% (25%–100%) of GTV-Histo, respectively. Best DSC (median: 0.54) between GTV-Histo and GTV-MRI was achieved by median expansion of 2 mm. The urethra was covered by initial GTVs-MRI in eight patients (36%). After applying an expansion with 2 mm the urethra was covered in one more patient by GTV-MRI. ConclusionUsing histopathology as reference, we demonstrated that MRI underestimates intraprostatic tumor volume. A 2 mm–expansion may improve accurate GTV-delineation while respecting the balance between histological tumor coverage and overtreatment.

scholarly journals Comparison of Manual and Semi-Automatic [18F]PSMA-1007 PET Based Contouring Techniques for Intraprostatic Tumor Delineation in Patients With Primary Prostate Cancer and Validation With Histopathology as Standard of Reference

2020 ◽  
Vol 10 ◽  
Author(s):  
Simon K. B. Spohn ◽  
Maria Kramer ◽  
Selina Kiefer ◽  
Peter Bronsert ◽  
August Sigle ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gross Tumor Volume ◽  
Interobserver Agreement ◽  
Tumor Volume ◽  
High Sensitivity ◽  
Dice Similarity Coefficient ◽  
Primary Prostate Cancer ◽  
Psma Pet ◽  
Significant Difference ◽  
Automatic Contouring

PurposeAccurate contouring of intraprostatic gross tumor volume (GTV) is pivotal for successful delivery of focal therapies and for biopsy guidance in patients with primary prostate cancer (PCa). Contouring of GTVs, using 18-Fluor labeled tracer prostate specific membrane antigen positron emission tomography ([18F]PSMA-1007/PET) has not been examined yet.Patients and MethodsTen Patients with primary PCa who underwent [18F]PSMA-1007 PET followed by radical prostatectomy were prospectively enrolled. Coregistered histopathological gross tumor volume (GTV-Histo) was used as standard of reference. PSMA-PET images were contoured on two ways: (1) manual contouring with PET scaling SUVmin-max: 0–10 was performed by three teams with different levels of experience. Team 1 repeated contouring at a different time point, resulting in n = 4 manual contours. (2) Semi-automatic contouring approaches using SUVmax thresholds of 20–50% were performed. Interobserver agreement was assessed for manual contouring by calculating the Dice Similarity Coefficient (DSC) and for all approaches sensitivity, specificity were calculated by dividing the prostate in each CT slice into four equal quadrants under consideration of histopathology as standard of reference.ResultsManual contouring yielded an excellent interobserver agreement with a median DSC of 0.90 (range 0.87–0.94). Volumes derived from scaling SUVmin-max 0–10 showed no statistically significant difference from GTV-Histo and high sensitivities (median 87%, range 84–90%) and specificities (median 96%, range 96–100%). GTVs using semi-automatic segmentation applying a threshold of 20–40% of SUVmax showed no significant difference in absolute volumes to GTV-Histo, GTV-SUV50% was significantly smaller. Best performing semi-automatic contour (GTV-SUV20%) achieved high sensitivity (median 93%) and specificity (median 96%). There was no statistically significant difference to SUVmin-max 0–10.ConclusionManual contouring with PET scaling SUVmin-max 0–10 and semi-automatic contouring applying a threshold of 20% of SUVmax achieved high sensitivities and very high specificities and are recommended for [18F]PSMA-1007 PET based focal therapy approaches. Providing high specificities, semi-automatic approaches applying thresholds of 30–40% of SUVmax are recommend for biopsy guidance.

scholarly journals 68Ga-PSMA-11 PET, 18F-PSMA-1007 PET, and MRI for Gross Tumor Volume Delineation in Primary Prostate Cancer: Intermodality and Intertracer Variability

2021 ◽  
Vol 11 (3) ◽  
pp. 202-211
Author(s):  
Cédric Draulans ◽  
Floris Pos ◽  
Robert J. Smeenk ◽  
Linda Kerkmeijer ◽  
Wouter V. Vogel ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gross Tumor Volume ◽  
Tumor Volume ◽  
Volume Delineation ◽  
Primary Prostate Cancer

Gross tumor volume and clinical target volume in prostate cancer: How do satellites relate to the index lesion

2015 ◽  
Vol 115 (1) ◽  
pp. 96-100 ◽  
Author(s):  
Birgit G. Hollmann ◽  
Baukelien van Triest ◽  
Ghazaleh Ghobadi ◽  
Greetje Groenendaal ◽  
Jeroen de Jong ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Gross Tumor Volume ◽  
Clinical Target Volume ◽  
Tumor Volume ◽  
Target Volume ◽  
Index Lesion

scholarly journals 68Ga-PSMA Cerenkov luminescence imaging in primary prostate cancer: first-in-man series

2020 ◽  
Vol 47 (11) ◽  
pp. 2624-2632 ◽  
Author(s):  
Judith olde Heuvel ◽  
Berlinda J. de Wit-van der Veen ◽  
Henk G. van der Poel ◽  
Elise M. Bekers ◽  
Maarten R. Grootendorst ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Ex Vivo ◽  
Surgical Margin ◽  
Ongoing Study ◽  
Positive Surgical Margin ◽  
Margin Assessment ◽  
Luminescence Imaging ◽  
Cerenkov Luminescence Imaging ◽  
Primary Prostate Cancer ◽  
Intraoperative Margin Assessment

Abstract Purpose Currently, approximately 11–38% of prostate cancer (PCa) patients undergoing radical prostatectomy have a positive surgical margin (PSM) on histopathology. Cerenkov luminescence imaging (CLI) using 68Ga-prostate-specific membrane antigen (68Ga-PSMA) is a novel technique for intraoperative margin assessment. The aim of this first-in-man study was to investigate the feasibility of intraoperative 68Ga-PSMA CLI. In this study, feasibility was defined as the ability to distinguish between a positive and negative surgical margin, imaging within 45 min and low radiation exposure to staff. Methods Six patients were included in this ongoing study. Following perioperative i.v. injection of ~ 100 MBq 68Ga-PSMA, the prostate was excised and immediately imaged ex vivo. Different acquisition protocols were tested, and hotspots on CLI images from the intact prostate were marked for comparison with histopathology. Results By using an acquisition protocol with 150 s exposure time, 8 × 8 binning and a 550 nm shortpass filter, PSMs and negative surgical margins (NSMs) were visually correctly identified on CLI in 3 of the 5 patients. Two patients had a hotspot on CLI from cancer < 0.1 mm from the excision margin. Conclusion Overall, the study showed that 68Ga-PSMA CLI is a feasible and low-risk technique for intraoperative margin assessment in PCa. The remaining patients in this ongoing study will be used to assess the diagnostic accuracy of the technique. Trial registration: NL8256 registered at www.trialregister.nl on 04/11/20109.

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