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3. Tools for large-scale data analytics of an international multi-center study in radiation oncology for cervical cancer

Author

Ecker, Stefan, Kirisits, Christian, Schmid, Maximilian, De Leeuw, Astrid, Seppenwoolde, Yvette, Knoth, Johannes, Trnkova, Petra, Heilemann, Gerd, Sturdza, Alina, Kirchheiner, Kathrin, Spampinato, Sofia, Serban, Monica, Jürgenliemk-Schulz, Ina, Chopra, Supriya, Nout, Remi, Tanderup, Kari, Pötter, Richard, and Eder-Nesvacil, Nicole

Published
2023
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4. GEC-ESTRO (ACROP)–ABS–CBG Consensus Brachytherapy Target Definition Guidelines for Recurrent Endometrial and Cervical Tumors in the Vagina

Author

Kamrava, Mitchell, Leung, Eric, Bachand, Francois, Beriwal, Sushil, Chargari, Cyrus, D'Souza, David, Erickson, Beth, Fokdal, Lars, Han, Kathy, Harkenrider, Matthew, Lin, Lilie, Mahantshetty, Umesh, Nesvacil, Nicole, Ravi, Ananth, Schmid, Max, Vigneault, Eric, Westerveld, Henrike, Yashar, Catheryn, and Nout, Remi

Published
2023
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6. Prognostic Implications of Uterine Cervical Cancer Regression During Chemoradiation Evaluated by the T-Score in the Multicenter EMBRACE I Study

Author

Lindegaard, Jacob Christian, Petric, Primoz, Schmid, Maximilian Paul, Nesvacil, Nicole, Haie-Meder, Christine, Fokdal, Lars Ulrik, Sturdza, Alina Emiliana, Hoskin, Peter, Mahantshetty, Umesh, Segedin, Barbara, Bruheim, Kjersti, Huang, Fleur, Rai, Bhavana, Cooper, Rachel, van der Steen-Banasik, Elzbieta, Van Limbergen, Erik, Pieters, Bradley Rumwell, Tan, Li-Tee, Nout, Remi A., De Leeuw, Astrid Agatha Catharina, Kirchheiner, Kathrin, Spampinato, Sofia, Jürgenliemk-Schulz, Ina, Tanderup, Kari, Kirisits, Christian, and Pötter, Richard

Published
2022
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10. MRI-guided adaptive brachytherapy in locally advanced cervical cancer (EMBRACE-I): a multicentre prospective cohort study

Author

Chargari, Cyrus, Dumas, Isabelle, Lowe, Gerry, Swamidas, Jamema, Hudej, Robert, Paulsen Hellebust, Taran, Menon, Geetha, Oinam, Arun S., Bownes, Peter, Christiaens, Melissa, De Brabandere, Marisol, Janssen, Hilde, Oosterveld, Bernard, Koedooder, Kees, Langeland Marthinsen, Anne Beate, Sundset, Marit, Whitney, Diane, Ketelaars, Martijn, Lutgens, Ludy C.H.W., Reinniers, Brigitte, Mora, Itxa, Villafranca, Elena, Antal, Gergely, Hadjiev, Janaki, Bachand, Francois, Batchelar, Deidre, Erickson, Beth, Rownd, Jason, Jacobson, Geraldine, Kim, Yusung, Anttila, Maarit, Palmgren, Jan-Erik, An, Jusheng, Assenholt, Marianne Sanggaard, Banerjee, Susovan, Bentzen, Sören, Berger, Thomas, Dankulchai, Pittaya, Diendorfer, Tamara, Dilworth, Ian, Dimopoulos, Johannes, Dörr, Elke, Ecker, Stefan, Federico, Mario, Fidarova, Elena, Fortin, Israel, Georg, Petra, Gora, Joanna, Hegazy, Neamat, Jastaniyah, Noha, Jensen, Nina Boje Kibsgaard, Liederer, Thomas, Majercakova, Katarina, Misimovic, Dragan, Motisi, Laura, Najjari Jamal, Dina, Nkiwane, Karen, Schwartz-Vittrup, Anders, Serban, Monica, Smet, Stephanie, Spampinato, Sofia, Trnkova, Petra, Valgma, Margit, Westerveld, Henrike, Wong, Joyce Siu Yu, Yoshida, Kenji, Pötter, Richard, Tanderup, Kari, Schmid, Maximilian Paul, Jürgenliemk-Schulz, Ina, Haie-Meder, Christine, Fokdal, Lars Ulrik, Sturdza, Alina Emiliana, Hoskin, Peter, Mahantshetty, Umesh, Segedin, Barbara, Bruheim, Kjersti, Huang, Fleur, Rai, Bhavana, Cooper, Rachel, van der Steen-Banasik, Elzbieta, Van Limbergen, Erik, Pieters, Bradley Rumwell, Tan, Li-Tee, Nout, Remi Abubakar, De Leeuw, Astrid Agatha Catharina, Ristl, Robin, Petric, Primoz, Nesvacil, Nicole, Kirchheiner, Kathrin, Kirisits, Christian, and Lindegaard, Jacob Christian

Published
2021
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12. Education and training for image-guided adaptive brachytherapy for cervix cancer—The (GEC)-ESTRO/EMBRACE perspective

Author

Tan, Li-Tee, Tanderup, Kari, Kirisits, Christian, Mahantshetty, Umesh, Swamidas, Jamema, Jürgenliemk-Schulz, Ina, Lindegaard, Jacob, de Leeuw, Astrid, Nesvacil, Nicole, Assenholt, Marianne, Berger, Daniel, Diendorfer, Tamara, Dimopoulos, Johannes, Duke, Simon, Ecker, Stefan, Fokdal, Lars, Hellebust, Taran, Jensen, Nina, Kirchheiner, Kathrin, Nout, Remi, Petric, Primoz, Schmid, Maximilian, Seppenwoolde, Yvette, Sturdza, Alina, Van Limbergen, Erik, Haie-Meder, Christine, and Pötter, Richard

Published
2020
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13. Ring Versus Ovoids and Intracavitary Versus Intracavitary-Interstitial Applicators in Cervical Cancer Brachytherapy: Results From the EMBRACE I Study

Author

Serban, Monica, Kirisits, Christian, de Leeuw, Astrid, Pötter, Richard, Jürgenliemk-Schulz, Ina, Nesvacil, Nicole, Swamidas, Jamema, Hudej, Robert, Lowe, Gerry, Hellebust, Taran Paulsen, Menon, Geetha, Oinam, Arun, Bownes, Peter, Oosterveld, Bernard, De Brabandere, Marisol, Koedooder, Kees, Langeland Marthinsen, Anne Beate, Whitney, Diane, Lindegaard, Jacob, and Tanderup, Kari

Published
2020
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16. Vienna-II ring applicator for distal parametrial/pelvic wall disease in cervical cancer brachytherapy: An experience from two institutions: Clinical feasibility and outcome

Author

Mahantshetty, Umesh, Sturdza, Alina, Naga CH, Pushpa, Berger, Daniel, Fortin, Israel, Motisi, Laura, Schmid, Maximilian P., Aravindakshan, Dheera, Ghadi, Yogesh, Swamidas, Jamema V., Chopra, Supriya, Gurram, Lavanya, Nesvacil, Nicole, Kirisits, Christian, and Pötter, Richard

Published
2019
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17. Importance of Technique, Target Selection, Contouring, Dose Prescription, and Dose-Planning in External Beam Radiation Therapy for Cervical Cancer: Evolution of Practice From EMBRACE-I to II

Author

Berger, Thomas, Seppenwoolde, Yvette, Pötter, Richard, Assenholt, Marianne Sanggaard, Lindegaard, Jacob C., Nout, Remi A., de Leeuw, Astrid, Jürgenliemk-Schulz, Ina, Tan, Li Tee, Georg, Dietmar, Kirisits, Christian, Dumas, Isabelle, Nesvacil, Nicole, Swamidas, Jamema, Hudej, Robert, Lowe, Gerry, Hellebust, Taran Paulsen, Menon, Geetha, Fokdal, Lars, and Tanderup, Kari

Published
2019
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18. Isodose surface volumes in cervix cancer brachytherapy: Change of practice from standard (Point A) to individualized image guided adaptive (EMBRACE I) brachytherapy

Author

Serban, Monica, Kirisits, Christian, Pötter, Richard, de Leeuw, Astrid, Nkiwane, Karen, Dumas, Isabelle, Nesvacil, Nicole, Swamidas, Jamema, Hudej, Robert, Lowe, Gerry, Hellebust, Taran Paulsen, Menon, Geetha, Oinam, Arun, Bownes, Peter, Oosterveld, Bernard, De Brabandere, Marisol, Koedooder, Kees, Marthinsen, Anne Beate Langeland, Lindegaard, Jacob, and Tanderup, Kari

Published
2018
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20. 890: Impact of cumulative cisplatin-dose on distant metastasis after chemoradiation of cervical cancer

Author

Knoth, Johannes, Nout, Remi, Mahantshetty, Umesh, Jürgenliemk-Schulz, Ina, Haie-Meder, Christine, Fokdal, Lars U., Sturdza, Alina, Hoskin, Peter, Segedin, Barbara, Bruheim, Kjersti, Huang, Fleur, Rai, Bhavana, Cooper, Rachel, van der Steen-Banasik, Elzbieta, van Limbergen, Erik, Pieters, Bradley R., Tan, Li T., Boryshchuk, Daniela, de Leeuw, Astrid A.C., Nesvacil, Nicole, Tanderup, Kari, Kirisits, Christian, Lindegaard, Jacob C., Pötter, Richard, and Schmid, Maximilian P.

Published
2024
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22. The EMBRACE II study: The outcome and prospect of two decades of evolution within the GEC-ESTRO GYN working group and the EMBRACE studies

Author

Pötter, Richard, Tanderup, Kari, Kirisits, Christian, de Leeuw, Astrid, Kirchheiner, Kathrin, Nout, Remi, Tan, Li Tee, Haie-Meder, Christine, Mahantshetty, Umesh, Segedin, Barbara, Hoskin, Peter, Bruheim, Kjersti, Rai, Bhavana, Huang, Fleur, Van Limbergen, Erik, Schmid, Max, Nesvacil, Nicole, Sturdza, Alina, Fokdal, Lars, Jensen, Nina Boje Kibsgaard, Georg, Dietmar, Assenholt, Marianne, Seppenwoolde, Yvette, Nomden, Christel, Fortin, Israel, Chopra, Supriya, van der Heide, Uulke, Rumpold, Tamara, Lindegaard, Jacob Christian, and Jürgenliemk-Schulz, Ina

Published
2018
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27. Risk Factors for Local Failure Following Chemoradiation and Magnetic Resonance Image-Guided Brachytherapy in Locally Advanced Cervical Cancer: Results From the EMBRACE-I Study

Author

Schmid, Maximilian P., Lindegaard, Jacob C., Mahantshetty, Umesh, Tanderup, Kari, Jürgenliemk-Schulz, Ina, Haie-Meder, Christine, Fokdal, Lars U., Sturdza, Alina, Hoskin, Peter, Segedin, Barbara, Bruheim, Kjersti, Huang, Fleur, Rai, Bhavana, Cooper, Rachel, van der Steen-Banasik, Elzbieta, Van Limbergen, Erik, Pieters, Bradley R., Petric, Primoz, Ramazanova, Dariga, Ristl, Robin, Kannan, Sadhana, Hawaldar, Rohini, Ecker, Stefan, Kirchheiner, Kathrin, Tan, Li Tee, Nout, Remi, Nesvacil, Nicole, de Leeuw, Astrid, Pötter, Richard, Kirisits, Christian, Radiotherapy, CCA - Cancer Treatment and Quality of Life, and CCA - Imaging and biomarkers

Subjects
Cancer Research, Oncology
Abstract

PURPOSE To report clinical and treatment characteristics, remission and failure patterns, and risk factors for local failure (LF) from the EMBRACE-I study. MATERIALS AND METHODS EMBRACE-I was a prospective, observational, multicenter cohort study on magnetic resonance imaging–based image-guided adaptive brachytherapy (MR-IGABT) in locally advanced cervical cancer. Treatment consisted of external beam radiotherapy, concurrent chemotherapy, and MR-IGABT. LF was defined as progressive or recurrent disease in the cervix, uterus, parametria, pelvic wall, or vagina. Competing risk analysis was used to estimate local tumor control (LC) and Cox proportional regression models for multivariable analysis and dose-response analysis. RESULTS One thousand three hundred eighteen patients with a median follow-up of 52 months were available for this analysis. Eighty-one patients had persistent disease 3 months after end of treatment. Of those, 60 patients achieved LC at 6-9 months without further treatment, whereas 21 patients had progressive disease. In addition, 77 patients developed a local recurrence after complete remission comprising a total number of 98 LFs. LFs were located inside the MR-IGABT target volumes in 90% of patients with LF. In multivariable analysis, histology, minimal dose to 90% of high-risk clinical target volume (CTVHR), maximum tumor dimension, CTVHR > 45 cm3, overall treatment time, tumor necrosis on magnetic resonance imaging at diagnosis, uterine corpus infiltration at diagnosis and at MR-IGABT, and mesorectal infiltration at MR-IGABT had significant impact on LF. Dose-response analysis showed that a minimal dose to 90% of 85 Gy to the CTVHR led to 95% (95% CI, 94 to 97) LC 3 years postintervention for squamous cell in comparison to 86% (95% CI, 81 to 90) for adeno/adenosquamous carcinoma histology. CONCLUSION The present study demonstrates the safety and validity of the GYN GEC-ESTRO/ICRU-89 target concept and provides large-scale evidence for dose prescription and new risk factors for LF in MR-IGABT in locally advanced cervical cancer.

Published
2023

31. Dose-effect relationship between vaginal dose points and vaginal stenosis in cervical cancer:An EMBRACE-I sub-study

Author

Westerveld, Henrike, Kirchheiner, Kathrin, Nout, Remi A., Tanderup, Kari, Lindegaard, Jacob C., Spampinato, Sofia, Sturdza, Alina, Nesvacil, Nicole, Bruheim, Kjersti, Hellebust, Taran P., Pieters, Bradley R., Kirisits, Christian, Jürgenliemk-Schulz, Ina M., Pötter, Richard, de Leeuw, Astrid A.C., Radiation Oncology, CCA - Cancer Treatment and Quality of Life, and Radiotherapy

Subjects
Radiotherapy, PIBS, Brachytherapy, RV-RP, Uterine Cervical Neoplasms, Radiotherapy Dosage, Constriction, Pathologic, Hematology, Vaginal morbidity, EMBRACE, SDG 3 - Good Health and Well-being, Oncology, ICRU-R, Vagina, Cervical cancer, Humans, Female, Radiology, Nuclear Medicine and imaging, Dose-effect
Abstract

Background and purpose: To evaluate dose–effect relationships between vaginal dose points and vaginal stenosis in patients treated for locally advanced cervical cancer with radio(chemo)therapy and image-guided adaptive brachytherapy. Material and methods: Patients from six centres participating in the EMBRACE-I study were included. Information on doses to different vaginal dose points, including the Posterior-Inferior Border of Symphysis (PIBS) points and recto-vaginal reference (RV-RP) point, were retrieved from the treatment planning system. In addition, the vaginal reference length (VRL) was evaluated. Vaginal stenosis was prospectively assessed according to the CTCAEv3.0 system at baseline and follow-up. Primary endpoint was grade 2 or higher (G ≥ 2) vaginal stenosis. Impact of dose to the vaginal dose points, and impact of VRL, age, vaginal involvement and applicator on vaginal stenosis G ≥ 2 was evaluated with a Cox proportional-hazard regression model. Results: 301 patients were included. Median follow-up was 49 months. During follow-up, the incidence of G0, G1, G2, and G3 vaginal stenosis was 25% (76), 52% (158), 20% (59) and 3% (8), respectively. Median total doses to PIBS+2 cm, PIBS, PIBS-2 cm and the RV-RP were 52.9 (IQR 49.3–64.7), 41.0 (IQR 15.4–49.0), 4.1 (IQR 2.9–7.0) and 64.6 (IQR 60.0–70.6) Gy EQD23, respectively. Higher doses to the PIBS, PIBS + 2 cm and RV-RP points were significantly associated with increased risk for vaginal stenosis G ≥ 2. Other risk factors for vaginal stenosis were: vaginal involvement at diagnosis, higher age, shorter VRL and use of a tandem-ovoid applicator. Conclusion: Higher doses to the PIBS+2 cm, PIBS and RV-RP dose points are associated with vaginal stenosis G ≥ 2.

Published
2022

33. Improved source path localisation in ring applicators and the clinical impact for gynecological brachytherapy

Author

Humer, Irene, Kirisits, Christian, Berger, Daniel, Trnková, Petra, Pötter, Richard, and Nesvacil, Nicole

Subjects
source path reconstruction, Original Paper, treatment planning, gynaecological, applicator geometry, brachytherapy, quality assurance
Abstract

Purpose The path of subsequent dwell positions of an afterloader source being moved through a ring applicator for cervix cancer brachytherapy deviates from an ideal circle and the position of marker wires. This can lead to deviations of several millimetres between real and assumed dwell positions for treatment planning with simplified source path models. The aim of this study was to test video- and autoradiography-based methods for source path determination, and to study the influence of dwell position accuracy on dose-volume histogram (DVH)-parameters. Material and methods Videos of the exact motion of the source wire through three different (r = 26, 30, 34 mm) computed tomography/magnetic resonance (CT/MR) compatible plastic ring applicators were recorded. Observed dwell positions covering the whole length of each applicators channel were used to adjust the circular source path model. The agreement of the true source positions derived from video analysis with those of the corrected circular source path was verified using autoradiography. The impact of an accurate source path definition on dose planning was analysed by simulating clinically relevant uncertainties in 10 clinical treatment plans. Results Depending on the ring size, source path diameters had to be increased by 0.5-1.0 mm in order to achieve acceptable maximum differences between observed and corrected dwell positions (1.3-2.0 mm). Autoradiography analysis showed a positional accuracy within ± 3 mm (extended standard deviation k = 2). For shifts of ± 2.5 mm for even all dwell positions, the systematic and random variation of the D2cm3 for bladder, rectum, and sigmoid was within 3%, while the impact on DVH uncertainties was much smaller for clinical target volume (CTV)HR and gross tumour volume (GTV). Conclusions It is strongly advised to verify the real source path for ring applicators during acceptance testing in order to assure accurate source path definition and dose planning. Autoradiography can be used for source path verification with acceptable accuracy for treatment planning and dose reporting.

Published
2015

35. Evidence-Based Dose Planning Aims and Dose Prescription in Image-Guided Brachytherapy Combined With Radiochemotherapy in Locally Advanced Cervical Cancer.

Author

Tanderup, Kari, Nesvacil, Nicole, Kirchheiner, Kathrin, Serban, Monica, Spampinato, Sofia, Jensen, Nina Boje Kibsgaard, Schmid, Maximilian, Smet, Stephanie, Westerveld, Henrike, Ecker, Stefan, Mahantshetty, Umesh, Swamidas, Jamema, Chopra, Supriya, Nout, Remi, Tan, Li Tee, Fokdal, Lars, Sturdza, Alina, Jürgenliemk-Schulz, Ina, de Leeuw, Astrid, and Lindegaard, Jacob Christian

Abstract

The last 2 decades have witnessed the development and broad adoption of image-guided adaptive brachytherapy (IGABT) combined with radiochemotherapy in patients with locally advanced cervical cancer. A variety of brachytherapy techniques and dose/fractionation schedules have been applied, and until recently, there was no strong evidence available for preferring one approach to another. However, large volumes of data have now provided high level clinical evidence for dose-effect relations for both disease and morbidity endpoints. It is therefore now possible to apply evidence based dose planning aims and dose prescription protocols in IGABT for locally advanced cervical cancer. This review gives an overview of targets/organs-at-risk and disease/morbidity endpoints which are relevant in the context of treatment planning and dose prescription in IGABT. The dosimetric and clinical evidence is summarized to support the implementation of dose prescription protocols which include hard and soft constraints for targets and organs at risk. [ABSTRACT FROM AUTHOR]

Published
2020
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36. Investigating conditional GAN performance with different generator architectures, an ensemble model, and different MR scanners for MR-sCT conversion.

Author

Fetty, Lukas, Löfstedt, Tommy, Heilemann, Gerd, Furtado, Hugo, Nesvacil, Nicole, Nyholm, Tufve, Georg, Dietmar, and Kuess, Peter

Subjects
SCANNING systems, MAGNETIC resonance, COMPUTED tomography, CERVICAL cancer
Abstract

Recent developments in magnetic resonance (MR) to synthetic computed tomography (sCT) conversion have shown that treatment planning is possible without an initial planning CT. Promising conversion results have been demonstrated recently using conditional generative adversarial networks (cGANs). However, the performance is generally only tested on images from one MR scanner, which neglects the potential of neural networks to find general high-level abstract features. In this study, we explored the generalizability of the generator models, trained on a single field strength scanner, to data acquired with higher field strengths. T2-weighted 0.35T MRIs and CTs from 51 patients treated for prostate (40) and cervical cancer (11) were included. 25 of them were used to train four different generators (SE-ResNet, DenseNet, U-Net, and Embedded Net). Further, an ensemble model was created from the four network outputs. The models were validated on 16 patients from a 0.35T MR scanner. Further, the trained models were tested on the Gold Atlas dataset, containing T2-weighted MR scans of different field strengths; 1.5T(7) and 3T(12), and 10 patients from the 0.35T scanner. The sCTs were dosimetrically compared using clinical VMAT plans for all test patients. For the same scanner (0.35T), the results from the different models were comparable on the test set, with only minor differences in the mean absolute error (MAE) (35-51HU body). Similar results were obtained for conversions of 3T GE Signa and the 3T GE Discovery images (40-62HU MAE) for three of the models. However, larger differences were observed for the 1.5T images (48-65HU MAE). The overall best model was found to be the ensemble model. All dose differences were below 1%. This study shows that it is possible to generalize models trained on images of one scanner to other scanners and different field strengths. The best metric results were achieved by the combination of all networks. [ABSTRACT FROM AUTHOR]

Published
2020
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37. Stage Migration between Clinical Examination and MRI in Locally Advanced Cervical Cancer

Author

Knoth, Johannes, Pötter, Richard, Jürgenliemk-Schulz, Ina, Haie-Meder, Christine, Fokdal, Lars, Sturdza, Alina, Hoskin, Peter, Mahantshetty, Umesh, Segedin, Barbara, Bruheim, Kjersti, Wiebe, Ericka, Rai, Bhavana, Cooper, Rachel, van der Steen-Banasik, Elzbieta, van Limbergen, Erik, Pieters, Bradley, Sundset, Marit, Tan, Li Tee, Nout, Remi, Tanderup, Kari, Kirisits, Christian, Nesvacil, Nicole, Lindegaard, Jacob Christian, and Schmid, Max

Published
2019
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41. Inflatable multichannel rectal applicator for adaptive image-guided endoluminal high-dose-rate rectal brachytherapy: design, dosimetric characteristics, and first clinical experiences.

Author

Schmid, Maximilian P., Berger, Daniel, Heilmann, Martin, Bör, Jessica, Wisgrill, Bernd, Azizi-Semrad, Ursula, Nesvacil, Nicole, Pötter, Richard, Kirisits, Christian, and Schmid, Rainer

Subjects
RECTAL cancer treatment, RECTAL cancer patients, RADIOISOTOPE brachytherapy, CANCER radiotherapy, URINARY catheters
Abstract

Purpose: To investigate the dosimetric results and first clinical experiences with a new designed balloon applicator with adjustable catheters for endoluminal brachytherapy for patients with locally advanced rectal cancer not undergoing surgery. Material and methods: The applicator consists of an inflatable rectal balloon with six attached Foley catheters used as guidance for the inserted brachytherapy plastic needles. The construction of the applicator and the dosimetric profile in terms of representative dose points in 0, 2, 5, 10 mm ipsilaterally and in 0 mm contralaterally are described. The first clinical outcomes in three patients are reported. Results: For all three patients, a reproducible dose gradient was achieved. The surface dose on the target side was 204 ± 19% of the normalized dose in 5 mm (100%) tissue depth, and 143 ± 8% in 2 mm and 64 ± 3% in 10 mm tissue depth, while the surface dose on the contra-lateral side was 20 ± 8%. After radiochemotherapy with 50 Gy external beam radiotherapy and concomitant administration of capecitabine, a HDR brachytherapy boost in 2-3 fractions of 7-10 Gy each was delivered. All patients achieved a clinical complete response 3 month after the treatment, and no major toxicity was observed. Conclusion: The use of the applicator was clinically feasible, and resulted in a stable and reproducible dose distribution. First clinical results are promising. [ABSTRACT FROM AUTHOR]

Published
2017
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45. Impact of heterogeneity-corrected dose calculation using a grid-based Boltzmann solver on breast and cervix cancer brachytherapy.

Author

Hofbauer, Julia, Kirisits, Christian, Resch, Alexandra, Yingjie Xu, Sturdza, Alina, Pötter, Richard, and Nesvacil, Nicole

Subjects
RADIATION dosimetry, RADIOISOTOPE brachytherapy, CERVICAL cancer research, IRRADIATION, SIGMOID colon
Abstract

Purpose: To analyze the impact of heterogeneity-corrected dose calculation on dosimetric quality parameters in gynecological and breast brachytherapy using Acuros, a grid-based Boltzmann equation solver (GBBS), and to evaluate the shielding effects of different cervix brachytherapy applicators. Material and methods: Calculations with TG-43 and Acuros were based on computed tomography (CT) retrospectively, for 10 cases of accelerated partial breast irradiation and 9 cervix cancer cases treated with tandem-ring applicators. Phantom CT-scans of different applicators (plastic and titanium) were acquired. For breast cases the V20Gyaβ3 to lung, the D0.1cm3, D1cm3, D2cm3 to rib, the D0.1cm3, D1cm3, D10cm3 to skin, and Dmax for all structures were reported. For cervix cases, the D0.1cm3, D2cm3 to bladder, rectum and sigmoid, and the D50, D90, D98, V100 for the CTVHR were reported. For the phantom study, surrogates for target and organ at risk were created for a similar dose volume histogram (DVH) analysis. Absorbed dose and equivalent dose to 2 Gy fractionation (EQD2) were used for comparison. Results: Calculations with TG-43 overestimated the dose for all dosimetric indices investigated. For breast, a decrease of ~8% was found for D10cm3 to the skin and 5% for D2cm3 to rib, resulting in a difference ~ -1.5 Gy EQD2 for overall treatment. Smaller effects were found for cervix cases with the plastic applicator, with up to -2% (-0.2 Gy EQD2) per fraction for organs at risk and -0.5% (-0.3 Gy EQD2) per fraction for CTVHR. The shielding effect of the titanium applicator resulted in a decrease of 2% for D2cm3 to the organ at risk versus 0.7% for plastic. Conclusions: Lower doses were reported when calculating with Acuros compared to TG-43. Differences in dose parameters were larger in breast cases. A lower impact on clinical dose parameters was found for the cervix cases. Applicator material causes systematic shielding effects that can be taken into account. [ABSTRACT FROM AUTHOR]

Published
2016
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46. Evaluation of planning aims and dose prescription in image-guided adaptive brachytherapy and radiochemotherapy for cervical cancer: Vienna clinical experience in 225 patients from 1998 to 2008.

Author

Majercakova, Katarina, Pötter, Richard, Kirisits, Christian, Banerjee, Susovan, Sturdza, Alina E., Georg, Petra, Nesvacil, Nicole, and Schmid, Maximilian P.

Abstract

Background.To assess planning aims (PAs) and dose prescription in image-guided adaptive brachytherapy (IGABT) of cervical cancer and investigate potential impact on clinical outcome. Material and methods.Our study population consists of 225 consecutive cervical cancer patients (FIGO stages IB–IVA) treated between 1998 and 2008 at the Medical University of Vienna by external beam radiotherapy (EBRT) ± chemotherapy and IGABT. For this retrospective study, patients were stratified into two treatment groups: PA+ group, all dose constraints fulfilled for prescription; PA-, one or more dose constraints not fulfilled for prescription. The following dose constraints (EBRT+ IGABT) were applied: clinical target volume (CTV)HRD90≥ 85 Gy, D2cm3Rectum < 70 Gy, D2cm3Bladder < 90 Gy. Differences in patient, tumor and treatment characteristics and clinical outcome (event: local failure or grade 3 + 4 toxicity) were compared between Group 1 and 2. Further, the impact of learning period (1998–2000) and protocol period (2001–2008) on the fulfillment of PAs for dose prescription and clinical outcome was analyzed. Results. In the PA+ group there were 77 (34%) and in the PA- group 148 (66%) patients. In the PA- group, CTVHRD90< 85 Gy was prescribed in 82 patients, D2cm3bladder > 90 Gy was prescribed in 80 patients and D2cm3Rectum > 70 Gy in 60 patients. Fulfillment of the PA for dose prescription improved from 4% in the learning period to 48% in the protocol period. The five-year event-free interval was 64% in the learning period and 84% in the protocol period (p = 0.008). Conclusion.Fulfillment of all PAs for dose prescription is challenging – especially in patients with more advanced tumors. However, with growing experience fulfillment of PA for dose prescription can be significantly increased (learning and protocol period). Such increase in fulfilling PA for dose prescription is followed by a significant improvement in clinical outcome. [ABSTRACT FROM PUBLISHER]

Published
2015
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48. High-risk clinical target volume delineation in CT-guided cervical cancer brachytherapy: Impact of information from FIGO stage with or without systematic inclusion of 3D documentation of clinical gynecological examination.

Author

Hegazy, Neamat, Pötter, Richard, Kirisits, Christian, Berger, Daniel, Federico, Mario, Sturdza, Alina, and Nesvacil, Nicole

Subjects
RADIOISOTOPE brachytherapy, GYNECOLOGIC examination, MAGNETIC resonance imaging, COMPUTERS in medicine, RADIOTHERAPY, RESEARCH funding, TOMOGRAPHY, TUMOR classification, CERVIX uteri tumors, RETROSPECTIVE studies, DESCRIPTIVE statistics
Abstract

Purpose. The aim of the study was to improve computed tomography (CT)-based high-risk clinical target volume (HR CTV) delineation protocols for cervix cancer patients, in settings without any access to magnetic resonance imaging (MRI) at the time of brachytherapy. Therefore the value of a systematic integration of comprehensive three-dimensional (3D) documentation of repetitive gynecological examination for CT-based HR CTV delineation protocols, in addition to information from FIGO staging, was investigated. In addition to a comparison between reference MRI contours and two different CT-based contouring methods (using complementary information from FIGO staging with or without additional 3D clinical drawings), the use of standardized uterine heights was also investigated. Material and methods. Thirty-five cervix cancer patients with CT- and MR-images and 3D clinical drawings at time of diagnosis and brachytherapy were included. HR CTVstage was based on CT information and FIGO stage. HR CTVstage + 3Dclin was contoured on CT using FIGO stage and 3D clinical drawing. Standardized HR CTV heights were: 1/1, 2/3 and 1/2 of uterine height. MRI-based HR CTV was delineated independently. Resulting widths, thicknesses, heights, and volumes of HR CTVstage, HR CTVstage + 3Dclin and MRI-based HR CTV contours were compared. Results. The overall normalized volume ratios (mean± SD of CT/MRIref volume) of HR CTVstage and HR stage + 3Dclin were 2.6 (± 0.6) and 2.1 (± 0.4) for 1/1 and 2.3 (± 0.5) and 1.8 (± 0.4), for 2/3, and 1.9 (± 0.5) and 1.5 (± 0.3), for 1/2 of uterine height. The mean normalized widths were 1.5 ± 0.2 and 1.2 ± 0.2 for HR CTVstage and HR CTVstage + 3Dclin, respectively (p < 0.05). The mean normalized heights for HR CTVstage and HR CTVstage + 3Dclin were both 1.7 ± 0.4 for 1/1 (p < 0.05.), 1.3 ± 0.3 for 2/3 (p < 0.05) and 1.1 ± 0.3 for 1/2 of uterine height. Conclusion. CT-based HR CTV contouring based on FIGO stage alone leads to large overestimation of width and volume. Target delineation accuracy can systematically improve through incorporation of additional information from comprehensive 3D documentation of repetitive gynecological examination in the contouring protocol, and thus help to improve the accuracy of dose optimization in settings with limited access to imaging facilities at the time of brachytherapy. If CT information is only available, minimum 2/3 of uterine height may be a good surrogate for the height of HR CTV. [ABSTRACT FROM AUTHOR]

Published
2013
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