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Westley RL, Alexander SE, Goodwin E, Dunlop A, Nill S, Oelfke U, McNair HA, Tree AC. Magnetic resonance image-guided adaptive radiotherapy enables safe CTV-to-PTV margin reduction in prostate cancer: a cine MRI motion study. Front Oncol 2024; 14:1379596. [PMID: 38894866 PMCID: PMC11183304 DOI: 10.3389/fonc.2024.1379596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/29/2024] [Indexed: 06/21/2024] Open
Abstract
Introduction We aimed to establish if stereotactic body radiotherapy to the prostate can be delivered safely using reduced clinical target volume (CTV) to planning target volume (PTV) margins on the 1.5T MR-Linac (MRL) (Elekta, Stockholm, Sweden), in the absence of gating. Methods Cine images taken in 3 orthogonal planes during the delivery of prostate SBRT with 36.25 Gray (Gy) in 5 fractions on the MRL were analysed. Using the data from 20 patients, the percentage of radiotherapy (RT) delivery time where the prostate position moved beyond 1, 2, 3, 4 and 5 mm in the left-right (LR), superior-inferior (SI), anterior-posterior (AP) and any direction was calculated. Results The prostate moved less than 3 mm in any direction for 90% of the monitoring period in 95% of patients. On a per-fraction basis, 93% of fractions displayed motion in all directions within 3 mm for 90% of the fraction delivery time. Recurring motion patterns were observed showing that the prostate moved with shallow drift (most common), transient excursions and persistent excursions during treatment. Conclusion A 3 mm CTV-PTV margin is safe to use for the treatment of 5 fraction prostate SBRT on the MRL, without gating. In the context of gating this work suggests that treatment time will not be extensively lengthened when an appropriate gating window is applied.
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Affiliation(s)
- Rosalyne L. Westley
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, United Kingdom
| | - Sophie E. Alexander
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, United Kingdom
| | - Edmund Goodwin
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
| | - Alex Dunlop
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
| | - Simeon Nill
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
| | - Uwe Oelfke
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
| | - Helen A. McNair
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, United Kingdom
| | - Alison C. Tree
- Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Sutton, United Kingdom
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Lakosi F, Antal G, Pall J, Farkas A, Jenei T, Nagy D, Liptak J, Sipocz I, Pytel A, Csima M, Gulyban A, Toller G. HDR brachytherapy boost using MR-only workflow for intermediate- and high-risk prostate cancer: 8-year results of a pilot study. Brachytherapy 2021; 20:576-583. [PMID: 33478906 DOI: 10.1016/j.brachy.2020.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/05/2020] [Accepted: 12/09/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To report 8-year clinical outcome with high-dose-rate brachytherapy (HDRBT) boost using MRI-only workflow for intermediate (IR) and high-risk (HR) prostate cancer (PC) patients. METHODS AND MATERIALS Fifty-two patients were treated with 46-60 Gy of 3D conformal radiotherapy preceded and/or followed by a single dose of 8-10 Gy MRI-guided HDRBT. Interventions were performed in a 0.35 T MRI scanner. Trajectory planning, navigation, contouring, catheter reconstruction, and dose calculation were exclusively based on MRI images. Biochemical relapse-free- (BRFS), local relapse-free- (LRFS), distant metastasis-free- (DMFS), cancer-specific-(CCS) and overall survival (OS) were analyzed. Late morbidity was scored using the Common Terminology Criteria for Adverse Events (CTCAE 4.0) combined with RTOG (Radiation Therapy Oncology Group) scale for urinary toxicity and rectal urgency (RU) determined by Yeoh. RESULTS Median follow-up time was 107 (range: 19-143) months. The 8-year actuarial rates of BRFS, LRFS, DMFS, CSS and OS were 85.7%, 97%, 97.6%, and 77.6%, respectively. There were no Gr.3 GI side effects. The 8-year actuarial rate of Gr.2 proctitis was 4%. The 8-year cumulative incidence of Gr.3 GU side effects was 8%, including two urinary stenoses (5%) and one cystitis (3%). EPIC urinary and bowel scores did not change significantly over time. CONCLUSIONS MRI-only HDR-BT boost with moderate dose escalation provides excellent 8-year disease control with a favorable toxicity profile for IRPC and HRPC patients. Our results support the clinical importance of MRI across the BT workflow.
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Affiliation(s)
- Ferenc Lakosi
- Somogy County Kaposi Mór Teaching Hospital, Dr. József Baka Center, Department of Radiation Oncology, Kaposvár, Hungary.
| | - Gergely Antal
- Somogy County Kaposi Mór Teaching Hospital, Dr. József Baka Center, Department of Radiation Oncology, Kaposvár, Hungary
| | - Janos Pall
- Somogy County Kaposi Mór Teaching Hospital, Dr. József Baka Center, Department of Radiation Oncology, Kaposvár, Hungary; Department of Radiation Oncology, Csolnoky Ferenc Hospital, Veszprém, Hungary
| | - Andrea Farkas
- Somogy County Kaposi Mór Teaching Hospital, Dr. József Baka Center, Department of Radiation Oncology, Kaposvár, Hungary
| | - Tibor Jenei
- Somogy County Kaposi Mór Teaching Hospital, Department of Urology, Kaposvár, Hungary
| | - Denes Nagy
- Somogy County Kaposi Mór Teaching Hospital, Department of Urology, Kaposvár, Hungary
| | - Jozsef Liptak
- Kanizsai Dorottya Hospital, Department of Urology, Nagykanizsa, Hungary
| | - Istvan Sipocz
- Petz Aladár County Teaching Hospital, Department of Radiation Oncology, Győr, Hungary
| | - Akos Pytel
- Pécs University, Department of Urology, Pecs, Hungary
| | - Melinda Csima
- Faculty of Pedagogy, Szent István University, Kaposvár Campus, Kaposvár, Hungary
| | - Akos Gulyban
- Medical Physics Department, Institut Jules Bordet, Bruxelles, Belgium
| | - Gabor Toller
- Somogy County Kaposi Mór Teaching Hospital, Dr. József Baka Center, Department of Radiation Oncology, Kaposvár, Hungary
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Hellebust T. Place of modern imaging in brachytherapy planning. Cancer Radiother 2018; 22:326-333. [DOI: 10.1016/j.canrad.2018.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 03/20/2018] [Indexed: 01/07/2023]
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Image Distortions on a Plastic Interstitial Computed Tomography/Magnetic Resonance Brachytherapy Applicator at 3 Tesla Magnetic Resonance Imaging and Their Dosimetric Impact. Int J Radiat Oncol Biol Phys 2017; 99:710-718. [PMID: 29280466 DOI: 10.1016/j.ijrobp.2017.06.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/04/2017] [Accepted: 06/13/2017] [Indexed: 11/21/2022]
Abstract
PURPOSE To quantify magnetic resonance imaging (MRI) distortions on a plastic intracavitary/interstitial applicator with plastic needles at a field strength of 3 T and to determine the dosimetric impact, using patient data. METHODS AND MATERIALS For 11 cervical cancer patients, our clinical MRI protocol was extended with 3 scans. From the first scan, a multi-echo acquisition, a map of the magnetic field (B0) was calculated and used to quantify the field inhomogeneity. The expected displacements of the applicator were quantified for the clinical sequence using the measured field inhomogeneity and the clinical sequence's bandwidth. The second and third scan were our routine clinical sequence (duration: <5 minutes each), acquired consecutively using opposing readout directions. The displacement of the applicator between these scans is approximately twice the displacement due to B0 inhomogeneity. The impact of the displacement on the dose was determined by reconstructing the applicator on both scans. The applicator was then shifted and rotated the same distance as the observed displacement to create a worst-case scenario (ie, twice the actual displacement due to B0 inhomogeneity). Next, the dose to 98%/90% (D98/D90) of the clinical target volume at high risk, as well as the dose to the most irradiated 2 cm3 for bladder and rectum, were calculated for the original plan as well as the shifted plan. RESULTS For a volume of interest containing the intrauterine device and the ovoids the 95th percentile of the absolute displacement ranged between 0.2 and 0.75 mm, over all patients. For all patients, the difference in D98/D90 in the opposing readout scans with the original plan was at most 4.7%/4.3%. For the dose to the most irradiated 2 cm3 of bladder/rectum, the difference was at most 6.0%/6.3%. CONCLUSIONS The dosimetric impact of distortions on this plastic applicator with plastic needles is limited. Applicator reconstruction for brachytherapy planning purposes is feasible at 3 T MRI.
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Rylander S, Buus S, Pedersen EM, Bentzen L, Tanderup K. Dosimetric impact of contouring and needle reconstruction uncertainties in US-, CT- and MRI-based high-dose-rate prostate brachytherapy treatment planning. Radiother Oncol 2017; 123:125-132. [PMID: 28284493 DOI: 10.1016/j.radonc.2017.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 01/05/2017] [Accepted: 01/11/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE The purpose was to evaluate the dosimetric impact of target contouring and needle reconstruction uncertainties in an US-, CT- and MRI-based HDR prostate BT treatment planning. MATERIAL AND METHODS US, CT, and MR images were acquired post-needle insertion in 22 HDR-BT procedures for 11 consecutive patients. Dose plans were simulated for an US-, CT- and MRI-based HDR-BT treatment planning procedure. Planning uncertainties in US- and CT-based plans were evaluated using MRI-based planning as reference. Target (CTVProstate) was re-contoured on MRI. Dose results were expressed in total equivalent dose given in 2Gy fractionation dose for EBRT (46Gy) plus 2 HDR-BT fractions. RESULTS Uncertainties in US- and CT-based planning caused the planned CTVProstate-D90% to decrease with a mean of 2.9±5.0Gy (p=0.03) and 2.9±2.9Gy (p=0.001), respectively. The intra-observer contouring variation on MRI resulted in a mean variation of 1.6±1.5Gy in CTVProstate-D90%. Reconstruction uncertainties on US resulted in a dose variation of±3Gy to the urethra, whereas data for CT were not available for this. CONCLUSIONS Uncertainties related to contouring and reconstruction in US- and CT-based HDR-BT treatment plans resulted in a systematic overestimation of the prescribed target dose. Inter-modality uncertainties (US and CT versus MR) were larger than MR intra-observer uncertainties.
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Affiliation(s)
- Susanne Rylander
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark.
| | - Simon Buus
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Erik M Pedersen
- Department of Radiology, Aarhus University Hospital, Aarhus, Denmark
| | - Lise Bentzen
- Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Kari Tanderup
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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Prostate: High-Dose Rate Brachytherapy in the Treatment of Clinically Organ-Confined Prostate Cancer. Brachytherapy 2016. [DOI: 10.1007/978-3-319-26791-3_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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van Heerden LE, Gurney-Champion OJ, van Kesteren Z, Houweling AC, Koedooder C, Rasch CRN, Pieters BR, Bel A. Quantification of image distortions on the Utrecht interstitial CT/MR brachytherapy applicator at 3T MRI. Brachytherapy 2015; 15:118-26. [PMID: 26614236 DOI: 10.1016/j.brachy.2015.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 10/02/2015] [Accepted: 10/25/2015] [Indexed: 11/18/2022]
Abstract
PURPOSE To quantify distortions on MR images of the Utrecht interstitial CT/MR applicator at a field strength of 3T using an MRI-only method. MATERIALS AND METHODS An MR-compatible phantom suspending the applicator in water was built and imaged on a Philips Ingenia 3T MRI scanner. A map of the magnetic field (B0) was calculated from multiecho images and used to quantify the field inhomogeneity. The expected displacements of the applicator could be quantified using the measured field inhomogeneity and sequence bandwidth. Additionally, two scans were acquired using opposing readout gradients. These scans were rigidly matched and their displacement was compared with the expected displacements from the B0 map. These same methods were applied in 4 patients. By rigid matching of the scans acquired with opposing readout direction the applicator displacement due to image distortion from B0 inhomogeneity as well as patient movement and organ deformation was determined. RESULTS According to the B0 map, the displacement on the intrauterine device of the plastic brachytherapy applicator was <0.4 mm for both the phantom and patients. Displacements obtained by the opposing readout method were ≤0.8 mm for each patient with a mean ± SD over the patients of 0.3 ± 0.1 mm. CONCLUSION The results of our study indicate that the B0 method agrees with the opposing readout method. Displacements caused by magnetic field inhomogeneity on 3T MRI were small compared with displacements due to patient movement and organ deformation.
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Affiliation(s)
- L E van Heerden
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - O J Gurney-Champion
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Z van Kesteren
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A C Houweling
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - C Koedooder
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - C R N Rasch
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - B R Pieters
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bel
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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The influence of a rectal ultrasound probe on the separation between prostate and rectum in high-dose-rate brachytherapy. Brachytherapy 2015; 14:711-7. [DOI: 10.1016/j.brachy.2015.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/29/2015] [Accepted: 06/01/2015] [Indexed: 01/01/2023]
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Diagnosis of Extracapsular Extension of Prostate Cancer on Prostate MRI: Impact of Second-Opinion Readings by Subspecialized Genitourinary Oncologic Radiologists. AJR Am J Roentgenol 2015; 205:W73-8. [PMID: 26102421 DOI: 10.2214/ajr.14.13600] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The purpose of this article is to investigate the added value of second-opinion evaluation of prostate MRI by subspecialized genitourinary oncologic radiologists for the assessment of extracapsular extension (ECE) of prostate cancer. MATERIALS AND METHODS We performed a retrospective evaluation of initial and second-opinion radiology reports of 76 patients who underwent MRI of the prostate before prostatectomy for histologically proven prostate cancer. Initial outside reports and second-opinion reports were unpaired and reviewed in random order by a urologist who was blinded to patients' clinical details and histopathologic data. Histopathologic analysis of the prostatectomy specimen served as the reference standard. RESULTS Among cases with diagnostic-quality images available (71/76; 93%), disagreement between the initial report and the second-opinion report was observed in 30% of cases (21/71; κ = 0.35); in 18 of these 21 cases (86%), histopathologic analysis proved that the second-opinion report was correct. The second-opinion interpretations had statistically significantly higher sensitivity (66% vs 24%; p < 0.0001) than did the initial reports, whereas there was no statistically significant difference in specificity (87% vs 93%; p = 0.317). On ROC curve analysis, the second-opinion reports yielded a statistically significantly higher AUC for the detection of ECE (0.80 vs 0.65; p = 0.004). CONCLUSION The reinterpretation of prostate MRI examinations by subspecialized genitourinary oncologic radiologists improved the detection of ECE of prostate cancer.
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Balgobind BV, Koedooder K, Ordoñez Zúñiga D, Dávila Fajardo R, Rasch CRN, Pieters BR. A review of the clinical experience in pulsed dose rate brachytherapy. Br J Radiol 2015; 88:20150310. [PMID: 26290399 DOI: 10.1259/bjr.20150310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pulsed dose rate (PDR) brachytherapy is a treatment modality that combines physical advantages of high dose rate (HDR) brachytherapy with the radiobiological advantages of low dose rate brachytherapy. The aim of this review was to describe the effective clinical use of PDR brachytherapy worldwide in different tumour locations. We found 66 articles reporting on clinical PDR brachytherapy including the treatment procedure and outcome. Moreover, PDR brachytherapy has been applied in almost all tumour sites for which brachytherapy is indicated and with good local control and low toxicity. The main advantage of PDR is, because of the small pulse sizes used, the ability to spare normal tissue. In certain cases, HDR resembles PDR brachytherapy by the use of multifractionated low-fraction dose.
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Affiliation(s)
- Brian V Balgobind
- 1 Department of Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands
| | - Kees Koedooder
- 1 Department of Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands
| | - Diego Ordoñez Zúñiga
- 1 Department of Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands
| | | | - Coen R N Rasch
- 1 Department of Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands
| | - Bradley R Pieters
- 1 Department of Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands
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Høyer M, Muren LP, Glimelius B. The evolution of radiotherapy techniques in the management of prostate cancer. Acta Oncol 2015; 54:821-4. [PMID: 25973556 DOI: 10.3109/0284186x.2015.1048555] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Morten Høyer
- Dept of Oncology, Aarhus University/Aarhus University Hospital , Aarhus , Denmark
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12
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Rylander S, Polders D, Steggerda MJ, Moonen LM, Tanderup K, Van der Heide UA. Re-distribution of brachytherapy dose using a differential dose prescription adapted to risk of local failure in low-risk prostate cancer patients. Radiother Oncol 2015; 115:308-13. [DOI: 10.1016/j.radonc.2015.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 05/14/2015] [Accepted: 05/17/2015] [Indexed: 11/15/2022]
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Improved dosimetry in prostate brachytherapy using high resolution contrast enhanced magnetic resonance imaging: a feasibility study. J Contemp Brachytherapy 2015; 6:337-43. [PMID: 25834576 PMCID: PMC4300354 DOI: 10.5114/jcb.2014.46555] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/04/2014] [Accepted: 09/14/2014] [Indexed: 12/04/2022] Open
Abstract
Purpose To assess detailed dosimetry data for prostate and clinical relevant intra- and peri-prostatic structures including neurovascular bundles (NVB), urethra, and penile bulb (PB) from postbrachytherapy computed tomography (CT) versus high resolution contrast enhanced magnetic resonance imaging (HR-CEMRI). Material and methods Eleven postbrachytherapy prostate cancer patients underwent HR-CEMRI and CT imaging. Computed tomography and HR-CEMRI images were randomized and 2 independent expert readers created contours of prostate, intra- and peri-prostatic structures on each CT and HR-CEMRI scan for all 11 patients. Dosimetry data including V100, D90, and D100 was calculated from these contours. Results Mean V100 values from CT and HR-CEMRI contours were as follows: prostate (98.5% and 96.2%, p = 0.003), urethra (81.0% and 88.7%, p = 0.027), anterior rectal wall (ARW) (8.9% and 2.8%, p < 0.001), left NVB (77.9% and 51.5%, p = 0.002), right NVB (69.2% and 43.1%, p = 0.001), and PB (0.09% and 11.4%, p = 0.005). Mean D90 (Gy) derived from CT and HR-CEMRI contours were: prostate (167.6 and 150.3, p = 0.012), urethra (81.6 and 109.4, p = 0.041), ARW (2.5 and 0.11, p = 0.003), left NVB (98.2 and 58.6, p = 0.001), right NVB (87.5 and 55.5, p = 0.001), and PB (11.2 and 12.4, p = 0.554). Conclusions Findings of this study suggest that HR-CEMRI facilitates accurate and meaningful dosimetric assessment of prostate and clinically relevant structures, which is not possible with CT. Significant differences were seen between CT and HR-CEMRI, with volume overestimation of CT derived contours compared to HR-CEMRI.
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Prostate volume and implant configuration during 48 hours of temporary prostate brachytherapy: limited effect of oedema. Radiat Oncol 2014; 9:272. [PMID: 25497373 PMCID: PMC4268808 DOI: 10.1186/s13014-014-0272-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 11/22/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In pulsed-dose rate prostate brachytherapy the dose is delivered during 48 hours after implantation, making the treatment sensitive to oedematic effects possibly affecting dose delivery. The aim was to study changes in prostate volume during treatment by analysing catheter configurations on three subsequent scans. METHODS Prostate expansion was determined for 19 patients from the change in spatial distribution of the implanted catheters, using three CT-scans: a planning CT (CT1) and two CTs after 24 and 48 hours (CT2, CT3). An additional 4 patients only received one repeat CT (after 24 hours). The mean radial distance (MRD) of all dwell positions to the geometric centre of all dwell positions used was calculated to evaluate volume changes. From three implanted markers changes in inter-marker distances were assessed. The relative shifts of all dwell positions were determined using catheter- and marker-based registrations. Wilcoxon signed-rank tests were performed to compare the results from the different time points. RESULTS The MRDs measured on the two repeat CTs were significantly different from CT1. The mean prostate volume change derived from the difference in MRD was +4.3% (range -9.3% to +15.6%) for CT1-CT2 (p < .05) and +4.4% (range -7.5% to +16.3%) for CT1-CT3 (p < .05). These values represented a mean increase of 1.2 cm(3) in the first 24 hours and 1.5 cm(3) in the subsequent 24 hours. There was no clear sign of prostate expansion from the change in inter-marker distance (CT1-CT2: 0.2 ± 1.8 mm; CT1-CT3: 0.6 ± 2.2 mm). Catheter configuration remained stable; shifts in catheter positions were largest in the C-C direction: 0 ± 1.8 mm for CT1-CT2 and 0 ± 1.4 mm for CT2-CT3. CONCLUSIONS The volume changes derived from catheter displacements were small and therefore considered clinically insignificant. Implant configuration remains stable during 2 days of treatment, confirming the safety of this technique.
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Panettieri V, Smith RL, Mason NJ, Millar JL. Comparison of IPSA and HIPO inverse planning optimization algorithms for prostate HDR brachytherapy. J Appl Clin Med Phys 2014; 15:5055. [PMID: 25493531 PMCID: PMC5711111 DOI: 10.1120/jacmp.v15i6.5055] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/06/2014] [Accepted: 08/02/2014] [Indexed: 11/23/2022] Open
Abstract
Publications have reported the benefits of using high‐dose‐rate brachytherapy (HDRB) for the treatment of prostate cancer, since it provides similar biochemical control as other treatments while showing lowest long‐term complications to the organs at risk (OAR). With the inclusion of anatomy‐based inverse planning optimizers, HDRB has the advantage of potentially allowing dose escalation. Among the algorithms used, the Inverse Planning Simulated Annealing (IPSA) optimizer is widely employed since it provides adequate dose coverage, minimizing dose to the OAR, but it is known to generate large dwell times in particular positions of the catheter. As an alternative, the Hybrid Inverse treatment Planning Optimization (HIPO) algorithm was recently implemented in Oncentra Brachytherapy V. 4.3. The aim of this work was to compare, with the aid of radiobiological models, plans obtained with IPSA and HIPO to assess their use in our clinical practice. Thirty patients were calculated with IPSA and HIPO to achieve our department's clinical constraints. To evaluate their performance, dosimetric data were collected: Prostate PTV D90(%),V100(%),V150(%), and V200(%), Urethra D10(%), Rectum D2cc(%), and conformity indices. Additionally tumor control probability (TCP) and normal tissue complication probability (NTCP) were calculated with the BioSuite software. The HIPO optimization was performed firstly with Prostate PTV (HIPOPTV) and then with Urethra as priority 1 (HIPOurethra). Initial optimization constraints were then modified to see the effects on dosimetric parameters, TCPs, and NTCPs. HIPO optimizations could reduce TCPs up to 10%–20% for all PTVs lower than 74 cm3. For the urethra, IPSA and HIPOurethra provided similar NTCPs for the majority of volume sizes, whereas HIPOPTV resulted in large NTCP values. These findings were in agreement with dosimetric values. By increasing the PTV maximum dose constraints for HIPOurethra plans, TCPs were found to be in agreement with IPSA without affecting the urethral NTCPs. PACS numbers: 87.55.‐x, 87.55.de, 87.55.dh, 87.53.Jw
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Sander L, Langkilde NC, Holmberg M, Carl J. MRI target delineation may reduce long-term toxicity after prostate radiotherapy. Acta Oncol 2014; 53:809-14. [PMID: 24358954 DOI: 10.3109/0284186x.2013.865077] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND AND PURPOSE Aiming for minimal toxicity after radical prostate cancer (PC) radiotherapy (RT), magnetic resonance imaging (MRI) target delineation could be a possible benefit knowing that clinical target volumes (CTV) are up to 30% smaller, when CTV delineation on MRI is compared to standard computed tomography (CT). This study compares long-term toxicity using CT or MRI delineation before PC RT. MATERIAL AND METHODS Urinary and rectal toxicity assessments 36 months after image-guided RT (78 Gy) using CTC-AE scores in two groups of PC patients. Peak symptom score values were registered. One group of patients (n=72) had standard CT target delineation and gold markers as fiducials. Another group of patients (n=73) had MRI target delineation and a nickel-titanium stent as fiducial. RESULTS At 36 months no difference in overall survival (92% in both groups, p=0.29) or in PSA-relapse free survival was found between the groups (MRI=89% and CT=94%, p=0.67). A significantly smaller CTV was found in the MRI group (p=0.02). Urinary retention and frequency were significantly reduced in the MRI group (p=0.03 in the matter of both). The overall urinary and rectal toxicity did not differ between the two groups. CONCLUSION MRI delineation leads to a significantly reduced CTV. Significantly lower urinary frequency and urinary retention toxicity scores were observed following MRI delineation. The study did not find significant differences in overall urinary or rectal toxicity between the two groups. PSA-relapse survival did not differ between the two groups at 36 months.
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Affiliation(s)
- Lotte Sander
- Department of Urology, Aalborg University Hospital , Aalborg , Denmark
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