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PURPOSE: To provide a comprehensive review of the means by which to optimize target volume definition for the purposes of treatment planning for patients with intact prostate cancer with a specific emphasis on focal boost volume definition. METHODS: Here we conduct a narrative review of the available literature summarizing the current state of knowledge on optimizing target volume definition for the treatment of localized prostate cancer. RESULTS: Historically, the treatment of prostate cancer included a uniform prescription dose administered to the entire prostate with or without coverage of all or part of the seminal vesicles. The development of prostate magnetic resonance imaging (MRI) and positron emission tomography (PET) using prostate-specific radiotracers has ushered in an era in which radiation oncologists are able to localize and focally dose-escalate high-risk volumes in the prostate gland. Recent phase 3 data has demonstrated that incorporating focal dose escalation to high-risk subvolumes of the prostate improves biochemical control without significantly increasing toxicity. Still, several fundamental questions remain regarding the optimal target volume definition and prescription strategy to implement this technique. Given the remaining uncertainty, a knowledge of the pathological correlates of radiographic findings and the anatomic patterns of tumor spread may help inform clinical judgement for the definition of clinical target volumes. CONCLUSION: Advanced imaging has the ability to improve outcomes for patients with prostate cancer in multiple ways, including by enabling focal dose escalation to high-risk subvolumes. However, many questions remain regarding the optimal target volume definition and prescription strategy to implement this practice, and key knowledge gaps remain. A detailed understanding of the pathological correlates of radiographic findings and the patterns of local tumor spread may help inform clinical judgement for target volume definition given the current state of uncertainty.
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The purpose of this European Society for Radiotherapy and Oncology (ESTRO) project, endorsed by the European Association of Urology, is to explore expert opinion on the management of patients with oligometastatic and oligoprogressive renal cell carcinoma by means of stereotactic ablative radiotherapy (SABR) on extracranial metastases, with the aim of developing consensus recommendations for patient selection, treatment doses, and concurrent systemic therapy. A questionnaire on SABR in oligometastatic renal cell carcinoma was prepared by a core group and reviewed by a panel of ten prominent experts in the field. The Delphi consensus methodology was applied, sending three rounds of questionnaires to clinicians identified as key opinion leaders in the field. At the end of the third round, participants were able to find consensus on eight of the 37 questions. Specifically, panellists agreed to apply no restrictions regarding age (25 [100%) of 25) and primary renal cell carcinoma histology (23 [92%] of 25) for SABR candidates, on the upper threshold of three lesions to offer ablative treatment in patients with oligoprogression, and on the concomitant administration of immune checkpoint inhibitor. SABR was indicated as the treatment modality of choice for renal cell carcinoma bone oligometatasis (20 [80%] of 25) and for adrenal oligometastases 22 (88%). No consensus or major agreement was reached regarding the appropriate schedule, but the majority of the poll (54%-58%) retained the every-other-day schedule as the optimal choice for all the investigated sites. The current ESTRO Delphi consensus might provide useful direction for the application of SABR in oligometastatic renal cell carcinoma and highlight the key areas of ongoing debate, perhaps directing future research efforts to close knowledge gaps.
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Carcinoma de Células Renales , Consenso , Técnica Delphi , Neoplasias Renales , Radiocirugia , Humanos , Masculino , Carcinoma de Células Renales/radioterapia , Carcinoma de Células Renales/secundario , Carcinoma de Células Renales/patología , Progresión de la Enfermedad , Europa (Continente) , Neoplasias Renales/patología , Neoplasias Renales/radioterapia , Metástasis de la Neoplasia , Radiocirugia/normas , Urología/normasRESUMEN
Background and purpose: MRI-guided radiotherapy (MRIgRT) offers multiple potential advantages over CT-guidance. This study examines the potential clinical benefits of MRIgRT for men with localised prostate cancer, in the setting of moderately hypofractionated radiotherapy. We evaluate two-year toxicity outcomes, early biochemical response and patient-reported outcomes (PRO), using data obtained from a multicentre international registry study, for the first group of patients with prostate cancer who underwent treatment on a 1.5 T MR-Linac. Materials and methods: Patients who were enrolled within the MOMENTUM study and received radical treatment with 60 Gy in 20 fractions were identified. PSA levels and CTCAE version 5.0 toxicity data were measured at follow-up visits. Those patients who consented to PRO data collection also completed EQ-5D-5L, EORTC QLQ-C30 and EORTC QLQ-PR25 questionnaires. Results: Between November 2018 and June 2022, 146 patients who had MRIgRT for localised prostate cancer on the 1.5 T MR-Linac were eligible for this study. Grade 2 and worse gastro-intestinal (GI) toxicity was reported in 3 % of patients at three months whilst grade 2 and worse genitourinary (GU) toxicity was 7 % at three months. There was a significant decrease in the median PSA at 12 months. The results from both the EQ-5D-5L data and EORTC global health status scale indicate a decline in the quality of life (QoL) during the first six months. The mean change in score for the EORTC scale showed a decrease of 11.4 points, which is considered clinically important. QoL improved back to baseline by 24 months. Worsening of hormonal symptoms in the first six months was reported with a return to baseline by 24 months and sexual activity in all men worsened in the first three months and returned to baseline at 12 months. Conclusion: This study establishes the feasibility of online-MRIgRT for localised prostate on a 1.5 T MR-Linac with low rates of toxicity, similar to that published in the literature. However, the clinical benefits of MRIgRT over conventional radiotherapy in the setting of moderate hypofractionation is not evident. Further research will focus on the delivery of ultrahypofractionated regimens, where the potential advantages of MRIgRT for prostate cancer may become more discernible.
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PURPOSE: The use of magnetic resonance imaging (MRI) in radiotherapy planning is becoming more widespread, particularly with the emergence of MRI-guided radiotherapy systems. Existing guidelines for defining the prostate bed clinical target volume (CTV) show considerable heterogeneity. This study aimed to establish baseline interobserver variability (IOV) for prostate bed CTV contouring on MRI, develop international consensus guidelines, and evaluate its effect on IOV. METHODS AND MATERIALS: Participants delineated the CTV on 3 MRI scans, obtained from the Elekta Unity MR-Linac, as per their normal practice. Radiation oncologist contours were visually examined for discrepancies, and interobserver comparisons were evaluated against simultaneous truth and performance level estimation (STAPLE) contours using overlap metrics (Dice similarity coefficient and Cohen's kappa), distance metrics (mean distance to agreement and Hausdorff distance), and volume measurements. A literature review of postradical prostatectomy local recurrence patterns was performed and presented alongside IOV results to the participants. Consensus guidelines were collectively constructed, and IOV assessment was repeated using these guidelines. RESULTS: Sixteen radiation oncologists' contours were included in the final analysis. Visual evaluation demonstrated significant differences in the superior, inferior, and anterior borders. Baseline IOV assessment indicated moderate agreement for the overlap metrics while volume and distance metrics demonstrated greater variability. Consensus for optimal prostate bed CTV boundaries was established during a virtual meeting. After guideline development, a decrease in IOV was observed. The maximum volume ratio decreased from 4.7 to 3.1 and volume coefficient of variation reduced from 40% to 34%. The mean Dice similarity coefficient rose from 0.72 to 0.75 and the mean distance to agreement decreased from 3.63 to 2.95 mm. CONCLUSIONS: Interobserver variability in prostate bed contouring exists among international genitourinary experts, although this is lower than previously reported. Consensus guidelines for MRI-based prostate bed contouring have been developed, and this has resulted in an improvement in contouring concordance. However, IOV persists and strategies such as an education program, development of a contouring atlas, and further refinement of the guidelines may lead to additional improvements.
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Radioterapia Guiada por Imagen , Masculino , Humanos , Radioterapia Guiada por Imagen/métodos , Próstata/diagnóstico por imagen , Variaciones Dependientes del Observador , Planificación de la Radioterapia Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia MagnéticaRESUMEN
BACKGROUND AND PURPOSE: The apparent diffusion coefficient (ADC), a potential imaging biomarker for radiotherapy response, needs to be reproducible before translation into clinical use. The aim of this study was to evaluate the multi-centre delineation- and calculation-related ADC variation and give recommendations to minimize it. MATERIALS AND METHODS: Nine centres received identical diffusion-weighted and anatomical magnetic resonance images of different cancerous tumours (adrenal gland, pelvic oligo metastasis, pancreas, and prostate). All centres delineated the gross tumour volume (GTV), clinical target volume (CTV), and viable tumour volume (VTV), and calculated ADCs using both their local calculation methods and each of the following calculation conditions: b-values 0-500 vs. 150-500 s/mm2, region-of-interest (ROI)-based vs. voxel-based calculation, and mean vs. median. ADC variation was assessed using the mean coefficient of variation across delineations (CVD) and calculation methods (CVC). Absolute ADC differences between calculation conditions were evaluated using Friedman's test. Recommendations for ADC calculation were formulated based on observations and discussions within the Elekta MRI-linac consortium image analysis working group. RESULTS: The median (range) CVD and CVC were 0.06 (0.02-0.32) and 0.17 (0.08-0.26), respectively. The ADC estimates differed 18% between b-value sets and 4% between ROI/voxel-based calculation (p-values < 0.01). No significant difference was observed between mean and median (p = 0.64). Aligning calculation conditions between centres reduced CVC to 0.04 (0.01-0.16). CVD was comparable between ROI types. CONCLUSION: Overall, calculation methods had a larger impact on ADC reproducibility compared to delineation. Based on the results, significant sources of variation were identified, which should be considered when initiating new studies, in particular multi-centre investigations.
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Imagen por Resonancia Magnética , Neoplasias , Masculino , Humanos , Reproducibilidad de los Resultados , Imagen de Difusión por Resonancia Magnética/métodos , Procesamiento de Imagen Asistido por Computador/métodosRESUMEN
PURPOSE: To quantify the difference in accuracy of adapt-to-position (ATP), adapt-to-rotation (ATR) and adapt-to-shape (ATS) workflows used in MRI-guided online adaptive radiotherapy for prostate carcinoma (PCa) by evaluating the margins required to accommodate intra-fraction motion of the clinical target volumes for prostate (CTVpros), prostate including seminal vesicles (CTVpros + sv) and gross tumor volume (GTV). MATERIALS AND METHODS: Clinical delineations of the CTVpros, CTVpros + sv and GTV of 24 patients with intermediate- and high-risk PCa, treated using ATS on a 1.5 T MR-Linac, were used for analysis. Delineations were available pre- and during beam-on. To simulate ATP and ATR workflows, we automatically generated the structures associated with these workflows using rigid transformations from the planning-MRI to the daily online MRIs. Clinical GTVs were analyzed as ATR GTVs and only ATP GTVs were simulated. Planning target volumes (PTVs) were generated with isotropic margins ranging 0.0-5.0 mm. The volumetric overlap was calculated between these PTVs and their corresponding clinical delineation on the MRI acquired during beam-on and averaged over all treatment fractions. RESULTS: The PTV margin required to cover > 95% of the CTVpros was equal (2.5 mm) for all workflows. For the CTVpros + sv, this margin increased to 5.0, 4.0 and 3.5 mm in the ATP, ATR and ATS workflow, respectively. GTV coverage improved from ATP to ATR for margins up to 4.0 mm. CONCLUSION: ATP, ATR and ATS workflows ensure equal coverage of the CTVpros for the current clinical margins. For the CTVpros + sv, ATS showed optimal performance. GTV coverage improves by additional adaptations to prostate rotations.
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Neoplasias de la Próstata , Planificación de la Radioterapia Asistida por Computador , Masculino , Humanos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/patología , Próstata/patología , Imagen por Resonancia Magnética , Adenosina Trifosfato , Dosificación RadioterapéuticaRESUMEN
BACKGROUND AND PURPOSE: The hypo-FLAME trial showed that once-weekly (QW) focal boosted prostate stereotactic body radiotherapy (SBRT) is associated with acceptable acute genitourinary (GU) and gastrointestinal (GI) toxicity. Currently, we investigated the safety of reducing the overall treatment time (OTT) of focal boosted prostate SBRT from 29 to 15 days. MATERIAL AND METHODS: Patients with intermediate- and high-risk prostate cancer were treated with SBRT delivering 35 Gy in 5 fractions to the whole prostate gland with an iso-toxic boost up to 50 Gy to the intraprostatic lesion(s) in a semi-weekly (BIW) schedule. The primary endpoint was radiation-induced acute toxicity (CTCAE v5.0). Changes in quality of life (QoL) were examined in terms of proportions achieving a minimal clinically important change (MCIC). Finally, acute toxicity and QoL scores of the BIW schedule were compared with the results of the prior QW hypo-FLAME schedule (n = 100). RESULTS: Between August 2020 and February 2022, 124 patients were enrolled and treated BIW. No grade ≥3 GU or GI toxicity was observed. The 90-days cumulative incidence of grade 2 GU and GI toxicity rates were 47.5% and 7.4%, respectively. Patients treated QW scored significant less grade 2 GU toxicity (34.0%, p = 0.01). No significant differences in acute GI toxicity were observed. Furthermore, patients treated QW had a superior acute bowel and urinary QoL. CONCLUSION: Semi-weekly prostate SBRT with iso-toxic focal boosting is associated with acceptable acute GU and GI toxicity. Based on the comparison between the QW and BIW schedule, patients should be counselled regarding the short-term advantages of a more protracted schedule. Registration number ClinicalTrials.gov: NCT04045717.
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Enfermedades Gastrointestinales , Neoplasias de la Próstata , Traumatismos por Radiación , Radiocirugia , Masculino , Humanos , Próstata , Radiocirugia/efectos adversos , Radiocirugia/métodos , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/cirugía , Calidad de Vida , Sistema Urogenital , Enfermedades Gastrointestinales/etiología , Traumatismos por Radiación/etiologíaRESUMEN
OBJECTIVE: The goal of this consensus expert opinion was to define quality assurance (QA) tests for online magnetic resonance image (MRI) guided radiotherapy (oMRgRT) systems and to define the important medical physics aspects for installation and commissioning of an oMRgRT system. MATERIALS AND METHODS: Ten medical physicists and two radiation oncologists experienced in oMRgRT participated in the survey. In the first round of the consensus expert opinion, ideas on QA and commissioning were collected. Only tests and aspects different from commissioning of a CT guided radiotherapy (RT) system were considered. In the following two rounds all twelve participants voted on the importance of the QA tests, their recommended frequency and their suitability for the two oMRgRT systems approved for clinical use as well as on the importance of the aspects to consider during medical physics commissioning. RESULTS: Twenty-four QA tests were identified which are potentially important during commissioning and routine QA on oMRgRT systems compared to online CT guided RT systems. An additional eleven tasks and aspects related to construction, workflow development and training were collected. Consensus was found for most tests on their importance, their recommended frequency and their suitability for the two approved systems. In addition, eight aspects mostly related to the definition of workflows were also found to be important during commissioning. CONCLUSIONS: A program for QA and commissioning of oMRgRT systems was developed to support medical physicists to prepare for safe handling of such systems.
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Oncología por Radiación , Radioterapia Guiada por Imagen , Humanos , Consenso , Testimonio de Experto , Planificación de la Radioterapia Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Física , Radioterapia Guiada por Imagen/métodosAsunto(s)
Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/cirugía , Prostatectomía , PacientesRESUMEN
Current risk-stratification systems for prostate cancer (PCa) do not sufficiently reflect the disease heterogeneity. Genomic classifiers (GC) enable improved risk stratification after surgery, but less data exist for patients treated with definitive radiation therapy (RT) or RT in oligo-/metastatic disease stages. To guide future perspectives of GCs for RT, we conducted (1) a systematic review on the evidence of GCs for patients treated with RT and (2) a survey of experts using the Delphi method, addressing the role of GCs in personalized treatments to identify relevant fields of future clinical and translational research. We performed a systematic review and screened ongoing clinical trials on ClinicalTrials.gov. Based on these results, a multidisciplinary international team of experts received an adapted Delphi method survey. Thirty-one and 30 experts answered round 1 and round 2, respectively. Questions with ≥75% agreement were considered relevant and included in the qualitative synthesis. Evidence for GCs as predictive biomarkers is mainly available to the postoperative RT setting. Validation of GCs as prognostic markers in the definitive RT setting is emerging. Experts used GCs in patients with PCa with extensive metastases (30%), in postoperative settings (27%), and in newly diagnosed PCa (23%). Forty-seven percent of experts do not currently use GCs in clinical practice. Expert consensus demonstrates that GCs are promising tools to improve risk-stratification in primary and oligo-/metastatic patients in addition to existing classifications. Experts were convinced that GCs might guide treatment decisions in terms of RT-field definition and intensification/deintensification in various disease stages. This work confirms the value of GCs and the promising evidence of GC utility in the setting of RT. Additional studies of GCs as prognostic biomarkers are anticipated and form the basis for future studies addressing predictive capabilities of GCs to optimize RT and systemic therapy. The expert consensus points out future directions for GC research in the management of PCa.
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Neoplasias de la Próstata , Masculino , Humanos , Consenso , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/tratamiento farmacológico , GenómicaRESUMEN
External beam radiotherapy (EBRT) is an important cornerstone in the treatment of localized prostate cancer. Current image-guided radiotherapy (IGRT) techniques allow for more accurate and precise delivery of radiation treatment by the use of imaging before each fraction. Magnetic resonance guided radiotherapy (MRgRT) is the next step in IGRT with hybrid systems combining linear accelerators with MRI-scanners. With MRgRT, it is possible to visualize pelvic anatomy in great detail and subsequently perform replanning of the radiation dose distribution before each radiotherapy fraction. This technique has the potential to increase the therapeutic window of EBRT, by improved normal tissue sparing due to margin reduction and more accurate target dose delivery. This is particularly promising for prostate cancer, with its biology lending itself to ultra-hypofractionation, reducing radiotherapy treatment to as little as five fractions. Also, recent studies have shown that focal dose escalation to the intraprostatic tumor to high ablative doses can substantially increase disease-free survival. In this article, we discuss these unique opportunities as well as the potential future benefits of MRgRT in prostate cancer treatment.
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Neoplasias de la Próstata , Radioterapia Guiada por Imagen , Masculino , Humanos , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/patología , Radioterapia Guiada por Imagen/métodos , Próstata/patología , Imagen por Resonancia Magnética/métodos , Dosificación RadioterapéuticaRESUMEN
PURPOSE: Magnetic resonance (MR)-guided radiation therapy (MRgRT) is a new technique for treatment of localized prostate cancer (PCa). We report the 12-month outcomes for the first PCa patients treated within an international consortium (the MOMENTUM study) on a 1.5T MR-Linac system with ultrahypofractionated radiation therapy. METHODS AND MATERIALS: Patients treated with 5 × 7.25 Gy were identified. Prostate specific antigen-level, physician-reported toxicity (Common Terminology Criteria for Adverse Events [CTCAE]), and patient-reported outcomes (Quality of Life Questionnaire PR25 and Quality of Life Questionnaire C30 questionnaires) were recorded at baseline and at 3, 6, and 12 months of follow-up (FU). Pairwise comparative statistics were conducted to compare outcomes between baseline and FU. RESULTS: The study included 425 patients with localized PCa (11.4% low, 82.0% intermediate, and 6.6% high-risk), and 365, 313, and 186 patients reached 3-, 6-, and 12-months FU, respectively. Median prostate specific antigen level declined significantly to 1.2 ng/mL and 0.1 ng/mL at 12 months FU for the nonandrogen deprivation therapy (ADT) and ADT group, respectively. The peak of genitourinary and gastrointestinal CTCAE toxicity was reported at 3 months FU, with 18.7% and 1.7% grade ≥2, respectively. The QLQ-PR25 questionnaire outcomes showed significant deterioration in urinary domain score at all FU moments, from 8.3 (interquartile range [IQR], 4.1-16.6) at baseline to 12.4 (IQR, 8.3-24.8; P = .005) at 3 months, 12.4 (IQR, 8.3-20.8; P = .018;) at 6 months, and 12.4 (IQR, 8.3-20.8; P = .001) at 12 months. For the non-ADT group, physician- and patient-reported erectile function worsened significantly between baseline and 12 months FU. CONCLUSIONS: Ultrahypofractionated MR-guided radiation therapy for localized PCa using a 1.5T MR-Linac is effective and safe. The peak of CTCAE genitourinary and gastrointestinal toxicity was reported at 3 months FU. Furthermore, for patients without ADT, a significant increase in CTCAE erectile dysfunction was reported at 12 months FU. These data are useful for educating patients on expected outcomes and informing study design of future comparative-effectiveness studies.
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Neoplasias de la Próstata , Radioterapia Guiada por Imagen , Masculino , Humanos , Antígeno Prostático Específico , Calidad de Vida , Planificación de la Radioterapia Asistida por Computador , Radioterapia Guiada por Imagen/efectos adversos , Radioterapia Guiada por Imagen/métodos , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/patología , Espectroscopía de Resonancia Magnética , Sistema de RegistrosRESUMEN
PURPOSE: This population-based study describes nationwide trends and variation in the use of primary radiotherapy for non-metastatic prostate cancer in The Netherlands in 2008-2019. METHODS: Prostate cancer patients were selected from the Netherlands Cancer Registry (N = 103,059). Treatment trends were studied over time by prognostic risk groups. Multilevel analyses were applied to identify variables associated with external beam radiotherapy (EBRT) and brachy-monotherapy versus no active treatment in low-risk disease, and EBRT versus radical prostatectomy in intermediate and high-risk disease. RESULTS: EBRT use remained stable (5-6%) in low-risk prostate cancer and increased from 21% to 32% in intermediate-risk, 37% to 45% in high-risk localized and 50% to 57% in high-risk locally advanced disease. Brachy-monotherapy decreased from 19% to 6% and from 15% to 10% in low and intermediate-risk disease, respectively, coinciding an increase of no active treatment from 55% to 73% in low-risk disease. Use of EBRT or brachy-monotherapy versus no active treatment in low-risk disease differed by region, T-stage and patient characteristics. Hospital characteristics were not associated with treatment in low-risk disease, except for availability of brachy-monotherapy in 2008-2013. Age, number of comorbidities, travel time for EBRT, prognostic risk group, and hospital characteristics were associated with EBRT versus prostatectomy in intermediate and high-risk disease. CONCLUSION: Intermediate/high-risk PCa was increasingly managed with EBRT, while brachy-monotherapy in low/intermediate-risk PCa decreased. In low-risk PCa, the no active treatment-approach increased. Variation in treatment suggests treatment decision related to patient/disease characteristics. In intermediate/high-risk disease, variation seems furthermore related to the treatment modalities available in the diagnosing hospitals.
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Braquiterapia , Neoplasias de la Próstata , Masculino , Humanos , Países Bajos/epidemiología , Prostatectomía , Neoplasias de la Próstata/patología , Próstata/patología , Vesículas SeminalesRESUMEN
In recent years, clinical use of novel advanced imaging modalities in prostate cancer detection, staging, and therapy has intensified and is currently reforming clinical guidelines. In the future, advanced imaging technologies will continue to develop and become even more accurate, which will offer new opportunities for improving patient selection, surgical treatment, and radiotherapy, with the potential to guide prostate cancer therapy.
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Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/terapia , Próstata/patología , Selección de Paciente , Estadificación de NeoplasiasRESUMEN
Introduction: Prostate cancer is a common malignancy for which radiation therapy (RT) provides an excellent management option with high rates of control and low toxicity. Historically RT has been given with CT based image guidance. Recently, magnetic resonance (MR) imaging capabilities have been successfully integrated with RT delivery platforms, presenting an appealing, yet complex, expensive, and time-consuming method of adapting and guiding RT. The precise benefits of MR guidance for localized prostate cancer are unclear. We sought to summarize optimal strategies to test the benefits of MR guidance specifically in localized prostate cancer. Methods: A group of radiation oncologists, physicists, and statisticians were identified to collectively address this topic. Participants had a history of treating prostate cancer patients with the two commercially available MRI-guided RT devices. Participants also had a clinical focus on randomized trials in localized prostate cancer. The goal was to review both ongoing trials and present a conceptual focus on MRI-guided RT specifically in the definitive treatment of prostate cancer, along with developing and proposing novel trials for future consideration. Trial hypotheses, endpoints, and areas for improvement in localized prostate cancer that specifically leverage MR guided technology are presented. Results: Multiple prospective trials were found that explored the potential of adaptive MRI-guided radiotherapy in the definitive treatment of prostate cancer. Different primary areas of improvement that MR guidance may offer in prostate cancer were summarized. Eight clinical trial design strategies are presented that summarize options for clinical trials testing the potential benefits of MRI-guided RT. Conclusions: The number and scope of trials evaluating MRI-guided RT for localized prostate cancer is limited. Yet multiple promising opportunities to test this technology and potentially improve outcomes for men with prostate cancer undergoing definitive RT exist. Attention, in the form of multi-institutional randomized trials, is needed.
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Magnetic resonance imaging (MRI)-guided radiotherapy allows for online adaptation of the radiation plan on the basis of anatomical and functional changes during treatment. MRI-guided radiotherapy holds significant promise for broadening the therapeutic window for multiple urological cancers.
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Radioterapia Guiada por Imagen , Neoplasias Urológicas , Humanos , Imagen por Resonancia Magnética/métodos , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia Guiada por Imagen/métodos , Neoplasias Urológicas/diagnóstico por imagen , Neoplasias Urológicas/radioterapia , UrólogosRESUMEN
Recently, two new treatment techniques, i.e. proton therapy and MR-linac based radiotherapy (RT), have been introduced in Dutch RT centres with major impact on daily practice. The content and context of these techniques are frequently described in scientific literature while little is reported about the implementation phase. This process is complex due to a variety of aspects, such as the involvement of multiple stakeholders, significant unpredictability in the start-up phase, the impact of the learning curve, standard operating procedures under development, new catchment areas, and extensive training programs. Insight about implementation in daily care is utterly important for clinics that are about to introduce these new technologies in order to prevent that every centre needs to reinvent the wheel. This position paper gives an overview of the implementation of proton therapy and MR-linac based RT in two large academic RT centres in the Netherlands, i.e. Maastro and Radboudumc respectively. With this paper we aim to report our lessons learned, in order to facilitate other RT centres that consider introducing these and other new techniques in their departments.