Abstract Dose escalated radiotherapy improves outcomes for men with prostate cancer. A plateau for benefit from dose escalation using EBRT may not have been reached for some patients with higher risk ...disease. The use of increasingly conformal techniques, such as step and shoot IMRT or more recently VMAT, has allowed treatment intensification to be achieved whilst minimising associated increases in toxicity to surrounding normal structures. To support further safe dose escalation, the uncertainties in the treatment target position will need be minimised using optimal planning and image-guided radiotherapy (IGRT). In particular the increasing usage of profoundly hypo-fractionated stereotactic therapy is predicated on the ability to confidently direct treatment precisely to the intended target for the duration of each treatment. This article reviews published studies on the influences of varies types of motion on daily prostate position and how these may be mitigated to improve IGRT in future. In particular the role that MRI has played in the generation of data is discussed and the potential role of the MR-Linac in next-generation IGRT is discussed.
Six UK studies investigating stereotactic ablative radiotherapy (SABR) are currently open. Many of these involve the treatment of oligometastatic disease at different locations in the body. Members ...of all the trial management groups collaborated to generate a consensus document on appropriate organ at risk dose constraints. Values from existing but older reviews were updated using data from current studies. It is hoped that this unified approach will facilitate standardised implementation of SABR across the UK and will allow meaningful toxicity comparisons between SABR studies and internationally.
The use of stereotactic ablative radiotherapy (SABR) in the UK has expanded over the past decade, in part as the result of several UK clinical trials and a recent NHS England Commissioning through ...Evaluation programme. A UK SABR Consortium consensus for normal tissue constraints for SABR was published in 2017, based on the existing literature at the time. The published literature regarding SABR has increased in volume over the past 5 years and multiple UK centres are currently working to develop new SABR services. A review and update of the previous consensus is therefore appropriate and timely. It is hoped that this document will provide a useful resource to facilitate safe and consistent SABR practice.
Oligometastatic disease (OMD) represents a spectrum of clinical scenarios and various classification systems have been proposed. Bone-only OMD can occur in patients with advanced prostate cancer and ...validated decision-making tools are needed to assist patient selection for metastasis-directed therapy. The aim of the present study was to determine the prognostic utility of a classification system for OMD.
A retrospective review was conducted of all patients with bone-only oligometastatic prostate cancer treated with stereotactic body radiotherapy (SBRT) since November 2011. SBRT was delivered using CyberKnife® and gantry-based linear accelerator platforms. All patients were classified into oligometastatic states based on the European Society for Radiotherapy and Oncology/European Organisation for Research and Treatment of Cancer (ESTRO/EORTC) classification system. Kaplan–Meier and Cox regression analyses were carried out to determine the prognostic utility of this classification system.
In total, 105 patients with 145 osseous metastases were treated over 119 sessions. The median follow-up after SBRT was 23 months (interquartile range 10–39.8). Twelve patients had died after a median time of 31 months. The 3-year metastatic progression-free survival was 23% (95% confidence interval 13–32) and the 3-year overall survival was 88% (95% confidence interval 80–96). Patients in a metachronous oligometastatic state were 4.50 (95% confidence interval 1.19–17.10, P = 0.03) times more likely to experience metastatic progression compared with those with synchronous oligometastases, and 6.69 (95% confidence interval 1.05–42.50, P = 0.04) times more likely to experience any failure. Hazard ratio magnitudes increased for patients in a repeat oligometastatic state. The multivariate model for both metastatic progression-free survival and failure-free survival found prostate-specific antigen doubling time <4 months (P = 0.002; P = 0.05) to independently predict for progression.
The ESTRO/EORTC classification of OMD predicts for progression in patients treated with SBRT for bone-only oligometastatic prostate cancer at our institution. Further validation in prospective series over multiple tumour sites is needed. These characterisation factors should be assessed in patients considered for metastasis-directed therapy together with established prognostic features.
•After SBRT, patients in a metachronous oligometastatic state were 4.50 times more likely to experience metastatic progression compared with those with synchronous oligometastases.•This relationship strengthened for patients in repeat and induced oligometastatic states.•Whilst awaiting prospective validation, our analysis supports the use of the ESTRO/EORTC classification system as a decision-making tool in the management of patients with bone-only oligometastatic prostate cancer.
Stereotactic Body Radiotherapy for Prostate Cancer Henderson, D.R; Tree, A.C; van As, N.J
Clinical oncology (Royal College of Radiologists (Great Britain)),
05/2015, Letnik:
27, Številka:
5
Journal Article
Recenzirano
Abstract The use of stereotactic body radiotherapy (SBRT) for localised prostate cancer is now supported by a substantial body of non-randomised data, with medium-term outcomes consistent with ...current standard radiotherapy. The ability to deliver profoundly hypofractionated treatment, combined with the relatively low α/β ratio of prostate cancer, may result in a more favourable therapeutic ratio, presenting an opportunity for isotoxic dose escalation. Furthermore, as treatment can be given in five attendances, SBRT has the potential both to reduce costs and improve patient quality of life. However, in a treatment landscape with many competing options of broadly similar efficacy, randomised trials are essential to define the relative benefits of this approach. SBRT also has an emerging application in oligometastatic prostate cancer, with promising early outcomes for delaying disease progression and deferring the need for androgen deprivation therapy.
Abstract Aims To report the relapse pattern of stereotactic body radiotherapy (SBRT) for oligorecurrent nodal prostate cancer (PCa). Materials and methods PCa patients with ≤3 lymph nodes (N1/M1a) at ...the time of recurrence were treated with SBRT. SBRT was defined as a radiotherapy dose of at least 5 Gy per fraction to a biological effective dose of at least 80 Gy to all metastatic sites. Distant progression-free survival was defined as the time interval between the first day of SBRT and appearance of new metastatic lesions, outside the high-dose region. Relapses after SBRT were recorded and compared with the initially treated site. Secondary end points were local control, time to palliative androgen deprivation therapy and toxicity scored using the Common Terminology Criteria for Adverse Events v4.0. Results Overall, 89 metastases were treated in 72 patients. The median distant progression-free survival was 21 months (95% confidence interval 16–25 months) with 88% of patients having ≤3 metastases at the time of progression. The median time from first SBRT to the start of palliative androgen deprivation therapy was 44 months (95% confidence interval 17–70 months). Most relapses (68%) occurred in nodal regions. Relapses after pelvic nodal SBRT ( n = 36) were located in the pelvis ( n = 14), retroperitoneum ( n = 1), pelvis and retroperitoneum ( n = 8) or in non-nodal regions ( n = 13). Relapses after SBRT for extrapelvic nodes ( n = 5) were located in the pelvis ( n = 1) or the pelvis and retroperitoneum ( n = 4). Late grade 1 and 2 toxicity was observed in 17% ( n = 12) and 4% of patients ( n = 3). Conclusion SBRT for oligometastatic PCa nodal recurrences is safe. Most subsequent relapses are again nodal and oligometastatic.
In Reply to Onal et al Nicholls, L; Chapman, E; Khoo, V ...
Clinical oncology (Royal College of Radiologists (Great Britain)),
04/2022, Letnik:
34, Številka:
4
Journal Article
Prostate morphological changes during external beam radiotherapy are poorly understood. Excellent soft-tissue visualisation offered by magnetic resonance image-guided radiotherapy (MRIgRT) provides ...an opportunity to better understand such changes. The aim of this study was to quantify prostate volume and dimension changes occurring during extreme and moderately hypofractionated schedules.
Forty prostate cancer patients treated on the Unity 1.5 Tesla magnetic resonance linear accelerator (MRL) were retrospectively reviewed. The cohort comprised patients treated with 36.25 Gy in five fractions (n = 20) and 60 Gy in 20 fractions (n = 20). The volume of the delineated prostates on reference planning computed tomography (fused with MRI) and daily T2-weighted 2-min session images acquired on Unity were charted. Forty planning computed tomography and 500 MRL prostate volumes were evaluated. The mean absolute and relative change in prostate volume during radiotherapy was compared using a paired t-test (P value <0.01 considered significant to control for multiple comparisons). The maximum dimension of the delineated prostate was measured in three isocentric planes.
Significant prostate volume changes, relative to MRL imaging fraction 1 (MRL#1), were seen at all time points for the five-fraction group. The peak mean relative volume increase was 21% (P < 0.001), occurring at MRL#3 and MRL#4 after 14.5 and 21.75 Gy, respectively. Prostate expansion was greatest in the superior-inferior direction; the peak mean maximal extension was 5.9 mm. The maximal extension in the left-right and anterior-posterior directions measured 1.1 and 2.2 mm, respectively. For the 20-fraction group, prostate volume increased relative to MRL#1, for all treatment time points. The mean relative volume increase was 11% (P < 0.001) at MRL#5 after 12 Gy, it then fluctuated between 8 and 13%. From MRL#5 to MRL#20, the volume increase was significant (P < 0.01) for 12 of 16 time points calculated. The peak mean maximal extension in the superior-inferior direction was 3.1 mm. The maximal extension in the left-right and anterior-posterior directions measured 1.7 and 3.7 mm, respectively.
Significant prostate volume and dimension changes occur during extreme and moderately hypofractionated radiotherapy. The extent of change was greater during extreme hypofractionation. MRIgRT offers the opportunity to reveal, quantify and correct for this deformation.
Stereotactic body radiotherapy (SBRT) with the delayed option of androgen deprivation therapy (ADT) is the current treatment paradigm in men relapsed with oligometastatic prostate cancer based on the ...outcome of a phase II randomised controlled study. The immediate (concomitant) use of ADT in this clinical setting potentially augments the efficacy of SBRT by improving systemic disease control. The aim of this study was to compare the clinical outcomes of these two treatment strategies.
Eighty-eight patients with up to three oligometastases and controlled primary disease who had been treated using SBRT with immediate or delayed ADT were included in this retrospective analysis. Progression-free survival (PFS), widespread failure-free survival (WFFS) and freedom from further interventions (FFFI) were assessed using Kaplan–Meier and Cox proportional hazard regression methods. Toxicity was evaluated using Common Terminology Criteria for Adverse Events (CTCAE) v4.0.
Thirty-nine patients (44.3%) were treated with SBRT and immediate ADT (continuous ADT, n = 7; intermittent ADT, n = 32) and 49 (55.7%) with SBRT and delayed ADT. The median follow-up was 24 months (interquartile range 13.5–37.0 months). PFS in the immediate and delayed ADT groups were 26 months and 16 months, respectively (P < 0.007). The median WFFS in the immediate ADT group was not reached compared with 21 months in the delayed ADT group (P = 0.025). The 1- and 2-year FFFI in the immediate ADT group were 88% and 64.1%, respectively, significantly higher than those in the delayed ADT group (63.8% and 30.2%, respectively, P < 0.002). Acute toxicities of grade 1–2 occurred in 17.9% of the immediate ADT group and 18.4% of the delayed ADT group (P = 0.96). Only one case of grade 3 late toxicity (pelvic insufficiency) was identified in this study.
SBRT with concomitant ADT improves PFS, WFFS and FFFI as compared with SBRT with delayed ADT; this finding needs validation in a prospective, randomised study.
•The immediate (concomitant) use of ADT in men relapsed with oligometastatic prostate cancer potentially augments the efficacy of SBRT by improving systemic disease control compared with the option of delayed ADT.•At 2 years, the concomitant use of ADT with SBRT is associated with improved progression-free survival and widespread failure-free survival.•At 2 years, men treated with SBRT and immediate ADT for oligometastatic disease have higher freedom from further interventions than those in whom ADT was delayed.
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