SEOR SBRT-SG stereotactic body radiation therapy consensus guidelines for non-spine bone metastasis.

The use of stereotactic body radiation therapy (SBRT) to treat non-spine bone metastases (NSBM) is becoming increasingly common in clinical practice. The clinical advantages of SBRT include good pain control and high local control rates, although only limited data are available. The Spanish Society of Radiation Oncology (SEOR) SBRT group recently convened a task force of experts in the field to address key questions related to SBRT for NSBM, including treatment indications, planning, techniques, and dose fractionation. The task force reviewed the available literature to develop evidence-based recommendations for the safe application of NSBM SBRT and to standardize and optimize SBRT processes. The present document provides a comprehensive analysis of the available data, including ongoing clinical trials and controversies, providing clinically applicable recommendations.

SEOR SBRT-SG survey on SRS/SBRT dose prescription criteria in Spain

Aim Stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) are essential tools in radiation oncology. In Spain, the use of these techniques continues to grow as older linear accelerators (linacs) are replaced with modern equipment. However, little is known about inter-centre variability in prescription and dose heterogeneity limits. Consequently, the SBRT-Spanish Task Group (SBRT-SG) of the Spanish Society of Radiation Oncology (SEOR) has undertaken an initiative to assess prescription and homogeneity in SRS/SBRT treatment. In the present study, we surveyed radiation oncology (RO) departments to obtain a realistic overview of prescription methods used for SBRT and SRS treatment in Spain. Methods A brief survey was developed and sent to 34 RO departments in Spain, mostly those who are members of the SEOR SBRT-SG. The survey contained seven questions about the specific prescription mode, dose distribution heterogeneity limits, prescription strategies according to SRS/SBRT type, and the use of IMRT–VMAT (Intensity Modulated Radiation Therapy–Volumetric Modulated Arc Therapy). Results Responses were received from 29 centres. Most centres (59%) used the prescription criteria D95% ≥ 100%. Accepted dose heterogeneity was wide, ranging from 107 to 200%. Most centres used IMRT–VMAT (93%). Conclusions This survey about SRS/SBRT prescription and dose heterogeneity has evidenced substantial inter-centre variability in prescription criteria, particularly for intended and accepted dose heterogeneity. These differences could potentially influence the mean planning target volume dose and its correlation with treatment outcomes. The findings presented here will be used by the SEOR SBRT-SG to develop recommendations for SRS/SBRT dose prescription and heterogeneity (AU)

Recommended procedures and responsibilities for radiosurgery (SRS) and extracranial stereotactic body radiotherapy (SBRT): report of the SEOR in collaboration with the SEFM

Today, patient management generally requires a multidisciplinary approach. However, due to the growing knowledge base and increasing complexity of Medicine, clinical practice has become even more specialised. Radiation oncology is not immune to this trend towards subspecialisation, which is particularly evident in ablative radiotherapy techniques that require high dose fractions, such as stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). The aim of the present report is to establish the position of the Spanish Society of Radiation Oncology (SEOR), in collaboration with the Spanish Society of Medical Physics (SEFM), with regard to the roles and responsibilities of healthcare professionals involved in performing SRS and SBRT. The need for this white paper is motivated due to the recent changes in Spanish Legislation (Royal Decree [RD] 601/2019, October 18, 2019) governing the use and optimization of radiotherapy and radiological protection for medical exposure to ionizing radiation (article 11, points 4 and 5) [1 ], which states: “In radiotherapy treatment units, the specialist in Radiation Oncology will be responsible for determining the correct treatment indication, selecting target volumes, determining the clinical radiation parameters for each volume, directing and supervising treatment, preparing the final clinical report, reporting treatment outcomes, and monitoring the patient’s clinical course.” Consequently, the SEOR and SEFM have jointly prepared the present document to establish the roles and responsibilities for the specialists—radiation oncologists (RO), medical physicists (MP), and related staff —involved in treatments with ionizing radiation. We believe that it is important to clearly establish the responsibilities of each professional group and to clearly establish the professional competencies at each stage of the radiotherapy process (AU)

SEOR SBRT-SG survey on SRS/SBRT dose prescription criteria in Spain.

AIM: Stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) are essential tools in radiation oncology. In Spain, the use of these techniques continues to grow as older linear accelerators (linacs) are replaced with modern equipment. However, little is known about inter-centre variability in prescription and dose heterogeneity limits. Consequently, the SBRT-Spanish Task Group (SBRT-SG) of the Spanish Society of Radiation Oncology (SEOR) has undertaken an initiative to assess prescription and homogeneity in SRS/SBRT treatment. In the present study, we surveyed radiation oncology (RO) departments to obtain a realistic overview of prescription methods used for SBRT and SRS treatment in Spain. METHODS: A brief survey was developed and sent to 34 RO departments in Spain, mostly those who are members of the SEOR SBRT-SG. The survey contained seven questions about the specific prescription mode, dose distribution heterogeneity limits, prescription strategies according to SRS/SBRT type, and the use of IMRT-VMAT (Intensity Modulated Radiation Therapy-Volumetric Modulated Arc Therapy). RESULTS: Responses were received from 29 centres. Most centres (59%) used the prescription criteria D95% ≥ 100%. Accepted dose heterogeneity was wide, ranging from 107 to 200%. Most centres used IMRT-VMAT (93%). CONCLUSIONS: This survey about SRS/SBRT prescription and dose heterogeneity has evidenced substantial inter-centre variability in prescription criteria, particularly for intended and accepted dose heterogeneity. These differences could potentially influence the mean planning target volume dose and its correlation with treatment outcomes. The findings presented here will be used by the SEOR SBRT-SG to develop recommendations for SRS/SBRT dose prescription and heterogeneity.

Recommended procedures and responsibilities for radiosurgery (SRS) and extracranial stereotactic body radiotherapy (SBRT): report of the SEOR in collaboration with the SEFM.

Today, patient management generally requires a multidisciplinary approach. However, due to the growing knowledge base and increasing complexity of Medicine, clinical practice has become even more specialised. Radiation oncology is not immune to this trend towards subspecialisation, which is particularly evident in ablative radiotherapy techniques that require high dose fractions, such as stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). The aim of the present report is to establish the position of the Spanish Society of Radiation Oncology (SEOR), in collaboration with the Spanish Society of Medical Physics (SEFM), with regard to the roles and responsibilities of healthcare professionals involved in performing SRS and SBRT. The need for this white paper is motivated due to the recent changes in Spanish Legislation (Royal Decree [RD] 601/2019, October 18, 2019) governing the use and optimization of radiotherapy and radiological protection for medical exposure to ionizing radiation (article 11, points 4 and 5) [1 ], which states: "In radiotherapy treatment units, the specialist in Radiation Oncology will be responsible for determining the correct treatment indication, selecting target volumes, determining the clinical radiation parameters for each volume, directing and supervising treatment, preparing the final clinical report, reporting treatment outcomes, and monitoring the patient's clinical course." Consequently, the SEOR and SEFM have jointly prepared the present document to establish the roles and responsibilities for the specialists-radiation oncologists (RO), medical physicists (MP), and related staff -involved in treatments with ionizing radiation. We believe that it is important to clearly establish the responsibilities of each professional group and to clearly establish the professional competencies at each stage of the radiotherapy process.

Salvage I-125 brachytherapy for locally-recurrent prostate cancer after radiotherapy.

PURPOSE: Retrospective, single-institution analysis of clinical outcomes and treatment-related toxicity in patients treated with salvage I-125 low-dose rate (LDR) brachytherapy (BT) for locally-recurrent prostate cancer after radiotherapy. MATERIALS AND METHODS: Between 2008 and 2018, 30 patients with biopsy-confirmed prostate cancer recurrence underwent salvage treatment with I-125 LDR-BT. Of these 30 patients, 14 were previously treated with primary external beam radiotherapy (EBRT; median dose, 73 Gy) and 16 with primary I-125 LDR-BT (145 Gy and 160 Gy in 14 and 2 cases, respectively). At seed implantation, the mean age was 75.8 years, with a median Gleason score of 7 and pre-salvage PSA of <10 ng/mL. Six patients received androgen deprivation therapy for six months after relapse diagnosis. The prescribed salvage I-125 BT dose to the gland was 120-130 Gy, with dose restrictions of Dmax <135% (urethra) and <100% (rectum). Toxicity was evaluated according to the CTCAE scale (v4.0). RESULTS: At a median follow-up of 45 months, the biochemical recurrence-free survival rates at 1, 3 and 5 years were 86.7%, 56.7% and 53.3%, respectively. Overall survival at 5 years was 87%. On the multivariate analysis, two variables were significant predictors of recurrence: PSA at relapse and nadir PSA post-salvage. Grade 3 genitourinary toxicity was observed in 5 patients (radiation-induced cystitis in 3 cases and urethral stenosis in 2) and G3 gastrointestinal toxicity in 3 patients (rectal bleeding). CONCLUSION: Salvage therapy with I-125 brachytherapy is a safe and effective treatment option for locally-recurrent prostate cancer in previously-irradiated patients. High pre-salvage PSA and post-salvage nadir PSA values were significantly associated with a worse disease control after salvage I-125 LDR-BT. In well-selected patients, I-125 LDR-BT is comparable to other salvage therapies in terms of disease control and toxicity. However, more research is needed to determine the optimal management of locally-recurrent prostate cancer.

100% peer review in radiation oncology: is it feasible?

PURPOSE: Peer review has been proposed as a strategy to ensure patient safety and plan quality in radiation oncology. Despite its potential benefits, barriers commonly exist to its optimal implementation in daily clinical routine. Our purpose is to analyze peer-review process at our institution. METHODS AND MATERIALS: Based on our group peer-review process, we quantified the rate of plan changes, time and resources needed for this process. Prospectively, data on cases presented at our institutional peer-review conference attended by physicians, resident physicians and physicists were collected. Items such as time to present per case, type of patient (adult or pediatric), treatment intent, dose, aimed technique, disease location and receipt of previous radiation were gathered. Cases were then analyzed to determine the rate of major change, minor change and plan rejection after presentation as well as the median time per session. RESULTS: Over a period of 4 weeks, 148 cases were reviewed. Median of attendants was six physicians, three in-training-physicians and one physicist. Median time per session was 38 (4-72) minutes. 59.5% of cases presented in 1-4 min, 32.4% in 5-9 min and 8.1% in ≥ 10 min. 79.1% of cases were accepted without changes, 11.5% with minor changes, 6% with major changes and 3.4% were rejected with indication of new presentation. Most frequent reason of change was contouring corrections (53.8%) followed by dose or fractionation (26.9%). CONCLUSION: Everyday group consensus peer review is an efficient manner to recollect clinical and technical data of cases presented to ensure quality radiation care before initiation of treatment as well as ensuring department quality in a feedback team environment. This model is feasible within the normal operation of every radiation oncology Department.

Impact of real-time, dose-escalated permanent seed implant brachytherapy in intermediate-risk prostate cancer.

PURPOSE: To retrospectively evaluate biochemical control and toxicity in patients who underwent 125I seed brachytherapy (BT) for intermediate-risk prostate cancer (PCa). MATERIALS AND METHODS: Between January 2004-December 2014, 395 patients with intermediate-risk PCa underwent 125I BT. Of these, 117 underwent preoperative planning (PP; 145 Gy) and 278 real-time intraoperative preplanning (IoP; 160 Gy). All patients were followed for ≥ 6 months (> 5 years in 48% of patients and > 7 years in 13%). Median follow-up was 59 months. RESULTS: Biochemical relapse-free survival (BRFS) rates at 5 and 8 years were, respectively, 91.7% and 82.1%. By treatment group, the corresponding BRFS rates were 93.5% and 90% for IoP and 89% and 76.8% for PP. The maximum dose to the urethra remained unchanged (217 Gy) despite the dose escalation (from 145 to 160 Gy), without any significant increase in treatment-related toxicity (p = 0.13). Overall toxicity outcomes in the series were excellent, with only 3 cases (0.76%) of grade 3 genitourinary toxicity. CONCLUSION: The real-time intraoperative planning technique at 160 Gy yields better biochemical controls than the preoperative planning technique at 145 Gy. Dose escalation did not increase urinary toxicity. The excellent results obtained with the IoP BT technique support its use as the first treatment option in this patient population.

PEACE V - Salvage Treatment of OligoRecurrent nodal prostate cancer Metastases (STORM): a study protocol for a randomized controlled phase II trial.

BACKGROUND: Pelvic nodal recurrences are being increasingly diagnosed with the introduction of new molecular imaging techniques, like choline and PSMA PET-CT, in the restaging of recurrent prostate cancer (PCa). At this moment, there are no specific treatment recommendations for patients with limited nodal recurrences and different locoregional treatment approaches are currently being used, mostly by means of metastasis-directed therapies (MDT): salvage lymph node dissection (sLND) or stereotactic body radiotherapy (SBRT). Since the majority of patients treated with MDT relapse within 2 years in adjacent lymph node regions, with an estimated median time to progression of 12-18 months, combining MDT with whole pelvic radiotherapy (WPRT) may improve oncological outcomes in these patients. The aim of this prospective multicentre randomized controlled phase II trial is to assess the impact of the addition of WPRT to MDT and short-term androgen deprivation therapy (ADT) on metastasis-free survival (MFS) in the setting of oligorecurrent pelvic nodal recurrence. METHODS & DESIGN: Patients diagnosed with PET-detected pelvic nodal oligorecurrence (≤5 nodes) following radical local treatment for PCa, will be randomized in a 1:1 ratio between arm A: MDT and 6 months of ADT, or arm B: WPRT added to MDT and 6 months of ADT. Patients will be stratified by type of PET-tracer (choline, FACBC or PSMA) and by type of MDT (sLND or SBRT). The primary endpoint is MFS and the secondary endpoints include clinical and biochemical progression-free survival (PFS), prostate cancer specific survival, quality of life (QoL), toxicity and time to castration-resistant prostate cancer (CRPC) and to palliative ADT. Estimated study completion: December 31, 2023. DISCUSSION: This is the first prospective multicentre randomized phase II trial assessing the potential of combined WPRT and MDT as compared to MDT alone on MFS for patients with nodal oligorecurrent PCa. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03569241, registered June 14, 2018, ; Identifier on Swiss National Clinical Trials Portal (SNCTP): SNCTP000002947, registered June 14, 2018.

Whole-body diffusion-weighted magnetic resonance imaging (WB-DW-MRI) vs choline-positron emission tomography-computed tomography (choline-PET/CT) for selecting treatments in recurrent prostate cancer.

OBJECTIVE: To determine the effectiveness of whole-body diffusion-weighted magnetic resonance imaging (WB-DW-MRI) in detecting metastases by comparing the results with those from choline-positron emission tomography-computed tomography (choline-PET/CT) in patients with biochemical relapse after primary treatment, and no metastases in bone scintigraphy, CT and/or pelvic MRI, or metastatic/oligometastatic prostate cancer (PCa). Patients with this disease profile who could benefit from treatment with stereotactic body radiation therapy (SBRT) were selected and their responses to these techniques were rated. MATERIALS AND METHODS: This was a prospective, controlled, unicentric study, involving 46 consecutive patients from our centre who presented biochemical relapse after adjuvant, salvage or radical treatment with external beam radiotherapy, or brachytherapy. After initial tests (bone scintigraphy, CT, pelvic MRI), 35 patients with oligometastases or without them were selected. 11 patients with multiple metastases were excluded from the study. WB-DW-MRI and choline-PET/CT was then performed on each patient within 1 week. The results were interpreted by specialists in nuclear medicine and MRI. If they were candidates for treatment with ablative SBRT (SABR), they were then evaluated every three months with both tests. RESULTS: Choline-PET/CT detected lesions in 16 patients that were not observable using WB-DW-MRI. The results were consistent in seven patients and in three cases, a lesion was observed using WB-DW-MRI that was not detected with choline-PET/CT. The Kappa value obtained was 0.133 (p = 0.089); the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of WB-DW-MRI were estimated at 44.93, 64.29, 86.11, and 19.15%, respectively. For choline-PET/CT patients, the sensitivity, specificity, PPV, and NPV were 97.10, 58.33, 93.06, and 77.78%, respectively. CONCLUSIONS: Choline-PET/CT has a high global sensitivity while WB-DW-MRI has a high specificity, and so they are complementary techniques. Future studies with more enrolled patients and a longer follow-up period will be required to confirm these data. The initial data show that the best technique for evaluating response after SBRT is choline-PET/CT. Trial registration number NCT02858128.

Spanish Society of Radiation Oncology clinical guidelines for stereotactic body radiation therapy in lymph node oligometastases.

Data in the literature support the existence of a state of limited metastases or oligometastases. Favorable outcomes have been observed in selected patients with such oligometastases that are treated with local ablative therapies, which include surgical extirpation, stereotactic body radiation therapy (SBRT), and radiofrequency ablation. The role of SBRT in the setting of lymph node oligometastases is still emerging but the early results for local control are promising. However, the biggest challenge is to identify patients who will benefit from treatment of their oligometastatic disease with local aggressive therapy. Patients are initially categorized based upon examination of the initial biopsy, location, stage, and previous treatments received. Appropriate patient management with SBRT requires an understanding of several clinicopathological features that help to identify several subsets of patients with more responsive tumors and a good tolerance to SBRT. In an effort to incorporate the most recent evidence, here the Spanish Society of Radiation Oncology presents guidelines for using SBRT in lymph node oligometastases.

The contribution of the cone beam Kv (CBKvCT) to the reduction in toxicity of prostate cancer treatment with external 3D radiotherapy

OBJECTIVE: Show that verification through cone beam Kv CT (CBKvCT) in a series of patients treated with 3D external radiotherapy (3DRT) for prostate cancer (PC) is related to a reduction in acute and late toxicity levels. MATERIALS AND METHOD: A retrospective, non-randomized study of two homogeneous groups of patients treated between 2005 and 2008, 46 were verified using electronic portal devices (EPIDs) and 48 through CBKvCT. They received 3DRT for localized PC (T1-T3N0M0) and were prescribed the same doses. Treatment was simulated and planned with the same criteria with the same equipment with a median follow-up time of 24 months (12-54 months). Urinary and gastrointestinal toxicity was determined using Common Toxicity Criteria scale, version 4 and RTOG scales. Statistical analysis of data was performed where p < 0.005 being significative. RESULTS AND DISCUSSION: With an overall median follow-up time of 24 months, the levels of proctitis were, respectively, 19.56, 15.21 and 15.2 % in the first group, compared with 4.17, 2.08 and 8.33 % in the second. Statistically, less total and late proctitis, late rectal bleeding, anal fissure, total and acute haematuria, total and acute urinary frequency and total urinary incontinence was observed. No statistically significant evidence of a lowering in toxicity neither in terms of acute and late dysuria nor of a relationship to the TNM, Gleason or PSA or in the grade of stability. CONCLUSION: Verification through CBKvCT in this series is associated with a statistically significant lowering toxicity. This justifies its use. Greater monitoring would be necessary to assess the impact of verification at the level of biochemical control (AU)

Uncertainties and CTV to PTV margins quantitative assessment using cone-beam CT technique in clinical application for prostate, and head and neck irradiation tumours.

PURPOSE To evaluate the magnitude of systematic and random errors from a subset of 100 prostate and 26 head and neck (H&N) cancer patients treated with conventional conformal radiotherapy and using image-guided radiotherapy (IGRT). After treatment, the uncertainties involved and the CTV to PTV margin were evaluated. MATERIAL AND METHODS An Elekta Synergy® linear accelerator was used, taking advantage of 3D on-board computed tomography. IGRT with no-action level (NAL) protocol was applied, reporting the 3D translation and rotation corrections. A statistical study was performed to analyse systematic, random and interobserver uncertainties, and, finally, to obtain the CTV to PTV margins. RESULTS The H&N patients' uncertainties found were smaller than those of prostate patients. The CTV to PTV margins assessed, following the guidelines found in the literature, in the three dimensions of space (right-left, superior-inferior, anterior-posterior) were (5.3, 3.5, 3.2) mm for H&N and (7.3, 7.0, 9.0) mm for prostate cancer treatments. CONCLUSIONS It was found that assessing all the involved uncertainties within radiation treatments was very revealing; their quality improves using IGRT techniques and performing extensive data analysis.

Uncertainties and CTV to PTV margins quantitative assessment using cone-beam CT technique in clinical application for prostate, and head and neck irradiation tumours

PURPOSE To evaluate the magnitude of systematic and random errors from a subset of 100 prostate and 26 head and neck (H&N) cancer patients treated with conventional conformal radiotherapy and using image-guided radiotherapy (IGRT). After treatment, the uncertainties involved and the CTV to PTV margin were evaluated. MATERIAL AND METHODS An Elekta Synergy® linear accelerator was used, taking advantage of 3D on-board computed tomography. IGRT with no-action level (NAL) protocol was applied, reporting the 3D translation and rotation corrections. A statistical study was performed to analyse systematic, random and interobserver uncertainties, and, finally, to obtain the CTV to PTV margins. RESULTS The H&N patients' uncertainties found were smaller than those of prostate patients. The CTV to PTV margins assessed, following the guidelines found in the literature, in the three dimensions of space (right-left, superior-inferior, anterior-posterior) were (5.3, 3.5, 3.2) mm for H&N and (7.3, 7.0, 9.0) mm for prostate cancer treatments. CONCLUSIONS It was found that assessing all the involved uncertainties within radiation treatments was very revealing; their quality improves using IGRT techniques and performing extensive data analysis (AU)

Contribution of hypoxia-measuring molecular imaging techniques to radiotherapy planning and treatment

Hypoxia is related to poor prognosis because it is associated to chemo- and radioresistance. During recent years the evolution of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring tumour hypoxia (AU)