Head and neck radiotherapy on the MR linac: a multicenter planning challenge amongst MRIdian platform users.

PURPOSE: Purpose of this study is to evaluate plan quality on the MRIdian (Viewray Inc., Oakwood Village, OH, USA) system for head and neck cancer (HNC) through comparison of planning approaches of several centers. METHODS: A total of 14 planners using the MRIdian planning system participated in this treatment challenge, centrally organized by ViewRay, for one contoured case of oropharyngeal carcinoma with standard constraints for organs at risk (OAR). Homogeneity, conformity, sparing of OARs, and other parameters were evaluated according to The International Commission on Radiation Units and Measurements (ICRU) recommendations anonymously, and then compared between centers. Differences amongst centers were assessed by means of Wilcoxon test. Each plan had to fulfil hard constraints based on dose-volume histogram (DVH) parameters and delivery time. A plan quality metric (PQM) was evaluated. The PQM was defined as the sum of 16 submetrics characterizing different DVH goals. RESULTS: For most dose parameters the median score of all centers was higher than the threshold that results in an ideal score. Six participants achieved the maximum number of points for the OAR dose parameters, and none had an unacceptable performance on any of the metrics. Each planner was able to achieve all the requirements except for one which exceeded delivery time. The number of segments correlated to improved PQM and inversely correlated to brainstem D0.1cc and to Planning Target Volume1 (PTV) D0.1cc. Total planning experience inversely correlated to spinal canal dose. CONCLUSION: Magnetic Resonance Image (MRI) linac-based planning for HNC is already feasible with good quality. Generally, an increased number of segments and increasing planning experience are able to provide better results regarding planning quality without significantly prolonging overall treatment time.

68Ga-PSMA-11 PET has the potential to improve patient selection for extended pelvic lymph node dissection in intermediate to high-risk prostate cancer.

INTRODUCTION: Radical prostatectomy with extended pelvic lymph node dissection (ePLND) is a curative treatment option for patients with clinically significant localised prostate cancer. The decision to perform an ePLND can be challenging because the overall incidence of lymph node metastasis is relatively low and ePLND is not free of complications. Using current clinical nomograms to identify patients with nodal involvement, approximately 75-85% of ePLNDs performed are negative. The aim of this study was to assess the added value of 68Ga-PSMA-11 PET in predicting lymph node metastasis in men with intermediate- or high-risk prostate cancer. METHODS: 68Ga-PSMA-11 PET scans of 60 patients undergoing radical prostatectomy with ePLND were reviewed for qualitative (visual) assessment of suspicious nodes and assessment of quantitative parameters of the primary tumour in the prostate (SUVmax, total activity (PSMAtotal) and PSMA positive volume (PSMAvol)). Ability of quantitative PET parameters to predict nodal metastasis was assessed with receiver operating characteristics (ROC) analysis. A multivariable logistic regression model combining PSA, Gleason score, visual nodal status on PET and primary tumour PSMAtotal was built. Net benefit at each risk threshold was compared with five nomograms: MSKCC nomogram, Yale formula, Roach formula, Winter nomogram and Partin tables (2016). RESULTS: Overall, pathology of ePLND specimens revealed 31 pelvic metastatic lymph nodes in 12 patients. 68Ga-PSMA-11 PET visual analysis correctly detected suspicious nodes in 7 patients, yielding a sensitivity of 58% and a specificity of 98%. The area under the ROC curve for primary tumour SUVmax was 0.70, for PSMAtotal 0.76 and for PSMAvol 0.75. The optimal cut-off for nodal involvement was PSMAtotal > 49.1. The PET model including PSA, Gleason score and quantitative PET parameters had a persistently higher net benefit compared with all clinical nomograms. CONCLUSION: Our model combining PSA, Gleason score and visual lymph node analysis on 68Ga-PSMA-11 PET with PSMAtotal of the primary tumour showed a tendency to improve patient selection for ePLND over the currently used clinical nomograms. Although this result has to be validated, 68Ga-PSMA-11 PET showed the potential to reduce unnecessary surgical procedures in patients with intermediate- or high-risk prostate cancer.

Impact of 68Ga-PSMA-11 PET staging on clinical decision-making in patients with intermediate or high-risk prostate cancer.

BACKGROUND: Accurate staging is of major importance to determine the optimal treatment modality for patients with prostate cancer. Positron emission tomography (PET) with prostate-specific membrane antigen (PSMA) is a promising technique that outperformed conventional imaging in the detection of nodal and distant metastases in previous studies. However, it is still unclear whether the superior sensitivity and specificity also translate into improved patient management. The aim of this study was to assess the performance of 68Ga-PSMA-11 PET for staging of intermediate and high-risk prostate cancer and its potential impact on disease management. METHODS: In this retrospective analysis, 116 patients who underwent 68Ga-PSMA-11 PET/CT or MRI scans for staging of their intermediate or high-risk prostate cancer between April 2016 and May 2018 were included. The potential impact of 68Ga-PSMA-11 PET staging on patient management was assessed within a simulated multidisciplinary tumour board where hypothetical treatment decisions based on clinical information and conventional imaging alone was determined. This treatment decision was compared with the treatment recommendation based on clinical information and 68Ga-PSMA-11 PET imaging. RESULTS: The primary tumour was positive on 68Ga-PSMA-11 PET in 113 patients (97%). Nodal metastases were detected in 28 patients (24%) and bone metastases in 14 patients (12%). Compared with clinical staging and conventional imaging, 68Ga-PSMA-11 PET resulted in new information in 42 of 116 patients (36%). In 32 of 116 patients (27%), this information would most likely have changed the management into a different therapy modality (15 patients, 13%) or adjusted treatment details (e.g. modification of radiotherapy field or lymph node dissection template; 17 patients, 14%). CONCLUSION: Information from 68Ga-PSMA-11 PET staging has the potential to change the management in more than a fourth of the patients who underwent PET staging for their intermediate to high-risk prostate cancer. Whether these more personalized 68Ga-PSMA-11 PET-based treatment decisions will improve patient outcome needs further investigation.

Clinical impact of 68Ga-PSMA-11 PET on patient management and outcome, including all patients referred for an increase in PSA level during the first year after its clinical introduction.

PURPOSE: The fast-increasing use of positron emission tomography (PET) with prostate-specific membrane antigen (PSMA) ligand for the imaging of prostate cancer (PCA) biochemical recurrence has led to a rapid change in treatment concepts. Since the superiority of 68Ga-PSMA-11 PET in detecting recurrent PCA is well established, the aim of our study was to assess its effect on management and outcome in all patients imaged during the first year after its introduction into clinical routine. METHODS: Of 327 patients imaged, 223 were referred for recurrent PCA and gave written informed consent for further analysis of their data for this retrospective consecutive cohort analysis. Twenty patients were lost to further follow-up. The rate of detection of recurrence by 68Ga-PSMA-11 PET was based on the clinical reports. Management before the availability of PET diagnostic information was assessed according to guidelines (therapy option without 68Ga-PSMA-11 PET). In the 203 patients with follow-up 6 months after 68Ga-PSMA-11 PET, the therapies effectively implemented as well as follow-up PSA levels were evaluated, with a PSA value of <0.2 ng/ml representing a complete response and a decrease in PSA value of at least 50% from baseline representing a partial response. RESULTS: 68Ga-PSMA-11 PET was positive and identified recurrence in 166 of the 223 patients (74%), with a detection rate of 50% for recurrent disease at low PSA values of <0.5 ng/ml. 68Ga-PSMA-11 PET led to a change in management in 122 of the 203 patients (60%). A substantial increase in the use of metastasis-targeted treatment and a reduction in the use of systemic treatment were observed, with 59 of the 203 patients (29%) undergoing targeted radiotherapy (RTXa) only, and 20 patients (10%) undergoing RTXa with hormonal therapy as the two most frequently selected therapy options. The proportion of patients in whom systemic therapy was selected decreased from 60% (133 of 223 patients) to 34% (70 of 203 patients) on the basis of the information provided by the 68Ga-PSMA-11 PET scan. PSMA PET-directed metastasis-targeted treatment led to a complete response after 6 months in 45% of patients. CONCLUSION: The high rate of recurrence detection by PSMA PET was confirmed and PSMA PET led to a change in management in 60% of patients. Focal therapy for PSMA-positive lesions is a promising approach with complete responses in 45% of patients.

Intra- and inter-fraction breath-hold variations and margins for radiotherapy of abdominal targets.

Radiotherapy in expiration breath-hold (EBH) has the potential to reduce treatment volumes of abdominal targets compared to an internal target volume concept in free-breathing. The reproducibility of EBH and required safety margins were investigated to quantify this volumetric benefit. Pre- and post-treatment diaphragm position difference and the positioning variability were determined on computed tomography. Systematic and random errors for EBH position reproducibility and positioning variability were calculated, resulting in margins of 7 to 12 mm depending on the prescription isodose and fractionation. A reduced volume was shown for EBH for lesions with superior-inferior breathing motion above 4 to 8 mm.

MR-guided beam gating: Residual motion, gating efficiency and dose reconstruction for stereotactic treatments of the liver and lung.

PURPOSE: This study aims to investigate the efficiency and the geometric as well as the dosimetric benefit of magnetic-resonance guided beam gating for stereotactic treatments in moving organs. METHOD: Patients treated with MR-guided (MRIdian system) SBRT for lung (n = 10) and liver (n = 10) targets were analyzed. Breath-hold gating was performed based on lesion tracking in sagittal cine MRI images. The target offset from the geometric center of the gating window with and without gating was evaluated. A dose reconstruction workflow based on convolution of these 2D position-probability maps and the daily 3D dose distribution was used to estimate the daily delivered dose including motion. The dose to the clinical target volume (CTV) and to a 2-cm ring structure around the planning target volume were evaluated. RESULTS: The applied gating protocol resulted in a mean (±standard deviation) gating efficiency of 55%±16%. Over all patients, the mean target offset (2D-root-mean-square error) was 8.3 ± 4.3 mm, which reduced to 2.4 ± 0.6 mm during gating. The dose reconstruction showed a mean deviation in CTV coverage (D95) from the static plans of -1.7%±1.8% with gating and -12.0%±8.4% if no gating would have been used. The mean dose (Dmean) in the ring structure, with respect to the static plans, showed mean deviations of -0.1%±0.3% with gating and -1.6%±1.8% without gating. CONCLUSION: The MRIdian system enables gating based on the inner anatomy and the implemented dose reconstruction workflow demonstrated geometric robust delivery of the planned radiation doses.

Targeting Treatment Resistance in Head and Neck Squamous Cell Carcinoma - Proof of Concept for CT Radiomics-Based Identification of Resistant Sub-Volumes.

PURPOSE: Radiomics has already been proposed as a prognostic biomarker in head and neck cancer (HNSCC). However, its predictive power in radiotherapy has not yet been studied. Here, we investigated a local radiomics approach to distinguish between tumor sub-volumes with different levels of radiosensitivity as a possible target for radiation dose intensification. MATERIALS AND METHODS: Of 40 patients (n=28 training and n=12 validation) with biopsy confirmed locally recurrent HNSCC, pretreatment contrast-enhanced CT images were registered with follow-up PET/CT imaging allowing identification of controlled (GTVcontrol) vs non-controlled (GTVrec) tumor sub-volumes on pretreatment imaging. A bi-regional model was built using radiomic features extracted from pretreatment CT in the GTVrec and GTVcontrol to differentiate between those regions. Additionally, concept of local radiomics was implemented to perform detection task. The original tumor volume was divided into sub-volumes with no prior information on the location of recurrence. Radiomic features from those sub-volumes were then used to detect recurrent sub-volumes using multivariable logistic regression. RESULTS: Radiomic features extracted from non-controlled regions differed significantly from those in controlled regions (training AUC = 0.79 CI 95% 0.66 - 0.91 and validation AUC = 0.88 CI 95% 0.72 - 1.00). Local radiomics analysis allowed efficient detection of non-controlled sub-volumes both in the training AUC = 0.66 (CI 95% 0.56 - 0.75) and validation cohort 0.70 (CI 95% 0.53 - 0.86), however performance of this model was inferior to bi-regional model. Both models indicated that sub-volumes characterized by higher heterogeneity were linked to tumor recurrence. CONCLUSION: Local radiomics is able to detect sub-volumes with decreased radiosensitivity, associated with location of tumor recurrence in HNSCC in the pre-treatment CT imaging. This proof of concept study, indicates that local CT radiomics can be used as predictive biomarker in radiotherapy and potential target for dose intensification.

MR-Guided Adaptive Radiotherapy for Head and Neck Cancer: Prospective Evaluation of Migration and Anatomical Changes of the Major Salivary Glands.

The aim of this study was to quantify anatomical changes of parotids and submandibular glands and evaluate potential dosimetric advantages during weekly adaptive MR-guided radiotherapy (MRgRT) for the definitive treatment of head and neck cancer (HNC). The data and plans of 12 patients treated with bilateral intensity-modulated radiotherapy for HNC using MR-linac, with weekly offline adaptations, were prospectively evaluated. The positional and volumetric changes of the salivary glands were analyzed by manual segmentation in weekly MRI images and the dosimetric impact of these anatomical changes on the adapted treatment plans was assessed. The mean volume change in parotid and submandibular gland volume was -31.9% (p < 0.0001) and -29.7% (p < 0.0001) after five weeks, respectively. The volume change was significantly correlated with the cumulative dose for the respective gland at the time of volume measurement. Inter-parotid distance changed by -5.4% (6.5 mm) on average after five weeks (p = 0.0005). The distance became significantly smaller only in the left-right direction. The inter-submandibular gland distance changed by 0.7 mm (p = 0.38). This study demonstrated significant changes in salivary gland volumes and position following daily MR guidance and weekly plan adaptation. Ongoing clinical trials will provide data on the clinical impact of these changes and novel MR-based adaptation strategies.

Operating procedures, risk management and challenges during implementation of adaptive and non-adaptive MR-guided radiotherapy: 1-year single-center experience.

BACKGROUND: Main purpose was to describe procedures and identify challenges in the implementation process of adaptive and non-adaptive MR-guided radiotherapy (MRgRT), especially new risks in workflow due to the new technique. We herein report the single center experience for the implementation of (MRgRT) and present an overview on our treatment practice. METHODS: Descriptive statistics were used to summarize clinical and technical characteristics of treatment and patient characteristics including sites treated between April 2019 and end of March 2020 after ethical approval. A risk analysis was performed to identify risks of the online adaptive workflow. RESULTS: A summary of the processes on the MR-Linac including workflows, quality assurance and possible pitfalls is presented. 111 patients with 124 courses were treated during the first year of MR-guided radiotherapy. The most commonly treated site was the abdomen (42% of all treatment courses). 73% of the courses were daily online adapted and a high number of treatment courses (75%) were treated with stereotactic body irradiation. Only 4/382 fractions could not be treated due to a failing online adaptive quality assurance. In the risk analysis for errors, the two risks with the highest risk priority number were both in the contouring category, making it the most critical step in the workflow. CONCLUSION: Although challenging, establishment of MRgRT as a routinely used technique at our department was successful for all sites and daily o-ART was feasible from the first day on. However, ongoing research and reports will have to inform us on the optimal indications for MRgRT because careful patient selection is necessary as it continues to be a time-consuming treatment technique with restricted availability. After risk analysis, the most critical workflow category was the contouring process, which resembles the need of experienced staff and safety check paths.

Comparison of beam segment versus full plan re-optimization in daily magnetic resonance imaging-guided online-adaptive radiotherapy.

The optimal approach for magnetic resonance imaging-guided online adaptive radiotherapy is currently unknown and needs to consider patient on-couch time constraints. The aim of this study was to compare two different plan optimization approaches. The comparison was performed in 238 clinically applied online-adapted treatment plans from 55 patients, in which the approach of re-optimization was selected based on the physician's choice. For 33 patients where both optimization approaches were used at least once, the median treatment planning dose metrics of both target and organ at risk differed less than 1%. Therefore, we concluded that beam segment weight optimization was chosen adequately for most patients without compromising plan quality.

Multimodal treatment strategies for colorectal liver metastases.

Colorectal cancer is the third most common cancer worldwide. Half of CRC patients develop liver metastases during the course of the disease, with a 5-year survival rate close to zero in the absence of therapy. Surgical resection remains the only possible curative option, and current guidelines recommend adjuvant chemotherapy, resulting in a 5-year survival rate exceeding 50%. Neoadjuvant systemic therapy is not indicated in cases with simple resection but should be offered to all patients with extensive bilobar disease. Personalised systemic treatment is essential to convert upfront non-resectable lesions to resectable ones. Anatomical resections, non-anatomical resections and two-stage hepatectomies can be performed though open or minimally invasive (laparoscopic or robotic) surgery. The extent of a hepatic resection is limited by the risk of postoperative liver failure due to a too small liver remnant, inflow or outflow obstruction or insufficient biliary drainage. About 75% of patients are diagnosed with non-resectable liver metastases not amenable to a standard upfront resection. In recent years, effective therapeutic approaches have revolutionised liver surgery and new strategies have enabled the conversion of primarily non-resectable metastatic disease for resection. These strategies include oncological and surgical therapies, as well as combinations of the two. From an oncological perspective, colorectal liver metastases  may be treated by systemic chemotherapy or immunotherapy, or selective intra-hepatic arterial infusion chemotherapy, depending on the extent of the disease and the mutational status. In surgery, we often apply two-stage strategies using portal vein occlusion, such as portal vein embolisation or ligation, or complex two-stage hepatectomy such as associating liver partition and portal vein ligation for staged hepatectomy. Other additive tools to reach curative resection are tumour ablations (electroporation, microwave or radiofrequency). The role of stereotactic radiation of liver metastases is not yet well defined. Modern radiation techniques, including image guidance, breath hold and gating, were only introduced for a larger patient population in recent years. Therefore, prospective studies with larger patient cohorts are still pending. Over the last decade, liver transplantation has gained increasing attention in selective cases of non-resectable colorectal liver metastases, with promising cohort studies, but definitive recommendations must await the results of ongoing randomised controlled trials. The optimal treatment of patients with colorectal liver metastases requires the timely association of various strategies, and all cases must be discussed at multidisciplinary team conferences. While colorectal liver metastases was a uniformly lethal condition a few decades ago, it has become amenable to curative therapies, with excellent quality of life in many scenarios. This review reports on up-to-date treatment modalities and their combinations in the treatment algorithm of colorectal liver metastases.    .

Benefit of replanning in MR-guided online adaptive radiation therapy in the treatment of liver metastasis.

PURPOSE: To assess the effects of daily adaptive MR-guided replanning in stereotactic body radiation therapy (SBRT) of liver metastases based on a patient individual longitudinal dosimetric analysis. METHODS: Fifteen patients assigned to SBRT for oligometastatic liver metastases underwent daily MR-guided target localization and on-table treatment plan re-optimization. Gross tumor volume (GTV) and organs at risk (OARs) were adapted to the anatomy-of-the-day. A reoptimized plan (RP) and a rigidly shifted baseline plan (sBP) without re-optimization were generated for each fraction. After extraction of DVH parameters for GTV, planning target volume (PTV), and OARs (stomach, duodenum, bowel, liver, heart) plans were compared on a per-patient basis. RESULTS: Median pre-treatment GTV and PTV were 14.9 cc (interquartile range (IQR): 7.7-32.9) and 62.7 cc (IQR: 42.4-105.5) respectively. SBRT with RP improved PTV coverage (V100%) for 47/75 of the fractions and reduced doses to the most proximal OARs (D1cc, Dmean) in 33/75 fractions compared to sBP. RP significantly improved PTV coverage (V100%) for metastases within close proximity to an OAR by 4.0% (≤ 0.2 cm distance from the edge of the PTV to the edge of the OAR; n = 7; p = 0.01), but only by 0.2% for metastases farther away from OAR (> 2 cm distance; n = 7; p = 0.37). No acute grade 3 treatment-related toxicities were observed. CONCLUSIONS: MR-guided online replanning SBRT improved target coverage and OAR sparing for liver metastases with a distance from the edge of the PTV to the nearest luminal OAR < 2 cm. Only marginal improvements in target coverage were observed for target distant to critical OARs, indicating that these patients do not benefit from daily adaptive replanning.

Detection Rate and Localization of Prostate Cancer Recurrence Using 68Ga-PSMA-11 PET/MRI in Patients with Low PSA Values ≤ 0.5 ng/mL.

A first analysis of simultaneous 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/MRI showed some improvement in the detection of recurrent disease at low serum prostate specific antigen (PSA) values below 0.5 ng/mL compared with the already high detection rate of 68Ga-PSMA-11 PET/CT. We therefore focused on all patients with biochemical recurrence and PSA values no higher than 0.5 ng/mL to assess the detection rate for 68Ga-PSMA-11 PET/MRI. Methods: We retrospectively analyzed a cohort of 66 consecutive patients who underwent 68Ga-PSMA-11 PET/MRI for biochemical recurrence with a PSA value no higher than 0.5 ng/mL at our institution. Median PSA level was 0.23 ng/mL (range, 0.03-0.5 ng/mL). Detection of PSMA-positive lesions within the prostate fossa, local and distant lymph nodes, bones, or visceral organs was recorded. In addition, all scans with 68Ga-PSMA-11 PET/MRI-positive lesions were retrospectively assessed to analyze if lesions were detected inside or outside a standard salvage radiotherapy volume. Results: Overall, in 36 of 66 patients (54.5%) PSMA-positive lesions were detected; in 26 of 40 (65%) patients with a PSA level between 0.2 and 0.5 ng/mL and in 10 of 26 (38.5%) patients with a PSA level less than 0.2 ng/mL. Even at those low PSA values, only 8 of 66 (12.1%) patients had exclusive local recurrence. Lymph nodes were detected in 23 patients and bone metastases in 5 on 68Ga-PSMA-11 PET/MRI. In 26 of 66 patients (39.4%), PSMA-positive lesions were located outside a standard salvage radiotherapy volume. Conclusion: Our data confirm that 68Ga-PSMA-11 PET/MRI has a high detection rate for recurrent prostate cancer, even at low PSA levels no higher than 0.5 ng/mL. In addition, we show that 68Ga-PSMA-11 PET/MRI detected PSMA-positive lesions outside a standard salvage radiotherapy volume in 39.4% of all patients.

Treatment plan quality during online adaptive re-planning.

BACKGROUND: Online adaptive radiotherapy is intended to prevent plan degradation caused by inter-fractional tumor volume and shape changes, but time limitations make online re-planning challenging. The aim of this study was to compare the quality of online-adapted plans to their respective reference treatment plans. METHODS: Fifty-two patients treated on a ViewRay MRIdian Linac were included in this retrospective study. In total 238 online-adapted plans were analyzed, which were optimized with either changing of the segment weights (n = 85) or full re-optimization (n = 153). Five different treatment sites were evaluated: prostate, abdomen, liver, lung and pelvis. Dosimetric parameters of gross tumor volume (GTV), planning target volume (PTV), 2 cm ring around the PTV and organs at risk (OARs) were considered. The Wilcoxon signed-rank test was used to assess differences between online-adapted and reference treatment plans, p < 0.05 was considered significant. RESULTS: The average duration of the online adaptation, consisting of contour editing, plan optimization and quality assurance (QA), was 24 ± 6 min. The GTV was slightly larger (average ± SD: 1.9% ± 9.0%) in the adapted plans than in the reference plans (p < 0.001). GTV-D95% exhibited no significant changes when considering all plans, but GTV-D2% increased by 0.40% ± 1.5% on average (p < 0.001). There was a very small yet significant decrease in GTV-coverage for the abdomen plans. The ring Dmean increased on average by 1.0% ± 3.6% considering all plans (p < 0.001). There was a significant reduction of the dose to the rectum of 4.7% ± 16% on average (p < 0.001) for prostate plans. CONCLUSIONS: Dosimetric quality of online-adapted plans was comparable to reference treatment plans and OAR dose was either comparable or decreased, depending on treatment site. However, dose spillage was slightly increased.

Skeletal muscle mass correlates with increased toxicity during neoadjuvant radiochemotherapy in locally advanced esophageal cancer: A SAKK 75/08 substudy.

BACKGROUND: Sarcopenia, the critical depletion of skeletal muscle mass, is an independent prognostic factor in several tumor entities for treatment-related toxicity and survival. In esophageal cancer, there have been conflicting results regarding the value of sarcopenia as prognostic factor, which may be attributed to the heterogeneous patient populations and the retrospective nature of previous studies. The aim of our study was therefore to determine the impact of sarcopenia on prospectively collected specific outcomes in a subgroup of patients treated within the phase III study SAKK 75/08 with trimodality therapy (induction chemotherapy, radiochemotherapy and surgery) for locally advanced esophageal cancer. METHODS: Sarcopenia was assessed by skeletal muscle index at the 3rd lumbar vertebra (L3) in cross-sectional computed tomography scans before induction chemotherapy, before radiochemotherapy and after neoadjuvant therapy in a subgroup of 61 patients from four centers in Switzerland. Sarcopenia was determined by previously established cut-off values (Martin et al., PMID: 23530101) and correlated with prospectively collected outcomes including treatment-related toxicity, postoperative morbidity, treatment feasibility and survival. RESULTS: Using the published cut-off values, the prevalence of sarcopenia increased from 29.5% before treatment to 63.9% during neoadjuvant therapy (p < 0.001). Feasibility of neoadjuvant therapy and surgery was not different in initially sarcopenic and non-sarcopenic patients. We observed in sarcopenic patients significantly increased grade ≥ 3 toxicities during chemoradiation (83.3% vs 52.4%, p = 0.04) and a non-significant trend towards increased postoperative complications (66.7% vs 42.9%, p = 0.16). No difference in survival according to sarcopenia could be observed in this small study population. CONCLUSIONS: Trimodality therapy in locally advanced esophageal cancer is feasible in selected patients with sarcopenia. Neoadjuvant chemoradiation increased the percentage of sarcopenia. Sarcopenic patients are at higher risk for increased toxicity during neoadjuvant radiochemotherapy and showed a non-significant trend to more postoperative morbidity.

Radiotherapy for pelvic nodal recurrences after radical prostatectomy: patient selection in clinical practice.

AIM: There is no general consensus on the optimal treatment for prostate cancer (PC) patients with intrapelvic nodal oligorecurrences after radical prostatectomy. Besides androgen deprivation therapy (ADT) as standard of care, both elective nodal radiotherapy (ENRT) and stereotactic body radiotherapy (SBRT) as well as salvage lymph node dissection (sLND) are common treatment options. The aim of our study was to assess decision making and practice patterns for salvage radiotherapy (RT) in this setting. METHODS: Treatment recommendations from 14 Swiss radiation oncology centers were collected and converted into decision trees. An iterative process using the objective consensus methodology was applied to assess differences and consensus. RESULTS: PSMA PET/CT was recommended by 93% of the centers as restaging modality. For unfit patients defined by age, comorbidities or low performance status, androgen deprivation therapy (ADT) alone was recommended by more than 70%. For fit patients with unfavorable tumor characteristics such as short prostate-specific antigen (PSA) doubling time or initial high-risk disease, the majority of the centers (57-71%) recommended ENRT + ADT for 1-4 lesions. For fit patients with favorable tumor characteristics, there were low levels of consensus and a wide variety of recommendations. For 1-4 nodal lesions, focal SBRT was offered by 64% of the centers, most commonly as a 5-fraction course. CONCLUSIONS: As an alternative to ADT, ENRT or SBRT for pelvic nodal oligorecurrences of PC are commonly offered to selected patients, with large treatment variations between centers. The exact number of lymph nodes had a major impact on treatment selection.