The relation of radiological tumor volume response to histological response and outcome in patients with localized Ewing Sarcoma

A reduction in tumor volume exceeding 65% predicts a good histological response to neoadjuvant chemotherapy in patients with Ewing sarcoma

OBJECTIVE

No consensus exists for tumor volume response criteria in patients with Ewing sarcoma. This study aimed to identify an optimal cutoff for predicting a good histological response by analyzing tumor volume changes and tumor necrosis after neoadjuvant chemotherapy.

MATERIALS AND METHODS

We performed a retrospective analysis of 184 Ewing sarcoma patients, analyzing tumor volume changes before and after neoadjuvant chemotherapy. Patients were divided into two groups based on histological response: good (tumor necrosis ≥ 95%) and poor (tumor necrosis < 95%) responders. The receiver operating characteristic (ROC) area under the curve (AUC) method was used to determine the optimal thresholds for predicting the histological response. Additionally, the prognostic value of this cutoff for relapse-free survival was assessed.

RESULTS

Out of 184 patients, 83 (45%) had tumor necrosis ≥ 95%, while 101 (55%) had tumor necrosis < 95%. ROC analysis identified the optimal cutoff for a good histological response as over 65% tumor volume reduction (AUC = 0.69; p < 0.001). Patients with volume reduction of ≥ 65% had a higher likelihood of a good histological response than those with lesser reductions (p = 0.004; odds ratio = 2.61). Multivariable analysis indicated a correlation between poor histological response and reduced relapse-free survival (hazard ratio = 2.17; p = 0.01), while tumor volume reduction itself did not impact survival.

CONCLUSION

We reported that a tumor volume reduction of ≥ 65% was able to predict a good histological response in Ewing sarcoma patients. We recommend preoperative tumor volume assessment to identify patients at greater risk for poor histological response who could benefit from more intensive chemotherapy protocols or additional radiotherapy.

Factors Influencing the Outcome of Patients with Primary Ewing Sarcoma of the Sacrum

Background

Ewing sarcoma (EwS) is a rare and highly malignant bone tumor primarily affecting children, adolescents, and young adults. The pelvis, trunk, and lower extremities are the most common sites, while EwS of the sacrum as a primary site is very rare, and only few studies focusing on this location are published. Due to the anatomical condition, local treatment is challenging in sacral malignancies. We analyzed factors that might influence the outcome of patients suffering from sacral EwS.

Methods

We retrospectively analyzed data of the GPOH EURO-E.W.I.N.G 99 trial and the EWING 2008 trial, with a cohort of 124 patients with localized or metastatic sacral EwS. The study endpoints were overall survival (OS) and event-free survival (EFS). OS and EFS were calculated using the Kaplan-Meier method, and univariate comparisons were estimated using the log-rank test. Hazard ratios (HRs) with respective 95% confidence intervals (CIs) were estimated in a multivariable Cox regression model.

Results

The presence of metastases (3y-EFS: 0.33 vs. 0.68; P < 0.001; HR = 3.4, 95% CI 1.7 to 6.6; 3y-OS: 0.48 vs. 0.85; P < 0.001; HR = 4.23, 95% CI 1.8 to 9.7), large tumor volume (≥200 ml) (3y-EFS: 0.36 vs. 0.69; P=0.02; HR = 2.1, 95% CI 1.1 to 4.0; 3y-OS: 0.42 vs. 0.73; P=0.04; HR = 2.1, 95% CI 1.03 to 4.5), and age ≥18 years (3y-EFS: 0.41 vs. 0.60; P=0.02; HR = 2.6, 95% CI 1.3 to 5.2; 3y-OS: 0.294 vs. 0.59; P=0.01; HR = 2.92, 95% CI 1.29 to 6.6) were revealed as adverse prognostic factors.

Conclusion

Young age seems to positively influence patients` survival, especially in patients with primary metastatic disease. In this context, our results support other studies, stating that older age has a negative impact on survival. Tumor volume, metastases, and the type of local therapy modality have an impact on the outcome of sacral EwS. Level of evidence: Level 2. This trial is registered with NCT00020566 and NCT00987636.

PET/MR of pediatric bone tumors: what the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.

Pleuropneumonectomy as Salvage Therapy in Children Suffering from Primary or Metastatic Sarcomas with Pleural Localizations

Simple Summary

Pediatric sarcoma patients with pleuropulmonary lesions have a dismal prognosis because the impossibility to achieve local control. Local therapy with radiotherapy, whether in combination with chemotherapy, appears to be insufficient to eliminate the tumor cells. The aim of this study was to determine if pleuropneumonectomy (PP) could be a therapeutic option. We retrospectively reviewed nine patients who underwent PP for pleuropulmonary localization of primary localized sarcoma or metastatic recurrence. Surgery and complications were analyzed, pulmonary function tests were conducted, and quality of life was determined. Outcome is variable, four patients died within 14 months after PP, one patient suffered from local recurrence, and four patients are in long-lasting remission. This extended operation is quite well tolerated. Lung function seems preserved, and quality of life is generally good. Because it gives improvement of survival in patients with pleural lesions, PP can be considered as effective salvage therapy in selected patients.

Abstract

Pediatric sarcoma patients with pleuropulmonary lesions have a dismal prognosis because the impossibility to obtain local control. The aim of this study was to determine if pleuropneumonectomy (PP) could be a therapeutic option. We retrospectively reviewed nine patients who underwent salvage PP for pleuropulmonary localization of primary localized sarcoma or metastatic recurrence. Surgery and complications were analyzed, pulmonary function tests were conducted, and quality of life was determined with EORTC-QLQ-C30 questionnaire. At the time of PP age was between 9–17 years. Underlying disease included metastatic osteosarcoma (n = 5), Ewing sarcoma (two metastatic, one primary), and one primary undifferentiated sarcoma. Early complications occurred in three patients. Mean postoperative hospitalization stay was 14.5 days. Pulmonary function test showed 19–66% reduction of total lung capacity which led to mild exercise intolerance but did not affect daily life. Four patients died of multi-metastatic relapse <14 months after PP, one patient had a local recurrence, and four patients are in complete remission between 1.5 and 12 years after PP. In conclusion, in this small patient group treated with a pleuropneumonectomy for primary or metastatic lesions, outcome is variable; however, this extended surgical technique was generally quite well tolerated. Postoperative lung function seems well preserved, and it seems to lead to at least an extension of life with good quality and therefor can be considered as salvage therapy.

Magnetic resonance biomarkers in radiation oncology: The report of AAPM Task Group 294

A magnetic resonance (MR) biologic marker (biomarker) is a measurable quantitative characteristic that is an indicator of normal biological and pathogenetic processes or a response to therapeutic intervention derived from the MR imaging process. There is significant potential for MR biomarkers to facilitate personalized approaches to cancer care through more precise disease targeting by quantifying normal versus pathologic tissue function as well as toxicity to both radiation and chemotherapy. Both of which have the potential to increase the therapeutic ratio and provide earlier, more accurate monitoring of treatment response. The ongoing integration of MR into routine clinical radiation therapy (RT) planning and the development of MR guided radiation therapy systems is providing new opportunities for MR biomarkers to personalize and improve clinical outcomes. Their appropriate use, however, must be based on knowledge of the physical origin of the biomarker signal, the relationship to the underlying biological processes, and their strengths and limitations. The purpose of this report is to provide an educational resource describing MR biomarkers, the techniques used to quantify them, their strengths and weakness within the context of their application to radiation oncology so as to ensure their appropriate use and application within this field.

[18F]FDG PET/CT quantitative parameters for the prediction of histological response to induction chemotherapy and clinical outcome in patients with localised bone and soft-tissue Ewing sarcoma

OBJECTIVE

The application of [¹⁸F]FDG PET/CT in predicting histologic response to induction chemotherapy in patients with Ewing sarcoma (EWS) has been proposed using the values of pre-post treatment SUV_max as a referral parameter, although with heterogeneous results. The aim of this retrospective study was to evaluate the diagnostic accuracy of [¹⁸F]FDG PET/CT volumetric parameters (metabolic tumour volume (MTV) and total lesion glycolysis (TLG)) as compared to SUV_max to predict response to chemotherapy and clinical outcome in patients with localised EWS of bone and soft-tissue.

METHODS

Twenty-eight patients with non-metastatic EWS of bone (n = 20) and soft tissues (n = 8) who underwent a [¹⁸F]FDG PET/CT scan before (PET₁) and after induction chemotherapy (PET₂) were enclosed in the analysis. Values of PET metrics (SUV_max, MTV, TLG) at diagnosis and after neoadjuvant chemotherapy as well as the percentage change between PET₁ and PET₂ (ΔSUV, ΔMTV and ΔTLG) were correlated to histological response and to progression-free survival (PFS).

RESULTS

ΔTLG (cut-off: -60%) is the best predictor for histologic response with 100% sensitivity and 77.8% specificity. MTV₁ > 33.4 cm³ and TLG₁ > 112 were also associated with a favourable histologic response (sensitivity 80% and specificity 77.8% for both). On multivariate analysis, SUV₂ (> 3.3) and ΔTLG (< -18%) were independent predictors of worse PFS.

CONCLUSIONS

[¹⁸F]FDG PET/CT could accurately predict histologic response to neoadjuvant chemotherapy in patients with EWS, also showing a possible prognostic value for future disease relapse.

KEY POINTS

• The variation of the PET parameter tumour lesion glycolysis (TLG) can predict the histologic response to induction chemotherapy (sensitivity 100%, specificity 77.8%), in patients with Ewing sarcoma. • The percentage variation of TLG and the value of the SUVmax at PET scan after chemotherapy show a prognostic role for future disease relapse. The combination of both the parameters identifies three prognostic classes of patients with low, intermediate and high risk of disease relapse.

Pediatric Rhabdomyosarcomas: Three-Dimensional Radiological Assessments after Induction Chemotherapy Predict Survival Better than One-Dimensional and Two-Dimensional Measurements

Radiological response to neoadjuvant chemotherapy is currently used to assess the efficacy of treatment in pediatric patients with rhabdomyosarcoma (RMS), but the association between early tumor response on imaging and survival is still controversial. The aim of this study was to investigate the prognostic value of assessing radiological response after induction therapy in pediatric RMS, comparing four different methods. This retrospective, two-center study was conducted on 66 non-metastatic RMS patients. Two radiologists measured tumor size on pre- and post-treatment magnetic resonance (MR) or computed tomography (CT) images using four methods: considering maximal diameter with the 1D-RECIST (Response Evaluation Criteria in Solid Tumors); multiplying the two maximal diameters with the 2D-WHO (World Health Organization); multiplying the three maximal diameters with the 3D-EpSSG (European pediatric Soft tissue sarcoma Study Group); obtaining a software-assisted volume assessment with the 3D-Osirix. Each patient was classified as a responder or non-responder based on the proposed thresholds for each method. Tumor response was compared with survival using Kaplan-Meier plots, the log-rank test, and Cox's regression. Agreement between methods and observers (weighted-κ) was also calculated. The 5-year event-free survival (5yr-EFS) calculated with the Kaplan-Meier plots was significantly longer for responders than for non-responders with all the methods, but the 3D assessments differentiated between the two groups better than the 1D-RECIST or 2D-WHO (p_1D-RECIST = 0.018, p_2D-WHO = 0.007, p_3D-EpSSG and p_3D-Osirix < 0.0001). Comparing the 5yr-EFS of responders and non-responders also produced adjusted hazard ratios of 3.57 (p = 0.0158) for the 1D-RECIST, 5.05 for the 2D-WHO (p = 0.0042), 14.40 for the 3D-EpSSG (p < 0.0001) and 11.60 for the 3D-Osirix (p < 0.0001), indicating that the volumetric measurements were significantly more strongly associated with EFS. Inter-method agreement was excellent between the 3D-EpSSG and the 3D-Osirix (κ = 0.98), and moderate for the other comparisons (0.5 < κ < 0.8). The 1D-RECIST and the 2D-WHO tended to underestimate response to treatment. Inter-observer agreement was excellent with all methods (κ > 0.8) except for the 2D-WHO (κ = 0.7). In conclusion, early tumor response was confirmed as a significant prognostic factor in RMS, and the 3D-EpSSG and 3D-Osirix methods predicted response to treatment better than the 1D-RECIST or 2D-WHO measurements.

Automatic segmentation and RECIST score evaluation in osteosarcoma using diffusion MRI: A computer aided system process

PURPOSE

Accuracy and consistency in RECIST (Response evaluation criteria in solid tumors) measurements are crucial for treatment planning. Manual RECIST measurement is tedious, prone-to-error and operator-subjective. Objective was to develop a fully automated system for tumor segmentation and RECIST score estimation with reasonable accuracy, consistency and speed.

METHODS

Diffusion weight images (DWI) of forty patients (N = 40; Male:Female = 30:10; Age = 17.7 ± 5.9years) with Osteosarcoma was acquired using 1.5 T MRI scanner before (baseline) and after neoadjuvant chemotherapy (follow-up). 3D tumor volume was segmented applying Simple-linear-iterative-clustering Superpixels (SLIC-S) and Fuzzy-c-means-clustering (FCM) separately. Connected-component-analysis was performed to identify image-slice with maximum tumor-burden (Max-burden-sliceno) and measure tumor-sizes (Tumor-diameter(cm) & Tumor-volume(cc)). Relative-percentage-changes in tumor-sizes across time-points were scored using RECIST1.1 and Volumetric-response criterion. Segmentation accuracy was estimated by Dice-coefficient (DC), Jaccard-Index (JI), Precision (P) and Recall (R). Evaluated Apparent-diffusion-coefficient (ADC), Tumor-diameter, Max-burden-sliceno and Tumor-volume in segmented tumor-mask and ground-truth tumor-mask were compared using paired-t-test (p < 0.05), Pearson-correlation-coefficient(PCC) and Bland-Altman plots. Misclassification-error-rate (MER) was evaluated for automated RECIST1.1 and Volumetric-response scoring methods.

RESULTS

Automated SLIC-S and FCM produced satisfactory tumor segmentation (DC:∼70-83%;JI:∼55-72%;P:∼64-85%;R:∼73-83%) and showed excellent correlation with ground-truth measurements in estimating ADC (p > 0.05; PCC=0.84-0.89), Tumor-diameters (p > 0.05; PCC=0.90-0.95; bias=0.3-2.41), Max-burden-sliceno (p > 0.05; PCC=0.87-0.96) and Tumor-volumes (p > 0.05; PCC=0.89-0.94; bias=15.19-131.81) at baseline and follow-up. MER for SLIC-S and FCM were comparable for RECIST1.1 (15-18 %) and Volumetric-response (18-20 %) scores and assessment times were 2-3s and 4-6s per patient respectively.

CONCLUSIONS

Proposed method produced promising segmentation and RECIST score measurements in current bone tumor dataset and might be useful as decision-support-tool for response evaluation in other tumors.

Circulating miR34a levels as a potential biomarker in the follow-up of Ewing sarcoma

Appropriate tools for monitoring sarcoma progression are still limited. The aim of the present study was to investigate the value of miR-34a-5p (miR34a) as a circulating biomarker to follow disease progression and measure the therapeutic response. Stable forced re-expression of miR34a in Ewing sarcoma (EWS) cells significantly limited tumor growth in mice. Absolute quantification of miR34a in the plasma of mice and 31 patients showed that high levels of this miRNA inversely correlated with tumor volume. In addition, miR34a expression was higher in the blood of localized EWS patients than in the blood of metastatic EWS patients. In 12 patients, we followed miR34a expression during preoperative chemotherapy. While there was no variation in the blood miR34a levels in metastatic patients at the time of diagnosis or after the last cycle of preoperative chemotherapy, there was an increase in the circulating miR34a levels in patients with localized tumors. The three patients with the highest fold-increase in the miR levels did not show evidence of metastasis. Although this analysis should be extended to a larger cohort of patients, these findings imply that detection of the miR34a levels in the blood of EWS patients may assist with the clinical management of EWS.

Somatostatin Receptor-Targeted Radioligand Therapy in Head and Neck Paraganglioma

OBJECTIVE

Surgical resection is the therapy of choice in head and neck paraganglioma but is associated with considerable morbidity. For treatment of inoperable or progressive disease, less aggressive adjuvant options are warranted. This study assessed effectiveness and safety of peptide receptor radionuclide therapy (PRRT) with lutetium-177-DOTATATE for head and neck paraganglioma with emphasis on response assessment.

METHODS

A retrospective analysis of 7 patients with head and neck paraganglioma treated with PPRT between May 2014 and October 2016 was performed. Three patients had jugulotympanic paraganglioma, 3 patients had carotid body tumors, and 1 patient had a combination of both. Patients underwent PRRT after discussion in the local tumor board regarding progressive disease, inoperability, or lack of other adjuvant options. All patients underwent 3-5 cycles of PRRT. Treatment response was evaluated by gallium-68-DOTATATE positron emission tomography/computed tomography and contrast-enhanced computed tomography or magnetic resonance imaging. Outcome measures were two-dimensional tumor diameters and total tumor volumes.

RESULTS

Median patient age was 60 years (interquartile range: 14-84 years). All patients had stable disease at posttherapy assessment. Decreasing tumor volumes were found in 4 patients. Clinical symptoms improved in 2 patients. No progression or adverse events occurred during a median follow-up of 39 months (interquartile range: 35-47 months).

CONCLUSIONS

Somatostatin receptor-targeted therapy using lutetium-177-DOTATATE shows promising effectiveness with a high safety profile. Patients in whom surgical morbidity outweighs oncologic benefit should be informed about PRRT as a treatment option.

The relation of radiological tumor volume response to histological response and outcome in patients with localized Ewing Sarcoma

Background

Magnetic resonance imaging (MRI) is the modality of choice for local staging and response evaluation of Ewing sarcoma (EwS). Aim of this study was to determine the relevance of tumor volume response (TVR) in relation to histological response (HisRes) and survival, in order to evaluate if early modification of chemotherapy might be indicated in patients with inadequate TVR.

Methods

Three dimensional (3D)‐tumor volume data at diagnosis, during early induction phase (1‐3 courses of chemotherapy; n = 195) and/or late induction phase (4‐6 courses; n = 175) from 241 localized patients were retrospectively analyzed. A distinction was made between adequate response (reduction ≥67%) and inadequate response (reduction <67% or progression). Correlations between TVR, HisRes, event free survival (EFS), and overall survival (OS) were analyzed using chi‐square tests, log‐rank tests, and the Cox‐regression model.

Results

Early adequate TVR, noted in 41% of patients, did not correlate with EFS (P = 0.92) or OS (P = 0.38). During late induction phase 62% of patients showed an adequate TVR. EFS for patients with late adequate TVR was better (78%) than for those with inadequate late TVR (61%) (P = 0.01); OS was 80% and 69% (P = 0.26), respectively. No correlation was found between TVR and HisRes. Multivariate analysis showed that poor HisRes, pelvic location and late inadequate TVR were associated with poor outcome.

Conclusions

Early inadequate TVR does not predict adverse outcome; therefore, changing the treatment to second line chemotherapy is not indicated in case of inadequate early TVR. Late adequate TVR and good HisRes correlate with better EFS; patients with late inadequate TVR might benefit from augmented therapy.