A retrospective study of SBRT of metastases in patients with primary sarcoma

The Role of Surgery in Oligometastatic Retroperitoneal Sarcoma

Retroperitoneal sarcomas are extremely rare, comprising <15% of primary sarcomas. Distant metastasis occurs in about 20% of cases, with pulmonary and hepatic metastasis as the most common sites of hematogenous spread. Although surgical resection is well established as the main treatment of localized primary disease, there are limited guidelines for the surgical treatment of intra-abdominal and distant metastases. There are inadequate systemic treatment options for patients with metastatic sarcoma, thereby necessitating the consideration of surgical options in carefully selected patients. Key points to consider include tumor biology, patient fitness and co-morbidities, overall prognosis, and goals of care. Multidisciplinary sarcoma tumor board discussion for each case is an essential practice in order to deliver the best care to these patients. The purpose of this review is to summarize the published literature on the past and present role of surgery in the treatment of oligometastatic retroperitoneal sarcoma in order to inform the management of this difficult disease.

Stereotactic body radiotherapy for recurrent and oligometastatic soft tissue sarcoma

Background

Soft tissue sarcoma (STS) is a malignant tumor of highly heterogeneous mesenchymal origin. STS has a biological pattern and clinical transformation with localized invasive growth and is susceptible to hematogenous metastasis. Local therapeutic strategies may treat recurrent and oligometastatic STS, including surgery and radiation therapy. This study aimed to evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for recurrent and oligometastatic STS.

Methods

We retrospectively analyzed 37 recurrent and oligometastatic STS patients with 58 lesions treated with SBRT from 2009 to 2019 at our institution. Oligometastatic is defined as metastatic lesions less than or equal to 3. The primary endpoint was local control (LC); secondary endpoints were survival and toxicity.

Results

The median follow-up was 21.0 months (3.0 to 125.0 months). Among 37 patients, 18 were recurrent patients, and 19 were oligometastatic patients. Median LC was 25.0 months (95% CI 20.0–45.0). The 1-, 2-, and 3-year LC rates were 80.2%, 58.3%, and 46.6%, respectively. Median overall survival (OS) was 24.0 months (95% CI 13.0–28.0), and the survival rates after SBRT were 71.5%, 40.0%, and 29.1% at 1, 2, and 3-year, respectively. Median progression-free survival (PFS) was 10.0 months (95% CI 8.0–15.0 months), PFS rate after SBRT was 43.6%, 26.8%, and 18.4% at 1, 2, and 3 years, respectively. Late grade 3 radiation dermatitis was observed in one patient (2.7%). Using univariate and multivariate COX analysis, better OS, PFS, and LC were obtained in the histologic grade 1(G1) group, and tumor size and a number of lesions influenced LC.

Conclusions

SBRT is a safe and effective treatment for patients with recurrent and oligometastatic STS. Histological grade influences local control and survival. SBRT may be a promising treatment option for recurrent and oligometastatic STS.

Stereotactic body radiation therapy (SBRT) for lung metastases from sarcoma in oligometastatic patients: a phase 2 study

PURPOSE

Lung is the most frequent site of metastasis in sarcoma patients. Pulmonary metastasectomy is the most common treatment performed. Stereotactic body radiation therapy(SBRT) has proven to be a potential alternative to resection. We aimed to assess role of SBRT for lung metastatic patients in a prospective phase 2 study.

METHODS AND MATERIALS

Adults patients with lung metastasis(LMs) up to 4, ≤5cm, unsuitable for surgery were included. Dose prescription was based on site and size: 30Gy/1fraction for peripheral lesions ≤10mm, 60 Gy/3fractions for peripheral lesions 11-20mm, 48 Gy/4fractions for peripheral lesions >20mm, and 60 Gy/8fractions for central lesions. Primary endpoint was proportion of treated lesions free from progression at 12 months. Secondary endpoints were disease free survival(DFS), overall survival(OS), and toxicity.

RESULTS

Between March 2015, and December 2020, 44 patients for 71 LMs were enrolled. Twelve-month local control was 98.5%±1.4, reaching primary aim; median DFS time,1,2,3,4,5-year PFS rates were 12 months(95%CI 8-16 months), 50%±7.5, 19.5%±6.6, 11.7%±5.8, 11.7%±5.8, and 11.7%±5.8, respectively. Median OS time,1,2,3,4,5-year OS rates were 49 months(95%CI 24-49 months), 88.6%±4.7, 66.7±7.6, 56.8%±8.4, 53.0%±8.6, and 48.2%±9.1, respectively. Prognostic factors recorded as significantly impacting survival were age, grade of primary sarcoma, interval time from diagnosis to occurrence of LMs, and number of LMs. No severe pulmonary toxicity(grade 3-4) occurred.

CONCLUSIONS

We found a local control of LMs in almost all patients treated, with negligible toxicity. Survival was also highly satisfactory. Well-designed randomized trials comparing surgery with SBRT for lung metastatic sarcoma patients are needed to confirm this preliminary data.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier XXXXXX.

Musculoskeletal Metastasis From Soft-tissue Sarcomas: A Review of the Literature

Soft-tissue sarcomas are a rare and extremely heterogeneous group of cancers, representing <1% of all human malignancies. The lungs are the most common site of distant metastasis, followed by the bone, lymph nodes, liver, brain, and subcutaneous tissue. Clinical experience suggests that skeletal metastasis is part of the natural history affecting the prognosis and quality of life in these patients. Approximately 2.2% of patients have skeletal metastasis at diagnosis. However, up to 10% will develop skeletal metastasis after a mean interval of 21.3 months. Although systemic therapy with conventional chemotherapy remains the primary treatment modality for those with metastatic sarcoma, increased survival has been achieved in selected patients who receive multimodality therapy, including surgery, for their metastatic disease. The 5-year overall survival of patients with isolated bone metastases was 41.2% (26.9% to 54.9%), which decreased to 32.9% (21.2% to 45.1%) in the setting of combined bone and lung metastases. Moreover, the resection of the primary soft-tissue sarcoma is a predictor of survival, resulting in a 58% decrease in mortality after surgery (hazard ratio, 0.42, P = 0.013). Understanding the effect of these metastases on patient survival may influence imaging, surveillance, and treatment decisions.

The Role of MRI-Guided Radiotherapy for Soft Tissue Sarcomas

Soft tissue sarcomas (STS) are a rare class of tumors that originate from mesenchymal tissues and occur most frequently in the extremities, trunk, and retroperitoneum. Surgical resection with R0 margins is the primary curative treatment for most localized STS. In this setting, radiation therapy is used either pre-operatively or post-operatively to reduce the rate of local recurrence. Modern pre- or post-operative radiation therapy rely on the use of MRI sequences to guide target delineation during treatment planning. MRI-guided radiotherapy also offers unique advantages over CT-guided approaches in differentiating STS from surrounding normal soft tissues and enabling better identification of target volumes on daily imaging. For patients with unresectable STS, radiation therapy may offer the best chance for local tumor control. However, most STS are relatively radioresistant with modest rates of local control achieved using conventionally fractionated radiation. Specialized techniques such as hypofractionated radiation may allow for dose intensification and may increase rates of local control for STS. In these settings, MRI becomes even more critical for the delineation of targets and organs at risk and management of tumor and organ at risk motion during and between radiotherapy treatment fractions.

Stereotactic radiotherapy for soft tissue and bone sarcomas: real-world evidence

Introduction:

Selected patients with locally advanced or metastatic soft tissue and bone sarcomas (STBS) may benefit from intensive local treatment, such as stereotactic radiotherapy (SRT). This study aimed to summarize the utilization and outcomes of SRT in STBS and to identify predictive factors for progression and survival.

Materials and methods:

Consecutive patients with advanced STBS who underwent STBS in a sarcoma tertiary center were identified. We collected tumor- and treatment-related factors. Endpoints comprised time to local progression (TTLP), local progression-free survival (LPFS), time to progression, progression-free survival, and overall survival (OS). The Cox proportional-hazards model was used to identify prognostic factors.

Results:

We identified 141 patients who underwent 233 SRTs. Median follow-up was 21 months. Local and distant progression occurred after 19 and 163 SRTs, respectively. SRT for lung metastases was predictive for better TTLP and LPFS (hazard ratio, HR = 0.12, p = 0.007 and HR = 0.42, p = 0.002, respectively). Bone sarcoma (HR for TTLP = 3.18, p = 0.043; HR for LPFS = 1.99, p = 0.028) and lower administered dose (HR for TTLP = 0.98, p = 0.007; HR for LPFS = 0.99, p = 0.012) were predictive for worse TTLP and LPFS. SRT for oligometastases (HR = 0.46, p = 0.021) and lung metastases (HR = 0.55, p = 0.046) was predictive for better OS, whereas diagnosis of bone sarcoma (HR = 2.05, p = 0.029) was predictive for worse OS.

Conclusion:

SRT provides excellent local control in STBS patients without significant toxicity. Patients with oligometastatic disease, lung metastases, and soft tissue sarcomas benefit the most from SRT. The dose escalation moderately enhances local control; however, it does not translate into better survival.

Stereotactic Body Radiotherapy in Oligomestatic/Oligoprogressive Sarcoma: Safety and Effectiveness Beyond Intrinsic Radiosensitivity

BACKGROUND

Metastatic soft tissue sarcoma (STS) patients may benefit from local ablative treatments due to modest efficacy of systemic chemotherapy. However, use of stereotactic body radiotherapy (SBRT) is controversial because of presumed radioresistance of STS.

METHODS

Patients treated with SBRT for oligometastatic and oligoprogressive metastatic STS were retrospectively reviewed to assess results in terms of local control (LC), disease-free survival (DFS), and overall survival (OS). Incidence and grade of adverse events were reported. Statistical analysis was performed to identify variables correlated with outcome and toxicity.

RESULTS

Forty patients were treated with SBRT to a median biologic effective dose (BED) of 105 (66-305) Gy5 to 77 metastases. Two-year LC, DFS, and OS were 67%, 23%, and 40%. Improved LC was shown in patients receiving a BED >150 Gy5 (hazard ratio [HR], 3.9; 95% confidence interval [CI], 1.6-9.7; P = 0.028). A delay >24 months between primary tumor diagnosis and onset of metastases was associated with improved DFS (HR, 0.46; 95% CI, 0.22-0.96; P = 0.01) and OS (HR, 0.48; 95% CI, 0.23-0.99; P = 0.03). No toxicity grade ≥3 was observed.

CONCLUSIONS

Stereotactic body radiotherapy is effective in metastatic STS with a benign toxicity profile. A BED >150 Gy5 is required to maximize tumor control rates. Metastatic relapse >24 months after diagnosis is correlated to improved survival.

Response of Canine Soft Tissue Sarcoma to Stereotactic Body Radiotherapy

Canine soft tissue sarcoma (STS) has served as a preclinical model for radiation, hyperthermia, experimental therapeutics, and tumor microenvironmental research for decades. Stereotactic body radiotherapy (SBRT) demonstrates promising results for the control of various tumors in human and veterinary medicine; however, there is limited clinical data for the management of STS with SBRT. In this retrospective study, we aimed to define overall efficacy and toxicity of SBRT for the treatment of macroscopic canine STS to establish this preclinical model for comparative oncology research. Fifty-two canine patients met inclusion criteria. Total radiation dose prescribed ranged from 20-50 Gy delivered in 1-5 fractions. Median progression-free survival time (PFST) was 173 days and overall survival time (OST) 228 days. Best overall response was evaluable in 46 patients, with 30.4% responding to treatment (complete response n = 3; partial response n = 11). For responders, OST significantly increased to 475 days vs. 201 days (P = 0.009). Prognostic factors identified by multivariable Cox regressions included size of tumor and metastasis at presentation. Dogs were 3× more likely to progress (P = 0.009) or 3.5× more likely to experience death (P = 0.003) at all times of follow up if they presented with metastatic disease. Similarly, every 100-cc increase in tumor volume resulted in a 5% increase in the risk of progression (P = 0.002) and death (P = 0.001) at all times of follow up. Overall, 30.8% of patients developed acute toxicities, 7.7% grade 3; 28.8% of patients developed late toxicities, 11.5% grade 3. Increased dose administered to the skin significantly affected toxicity development. SBRT serves as a viable treatment option to provide local tumor control for canine macroscopic STS, particularly those with early-stage disease and smaller tumors. The results of this study will help to define patient inclusion criteria and to set dose limits for preclinical canine STS trials involving SBRT.

Radiotherapy for oligometastatic non-small cell lung cancer: a narrative review

Preclinical and early clinical evidence suggest that radical radiotherapy of oligometastatic disease in non-small cell lung cancer (NSCLC) patients can impact outcomes with relatively limited toxicity. Whilst data from phase 2 randomized trials suggesting an improved overall survival (OS) with this treatment is promising, it has also illustrated the heterogeneity in this patient population and treatment. Oligometastatic disease in itself comprises a broad spectrum of patients, in terms of tumor load and location, stage of the disease and treatment history. This real-life variety in patient characteristics is often reflected in studies to a certain extent, hinting to the fact that all might benefit from radical radiotherapy to limited metastatic disease, yet leaving the question unanswered as to whom the ideal candidate is. Furthermore, differences between and within studies with regards to treatment modality, timing, radiation technique, and radiation dose are substantial. Also, preclinical and early clinical trials suggest that radiotherapy can work synergistically with checkpoint inhibitors by acting as an in situ cancer vaccine, therefore the combination of these two treatments in oligometastatic patients might entail the largest benefit. Ongoing randomized controlled phase 3 trials and prospective registry trials will further elucidate the true extent of benefit of this local treatment strategy and aid in identifying the ideal patient population and therapy. The current narrative review summarizes the clinical evidence on radiotherapy for oligometastatic NSCLC and highlights the remaining unknowns.

Combined Preoperative Hypofractionated Radiotherapy With Doxorubicin-Ifosfamide Chemotherapy in Marginally Resectable Soft Tissue Sarcomas: Results of a Phase 2 Clinical Trial

PURPOSE

There is no standard treatment for marginally resectable soft tissue sarcomas (STSs) of the extremities and trunk wall, and current approaches produce unsatisfactory results. We hypothesized that the combination of doxorubicin-ifosfamide (AI) chemotherapy and 5 × 5 Gy hypofractionated radiotherapy can generate a higher ratio of limb-sparing or conservative surgeries with negative microscopic margins (R0) and acceptable treatment toxicity.

METHODS AND MATERIALS

We conducted a single-arm prospective clinical trial. Treatment combined 1 cycle of AI with subsequent 5 × 5 Gy radiotherapy within 1 week, followed by 2 cycles of AI and surgery. The primary endpoint was to assess the number of patients in whom en bloc R0 resection was achieved.

RESULTS

Forty-six patients met the eligibility criteria. Three patients had resectable lung metastases at baseline. Forty-two received the planned protocol treatment. In 2 patients, the treatment was prematurely stopped because of the toxicity of chemotherapy. One patient died of septic shock because of severe bone marrow suppression after the second AI cycle; a second death was not related to treatment for STS. Three patients underwent amputation. In 72% of patients in the intention-to-treat analysis, we achieved en bloc R0 resections. Grade 3+ Common Terminology Criteria for Adverse Events 4.03 chemotherapy toxicity requiring dose reduction or treatment interruption occurred in 15 patients. Wound complications occurred in 18 patients, but they were severe in only 6 patients.

CONCLUSIONS

Preoperative AI combined with 5 × 5 Gy radiotherapy is a promising method for the management of marginally resectable STS. This protocol enables a high ratio of R0 limb-sparing or conservative surgeries. Further evaluation of this strategy is warranted.

Multiple Site SBRT in Pediatric, Adolescent, and Young Adult Patients With Recurrent and/or Metastatic Sarcoma

BACKGROUND

Stereotactic body radiation therapy (SBRT) is increasingly used for patients with recurrent and or metastatic tumors. Sarcomas are generally considered not sensitive to radiotherapy and SBRT may allow for increased biological effectiveness. We report intermediate outcomes and toxicity for pediatric, adolescent, and young adult patients treated with SBRT to sites of recurrent and or metastatic sarcoma.

PROCEDURE

We queried an Institutional Review Board-approved registry of patients treated with SBRT for metastases from pediatric sarcomas. Patients age 29 and below were assessed for local control, survival, and toxicity.

RESULTS

Thirty-one patients with a total of 88 lesions met eligibility criteria. Median patient age was 17.9 years at treatment. Sixteen patients were treated with SBRT to >1 site of disease. The median dose was 30 Gy in 5 fractions. The median follow-up time was 7.4 months (range: 0.2 to 31.4 mo). Patients were heavily pretreated with systemic therapy. In 57 lesions with >3 months of radiographic follow-up, the 6-month and 12-month local control rates were 88.3%±4.5% and 83.4%±5.5%, respectively. Radiographic local failures were rare (6/57 in-field, 4/57 marginal). Only 1/88 treated lesions was associated with a radiation-related high-grade toxicity; late grade 3 intestinal obstruction in a re-irradiated field while on concurrent therapy (gemcitabine and docetaxel). No acute grade ≥3 toxicity was observed.

CONCLUSIONS

SBRT was well tolerated in the majority of patients with favorable local control outcomes. Additional studies will be required to determine the optimal SBRT dose and fractionation, treatment volume, and appropriate concurrent therapies.

Non-surgical Treatments for Lung Metastases in Patients with Soft Tissue Sarcoma: Stereotactic Body Radiation Therapy (SBRT) and Radiofrequency Ablation (RFA)

BACKGROUND

Radio-frequency ablation (RFA) and Stereotactic Body Radiation Therapy (SBRT) are two emerging therapies for lung metastases.

INTRODUCTION

Aliterature review was performed to evaluate the outcomes and complications of these procedures in patients with lung metastases from soft tissue sarcoma (STS).

METHODS

After selection, seven studies were included for each treatment encompassing a total of 424 patients: 218 in the SBRT group and 206 in the RFA group.

RESULTS

The mean age ranged from 47.9 to 64 years in the SBRT group and from 48 to 62.7 years in the RFA group. The most common histologic subtype was, in both groups, leiomyosarcoma. In the SBRT group, median overall survival ranged from 25.2 to 69 months and median disease- free interval was from 8.4 to 45 months. Two out of seven studies reported G3 and one G3 toxicity, respectively. In RFA patients, overall survival ranged from 15 to 50 months. The most frequent complication was pneumothorax. Local control showed a high percentage for both procedures.

CONCLUSION

SBRT is recommended in patients unsuitable to surgery, in synchronous bilateral pulmonary metastases, in case of deep lesions and patients receiving high-risk systemic therapies. RFA is indicated in case of a long disease-free interval, in oligometastatic disease, when only the lung is involved, in small size lesions far from large vessels. Further large randomized studies are necessary to establish whether these treatments may also represent a reliable alternative to surgery.

Radiotherapy in the Management of Pediatric and Adult Osteosarcomas: A Multi-Institutional Cohort Analysis

Background: Due to the rarity of osteosarcoma and limited indications for radiotherapy (RT), data on RT for this tumor are scarce. This study aimed to investigate the utilization of RT for osteosarcomas in the recent 20 years and to identify factors related to patients’ response to radiation. Methods: We performed a retrospective analysis of patients irradiated for osteosarcoma treatment. We planned to assess differences in the utilization of RT between the periods of 2000–2010 and 2011–2020, identify the risk factors associated with local progression (LP), determine whether RT-related parameters are associated with LP, and calculate patients’ survival. Results: A total of 126 patients with osteosarcoma who received 181 RT treatments were identified. We found a difference in RT techniques between RT performed in the years 2000–2010 and that performed in the years 2011–2020. LP was observed after 37 (20.4%) RT treatments. Intent of RT, distant metastases, and concomitant systemic treatment affected the risk of LP. Five-year overall survival was 33% (95% confidence interval (26%–43%)). Conclusions: RT for osteosarcoma treatment has evolved from simple two-dimensional palliative irradiation into more conformal RT applied for new indications including oligometastatic and oligoprogressive disease. RT may be a valuable treatment modality for selected patients with osteosarcoma.

Definitive Radiotherapy in the Management of Non-Resectable or Residual Retroperitoneal Sarcomas: Institutional Cohort Analysis and Systematic Review

BACKGROUND

There is currently no consensus on optimal management of patients with primary or recurrent non-resectable/residual retroperitoneal sarcomas (RPS). The objective of this study was to document the outcomes of patients with primary or recurrent non-resectable/residual RPS treated in our center with definitive radiotherapy (RT) and to perform a systematic review on the topic.

METHODS

A retrospective analysis of consecutive RPS patients treated in our center between 2000 and 2019 was performed. All consecutive patients who underwent definitive conformal RT with image guidance for primary or recurrent non-resectable or macroscopically residual RPS were included. Additionally, a systematic review compliant with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was performed.

RESULTS

The study enrolled 14 patients who met the aforementioned criteria. Data on clinicopathological characteristics, RT and response to treatment were assessed. RT allowed achieving prolonged local control of the disease, i.e. no local progression of the disease for more than 12 months after RT in 10 patients. Local control lasted more than 24 months in 6 cases, with minimal or no toxicity. A systemic review of 11 studies revealed concordance of our results with previous reports of primary or recurrent non-resectable/residual RPS.

CONCLUSIONS

RT provided satisfactory local disease control with acceptable treatment tolerance in patients with primary or recurrent non-resectable/residual RPS and represents a valuable treatment modality in the selected group of patients. Additional RT modalities i.e. BT, particle therapy, MRI-guided RT, or GRID/Lattice RT may be introduced to improve local control and further minimize toxicity.

Assessment of Safety and Efficacy of Combined Trabectedin and Low-Dose Radiotherapy for Patients With Metastatic Soft-Tissue Sarcomas: A Nonrandomized Phase 1/2 Clinical Trial

Importance

Active therapeutic combinations, such as trabectedin and radiotherapy, offer potentially higher dimensional response in second-line treatment of advanced soft-tissue sarcomas. Dimensional response can be relevant both for symptom relief and for survival.

Objective

To assess the combined use of trabectedin and radiotherapy in treating patients with progressing metastatic soft-tissue sarcomas.

Design, Setting, and Participants

Phase 1 of this nonrandomized clinical trial followed the classic 3 + 3 design, with planned radiotherapy at a fixed dose of 30 Gy (3 Gy/d for 10 days) and infusion of trabectedin at 1.3 mg/m2 as the starting dose, 1.5 mg/m2 as dose level +1, and 1.1 mg/m2 as dose level -1. Phase 2 followed the Simon optimal 2-stage design. Allowing for type I and II errors of 10%, treatment success was defined as an overall response rate of 35%. This study was conducted in 9 sarcoma referral centers in Spain, France, and Italy from April 13, 2015, to November 20, 2018. Adult patients with progressing metastatic soft-tissue sarcoma and having undergone at least 1 previous line of systemic therapy were enrolled. In phase 2, patients fitting inclusion criteria and receiving at least 1 cycle of trabectedin and the radiotherapy regimen constituted the per-protocol population; those receiving at least 1 cycle of trabectedin, the safety population.

Interventions

Trabectedin was administered every 3 weeks in a 24-hour infusion. Radiotherapy was required to start within 1 hour after completion of the first trabectedin infusion (cycle 1, day 2).

Main Outcomes and Measures

The dose-limiting toxic effects of trabectedin (phase 1) and the overall response rate (phase 2) with use of trabectedin plus irradiation in metastatic soft-tissue sarcomas.

Results

Eighteen patients (11 of whom were male) were enrolled in phase 1, and 27 other patients (14 of whom were female) were enrolled in phase 2. The median ages of those enrolled in phases 1 and 2 were 42 (range, 23-74) years and 51 (range, 27-73) years, respectively. In phase 1, dose-limiting toxic effects included grade 4 neutropenia lasting more than 5 days in 1 patient at the starting dose level and a grade 4 alanine aminotransferase level increase in 1 of 6 patients at the +1 dose level. In phase 2, among 25 patients with evaluable data, the overall response rate was 72% (95% CI, 53%-91%) for local assessment and 60% (95% CI, 39%-81%) for central assessment.

Conclusions and Relevance

The findings of this study suggest that the recommended dose of trabectedin for use in combination with this irradiation regimen is 1.5 mg/m2. The trial met its primary end point, with a high overall response rate that indicates the potential of this combination therapy for achieving substantial tumor shrinkage beyond first-line systemic therapy in patients with metastatic, progressing soft-tissue sarcomas.

Trial Registration

ClinicalTrials.gov Identifier: NCT02275286.

A multi-institutional phase 2 trial of stereotactic body radiotherapy in the treatment of bone metastases in pediatric and young adult patients with sarcoma

BACKGROUND

Metastasectomy is standard of care for pediatric patients with metastatic sarcoma with limited disease. For patients with unresectable disease, stereotactic body radiotherapy (SBRT) may serve as an alternative. Herein, the authors report the results of a prospective, multi-institutional phase 2 trial of SBRT in children and young adults with metastatic sarcoma.

METHODS

Patients aged >3 years and ≤40 years with unresected, osseous metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone were eligible. Patients received SBRT to a dose of 40 Gray (Gy) in 5 fractions. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method.

RESULTS

Fourteen patients with a median age of 17 years (range, 4-25 years) were treated to 37 distinct metastatic lesions. With a median follow-up of 6.8 months (30.5 months in surviving patients), the Kaplan-Meier patient-specific and lesion-specific LC rates at 6 months were 89% and 95%, respectively. The median PFS was 6 months and the median OS was 24 months. In a post hoc analysis, PFS (median, 9.3 months vs 3.7 months; log-rank P = .03) and OS (median not reached vs 12.7 months; log-rank P = .02) were improved when all known sites of metastatic disease were consolidated with SBRT compared with partial consolidation. SBRT was well tolerated, with 2 patients experiencing grade 3 toxicities.

CONCLUSIONS

SBRT achieved high rates of LC in pediatric patients with inoperable metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone. These results suggest that the ability to achieve total consolidation of metastatic disease with SBRT is associated with improved PFS and OS.

Epithelioid Sarcoma-From Genetics to Clinical Practice

Epithelioid sarcoma is a mesenchymal soft tissue sarcoma often arising in the extremities, usually in young adults with a pick of incidence at 35 years of age. Epithelioid sarcoma (ES) is characterized by the loss of SMARCB1/INI1 (integrase interactor 1) or other proteins of the SWI/SNF complex. Two distinct types, proximal and distal, with varying biology and treatment outcomes, are distinguished. ES is known for aggressive behavior, including a high recurrence rate and regional lymph node metastases. An optimal long-term management strategy is still to be defined. The best treatment of localized ES is wide surgical resection. Neo-adjuvant or adjuvant radiotherapy may be recommended, as it reduces the local recurrence rate. Sentinel lymph node biopsy should be considered in ES patients. Patients with metastatic ES have a poor prognosis with an expected median overall survival of about a year. Doxorubicin-based regimens are recommended for advanced ES. Tazemetostat, an EZH2 methyltransferase, has shown promising results in ES patients. Novel therapies, including immunotherapy, are still needed.

Neoadjuvant Treatment Options in Soft Tissue Sarcomas

Due to the heterogeneity of soft tissue sarcomas (STS), the choice of the proper perioperative treatment regimen is challenging. Neoadjuvant therapy has attracted increasing attention due to several advantages, particularly in patients with locally advanced disease. The number of available neoadjuvant modalities is growing continuously. We may consider radiotherapy, chemotherapy, targeted therapy, radiosensitizers, hyperthermia, and their combinations. This review discusses possible neoadjuvant treatment options in STS with an emphasis on available evidence, indications for each treatment type, and related risks. Finally, we summarize current recommendations of the STS neoadjuvant therapy response assessment.

Spine radiosurgery in adolescents and young adults: early outcomes and toxicity in patients with metastatic Ewing sarcoma and osteosarcoma

OBJECTIVE

There are limited data on spine stereotactic radiosurgery (SRS) in treating adolescent and young adult (AYA) patients. SRS has the advantages of highly conformal radiation dose delivery in the upfront and retreatment settings, means for dose intensification, and administration over a limited number of sessions leading to a decreased treatment burden. In this study, the authors report the oncological and toxicity outcomes for AYA patients with metastatic sarcoma treated with spine radiosurgery and provide clinicians a guide for considerations in dose, volume, and fractionation.

METHODS

An institutional review board-approved database of patients treated with SRS in the period from October 2014 through December 2018 was queried. AYA patients, defined by ages 15-29 years, who had been treated with SRS for spine metastases from Ewing sarcoma or osteosarcoma were included in this analysis. Patients with follow-ups shorter than 6 months after SRS were excluded. Local control, overall survival, and toxicity were reported.

RESULTS

Seven patients with a total of 11 treated lesions were included in this study. Median patient age was 20.3 years (range 15.1-26.1 years). Three patients had Ewing sarcoma (6 lesions) and 4 patients had osteosarcoma (5 lesions). The median dose delivered was 35 Gy in 5 fractions (range 16-40 Gy, 1-5 fractions). The median follow-up was 11.1 months (range 6.8-26.0 months). Three local failures were observed within the follow-up period. No acute grade 3 or greater toxicity was observed. One patient developed late grade 3 toxicity consisting of radiation enteritis. This patient had previously received radiation to an overlapping volume with conventional fractionation. SRS re-irradiation for this patient was also performed concurrently with chemotherapy administration. No late grade 4 or higher toxicities were observed. No pain flare or vertebral compression fracture was observed. Three patients died within the follow-up period.

CONCLUSIONS

SRS for spine metastases from Ewing sarcoma and osteosarcoma can be considered as a treatment option in AYA patients and is associated with acceptable toxicity rates. Further studies must be conducted to determine long-term local control and toxicity for this treatment modality.

Stereotactic Body Radiotherapy Versus Metastasectomy in Patients With Pulmonary Metastases From Soft Tissue Sarcoma

The lung is the preferred site of metastasis from soft tissue sarcoma (STS). This systematic review aims to evaluate the outcomes of stereotactic body radiotherapy (SBRT) and metastasectomy (MTS) for the treatment of lung metastases from STS. A systematic review was carried out according to the PRISMA protocol. PubMed, Medline, EMBASE, Cochrane Library, Ovid and Web of Knowledge databases were searched for English-language articles to December 2018 using a predefined strategy. Retrieved studies were independently screened and rated for relevance. Data were extracted by two researchers. In total, there were 1306 patients with STS: 1104 underwent MTS and 202 had SBRT. The mean age ranged from 40 to 55.8 years in the MTS group and from 47.9 to 64 years in the SBRT group. The cumulative death rate was 72% (95% confidence interval 59-85%) in the MTS group and 56% (38-74%) in the SBRT group. The cumulative mean overall survival time was 46.7 months (36.4-57.0%) in the MTS group and 47.6 months (33.7-61.5%) in the SBRT group. The cumulative rate of patients alive with disease was 5% (2-9%) in the MTS group and 15% (6-36%) in the SBRT group. Finally, the cumulative rate of patients alive without disease in the two groups was 19% (9-29%) and 20% (10-50%), respectively. Our study showed that local treatment of pulmonary metastases from STS with SBRT, compared with surgery, was associated with a lower cumulative overall death rate and similar overall survival time and survival rates without disease. By contrast, SBRT was associated with a higher survival rate with disease than MTS. Large randomised trials are necessary to confirm these findings and to establish whether SBRT may be a reliable option for early stage disease.

Optimization of the Therapeutic Approach to Patients with Sarcoma: Delphi Consensus

Soft tissue sarcomas (STS) constitute a heterogeneous group of rare solid tumors associated with significant morbidity and mortality. The evaluation and treatment of STS require a multidisciplinary team with extensive experience in the management of these types of tumors. National and international clinical practice guidelines for STS do not always provide answers to a great many situations that specialists have to contend with in their everyday practice. This consensus provides a series of specific recommendations based on available scientific evidence and the experience of a group of experts to assist in decision-making by all the specialists involved in the management of STS.

Value of ablation therapy in the treatment of lung metastases

Tumor metastases are the basic biological characteristics of malignant tumors, and the lungs are the second most prominent metastatic organs in which these develop after the liver. Currently, with the rapid development of ablation technology, ablation therapy as a local treatment is playing an increasingly important role in the treatment of lung metastases. Whether alone or in combination with other treatments, ablation therapy has achieved good therapeutic effects for the treatment of partial lung metastases. This article briefly summarizes the results of current and previous ablation treatments for lung metastases, and focuses on the value of ablation therapy for different kinds of lung metastases.

Single-institution Experience of SBRT for Lung Metastases in Sarcoma Patients

OBJECTIVES

Lung metastasectomy is regarded as the standard procedure for improving the prognosis of patients with metastatic sarcoma. Few reports are available in the literature describing the value of stereotactic body radiation therapy (SBRT) of lung metastases from primary sarcoma as an alternative to surgical treatment. We therefore sought to expand the evidence base for this modality.

MATERIALS AND METHODS

Twenty-two patients with metastatic sarcoma to lung were treated by SBRT. The retrospective analysis of overall survival, toxicity, and local control of 53 treated lesions is presented in the study. Lung lesions were grouped into 2 categories for follow-up: <10 mm or ≥10 mm diameter.

RESULTS

Of 34 lesions <10 mm, 24 achieved complete response, 3 partial response, and 7 stable disease. The results of 18 lesions measuring >10 mm were as follows: 5 complete response, 5 progressive disease, and 8 stable disease. No progressive disease of all SBRT treated lesions was found at a median follow-up of 95 months (SD 32). Five-year overall survival of the entire group was 62% from the time of diagnosis and 50% from start of treatment. The treatment was well tolerated with minimal, mainly skin toxicity.

CONCLUSION

SBRT is an effective tool that might be used as an alternative to operative treatment of lung metastases in sarcoma patients.

Radiation Therapy for Soft-Tissue Sarcomas: A Primer for Radiologists

Radiation therapy (RT) plays an important role in multimodality therapy for soft-tissue sarcomas (STS). RT treatment paradigms have evolved significantly in recent years, and many different complex RT modalities are commonly used in STS. These include external-beam RT, intensity-modulated RT, stereotactic body RT, and brachytherapy. Imaging is essential throughout the treatment process. Plain radiographs, computed tomography (CT), magnetic resonance imaging, ultrasonography, and positron emission tomography/CT all play potential roles in the management of STS. Before RT, high-quality imaging is needed to direct management decisions, both by global tumor staging and detailed assessment of the extent of local disease. At the time of RT, precise planning imaging is required to delineate tumor volumes, including gross tumor volume, clinical target volume, and planning target volume, which are used to direct therapy. In addition, imaging at the time of RT must outline the location of adjacent vital organs, to optimize treatment efficacy and minimize toxicity. After RT, imaging is needed to assess the patient for tumor response to therapy. In addition, imaging at regular intervals is often required to monitor for recurrence of disease and potential complications of therapy. The purpose of this review is to familiarize radiologists with the indications for RT in STS, common therapeutic modalities used, roles of imaging throughout the treatment process, and complications of therapy.

Local tumor control probability modeling of primary and secondary lung tumors in stereotactic body radiotherapy

BACKGROUND AND PURPOSE

To evaluate whether local tumor control probability (TCP) in stereotactic body radiotherapy (SBRT) varies between lung metastases of different primary cancer sites and between primary non-small cell lung cancer (NSCLC) and secondary lung tumors.

MATERIALS AND METHODS

A retrospective multi-institutional (n=22) database of 399 patients with stage I NSCLC and 397 patients with 525 lung metastases was analyzed. Irradiation doses were converted to biologically effective doses (BED). Logistic regression was used for local tumor control probability (TCP) modeling and the second-order bias corrected Akaike Information Criterion was used for model comparison.

RESULTS

After median follow-up of 19 months and 16 months (n.s.), local tumor control was observed in 87.7% and 86.7% of the primary and secondary lung tumors (n.s.), respectively. A strong dose-response relationship was observed in the primary NSCLC and metastatic cohort but dose-response relationships were not significantly different: the TCD90 (dose to achieve 90% TCP; BED of maximum planning target volume dose) estimates were 176 Gy (151-223) and 160 Gy (123-237) (n.s.), respectively. The dose-response relationship was not influenced by the primary cancer site within the metastatic cohort.

CONCLUSIONS

Dose-response relationships for local tumor control in SBRT were not different between lung metastases of various primary cancer sites and between primary NSCLC and lung metastases.

Significance of local treatment in patients with metastatic soft tissue sarcoma

Metastatic soft tissue sarcomas (STS) represent enormous challenges to improve the low survival rate, which is almost the same as past 2 decades ago, although surgery, radiotherapy and radiofrequency ablation has been accepted in the treatment of metastatic STS. Moreover, STS varies between elderly and younger victims in the aspect of diagnoses, prognosis, and treatment strategies. In order to evaluate the role of local treatment in improving prognosis for patients with metastatic STS and select the proper candidates who will benefit from local therapy, a single-institution nearly 50-year experience were collected and reviewed. Finally, we found that local treatments could improve treatment response and survival, but overall survival advantage could not be seen in elderly patients. This conclusion from a single institution could serve as a basis for future prospective multi-institutional large-scale studies.

Effect on survival of local ablative treatment of metastases from sarcomas: a study of the French sarcoma group

AIMS

Recent data suggest that patients with pulmonary metastases from sarcomas might benefit from ablation of their metastases. Some data are available regarding osteosarcomas/angiosarcomas and lung metastases. The purpose of this study was to assess the efficacy of local ablative treatment on the survival of patients with oligometastases (one to five lesions, any metastatic site, any grade/histology) from sarcomas.

MATERIALS AND METHODS

A multicentric retrospective study of the French Sarcoma Group was conducted in sarcoma patients with oligometastases who were treated between 2000 and 2012. Survival was analysed using multivariate sensitivity analyses with propensity scores to limit bias.

RESULTS

Of the 281 patients evaluated, 164 patients received local treatment for oligometastases between 2000 and 2012. The groups' characteristics were similar in terms of tumour size and remission of the primary tumours. The median follow-up was 25.7 months; 129 (45.9%) patients had died at this point. The median overall survivals were 45.3 (95% confidence interval = 34-73) months for the local treatment group and 12.6 for the other group (95% confidence interval = 9.33-22.9). Survival was better among patients who received local treatment (hazard ratio = 0.47; 95% confidence interval = 0.29-0.78; P < 0.001). Subgroup analyses revealed similar findings in the patients with single oligometastases (hazard ratio = 0.48; 95% confidence interval = 0.28-0.82; P = 0.007); a significant benefit was observed for grade 3, and a trend was observed for grade 2.

CONCLUSION

Local ablative treatment seemed to improve the overall survival of the patients who presented with oligometastatic sarcomas, including soft tissue and bone sarcomas. The survival benefit remained after repeated local treatments for several oligometastatic events. Surgery yielded the most relevant results, but alternative approaches (i.e. radiofrequency ablation and radiotherapy) seemed to be promising. The relevance of these results is strengthened by our analysis, which avoided biases by restricting the population to patients with oligometastatic disease and used propensity scores.

Combining targeted agents with modern radiotherapy in soft tissue sarcomas

Improved understanding of soft-tissue sarcoma (STS) biology has led to better distinction and subtyping of these diseases with the hope of exploiting the molecular characteristics of each subtype to develop appropriately targeted treatment regimens. In the care of patients with extremity STS, adjunctive radiation therapy (RT) is used to facilitate limb and function, preserving surgeries while maintaining five-year local control above 85%. In contrast, for STS originating from nonextremity anatomical sites, the rate of local recurrence is much higher (five-year local control is approximately 50%) and a major cause of death and morbidity in these patients. Incorporating novel technological advancements to administer accurate RT in combination with novel radiosensitizing agents could potentially improve local control and overall survival. RT efficacy in STS can be increased by modulating biological pathways such as angiogenesis, cell cycle regulation, cell survival signaling, and cancer-host immune interactions. Previous experiences, advancements, ongoing research, and current clinical trials combining RT with agents modulating one or more of the above pathways are reviewed. The standard clinical management of patients with STS with pretreatment biopsy, neoadjuvant treatment, and primary surgery provides an opportune disease model for interrogating translational hypotheses. The purpose of this review is to outline a strategic vision for clinical translation of preclinical findings and to identify appropriate targeted agents to combine with radiotherapy in the treatment of STS from different sites and/or different histology subtypes.