Preliminary results from a prospective study using limited margin radiotherapy in pediatric and young adult patients with high-grade nonrhabdomyosarcoma soft-tissue sarcoma

Local Control For High-Grade Nonrhabdomyosarcoma Soft Tissue Sarcoma Assigned to Radiation Therapy on ARST0332: A Report From the Childrens Oncology Group

PURPOSE

The ARST0332 trial for pediatric and young adults with nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) used risk-based treatment including primary resection with lower-than-standard radiation doses to optimize local control (LC) while minimizing long-term toxicity in those requiring radiation therapy (RT). RT for high-grade NRSTS was based on extent of resection (R0: negative margins, R1: microscopic margins, R2/U: gross disease/unresectable); those with >5 cm tumors received chemotherapy (CT; ifosfamide/doxorubicin). This analysis evaluates LC for patients assigned to RT and prognostic factors associated with local recurrence (LR).

METHODS AND MATERIALS

Patients aged <30 years with high-grade NRSTS received RT (55.8 Gy) for R1 ≤5 cm tumor (arm B); RT (55.8 Gy)/CT for R0/R1 >5 cm tumor (arm C); or neoadjuvant RT (45 Gy)/CT plus delayed surgery, CT, and postoperative boost to 10.8 Gy R0 <5 mm margins/R1 or 19.8 Gy for R2/unresected tumors (arm D).

RESULTS

One hundred ninety-three eligible patients had 24 LRs (arm B 1/15 [6.7%], arm C 7/65 [10.8%], arm D 16/113 [14.2%]) at median time to LR of 1.1 years (range, 0.11-5.27). Of 95 eligible for delayed surgery after neoadjuvant therapy, 89 (93.7%) achieved R0/R1 margins. Overall LC after RT were as follows: R0, 106 of 109 (97%); R1, 51 of 60 (85%); and R2/unresectable, 2 of 6 (33%). LR predictors include extent of delayed resection (P <.001), imaging response before delayed surgery (P < .001), histologic subtype (P <.001), and no RT (P = .046). The 5-year event-free survival was significantly lower (P = .0003) for patients unable to undergo R0/R1 resection.

CONCLUSIONS

Risk-based treatment for young patients with high-grade NRSTS treated on ARST0332 produced very high LC, particularly after R0 resection (97%), despite lower-than-standard RT doses. Neoadjuvant CT/RT enabled delayed R0/R1 resection in most patients and is preferred over adjuvant therapy due to the lower RT dose delivered.

Stereotactic radiosurgery as a primary treatment for metastatic skull base alveolar soft part sarcoma: a case report

Alveolar soft part sarcoma (ASPS) is a rare malignancy that typically arises in the trunk or extremities and preferentially metastasises to the brain. Radical resection is generally recommended for cranial metastatic ASPS, but stereotactic radiosurgery (SRS) is a recognised alternative for tumours in surgically challenging locations. Here, we present the case of a 22-year-old female, who underwent SRS and systemic therapy with pazopanib for a metastatic ASPS in the left temporal bone. The tumour was successfully controlled without further intervention over 23 months following SRS, which should be considered for metastatic ASPS when surgical resection is not appropriate.

Pre- or postoperative radiotherapy for soft tissue sarcomas

Sarcomas are rare tumours arising from mesenchymal tissue. A multimodal management in an expert centre combining surgery and radiotherapy is the current standard of care for localized soft-tissue sarcomas of the extremities, to enable limb-sparing strategies. The delivery of pre- radiotherapy or postoperative radiotherapy offers similar local control and survival rates but the toxicity profile is quite different: preoperative radiotherapy increases the risk of wound complications and postoperative radiotherapy affects long-term functional outcomes. While postoperative radiotherapy has long been the rule, especially in Europe, technical improvements with image-guided- and intensity-modulated radiotherapy associated with a better management of postoperative wounds has tended to change practices with more frequent preoperative radiotherapy. More recently the possibilities of a hypofractionated regimen or potentiation by nanoparticles to increase the therapeutic index plead in favour of a preoperative delivery of radiotherapy. The aim of this paper is to report pros and cons of pre- and post-operative radiotherapy for soft-tissue sarcomas.

Local recurrence is correlated with decreased overall survival in patients with intermediate high-grade localized primary soft tissue sarcoma of extremity and abdominothoracic wall

AIM

The aim of this study was to determine the effect of local recurrence on overall survival in patients with intermediate high-grade localized primary soft tissue sarcoma (STS) of extremity and abdominothoracic wall.

METHODS

This retrospective study identified 133 consecutive patients with intermediate high-grade localized primary STS of extremity and abdominothoracic wall from January 2000 to July 2010. Survival curves were constructed by the Kaplan-Meier method and log-rank test was used to assess statistical significance. Hazard ratios (HRs) were calculated based on multivariable Cox logistic regression method.

RESULTS

The 5-year cumulative incidence of local recurrence was 26.0% with a median follow-up of 68 months (range, 5-127 months). The univariate analysis showed that local recurrence was associated with decreased overall survival, with 5-year overall survival of 80.5% and 53.6% in the no local recurrence patients and local recurrence patients, respectively (P = 0.001). The multivariate analysis demonstrated that local recurrence was a negative prognostic factor for overall survival (HR = 2.115, 95% confidence interval [CI] 1.036-4.319, P = 0.040). Radiotherapy significantly reduced local recurrence compared with surgery alone (HR = 0.387, 95% CI 0.180-0.877, P = 0.019), while larger tumor size (HR = 3.184, 95% CI 1.351-7.506 P = 0.008) was correlated with higher rate of local recurrence.

CONCLUSION

Local recurrence in patients with intermediate high-grade localized primary STS is associated with decreased overall survival.

Nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) in pediatric and young adult patients: Results from a prospective study using limited-margin radiotherapy

BACKGROUND

Indications for and delivery of adjuvant therapies for pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) have been derived largely from adult studies; therefore, significant concern remains regarding radiation exposure to normal tissue. The authors report long-term treatment outcomes and toxicities for pediatric and young adult patients with high-grade NRSTS who were treated on a prospective trial using limited-margin radiotherapy.

METHODS

Sixty-two patients (ages 3-22 years) with predominantly high-grade NRSTS requiring radiation were treated on a phase 2 institutional study of conformal external-beam radiotherapy and/or brachytherapy using a 1.5-cm to 2-cm anatomically constrained margin. The estimated cumulative incidence of local failure, Gray's method estimated cumulative incidence of local failure, Kaplan-Meier method estimated survival, competing-risk regression model determined predictors of disease outcome, and toxicity was reported according to CTCAE v2.0.

RESULTS

At a median follow-up of 5.1 years (range, 0.2-10.9 years), 9 patients had experienced local failure. The 5-year overall cumulative incidence of local failure was 14.8% (95% confidence interval [CI], 7.2%-25%), and all but 1 local failure occurred outside the highest-dose irradiation volume. The 5-year Kaplan-Meier estimates for event-free and overall survival were 49.3% (95% CI, 36.3%-61.1%) and 67.9% (95% CI, 54.2%-78.3%), respectively. Multivariable analysis indicated that younger age was the only independent predictor of local recurrence (P = .004). The 5-year cumulative incidence of grade 3 or 4 late toxicity was 15% (95% CI, 7.2%-25.3%).

CONCLUSIONS

The delivery of limited-margin radiotherapy using conformal external-beam radiotherapy or brachytherapy provides a high rate of local tumor control without an increase in marginal failures and with acceptable treatment-related morbidity. Cancer 2017;123:4419-29. © 2017 American Cancer Society.

[Radiotherapy for soft tissue sarcomas: Technical evolution and impact on clinical benefit]

The standard treatment for extremity soft tissue sarcomas is based on the association of surgery and radiotherapy. This strategy allows local control improvement with the risk of increased toxicity. There is therefore a growing interest to identify those patients who will benefit from radiotherapy and those who will have the same local control with surgery alone. Furthermore, the development of toxicity has been correlated with the extension of the irradiated volume and the volume receiving high doses. Technological development as intensity modulated radiotherapy and image-guided radiotherapy allows limited irradiated volume improving the protection of the organs at risk leading to clinical benefit improvement. Moreover, efforts are being done to improve local control for the patients at high risk of local relapse. In this paper, we discuss all these mentioned aspects.

Limited Margin Radiation Therapy for Children and Young Adults With Ewing Sarcoma Achieves High Rates of Local Tumor Control

PURPOSE

To determine the rate of local failure using focal conformal, limited margin radiation therapy (RT) and dose escalation for tumors ≥8 cm (greatest dimension at diagnosis) in children and young adults with Ewing sarcoma (EWS).

METHODS AND MATERIALS

Eligible patients with EWS were treated on a phase 2 institutional trial of focal conformal, limited margin RT using conformal or intensity modulated techniques. The treatment volume incorporated a 1-cm constrained margin around the gross tumor. Unresected tumors, <8 cm at diagnosis, received a standard dose of 55.8 Gy and tumors ≥8 cm, an escalated dose to 64.8 Gy. Patients with microscopic residual disease after resection received adjuvant RT to 50.4 Gy. Adjuvant brachytherapy was permitted in selected patients.

RESULTS

Forty-five patients were enrolled: 26 with localized and 19 with metastatic disease. Median (range) age, tumor size, and follow-up were 13.0 years (2.9-24.7 years), 9.0 cm (2.4-17.0 cm), and 54.5 months (1.9-122.2 months), respectively. All patients received systemic chemotherapy. The median (range) RT dose for all patients was 56.1 Gy (45-65.5 Gy). Seventeen patients received adjuvant, 16 standard-dose, and 12 escalated-dose RT. Failures included 1 local, 10 distant, and 1 local/distant. The estimated 10-year cumulative incidence of local failure was 4.4% ± 3.1%, with no statistical difference seen between RT treatment groups and no local failures in the escalated-dose RT treatment group.

CONCLUSIONS

Treatment with focal conformal, limited margin RT, including dose escalation for larger tumors, provides favorable local tumor control in EWS.

Dosimetric advantages of proton therapy over conventional radiotherapy with photons in young patients and adults with low-grade glioma

Background and purpose

Low-grade glioma (LGG) is a very common brain tumor in pediatric patients typically associated with a very good prognosis. This prognosis makes it imperative that the risk of long-term treatment-related side effects be kept at an absolute minimum. Proton therapy (PRT) provides a radiation technique that has the potential to further reduce the genesis of radiogenic impairment.

Materials and methods

We retrospectively assessed 74 patients with LGG who underwent PRT. Conventional three-dimensional photon and PRT plans were generated after contouring structures of neurogenesis, crucial neuronal structures, and areas susceptible to secondary malignancies. Target volume coverage was evaluated using the homogeneity index (HI) and inhomogeneity coefficient (IC). Results were compared using the Wilcoxon-signed rank test, with p < 0.05 being statistically significant.

Results

Target volume coverage was comparable for the photon and proton plans. Overall, we could show an essential reduction in maximal, mean, and integral doses in critical neurologic structures, areas of neurogenesis, and structures of neurocognitive function. The study indicated specifically how contralaterally located structures could be spared with PRT.

Conclusion

PRT is a highly conformal radiation technique offering superior dosimetric advantages over conventional radiotherapy by allowing significant dose reduction for organs at risk (OAR) that are essential for neurologic function, neurocognition, and quality of life, thus demonstrating the potential of this technique for minimizing long-term sequelae.

Adjuvant hypofractionated partial-brain radiation therapy for pediatric Ewing sarcoma brain metastases: case report

This case report demonstrates that hypofractionated partial-brain radiation therapy with limited margins is a reasonable approach following gross tumor resection of Ewing sarcoma metastases to the brain. The patient presented with 2 intracranial metastases treated with gross-total resection followed by radiation therapy to 30 Gy in 5 fractions. The patient experienced symptomatic treatment-related inflammatory changes with resolution after receiving dexamethasone. He remains alive at 21 months of follow-up with no evidence of disease.

The efficacy of postoperative radiotherapy in localized primary soft tissue sarcoma treated with conservative surgery

Background

To evaluate the efficacy of postoperative radiotherapy (RT) on local failure-free survival (LFFS), distant metastasis-free survival (DMFS) and overall survival (OS) in patients with localized primary soft tissue sarcoma (STS) and to identify prognostic factors.

Methods and materials

Between January 2000 and July 2010, 220 consecutive patients with localized primary STS, who received conservative surgery with or without postoperative RT, were enrolled in the study. Survival curves were constructed by the Kaplan-Meier method and log-rank test was used to assess statistical significance. Multivariate analysis was applied to identify the prognostic factors.

Results

After a median follow-up of 68 months (range, 5–127 months), the 5-year LFFS, DMFS and OS were 70.0, 78.2 and 71.2 %, respectively. Tumor size, histological subtypes, margin status and postoperative RT were independent predictors for OS. Postoperative RT was associated with a significant reduced local recurrence risk versus surgery alone (hazard ratio [HR] = 0.408, 95 % confidence interval [CI] 0.235–0.707, P = 0.001), with 5-year LFFS of 81.1 and 63.6 %, respectively (log-rank, P = 0.004). The log-rank test showed that postoperative RT had a tendency of improving OS compared with surgery alone, with 5-year OS of 74.8 and 65.0 %, respectively (P = 0.089). Multivariate analysis demonstrated that postoperative RT significantly reduced mortality rate compared with surgery alone (HR = 0.512, 95 % CI 0.296–0.886, p = 0.017), especially in patients with liposarcoma (p = 0.034).

Conclusion

Postoperative radiotherapy reduce both local recurrence and STS mortality in patients with localized primary STS. The efficacy of RT on survival warrants further prospective study.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0605-y) contains supplementary material, which is available to authorized users.

Study of Preoperative Radiotherapy for Sarcomas of the Extremities with Intensity-Modulation, Image-Guidance and Small Safety-margins (PREMISS)

Background

The aim of the trial is to demonstrate that with the use of modern IMRT/IGRT and reduction of safety margins postoperative wound complications can be reduced.

Methods/ Design

The trial is designed as a prospective, monocentric clinical phase II trial. The treatment is performed with helical IMRT on the Tomotherapy HiArt System© or with RapidArc© IMRT as available. All treatments are performed with 6 MV photons and daily online CT-based IGRT.

A dose of 50 Gy in 2 Gy single fractions (5 fractions per week) is prescribed. Restaging including MRI of the primary tumor site as well as CT of the thorax/abdomen is planned 4 weeks after RT. PET-examinations or any other imaging can be performed as required clinically. In cases of R1 resection, brachytherapy is anticipated in the 2nd postoperative week. Brachytherapy catheters are implanted into the tumor bed depending on the size and location of the lesion. Surgery is planned 5–6 weeks after completion of neoadjuvant RT. All patients are seen for a first follow-up visit 2 weeks after wound healing is completed, thereafter every 3 months during the first 2 years. The endpoints of the study are evaluated in detail during the first (2 weeks) and second (3 months) follow-up. Functional outcome and QOL are documented prior to treatment and at year 1 and 2. Treatment response and efficacy will be scored according to the RECIST 1.1 criteria. A total patient number of 50 with an expected 20 % rate of wound complications were calculated for the study, which translates into a 95 % confidence interval of 10.0-33.7 % for wound complication rate in a binomial distribution.

Discussion

The present study protocol prospectively evaluates the use of IMRT/IGRT for neoadjuvant RT in patients with soft tissue sarcomas of the extremity with the primary endpoint wound complications, which is the major concern with this treatment sequence. Besides complications rates, local control rates and survival rates, as well as QOL, functional outcome and treatment response parameters (imaging and pathology) are part of the protocol. The data of the present PREMISS study will enhance the current literature and support the hypothesis that neoadjuvant RT with IMRT/IGRT offers an excellent risk-benefit ratio in this patient population.

Trial registration

NCT01552239

Malignant peripheral nerve sheath tumors (MPNST): a SEER analysis of incidence across the age spectrum and therapeutic interventions in the pediatric population

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNST) are very rare in the general population and challenging to treat. A paucity of data exists regarding the incidence of MPNST across all age groups and treatment outcomes in the pediatric population. We aimed to characterize both using the Survival, Epidemiology, and End Results (SEER) database.

PROCEDURE

The SEER-18 database with information on the United States population from 1973 to 2009 was queried for cases of MPNST. For incidence data, 1,182 cases were found among the general population. Of those, 165 cases were in individuals aged 0-19. After exclusions, 139 cases from the SEER-18 database met study criteria for outcomes analysis. For each patient, variables including gender, age, race, stage (localized, regional, or distant), surgical treatment, and radiotherapy were obtained.

RESULTS

The overall incidence of MPNST was 1.46 per million person-years, with increased incidence among the elderly. In the pediatric population, the incidence was 0.56 per million person-years, and was higher among post-pubertal children aged 10-19. Median overall survival in the pediatric population was 30 months, with only localized disease and treatment with surgery being positive prognostic factors on multivariate analysis.

CONCLUSIONS

MPNST is a rare disease and, among children, is most frequent seen in adolescents. Surgery is crucial as first-line treatment for MPNST, especially if the tumor is localized at diagnosis. In patients with non-localized MPNST, the disease remains extremely difficult to manage, and both surgery and radiotherapy are interventions that should be considered.

Brain metastasis in bone and soft tissue cancers: a review of incidence, interventions, and outcomes

Bone and soft tissue malignancies account for a small portion of brain metastases. In this review, we characterize their incidence, treatments, and prognosis. Most of the data in the literature is based on case reports and small case series. Less than 5% of brain metastases are from bone and soft tissue sarcomas, occurring most commonly in Ewing's sarcoma, malignant fibrous tumors, and osteosarcoma. Mean interval from initial cancer diagnosis to brain metastasis is in the range of 20-30 months, with most being detected before 24 months (osteosarcoma, Ewing sarcoma, chordoma, angiosarcoma, and rhabdomyosarcoma), some at 24-36 months (malignant fibrous tumors, malignant peripheral nerve sheath tumors, and alveolar soft part sarcoma), and a few after 36 months (chondrosarcoma and liposarcoma). Overall mean survival ranges between 7 and 16 months, with the majority surviving < 12 months (Ewing's sarcoma, liposarcoma, malignant fibrous tumors, malignant peripheral nerve sheath tumors, angiosarcoma and chordomas). Management is heterogeneous involving surgery, radiosurgery, radiotherapy, and chemotherapy. While a survival advantage may exist for those given aggressive treatment involving surgical resection, such patients tended to have a favorable preoperative performance status and minimal systemic disease.

Resectable pediatric nonrhabdomyosarcoma soft tissue sarcoma: which patients benefit from adjuvant radiation therapy and how much?

It remains unclear which children and adolescents with resected nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) benefit from radiation therapy, as well as the optimal dose, volume, and timing of radiotherapy when used with primary surgical resection. This paper reviews the sparse literature from clinical trials and retrospective studies of resected pediatric NRSTS to discern local recurrence rates in relationship to the use of radiation therapy.

The enigma of myxofibrosarcoma of the extremity

BACKGROUND

The reported high rate of local recurrence (LR) in myxofibrosarcoma raises the question of whether this sarcoma histology should be considered radioresistant. In this study, the authors compared rates and patterns of LR of high-grade (HG) myxofibrosarcoma with rates and patterns of HG leiomyosarcoma, which was chosen because of the similarity in incidence and general treatment approach.

METHODS

Two hundred two patients with primary, nonmetastatic extremity myxofibrosarcoma (n = 114) and leiomyosarcoma (n = 88) underwent limb-sparing surgery and were followed prospectively. All 202 patients had HG tumors, and 138 patients (68%) received adjuvant radiation therapy.

RESULTS

The groups were comparable in terms of age, sex, and receipt of chemotherapy. Compared with leiomyosarcoma, myxofibrosarcoma presented more frequently with tumors >5 cm (P < .001), deep location (P = .036), and upper extremity site (P = .015). In addition, rates of positive/close margins (P < .001) and the receipt of radiation therapy (P < .001) were significantly higher in the myxofibrosarcoma group. The 5-year overall LR rate was not significantly different according to histology (14.6% for myxofibrosarcoma, 13.2% for leiomyosarcoma; P = .594). The only predictor of LR for the whole cohort of patients was positive/close margins (P = .01). Of 17 myxofibrosarcoma LRs, 8 (47%) occurred out of field, versus 1 of 12 (8%) leiomyosarcoma LRs (P = .04). Leiomyosarcoma more commonly recurred distantly (54.1% vs 24.3% at 5 years; P = .014).

CONCLUSIONS

Despite more adverse clinical features, myxofibrosarcoma recurred distantly less often than leiomyosarcoma, whereas the LR rates were comparable between the 2 groups, suggesting that adjuvant radiation therapy is effective in myxofibrosarcoma. Myxofibrosarcoma LRs more commonly occurred out of field. Reduction in radiation field margins may not be advisable in patients with myxofibrosarcoma.

Jaw dysfunction related to pterygoid and masseter muscle dosimetry after radiation therapy in children and young adults with head-and-neck sarcomas

PURPOSE

To investigate the relationship between jaw function, patient and treatment variables, and radiation dosimetry of the mandibular muscles and joints in children and young adults receiving radiation for soft-tissue and bone sarcomas.

METHODS AND MATERIALS

Twenty-four pediatric and young adult patients with head-and-neck sarcomas were treated on an institutional review board-approved prospective study of focal radiation therapy for local tumor control. Serial jaw depression measurements were related to radiation dosimetry delivered to the medial and lateral pterygoid muscles, masseter muscles, and temporomandibular joints to generate mathematical models of jaw function.

RESULTS

Baseline jaw depression was only influenced by the degree of surgical resection. In the first 12 weeks from initiation of radiation, surgical procedures greater than a biopsy, administration of cyclophosphamide containing chemotherapy regimes, and large gross tumor volumes adversely affected jaw depression. Increasing dose to the pterygoid and masseter muscles above 40 Gy predicted loss of jaw function over the full course of follow-up.

CONCLUSIONS

Clinical and treatment factors are related to initial and subsequent jaw dysfunction. Understanding these complex interactions and the affect of specific radiation doses may help reduce the risk for jaw dysfunction in future children and young adults undergoing radiation therapy for the management of soft-tissue and bone sarcomas.

Sarcoma metastatic to the brain: a series of 35 cases and considerations from 27 years of experience

The authors report their 27-year experience regarding 35 cases of supratentorial brain metastasis from sarcoma treated in a single institution: these included ten osteosarcomas, seven leiomyosarcomas, five Ewing sarcomas, four malignant fibrous histiocytomas, three alveolar soft-part sarcomas (ASPS), two rhabdomyosarcomas, one liposarcoma, and three unclassified sarcomas. The first 15 cases of the series have already been described in a previous publication. Median survival after craniotomy was 9.8 months (range: 4-24). In patients with preoperative Karnofsky performance score (KPS) > 60 it was 12.8 months (range: 6.5-24 months) versus 5.4 months for those patients with a KPS < or = 60 (P = 0.01). Eight patients had more than one lesion, six of which were treated in the last ten years. Of the three patients with ASPS, the first two were alive at 15 and 20 months (before being lost to follow-up) whereas the third patient is alive at 24 month follow-up. The authors conclude that surgery is more effective in treating selected patients with sarcoma metastatic to the brain, and that patients with metastasis from ASPS have good prognosis when submitted to surgical treatment. The complete removal of all brain metastases "en bloc" and a KPS > 60 are associated with the best prognosis. Finally, it seems that surgical indications for multiple brain metastases from sarcoma have increased during the last ten years.