An Effective Preoperative Three-Dimensional Radiotherapy Target Volume for Extremity Soft Tissue Sarcoma and the Effect of Margin Width on Local Control

Neoadjuvant Radiation Therapy with Interdigitated High-Dose LRT for Voluminous High-Grade Soft-Tissue Sarcoma

Purpose

To report a case of large extremity soft tissue sarcoma (2933 cc), safely treated with a novel approach of interdigitating high-dose LATTICE radiation therapy (LRT) with standard radiation therapy as a neoadjuvant treatment to surgery.

Patients and Methods

Four sessions of high-dose LRT were delivered in a weekly interval, interdigitated with standard radiation therapy. The LRT plan consisted of 15 high-dose vertices receiving a dose >12 Gy per session, with 2-3 Gy to the peripheral margin of the tumor. The patient underwent surgical excision 2 months after the new regimen of induction radiation therapy.

Results and Discussion

The patient tolerated the radiation therapy regimen well. The post-operative assessment revealed a negative surgical margin and over 95% necrosis of the total tumor volume. The post-surgical wound complication was mitigated by outpatient wound care. Interdigitating multiple sessions of high-dose LATTICE radiation treatments with standard neoadjuvant radiation therapy as a neoadjuvant therapy for soft tissue sarcoma was feasible and did not incur additional toxicity in this clinical case. A phase-I/II trial will be conducted to further evaluate the toxicity and efficacy of the new treatment strategy with the intent to increase the rate of pathologic necrosis, which has been shown to positively correlate with the overall survival.

Soft Tissue Sarcoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare malignancies of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Soft Tissue Sarcoma provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as retroperitoneal/intra-abdominal STS, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis and treatment of retroperitoneal/intra-abdominal STS, outlines treatment recommendations, and reviews the evidence to support the guidelines recommendations.

The Effect of Resection Margin on Local Recurrence and Survival in High Grade Soft Tissue Sarcoma of the Extremities: How Far Is Far Enough?

Simple Summary

In soft tissue sarcomas the width of surgical margins after resection determines the extent of surgery and the function after resection. But how far is really necessary? 305 patients with deep-seated, G2/3 soft tissue sarcomas of the extremity, the trunk wall, or the pelvis were reviewed. The 5-year local recurrence-free survival (LRFS) was 82%. Overall survival (OS) at 5 years was 66%. Positive (contaminated) margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. In conclusion the margin should at least be free of tumor, in sound tissue. A margin of >5 mm sound tissue seems to be sufficient. Resecting more tissue does not benefit the patient.

Abstract

Background: The significance of surgical margins after resection of soft tissue sarcomas in respect to local-recurrence-free survival and overall survival is evaluated. Methods: A total of 305 patients with deep-seated, G2/3 soft tissue sarcomas (STS) of the extremity, the trunk wall, or the pelvis were reviewed. The margin was defined according to the Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) classification system (R0-2), the Union Internationale Contre le Cancer (UICC) classification (R + 1 mm) for which a margin <1 mm is included into the R1 group, and in groups of <1 mm, 1–5 mm, >5 mm, or >10 mm. Results: Of these patients, 31 (10.2%) had a contaminated margin, 64 (21%) a margin of <1 mm, 123 (40.3%) a margin of 1–5 mm, 47 (15.4%) a margin of >5 mm, and 40 (13.1%) a margin of >10 mm. The 5-year local recurrence-free survival (LRFS) was 81.6%. Overall survival (OS) at 5 years was 65.9%. Positive margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. Conclusions: A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. This finding supports use of the UICC classification. A margin of more than 10 mm did not improve LRFS or OS.

Neoadjuvant Radiotherapy-Related Wound Morbidity in Soft Tissue Sarcoma: Perspectives for Radioprotective Agents

Historically, patients with localized soft tissue sarcomas (STS) of the extremities would undergo limb amputation. It was subsequently determined that the addition of radiation therapy (RT) delivered prior to (neoadjuvant) or after (adjuvant) a limb-sparing surgical resection yielded equivalent survival outcomes to amputation in appropriate patients. Generally, neoadjuvant radiation offers decreased volume and dose of high-intensity radiation to normal tissue and increased chance of achieving negative surgical margins-but also increases wound healing complications when compared to adjuvant radiotherapy. This review elaborates on the current neoadjuvant/adjuvant RT approaches, wound healing complications in STS, and the potential application of novel radioprotective agents to minimize radiation-induced normal tissue toxicity.

Soft Tissue Tumors of the Extremity

Although the vast majority of soft tissue extremity masses are benign, approximately 13,000 people in the United States were diagnosed with soft tissue sarcoma in 2019. This article focuses on the optimal workup of soft tissue masses including the indications for ultrasound and MRI, as well as use of preoperative core needle biopsy. Current AJCC staging, surgical principles of soft tissue sarcoma management, and data regarding indications for radiation therapy and chemotherapy are reviewed. As up to 50% of patients with soft tissue sarcoma will develop recurrent disease, surgical management of locally recurrent and distant metastatic disease is discussed.

Time dependent dynamics of wound complications after preoperative radiotherapy in Extremity Soft Tissue Sarcomas

AIMS

The purpose of the study was to investigate the time dependent dynamics of wound complications and local control after preoperative radiotherapy (RT) in Extremity Soft Tissue Sarcomas (ESTS).

PATIENTS & METHODS

In this retrospective cohort study, all patients treated for an extremity sarcoma with pre-operative radiotherapy followed by surgery were identified from a prospectively maintained database. A wound complication (WC) was defined as any local complication of the surgical area requiring intervention, hospital readmission or significant extension of the initial admission period.

RESULTS

A total of 191 preoperatively irradiated ESTS patients were included in this study. WC was seen in 31% of the patients (n = 60). WC started after a median time of 25 days from surgery, with a median duration of 76 days. Adiposity, smoking and a lower extremity or superficial tumor localization were significantly correlated with an increased WC rate. Risk factors for a duration of WC ≥ 120 days are early development of WC (≤21 days after surgery) and smoking. Local control rates after 1, 3 and 5 years were 99%, 93% and 93%, respectively.

CONCLUSION

Approximately one-third of patients selected for preoperative RT develops a WC, typically in smoking, adipose patients with superficial tumor localizations in the lower extremity. Based upon the well-established superior long-term functional outcome, maintained excellent local control rates and the temporary nature of the WC issue, preoperative RT remains our preferred treatment. Although, in patients at high risk of WC, post-operative RT might be considered.

Image-guided surgery in cancer: A strategy to reduce incidence of positive surgical margins

Primary treatment for many solid cancers includes surgical excision or radiation therapy, with or without the use of adjuvant therapy. This can include the addition of radiation and chemotherapy after primary surgical therapy, or the addition of chemotherapy and salvage surgery to primary radiation therapy. Both primary therapies, surgery and radiation, require precise anatomic localization of tumor. If tumor is not targeted adequately with initial treatment, disease recurrence may ensue, and if targeting is too broad, unnecessary morbidity may occur to nearby structures or remaining normal tissue. Fluorescence imaging using intraoperative contrast agents is a rapidly growing field for improving visualization in cancer surgery to facilitate resection in order to obtain negative margins. There are multiple strategies for tumor visualization based on antibodies against surface markers or ligands for receptors preferentially expressed in cancer. In this article, we review the incidence and clinical implications of positive surgical margins for some of the most common solid tumors. Within this context, we present the ongoing clinical and preclinical studies focused on the use of intraoperative contrast agents to improve surgical margins. This article is categorized under: Laboratory Methods and Technologies > Imaging.

Predictors of Wound Complications following Radiation and Surgical Resection of Soft Tissue Sarcomas

Wound complications represent a major source of morbidity in patients undergoing radiation therapy (RT) and surgical resection of soft tissue sarcomas (STS). We investigated whether factors related to RT, surgery, patient comorbidities, and tumor histopathology predict the development of wound complications. An observational study of patients who underwent STS resection and RT was performed. The primary outcome was the occurrence of any wound complication up to four months postoperatively. Significant predictors of wound complications were identified using multivariable logistic regression. Sixty-five patients representing 67 cases of STS were identified. Median age was 59 years (range 22-90) and 34 (52%) patients were female. The rates of major wound complications and any wound complications were 21% and 33%, respectively. After adjusting for radiation timing, diabetes (OR 9.6; 95% CI 1.4-64.8; P = 0.02), grade ≥2 radiation dermatitis (OR 4.8; 95% CI 1.2-19.2; P = 0.03), and the use of 3D conformal RT (OR 4.6; 95% CI 1.1-20.0; P = 0.04) were associated with an increased risk of any wound complication on multivariable analysis. These data suggest that radiation dermatitis and radiation modality are predictors of wound complications in patients with STS.

Patterns of major wound complications following multidisciplinary therapy for lower extremity soft tissue sarcoma

BACKGROUND AND OBJECTIVES

The purpose of this study was to determine the pattern and timing of major wound complications (MWCs) in patients at our institution who received multimodality treatment for lower extremity soft tissue sarcoma (LE-STS) and to evaluate the impact of MWCs on tumor control and patient outcomes.

METHODS

The medical records of 102 LE-STS patients treated with limb-sparing surgery and radiation therapy were reviewed. MWCs were defined as secondary operations with anesthesia, seroma/hematoma aspiration, admission for IV antibiotics, or persistent deep packing.

RESULTS

MWCs occurred in 22% of patients, with 45% of events occurring >120 days after resection. On multivariate analysis, preoperative external beam radiation therapy (EBRT) (OR 4.29, 95% CI 1.06-17.40, P = 0.042) and skin graft placement (OR 6.39, 95% CI 1.37-29.84, P = 0.018) were found to be independent predictors of MWCs. MWC occurrence did not predict for chronic toxicity and did not impact tumor control or survival.

CONCLUSIONS

A considerable proportion of MWCs occur >120 days from surgical resection with preoperative EBRT and skin graft placement independent predictors for MWCs. While an additional source of morbidity, MWC occurrence did not impact tumor control, nor did it predict for chronic toxicity. J. Surg. Oncol. 2016;114:385-391. © 2016 Wiley Periodicals, Inc.

Preoperative radiotherapy for extremity soft tissue sarcoma; past, present and future perspectives on dose fractionation regimens and combined modality strategies

INTRODUCTION

This critical review aims to summarize published data on limb sparing surgery for extremity soft tissue sarcoma in combination with pre-operative radiotherapy (RT).

METHODS

This review is based on peer-reviewed publications using a PubMed search on the MeSH headings "soft tissue sarcoma" AND "preoperative radiotherapy". Titles and abstracts screened for data including "fraction size AND/OR total dose AND/OR overall treatment time", "chemotherapy", "targeted agents AND/OR tyrosine kinase inhibitors", are collated. Reference lists from some articles have been studied to obtain other pertinent articles. Additional abstracts presented at international sarcoma meetings have been included as well as information on relevant clinical trials available at the ClinicalTrials.gov website.

RESULTS

Data are presented for the conventional regimen of 50-50.4Gy in 25-28 fractions in 5-6 of weeks preoperative external beam RT with respect to the regimen's local control probability compared to surgery alone, as well as acute and late toxicities. The rationale and outcome data for hypofractionated and/or reduced dose regimens are discussed. Finally, combination schedules with conventional chemotherapy and/or targeted agents are summarized.

CONCLUSION

Outside the setting of well-designed prospective clinical trials, the conventional 50Gy in 5-6week schedule should be considered as standard. However, current and future studies addressing alternative fraction size, total dose, overall treatment time and/or combination with chemotherapy or targeted agents may reveal regimens of equal or increased efficacy with reduced late morbidities.

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

Marginal miss or radioresistance? The pattern of local recurrence after operation and 3D planned radiation treatment in soft tissue sarcoma of the extremities and the limb girdles; an analysis based on image fusion

BACKGROUND

Most local recurrences have developed in the clinical target volume in previously published series after combined modality treatment for soft tissue sarcoma. However, marginal misses were seen in almost 20% of the patients. The aim of the present study was to determine the location of the recurrence and the total dose at the centre point of the local recurrence for future radiation therapy planning.

MATERIAL AND METHODS

We included only patients with images in digital form, during 1999-2006 (n = 17), treated for soft tissue sarcoma with combined surgical therapy and radiotherapy at Helsinki University Central Hospital. Image fusion was used to determine the location of the recurrence in relation to radiation therapy target.

RESULTS

In the present study utilising digital image fusion, in patients with 3D CT-based radiation treatment planning the risk of marginal miss was low as only one patient of 17 relapsed outside the target. Estimated mean radiation dose at the site of local recurrence was 49.1 Gy in patients with positive margins and 48.1 Gy in patients with negative margins.

CONCLUSION

The risk of marginal miss in soft tissue sarcoma is low after modern 3D planned radiation treatment combined with surgery. More generous use of boost might improve in-target local control.

Neoadjuvant treatment of soft tissue sarcoma

PURPOSE

The aim of this study was to evaluate disease-free survival (DFS), overall survival and toxicity of patients who underwent preoperative therapy for soft tissue sarcoma.

MATERIALS AND METHODS

The data of 38 consecutive patients affected by soft tissue sarcoma were retrospectively analysed. Six (15.8 %) patients were treated only with neoadjuvant radiotherapy, and 32 (84.2 %) with neoadjuvant chemo-radiation therapy. Surgery was performed within 4-6 weeks after the completion of neoadjuvant treatment.

RESULTS

Median follow-up was 4.9 years (range 1-13.7 years). All patients received preoperative external beam radiotherapy (RT). Most patients (84.2 %) underwent neoadjuvant chemotherapy treatment associated with radiotherapy. After neoadjuvant treatment, the majority of patients underwent wide excision (32 out of 38) and five patients had marginal surgery; only one patient underwent amputation. Local recurrence was observed in only two patients (5.2 %). Fourteen (36.8 %) patients experienced metastatic relapse. At the time of our analysis 13 patients (34.2 %) had died due to metastatic spread of the disease. In our series, DFS in relation to distant metastases (DM) showed a significant result for lower limb involvement (p = 0.038) and marginal excision (p = 0.024), both predictors of a worse DFS, histology was statistically significant although it was not possible to evaluate the risk for specific histology due to the small number of events in the different subtypes.

CONCLUSIONS

The results obtained from our study are encouraging with regard to the feasibility and efficacy of preoperative RT in the treatment of soft tissue sarcoma in view of the results obtained in terms of local control, limb sparing and safety.

Patterns of local recurrence and dose fractionation of adjuvant radiation therapy in 462 patients with soft tissue sarcoma of extremity and trunk wall

PURPOSE

To study the impact of dose fractionation of adjuvant radiation therapy (RT) on local recurrence (LR) and the relation of LR to radiation fields.

METHODS AND MATERIALS

LR rates were analyzed in 462 adult patients with soft tissue sarcoma who underwent surgical excision and adjuvant RT at five Scandinavian sarcoma centers from 1998 to 2009. Medical records were reviewed for dose fractionation parameters and to determine the location of the LR relative to the radiation portals.

RESULTS

Fifty-five of 462 patients developed a LR (11.9%). Negative prognostic factors included intralesional surgical margin (hazard ratio [HR]: 7.83, 95% confidence interval [CI]: 3.08-20.0), high malignancy grade (HR: 5.82, 95% CI: 1.31-25.8), age at diagnosis (HR per 10 years: 1.27, 95% CI: 1.03-1.56), and malignant peripheral nerve sheath tumor histological subtype (HR: 6.66, 95% CI: 2.56-17.3). RT dose was tailored to margin status. No correlation between RT dose and LR rate was found in multiple Cox regression analysis. The majority (65%) of LRs occurred within the primary RT volume.

CONCLUSIONS

No significant dose-response effect of adjuvant RT was demonstrated. Interestingly, patients given 45-Gy accelerated RT (1.8 Gy twice daily/2.5 weeks) had the best local outcome. A total dose of 50 Gy in 25 fractions seemed adequate following wide margin surgery. The risk of LR was associated with histopathologic subtype, which should be included in the treatment algorithm of adjuvant RT in soft tissue sarcoma.

Practical radiation oncology for extremity sarcomas

Soft tissue sarcomas are rare cancers. They should be managed by a multidisciplinary team with experience caring for these diverse malignancies. Local control is frequently achieved with a combination of radiation therapy and surgery. This article reviews the data supporting the role of adjuvant radiotherapy in the care of patients with soft tissue sarcoma and describes the side effects of surgery and radiation therapy. Preoperative radiation therapy increases the risk of wound complication from surgery, but has fewer long-term side effects than postoperative radiation therapy. The timing of radiation therapy can be tailored to each patient.

Predictors for major wound complications following preoperative radiotherapy and surgery for soft-tissue sarcoma of the extremities and trunk: importance of tumor proximity to skin surface

PURPOSE

Preoperative and postoperative RT for the treatment of high-grade soft-tissue sarcoma result in similar local control and overall survival rates, but morbidities differ. Postoperative RT is associated with a higher rate of long-term fibrosis, edema, and joint stiffness. Preoperative RT is associated with higher rates of wound complications. It is important to identify predictors for major wound complications (MWC) and to develop strategies to minimize this outcome. We reviewed our experience to determine predictors for MWC following preoperative radiotherapy (RT) and surgery for soft-tissue sarcoma.

METHODS

Between January 2006 and May 2011, 103 patients with soft-tissue sarcoma of the extremities and trunk were treated with preoperative RT followed by surgery. MWCs were defined as those requiring operative or prolonged nonoperative management. Fisher's exact test was used to compare rates. Logistic regression was used for multivariable analysis of factors potentially associated with MWCs.

RESULTS

Median tumor size was 8.4 cm (range 2-25). All patients had wide or radical resections. Wound closures were primary in 70 %, a vascularized flap in 27 %, and split-thickness skin graft (STSG) in 3 %. There were 36 MWCs (35 %). Significant predictors for MWCs on univariate analysis included diabetes, tumors >10 cm, tumors <3 mm from skin surface, and vascularized flap/STSG closure. The same four variables were significant predictors on multivariable analysis.

CONCLUSIONS

MWCs following preoperative RT and surgery were common. Tumor proximity to skin surface <3 mm is a previously unreported independent predictor, and further strategies to minimize wound complications are needed.

Neoadjuvant chemoradiotherapy for patients with high-risk extremity and truncal sarcomas: a 10-year single institution retrospective study

BACKGROUND

Patients with large, high-grade extremity and truncal soft tissue sarcomas (STS) are at considerable risk for recurrence. A regimen of pre-operative chemotherapy consisting of mesna, adriamycin, ifosfamide and dacarbazine (MAID), interdigitated with radiotherapy (RT), followed by resection and post-operative chemotherapy with or without RT, has demonstrated high rates of local and distant control. The goal of this study is to assess outcomes in a recent cohort of patients treated on this regimen.

METHODS

We retrospectively reviewed records of 66 consecutive patients with STS of the extremity or trunk who were treated with the aforementioned regimen from May 2000 to April 2011. Clinicopathologic characteristics and patient outcomes were analysed.

RESULTS

Sixty-six patients were analysed and were equally divided between grade 2 and 3 tumours. Margins were negative in 57 (89%) patients and positive in seven (11%) patients. At a median follow-up of 46 months, there were six (9%) locoregional and 20 (30%) distant recurrences. The locoregional and distant 5-year recurrence-free survival (RFS) rates were 91% and 64%, respectively. The 5-year overall (OS) and disease-specific survival rates were 86% and 89%, respectively. There were no treatment-related deaths or secondary myelodysplasias. Thirty-four (52%) patients had grade 3 or 4 acute haematologic chemotherapy-related toxicity. There were no statistically significant predictors of OS or RFS.

CONCLUSIONS

For a contemporary cohort of patients with high-risk extremity and truncal STS, a regimen of neoadjuvant chemoradiotherapy and surgery continues to result in high rates of survival with tolerable short- and long-term toxicity.

Radiotherapy for management of extremity soft tissue sarcomas: why, when, and where?

This critical review will focus on published data on the indications for radiotherapy in patients with extremity soft tissue sarcomas and its role in local control, survival, and treatment complications. The differences between pre- and postoperative radiotherapy will be discussed and consensus recommendations on target volume delineation proposed.

Extremity soft tissue sarcoma resections: how wide do you need to be?

BACKGROUND

Sarcomas require a wide margin of resection including a cuff of normal tissue to minimize the risk of local recurrence. The amount of tissue that constitutes a wide margin is unclear in the literature.

QUESTIONS/PURPOSES

We therefore determined whether a close resection margin for soft tissue sarcoma resulted in an increased incidence of locally recurrent disease and whether additional factors, including radiation therapy, outside biopsies, and tumor biology, affected the risk of local recurrence.

METHODS

We retrospectively reviewed 117 patients with soft tissue sarcomas resected with negative margins from 2001 to 2007. Gross specimens were inked and the closest macroscopic margins were sent for microscopic examination. Resection margins were categorized as less than 1 mm, 1-5 mm, or greater than 5 mm. We evaluated additional factors that might influence local recurrence, including radiation therapy, outside biopsies, sarcoma type, grade, and stage at presentation, and development of metastatic disease.

RESULTS

Four of 117 patients (3.4%) developed local recurrence. The incidence of local recurrence was similar in patients with less than 1-mm margins and greater than 1-mm margins: two of 45 patients (4.4%) and two of 64 patients (3.1%), respectively. Due to the low number of local recurrences, quantitative margin extent and the other factors evaluated did not affect local recurrence.

CONCLUSIONS

The extent of a margin necessary to prevent local recurrence of soft tissue sarcoma remains unclear as the power of our study was limited by the low number of local recurrences. Relatively low local recurrence rates can be achieved even with close margins.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The significance of a marginal excision after preoperative radiation therapy for soft tissue sarcoma of the extremity

BACKGROUND

Marginal excision of soft tissue sarcoma (STS), defined as resection through the tumor pseudocapsule or surrounding reactive tissue, increases the likelihood of local recurrence and necessitates re-excision or postoperative radiation. However, its impact after preoperative radiation therapy (RT) remains unclear. This study therefore investigated the significance of marginal margins in patients treated with preoperative RT for extremity STS, reporting long-term local control and limb preservation endpoints.

METHODS

The records of 317 adults at the University of Florida with nonmetastatic extremity STS treated from 1980 to 2008 with preoperative RT as part of a limb conservation strategy were reviewed. The median follow-up was 4.7 years (8.3 years for living patients). The median tumor size was 10 cm (range, 2-36 cm), and 86% were high grade. The median RT dose was 50.4 Gy (range, 12.5-57.6 Gy). Margins were classified as wide/radical (n = 105), marginal (n = 179), contaminated (n = 15), positive (n = 17), or unknown (n = 1). Endpoints were local control (LC), amputation-free survival (AFS), cause-specific survival (CSS), and overall survival (OS).

RESULTS

Five-year CSS and OS rates were 62% and 59%, respectively. Five-year LC and AFS was 93% and 89%, respectively. AFS by margin status was 64%, 83%, 97%, and 92% for positive, contaminated, marginal, and wide/radical margins, respectively (P<.005). Marginal excision following preoperative RT resulted in equivalent LC and AFS compared with wide/radical margins.

CONCLUSIONS

Marginal resection after preoperative RT does not compromise LC or AFS in extremity STS. This finding may be related to radiosterilization of tumor cells within the reactive zone following preoperative RT.

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.

The relationship between local recurrence and radiotherapy treatment volume for soft tissue sarcomas treated with external beam radiotherapy and function preservation surgery

PURPOSE

To examine the geometric relationship between local recurrence (LR) and external beam radiotherapy (RT) volumes for soft-tissue sarcoma (STS) patients treated with function-preserving surgery and RT.

METHODS AND MATERIALS

Sixty of 768 (7.8%) STS patients treated with combined therapy within our institution from 1990 through 2006 developed an LR. Thirty-two received preoperative RT, 16 postoperative RT, and 12 preoperative RT plus a postoperative boost. Treatment records, RT simulation images, and diagnostic MRI/CT data sets of the original and LR disease were retrospectively compared. For LR location analysis, three RT target volumes were defined according to the International Commission on Radiation Units and Measurements 29 as follows: (1) the gross tumor or operative bed; (2) the treatment volume (TV) extending 5 cm longitudinally beyond the tumor or operative bed unless protected by intact barriers to spread and at least 1-2 cm axially (the TV was enclosed by the isodose curve representing the prescribed target absorbed dose [TAD] and accounted for target/patient setup uncertainty and beam characteristics), and (3) the irradiated volume (IRV) that received at least 50% of the TAD, including the TV. LRs were categorized as developing in field within the TV, marginal (on the edge of the IRV), and out of field (occurring outside of the IRV).

RESULTS

Forty-nine tumors relapsed in field (6.4% overall). Nine were out of field (1.1% overall), and 2 were marginal (0.3% overall).

CONCLUSIONS

The majority of STS tumors recur in field, indicating that the incidence of LR may be affected more by differences in biologic and molecular characteristics rather than aberrations in RT dose or target volume coverage. In contrast, only two patients relapsed at the IRV boundary, suggesting that the risk of a marginal relapse is low when the TV is appropriately defined. These data support the accurate delivery of optimal RT volumes in the most precise way using advanced technology and image guidance.

Long-term results of a phase 2 study of neoadjuvant chemotherapy and radiotherapy in the management of high-risk, high-grade, soft tissue sarcomas of the extremities and body wall: Radiation Therapy Oncology Group Trial 9514

BACKGROUND

The use of neoadjuvant and adjuvant chemotherapy in soft tissue sarcomas is controversial. This is a report of long-term (≥5 years) follow-up in patients with high-grade, high-risk soft tissue sarcomas treated with neoadjuvant chemotherapy, preoperative radiotherapy (RT), and adjuvant chemotherapy.

METHODS

Patients with high-grade soft tissue sarcoma≥8 cm in diameter of the extremities and body wall received 3 cycles of neoadjuvant chemotherapy (mesna, doxorubicin, ifosfamide, and dacarbazine) and preoperative RT (44 grays administered in split courses), and 3 cycles of postoperative chemotherapy (mesna, doxorubicin, ifosfamide, and dacarbazine).

RESULTS

Sixty-four of 66 patients were analyzed. After chemotherapy and RT, 61 patients had surgery; 58 had R0 resections (5 amputations), and 3 had R1 resections. Ninety-seven percent experienced grade 3 or higher toxicity, including 3 deaths. These toxicities were short term. With a median follow-up of 7.7 years in surviving patients, the 5-year rates of locoregional failure (including amputation), and distant metastasis were 22.2% (95% confidence interval [CI], 11.8-32.6) and 28.1% (95% CI, 17.0-39.2). The most common site of metastasis was lung. Estimated 5-year rates of disease-free survival, distant disease-free survival, and overall survival were 56.1% (95% CI, 43.9-68.3), 64.1% (95% CI, 52.3-75.8), and 71.2% (95% CI, 60.0-82.5), respectively.

CONCLUSIONS

Although the toxicity was significant, it was limited in its course and for the most part resolved by 1 year. The long-term outcome was better than might be expected in such high-risk tumors.