Conservative surgery and adjuvant radiation therapy in the management of adult soft tissue sarcoma of the extremities: clinical and radiobiological results

What is the Optimal Treatment Strategy after Sarcoma R2 Surgery?

OPINION STATEMENT

Soft tissue sarcomas (STS) are rare tumours of mesenchymal origin, most commonly occurring in the extremity but also in the retroperitoneum. The curative treatment for STS is radical surgery with wide margins, in some cases in combination with perioperative radiotherapy and chemotherapy. Nonradical resection (R2) of STS has been an emerging issue in recent decades, as optimal subsequent management remains debatable. Similarly, there is still no consensus on optimal surgical margins. Combining multiple treatment modalities in adjuvant therapy can achieve local and distant control in patients following surgery with positive margins. Patients who have undergone nonradical resection therefore require additional surgical interventions, and adjuvant radiotherapy resulting in a better prognosis but a higher number of complications. Following non-radical treatment, patients with limb and trunk wall sarcomas and retroperitoneal sarcomas should also undergo increased oncological surveillance. Given the potential issues that may emerge in such clinical situations, it is crucial to up-date the current guidelines to enhance the long-term prognosis of these patients.

Dosimetric comparison between proton beam therapy, intensity modulated radiation therapy, and 3D conformal therapy for soft tissue extremity sarcoma

PURPOSE/OBJECTIVES

Proton beam therapy (PBT) may provide a dosimetric advantage in sparing soft tissue and bone for selected patients with extremity soft sarcoma (eSTS). We compared PBT with photons plans generated using intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT).

MATERIALS/METHODS

Seventeen patients previously treated with pencil beam scanning PBT were included in this study. Of these patients, 14 treated with pre-operative 50 Gy in 25 fractions were analyzed. IMRT and 3D-CRT plans were created to compare against the original PBT plans. Dose-volume histogram (DVH) indices were evaluated amongst PBT, IMRT, and 3D plans. Kruskal-Wallis rank sum tests were used to get the statistical significance. A p value smaller than .05 was considered to be statistically significant.

RESULTS

For the clinical target volume (CTV), D2%, D95%, D98%, D_min, D_max, and V50Gy, were assessed. D_min, D1%, D_max, D_mean, V1Gy, V5Gy, and V50Gy were evaluated for the adjacent soft tissue. D1%, D_max, D_mean, and V35-50% were evaluated for bone. All plans met CTV target coverage. The PBT plans delivered less dose to soft tissue and bone. The mean dose to the soft tissue was 2 Gy, 11 Gy, and 13 Gy for PBT, IMRT, and 3D, respectively (p < .001). The mean dose to adjacent bone was 15 Gy, 26 Gy, and 28 Gy for PBT, IMRT, and 3D, respectively (p = .022).

CONCLUSION

PBT plans for selected patients with eSTS demonstrated improved sparing of circumferential soft tissue and adjacent bone compared to IMRT and 3D-CRT. Further evaluation will determine if this improved dosimetry correlates with reduced toxicity and improved quality of life.

Radiotherapy and Limb-Sparing Surgery in the Management of Localized Soft Tissue Sarcomas: Tertiary Care Center Experience From Pakistan

PURPOSE

When combined with radiotherapy, limb salvage surgery is an alternative to amputation. This study sought to determine the limb-sparing treatment outcomes in patients diagnosed with soft tissue extremity sarcomas treated at our institution.

MATERIALS AND METHODS

All adult patients with extremity soft tissue sarcoma treated with the radical limb salvage strategy at Shaukat Khanum Memorial Cancer Hospital and Research Canter, Lahore, Pakistan, between January 2017 and December 2019 were retrospectively assessed.

RESULTS

A total of 122 patients were included in the study. The mean age was 42 years (range 19-82), and 64 (52.5%) were males. The majority of patients, 65 (53.3%), were diagnosed with stage III and grade III disease according to American Joint Committee on Cancer TNM classification (Eighth edition). The most common surgical modality was wide local excision that was performed in 106 (86.9%) patients. Adjuvant radiation treatment was given in 111 (91%) patients, whereas 11 (9%) patients received neoadjuvant radiation treatment. The mean dose was 58 Gy (range: 46-66 Gy). Eighty-two (67.2%) of the patients were disease-free on post-treatment radiologic scans with disease recurrence observed in 40 (32.8%) patients. The median disease-free survival was 8 months (95% CI, 5.45 to 10.55). Local recurrence and distant metastases developed in 16 (13%) and 24 (20%) patients, respectively.

CONCLUSION

About two thirds of patients with extremity soft tissue sarcoma were successfully treated with limb salvage strategy, surgery, and radiation therapy. However, high rate of relapse warrants further novel strategies in this patient population.

Real-world clinical outcomes with daily image-guided IMRT in extremity soft tissue sarcomas

PURPOSE

We report the clinical outcomes of patients with soft tissue sarcomas (STS) arising in extremities treated with image-guided intensity modulated radiotherapy (IG-IMRT) at our institute. Local control of the tumors treated with RT was the primary end point of this study. Analyzing overall survival and long-term toxicities were the secondary objectives.

METHODS AND MATERIALS

The database of the patients with STS who received wide local excision and IG-IMRT at our institution from January 2012 to December 2020 was reviewed. Radiation was offered either preoperatively or postoperatively as part of multi-modality treatment.

RESULTS

Thirty-three consecutive patients were identified and included for analysis. Twenty-eight patients (84.8%) received postoperative adjuvant radiotherapy. Dedicated MRI simulation studies were performed in 31 patients (93.9%) in the treatment position. RapidArc IMRT technique was used in 31 patients (93.9%). A total of 2954 images were acquired during 991 treatment sessions. Errors exceeding 1 mm in the x, y and z directions were corrected online before the treatment. With a median follow-up of 36 months, two patients (6.1%) developed local recurrence. The 3-year local control was 90.9% (95% CI, 0.76 - 0.98), and the 5-year overall survival was 71.7% (95% CI, 0.44 - 0.88). One patient (3.03%) sustained a pathological fracture during the follow-up period.

CONCLUSION

Our results showed that IMRT with daily imaging offered excellent local control with acceptable long-term toxicity, as well as being feasible and practical to implement in our routine clinical practice.

Long-term experience with intraoperative electron radiation therapy boost in extremity sarcoma

BACKGROUND

In patients with extremity soft tissue sarcoma (eSTS), we describe outcomes of preoperative external beam radiation therapy (EBRT), limb-sparing surgery (LSS), and intraoperative electron radiation therapy (IOERT).

METHODS

One hundred and eighteen patients with eSTS treated between October 17, 2002 and July 28, 2021 were identified. EBRT was delivered preoperatively followed by LSS and IOERT.

RESULTS

The median follow-up was 24.9 months. The presentation was primary in 102 (94%) patients and recurrent in 6 (6%) patients. Tumor location was lower extremity in 82 (76%) patients and upper extremity in 26 (24%) patients. Stage distribution was as follows: 3 (3%) IA, 24 (22%) IB, 31 (29%) II, 24 (22%) IIIA, and 25 (23%) IIIB. Final surgical margins were negative in 96 (89%) patients. The 5-year local control, failure-free survival, and overall survival were 94%, 75%, and 64%, respectively. Univariate analysis identified age >50, lower extremity, and higher grade as significant negative prognostic factors for overall survival. Grade 3 fracture or osteoradionecrosis requiring surgical fixation, neuropathy, and lymphedema occurred in 7 (6%), 1 (1%), and 0 patients, respectively.

CONCLUSIONS

This study represents one of the largest series using preoperative EBRT, LSS, and IOERT for eSTS, with high local control and a low rate of late severe toxicity.

Early Experience Using Proton Beam Therapy for Extremity Soft Tissue Sarcoma: A Multicenter Study

Purpose

Proton beam therapy (PBT) may provide an advantage when planning well-selected patients with extremity soft tissue sarcoma (eSTS), specifically for large, anatomically challenging cases. We analyzed our early experience with PBT on toxicity and outcomes.

Materials and Methods

A retrospective study was performed for eSTS treated between June 2016 and October 2020 with pencil beam scanning PBT at 2 institutions. Diagnostic, treatment, and toxicity characteristics were gathered from baseline to last follow-up or death. Wound complications were defined as secondary operations for wound repair (debridement, drainage, skin graft, and muscle flap) or nonoperative management requiring hospitalization. Statistical analysis was performed with R software.

Results

Twenty consecutive patients with a median age 51.5 years (range, 19–78 years) were included. Median follow-up was 13.7 months (range, 1.7–48.1 months). Tumor presentation was primary (n = 17) or recurrent after prior combined modality therapy (n = 3). Tumor location was either lower extremity (n = 16) or upper extremity (n = 4). Radiation was delivered preoperatively in most patients (n = 18). Median pretreatment tumor size was 7.9 cm (range, 1.3 –30.0 cm). The 1-year locoregional control was 100%. Four patients (20%) had developed metastatic disease by end of follow-up. Maximum toxicity for acute dermatitis was grade 2 in 8 patients (40%) and grade 3 in 3 patients (15%). After preoperative radiation and surgical resection, acute wound complications occurred in 6 patients (35%). Tumor size was larger in patients with acute wound complications compared with those without (medians 16 cm, range [12–30.0 cm] vs 6.3 cm, [1.3–14.4 cm], P = .003).

Conclusion

PBT for well selected eSTS cases demonstrated excellent local control and similar acute wound complication rate comparable to historic controls. Long-term follow-up and further dosimetric analyses will provide further insight into potential advantages of PBT in this patient population.

Reirradiation in Conservative Salvage of Recurrent Soft-tissue Sarcoma: An Analysis of Treatment Efficacy and Toxicities

OBJECTIVE

Compared with radical resection alone, perioperative radiation therapy (RT) combined with neurovascular preserving surgery is the standard for the management of virgin soft-tissue sarcomas. Yet, the optimal management of a local recurrence remains unclear. We report outcomes of patients with locally recurrent soft-tissue sarcoma treated with resection and reirradiation at the University of Florida.

MATERIALS AND METHODS

We reviewed the records of patients treated with primary conservative surgery and radiation for soft-tissue sarcoma followed by salvage resection and reirradiation for a local recurrence at our institution.

RESULTS

We analyzed 23 patients treated between 1976 and 2014 (median follow-up, 46 mo). Tumor sites included: proximal extremity, 11 patients; trunk, 6; distal extremity, 5; and head and neck, 1. All patients had conservative gross total resection of their recurrent tumor, without amputation. For reirradiation, 16 patients received external-beam RT alone, 6 received external-beam RT and brachytherapy, and 1 received brachytherapy alone. Two patients received chemotherapy. After retreatment, the 5-year overall survival, cause-specific survival, local control, and distant control rates were 39%, 42%, 46%, and 60%, respectively. Ten patients experienced local recurrences, 1 experienced regional recurrence, and 9 developed distant metastases. Retreatment-related complications ranged from delayed wound healing to limb amputation; 8 patients required amputation. Only 3 patients remained disease-free at last follow-up. No statistically significant associations were found between treatment factors (eg, RT dose) and local control.

CONCLUSIONS

Achieving local control of recurrent soft-tissue sarcoma is challenging. Treatment with reoperation and reirradiation can lead to debilitating complications affecting function and quality of life.

Radiation Therapy for Treatment of Soft Tissue Sarcoma in Adults: Executive Summary of an ASTRO Clinical Practice Guideline

PURPOSE

This guideline provides evidence-based recommendations addressing the indications for radiation therapy (RT), sequencing of local therapies, and appropriate dose and planning techniques for management of primary, operable, localized, soft tissue sarcoma (STS) in adults.

METHODS

The American Society for Radiation Oncology convened a task force to address 5 key questions focused on the use of RT for management of STS. These questions included indications for RT for STS of the extremity and superficial trunk; considerations for sequencing of RT with respect to surgery, dose of RT, appropriate treatment volumes and techniques; and the role of RT in management of retroperitoneal sarcoma. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Multidisciplinary evaluation and decision making are recommended for all cases of STS. RT is recommended for patients in whom there is increased risk of local recurrence of resected STS, particularly if close or microscopically positive margins are anticipated or have occurred. When RT is indicated, preoperative RT is strongly recommended over postoperative RT. Postoperative RT is conditionally recommended in specific clinical circumstances (eg, uncontrolled pain or bleeding) or when the risk of wound complications outweighs that of late toxicity from RT. Routine use of RT in addition to oncologic resection for retroperitoneal sarcoma is conditionally not recommended. When RT is used for retroperitoneal sarcoma, preoperative RT is recommended, whereas postoperative RT is not recommended.

CONCLUSIONS

Based on currently published data, the American Society for Radiation Oncology task force has proposed evidence-based recommendations regarding the use of RT for STS in adults. Future studies will ascertain whether alterations in dosing and sequencing may optimize outcomes and quality of life.

Malignant fibrous histiocytoma of the floor of mouth: a case report and review of the literature

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in late adulthood and usually occurs in the limbs, trunk, and peritoneum. Less than 10% of MFH cases occur in the head and neck region. The clinical manifestations and pathological features of MFH are atypical, and it is difficult to make a clinical diagnosis. We describe a rare case of MFH of the floor of mouth and provide our diagnosis and treatment experiences. Through this review, we also evaluate the origin, World Health Organization (WHO) classification, clinical presentations, pathological features, treatment methods, and prognosis of MFH. MFH may originate from fibroblasts or primitive mesenchymal cells. MFH was defined as undifferentiated pleomorphic sarcoma in the 2002 WHO classification of bone and soft tissue tumors. The most common manifestation of MFH is a painless enlarging nodule, often without overlying epidermal ulcers. Jaw lesions are usually found after displays of swelling, pain, paresthesia, and loose teeth. MFH is composed of pleomorphic spindle cells, usually with hemorrhage, necrosis, and lymphocyte infiltration. The main treatment method is surgical resection. Moreover, radiotherapy and chemotherapy have certain auxiliary effects. The local recurrence and distant metastasis of MFH are common, and the prognosis is poor. Therefore, determining the histopathological features of MFH and conducting appropriate immunohistochemical examinations are crucial in establishing the correct diagnosis. In-depth study is required in order to have a better understanding of head and neck MFH.

Pathologic femur fractures following surgery and radiotherapy for soft tissue sarcomas: A case series

Introduction

Combined limb-sparing surgery and radiation therapy are considered the standard of care for higher grade soft tissue sarcomas (STS) of the extremities. The risk of post-radiation fracture after this treatment modality is well known, but still underestimated, and can end in serious long-term secondary problems years later.

Presentation of case

We reviewed the records of three patients with pathological femur fractures years after wide local excision of an STS of the proximal lower extremity. All patients received more than 50 Gy (Gy) to the entire femur circumference. During surgery, all patients had bone exposure, and in two patients with stripping of the periosteum. The median time from surgery to fracture was 116 months (range from 84 to 156 months). The median age at the time of diagnosis was 66 years old. Despite standard operative fracture treatment, all three patients developed a non-union. One patient later died due to uncontrolled pulmonary metastasis independent from the femoral non-union. In the second case, an exarticulation at hip level due to an uncontrolled infected non-union had to be performed. The third patient finally achieved fracture union after two years of treatment.

Discussion

Our study confirms the high occurrence rate of postoperative complications and difficulties one encounters in treating these pathologic fractures. Only in one patient, following several revisions with intramedullary nailing, the fracture healed. In pathologic femur shaft fractures we recommend a minimal invasive procedure using intramedullary nailing devices.

Conclusion

The risk of pathological fractures at the former treatment site is high, even years later. The rate of non-unions after a difficult fracture treatment in this particular clinical situation seems to be very high and may be associated with severe complications.

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3 patients with pathological femur fractures after excision of sarcoma are reviewed.

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Risk of post-radiation fracture after this treatment modality is underestimated.

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Despite standard operative fracture treatment, rate of non-unions is very high.

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We recommend a minimal invasive procedure using intramedullary nailing devices.

Risk Factors for Lymphedema after Thigh Sarcoma Resection and Reconstruction

Secondary lymphedema can be a lifelong and debilitating consequence of lower extremity oncologic resection and reconstruction. The goal of this study was to identify risk factors for the development of lymphedema in patients treated for thigh sarcoma.

Enhanced recovery after surgery pathway in patients with soft tissue sarcoma

BACKGROUND

Patients undergoing surgery for soft tissue sarcoma have high morbidity rates, particularly after preoperative radiation therapy (RT). An enhanced recovery after surgery (ERAS) programme may improve perioperative outcomes in abdominal surgery. This study reported outcomes of an ERAS programme tailored to patients with soft tissue sarcoma.

METHODS

A prospective ERAS protocol was implemented in 2015 at a high-volume sarcoma centre. Patients treated within the ERAS programme from 2015 to 2018 were case-matched retrospectively with patients treated between 2012 and 2018 without use of the protocol, matched by surgical site, surgeon, sarcoma histology and preoperative RT treatment. Postoperative outcomes, specifically wound complications and duration of hospital stay, were reported.

RESULTS

In total, 234 patients treated within the ERAS programme were matched with 237 who were not. The ERAS group had lower wound dehiscence rates overall (2 of 234 (0·9 per cent) versus 31 of 237 (13·1 per cent); P < 0·001), after preoperative RT (0 of 41 versus 11 of 51; P = 0·004) and after extremity sarcoma surgery (0 of 54 versus 6 of 56; P = 0·040) compared with the non-ERAS group. Rates of postoperative ileus or obstruction were lower in the ERAS group (21 of 234 (9·9 per cent) versus 40 of 237 (16·9 per cent); P = 0·016) and in those with retroperitoneal sarcoma (4 of 36 versus 15 of 36; P = 0·007). Duration of hospital stay was shorter in the ERAS group (median 5 (range 0-36) versus 6 (0-67) days; P = 0·003).

CONCLUSION

Treatment within an ERAS protocol for patients with soft tissue sarcoma was associated with lower morbidity and shorter hospital stay.

Dosimetric comparison of volumetric-arc therapy versus sliding window intensity-modulated radiotherapy in postoperative treatment for primary soft tissue sarcoma of the thigh

AIM

Intensity-modulated radiotherapy (IMRT) has demonstrated improved local control in extremity soft tissue sarcoma (STS) after limb-sparing surgery compared with three-dimensional conformal radiation therapy. Our purpose was to evaluate sliding-window IMRT (SW-IMRT) and volumetric arc therapy (VMAT) in planning target volume (PTV) coverage and dose to organs-at-risk (OAR).

METHODS

Sixteen patients undergoing postoperative RT for lower extremity STS were included. For each patient, one VMAT plan and one SW-IMRT plan were proposed. Both were evaluated using cumulative dose-volume histogram data for OAR and PTVs. Prescribed dose was 66 Gy (2 Gy/fraction) to PTV1 and 56 Gy (1.69 Gy/fraction) to PTV2. OARs contoured were femur, neurovascular bundle, minimum tissue corridor, normal tissue outside PTV2, joint and genitalia. T-Student test was performed.

RESULTS

Eleven male (69%) and five female patients (31%) were analyzed. Mean age was 60 years. Both techniques showed optimal target coverage, conformity index (CI) and homogeneity index (HI). VMAT PTV2 CI was 1.13 (mean) ± 0.08 (standard deviation) versus 1.19 ± 0.10 SW-IMRT PTV2 CI (P < 0.05). VMAT PTV1 HI was 0.09 ± 0.01 versus 0.08 ± 0.01 SW-IMRT PTV1 HI (P < 0.05). Regarding OARs, VMAT delivered lower dose to femur, genitalia, normal tissue outside PTV2 and joints. SW-IMRT spared tissue corridor mean dose (10.4 Gy ± 6.8 Gy) versus (14.7 ± 6.5 Gy) VMAT (P < 0.05).

CONCLUSIONS

Both techniques achieved great conformity, homogeneity and coverage of PTV. VMAT produced lower dose to OARS and SW-IMRT was superior in sparing dose to normal-tissue-corridor, which could reduce risk of lymphedema.

The role of radiation therapy and margin width in localized soft-tissue sarcoma: Analysis from the US Sarcoma Collaborative

BACKGROUND AND OBJECTIVES

Soft-tissue sarcomas (STSs) are often treated with resection and radiation (RT)±chemotherapy. The role of RT in decreasing resection width to achieve local control is unclear. We evaluated RT on margin width to achieve local control and local recurrence (LR).

METHODS

From 2000 to 2016, 514 patients with localized STS were identified from the US Sarcoma Collaborative database. Patients were stratified by a margin and local control was compared amongst treatment groups.

RESULTS

LR was 9% with positive, 4.2% with ≤1 mm, and 9.3% with >1 mm margins (P = .315). In the ≤1 mm group, LR was 5.7% without RT, 0% with preoperative RT, and 0% with postoperative RT (P < .0001). In the >1 mm group, LR was 10.2%, 0%, and 3.7% in the no preoperative and postoperative RT groups, respectively (P = .005). RT did not influence LR in patients with positive margins. In stage I-III and II-III patients, local recurrence-free survival was higher following RT (P = .008 and P = .05, respectively).

CONCLUSIONS

RT may play a larger role in minimizing LR than margin status. In patients with positive margins, RT may decrease LR to similar rates as a negative margin without RT and may be considered to decrease the risk of LR with anticipated close/positive margins.

Pathologic necrosis following neoadjuvant radiotherapy or chemoradiotherapy is prognostic of poor survival in soft tissue sarcoma

PURPOSE

Neoadjuvant radiotherapy ± chemotherapy and wide local excision is an accepted management of localized soft tissue sarcomas (STS). Necrosis is prognostic for survival in osteosarcomas, but the significance for STS is undetermined. This study aimed to determine if percent true necrosis, opposed to a combination of necrosis and fibrosis, leads to improved survival in extremity and trunk STS.

METHODS

From 2000 to 2015, 162 patients with STS were treated with neoadjuvant therapy and resection. Patient and tumor variables were reviewed, and resected specimens underwent pathological assessment. Necrosis was ratiometrically determined. Overall (OS), distant metastasis-free (DMFS), and progression-free survival (PFS) were calculated using Kaplan-Meier estimator. Survival was determined using the Fisher's exact test for univariate analysis (UVA) and logistic regression for multivariate analysis (MVA).

RESULTS

Median follow-up was 4.5 years and median necrosis was 24.97%. Necrosis predicted worse OS, DMFS, and PFS on UVA, and DMFS and PFS on MVA. Necrosis was positively correlated with size and grade. To mitigate the role of size, a sub-analysis of ≥ 10 cm tumors was performed revealing necrosis predicted decreased DMFS and PFS on UVA and MVA. In high-grade tumors, necrosis correlated with decreased DMFS and PFS on UVA. Necrosis did not predict OS in ≥ 10 cm or high-grade tumors.

CONCLUSIONS

Our data suggests necrosis may be an additional independent, prognostic variable with increased necrosis predicting a worse prognosis. Necrosis may not be a measure of treatment response and instead suggests more aggressive tumor biology as high-grade, large STS were associated with increased necrosis.

Characterization and predictive value of volume changes of extremity and pelvis soft tissue sarcomas during radiation therapy prior to definitive wide excision

PURPOSE

The purpose of this study was to characterize and evaluate the clinical significance of volume changes of soft tissue sarcomas during radiation therapy (RT), prior to definitive surgical resection.

MATERIALS AND METHODS

Patients with extremity or pelvis soft tissue sarcomas treated at our institution from 2013 to 2016 with RT prior to resection were identified retrospectively. Tumor volumes were measured using cone-beam computed tomography obtained daily during RT. Linear regression evaluated the linearity of volume changes. Kruskal-Wallis tests, Mann-Whitney U tests, and linear regression evaluated predictors of volume change. Logistic and Cox regression evaluated volume change as a predictor of resection margin status, histologic treatment response, and tumor recurrence.

RESULTS

Thirty-three patients were evaluated. Twenty-nine tumors were high grade. Prior to RT, median tumor volume was 189 mL (range, 7.2 to 4,885 mL). Sixteen tumors demonstrated significant linear volume changes during RT. Of these, 5 tumors increased and 11 decreased in volume. Myxoid liposarcoma (n = 5, 15%) predicted decreasing tumor volume (p = 0.0002). Sequential chemoradiation (n = 4, 12%) predicted increasing tumor volume (p = 0.008) and corresponded to longer times from diagnosis to RT (p = 0.01). Resection margins were positive in three cases. Five patients experienced local recurrence, and 7 experienced distant recurrence, at median 8.9 and 6.9 months post-resection, respectively. Volume changes did not predict resection margin status, local recurrence, or distant recurrence.

CONCLUSION

Volume changes of pelvis and extremity soft tissue sarcomas followed linear trends during RT. Volume changes reflected histologic subtype and treatment characteristics but did not predict margin status or recurrence after resection.

Comparison of outcome and toxicity of postoperative intensity-modulated radiation therapy with two-dimensional radiotherapy in patients with soft tissue sarcoma of extremities and trunk

BACKGROUND

To compare the survival outcomes and late toxicities of postoperative intensity-modulated radiation therapy (IMRT) with two-dimensional radiotherapy (2D-RT) for patients with soft tissue sarcoma (STS) of extremities and trunk.

METHODS

274 consecutive patients with nonmetastatic STS of extremities and trunk treated with postoperative IMRT (n = 187) and 2D-RT (n = 87) were analyzed. Survival was calculated by using Kaplan-Meier method. Independent prognostic factors were identified using Cox stepwise regression analysis for variables with a P-value <0.1 in univariate analysis.

RESULTS

With a median follow-up time of 58.1 months, 30 local recurrences, 66 distant metastases, and 40 deaths occurred. Compared to 2D-RT group, the IMRT group had higher 5-year local recurrence-free survival (LRFS) (91.1% vs 80.8%; P = 0.029), distant metastasis-free survival (DMFS) (80.0% vs 69.7%; P = 0.048), disease-free survival (DFS) (75.2% vs 59.2%; P = 0.021), and overall survival (OS) (90.2% vs 81.0%; P = 0.029). Multivariate analysis showed IMRT was an independent favorable factor for LRFS, DMFS, DFS, and OS. For late toxicities, the patients in IMRT group enjoyed lower incidences of ≥Grade 2 joint stiffness (3.9% vs 12.3%; P = 0.041) and ≥Grade 3 fractures (0.0% vs 3.4%; P = 0.25) than those in 2D-RT group. ≥Grade 2 Edema was similar between these two groups (4.8% vs 9.2%; P = 0.183).

CONCLUSIONS

When compared with conventional techniques, postoperative IMRT seems to provide better LRFS, DMFS, DFS, and OS and less late toxicities in patients with STS of extremities and trunk, which should be offered as a preferred treatment.

Feasibility of using stereotactic body radiation therapy for unresectable soft tissue tumors of the trunk

Purpose

To evaluate the feasibility of stereotactic body radiation therapy (SBRT) for unresectable soft tissue tumors of the trunk.

Materials and Methods

Between January 2002 and December 2008, 23 patients with 36 lesions of soft tissue tumors, which were located in the trunk and not suitable for resection, underwent SBRT. Among the 36 lesions, 31 were malignant and 5 were benign. The median tumor volume was 24 cm³ (range, 2.6–213 cm₃). SBRT doses ranged from 20 to 48 Gy in 1–5 fractions.

Results

With a median follow-up of 73 months, the overall survival (OS) and local control (LC) rates at 5 years were 39% and 52%, respectively. For malignant tumors, the OS and LC rates at 5 years were 28% and 47%, respectively. For benign tumors, the OS and LC rates at 5 years were 80% and 100%, respectively. There was no acute toxicity of grade ≥3. One case of grade 3 late skin toxicity was reported 10 months after SBRT.

Conclusion

SBRT may be an effective and safe treatment modality for the local control of unresectable soft tissue tumors of the trunk including tumors of a benign nature.

Adequate Local Control in High-Risk Soft Tissue Sarcoma of the Extremity Treated with Surgery Alone at a Reference Centre: Should Radiotherapy Still be a Standard?

BACKGROUND

Established practice for the management of soft tissue sarcoma (STS) of the extremity and trunk wall combines perioperative radiotherapy (RT) with limb-preserving surgery.

OBJECTIVE

The aim of this study was to explore whether high-quality surgery at high-volume centers may offer equivalent local control in selected cases, when RT needs to be avoided.

METHODS

All consecutive adult cases of primary, high-risk STSs treated in a high-volume reference center over a 12-year timeframe were included, and, on retrospective analysis, were divided into two groups. Group A received RT with surgery, and Group B received surgery alone. The primary endpoint was local recurrence-free survival (LRFS).

RESULTS

Overall, 390 patients were included (318 in Group A and 72 in Group B), with a median follow-up of 53 months. The main reasons for avoiding RT were patient choice and technical considerations (vascular bypass or flap reconstruction). No difference in R0 resection was seen between the groups (79% vs. 70%; p = 0.18), but Group A had more G3 tumors (80.5% vs. 68%; p = 0.021). No difference in 5-year LRFS was evident (84% vs. 81%; p = 0.16).

CONCLUSIONS

LRFS did not differ between patients with high-risk STSs receiving perioperative RT and those treated with surgery alone. The study was retrospective and omission of RT was largely uncontrolled with inherent bias. Nonetheless, data suggest that in experienced centers, the omission of RT did not diminish local disease outcome. Future studies on a selective approach to RT administration are awaited.

Smoking is predictive of poorer distant metastasis-free and progression free-survival in soft tissue sarcoma patients treated with pre-operative radiotherapy or chemoradiotherapy

Background

Soft tissue sarcomas (STS) are often treated with pre-operative radiation (RT), with or without chemotherapy, followed by wide local excision. Prognosis for these patients involves an interplay of tumor and patient characteristics. Known prognostic determinants include tumor size, grade, response to therapy, and patient characteristics such as age. While smoking is negatively correlated with outcomes in various malignancies, the impact on STS is unknown. We aimed to assess if smoking impacts overall (OS), distant metastasis-free (DMFS), and progression-free (PFS) survival in patients with STS treated with pre-operative RT.

Methods

Between 2000 and 2015, 166 patients with STS were identified from our prospective database. Patient variables were retrospectively reviewed. Smoking was defined as a ≥ 10 pack year history of current and former smokers. Survival was evaluated using the fisher exact test for univariate (UVA) and logistic regression for multivariate (MVA) analysis.

Results

Fifty-seven (34.3%) patients had smoking histories of ≥ 10 pack years. On UVA, smoking was associated with decreased DMFS (p = 0.0009) and PFS (p = 0.0036), but not OS (p = 0.05). Smoking held significance on MVA for both DMFS and PFS. Current smokers and patients with ≥ 24-month follow-up demonstrated decreased DMFS and PFS on UVA and MVA.

Conclusions

Current smokers and patients with a significant smoking history demonstrated decreased DMFS and PFS in STS patients treated with pre-operative RT. Smoking may cause immunologic compromise and therefore lead to higher rates of progression and distant metastasis.

Adjuvant radiotherapy with brachytherapy boost in soft tissue sarcomas

Purpose

The standard primary treatment for soft tissue sarcoma (STS) is a wide surgical resection, preceded or followed by radiotherapy. Purpose of this retrospective study was to assess the efficacy of perioperative brachytherapy (BRT) plus postoperative external beam radiation therapy (EBRT) in patients with intermediate-high risk STS.

Material and methods

BRT delivered dose was 20 Gy. External beam radiation therapy was delivered with 3D-technique using multiple beams. The prescribed dose was 46 Gy to the PTV. Neoadjuvant and adjuvant chemotherapy (CHT) was used in patients with potentially chemosensitive histological subtypes. The primary aim of the study was to analyze overall survival (OS) and local control (LC) in a large patient population treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Secondary objective was to identify prognostic factors for patients outcome in terms of LC, disease-free survival (DFS), and OS.

Results

From 2000 to 2011, 107 patients presenting 2-3 grade (FNLCC) primary or recurrent STS were treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Five-year LC and OS were 80.9% and 87.4%, respectively. At univariate analysis, a higher LC was recorded in primary vs. recurrent tumors (p = 0.015), and in lower limb tumors vs. other sites (p = 0.027). An improved DFS was recorded in patients with lower limb tumors vs. other sites (p = 0.034).

Conclusions

The combination of BRT and EBRT was able to achieve satisfactory results even in a patients population with intermediate-high risk STS. Patients with recurrent or other than lower limb sited tumors show a worse LC.

Solitary Fibrous Tumors of Chest: Another Look with the Oncologic Perspective

Solitary fibrous tumors are mesenchymal lesions that arise at a variety of sites, most commonly the pleura. Most patients are asymptomatic at diagnosis, with lesions being detected incidentally. Nevertheless, some patients present due to symptoms from local tumor compression (eg. of the airways and pulmonary parenchyma). Furthermore, radiological methods are not always conclusive in making a diagnosis, and thus, pathological analysis is often required. In the past three decades, immunohistochemical techniques have provided a gold standard in solitary fibrous tumor diagnosis. The signature marker of solitary fibrous tumor is the presence of the NAB2-STAT6 fusion that can be reliably detected with a STAT6 antibody. While solitary fibrous tumors are most often benign, they can be malignant in 10-20% of the cases. Unfortunately, histological parameters are not always predictive of benign vs malignant solitary fibrous tumors. As solitary fibrous tumors are generally regarded as relatively chemoresistant tumors; treatment is often limited to localized treatment modalities. The optimal treatment of solitary fibrous tumors appears to be complete surgical resection for both primary and local recurrent disease. However, in cases of suboptimal resection, large disease burden, or advanced recurrence, a multidisciplinary approach may be preferable. Specifically, radiotherapy for inoperable local disease can provide palliation/shrinkage. Given their sometimes -unpredictable and often- protracted clinical course, long-term follow-up post-resection is recommended.

[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.

Is grid therapy useful for all tumors and every grid block design?

Grid therapy is a treatment technique that has been introduced for patients with advanced bulky tumors. The purpose of this study is to investigate the effect of the radiation sensitivity of the tumors and the design of the grid blocks on the clinical response of grid therapy. The Monte Carlo simulation technique is used to determine the dose distribution through a grid block that was used for a Varian 2100C linear accelerator. From the simulated dose profiles, the therapeutic ratio (TR) and the equivalent uniform dose (EUD) for different types of tumors with respect to their radiation sensitivities were calculated. These calculations were performed using the linear quadratic (LQ) and the Hug-Kellerer (H-K) models. The results of these calculations have been validated by comparison with the clinical responses of 232 patients from different publications, who were treated with grid therapy. These published results for different tumor types were used to examine the correlation between tumor radiosensitivity and the clinical response of grid therapy. Moreover, the influence of grid design on their clinical responses was investigated by using Monte Carlo simulations of grid blocks with different hole diameters and different center-to-center spacing. The results of the theoretical models and clinical data indicated higher clinical responses for the grid therapy on the patients with more radioresistant tumors. The differences between TR values for radioresistant cells and radiosensitive cells at 20 Gy and 10 Gy doses were up to 50% and 30%, respectively. Interestingly, the differences between the TR values with LQ model and H-K model were less than 4%. Moreover, the results from the Monte Carlo studies showed that grid blocks with a hole diameters of 1.0 cm and 1.25 cm may lead to about 19% higher TR relative to the grids with hole diameters smaller than 1.0 cm or larger than 1.25 cm (with 95% confidence interval). In sum-mary, the results of this study indicate that grid therapy is more effective for tumors with radioresistant characteristics than radiosensitive tumors.

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

Excellent local control and survival after postoperative or definitive radiation therapy for sarcomas of the head and neck

BACKGROUND

To report our results with postoperative or definitive radiation therapy in head and neck sarcomas.

METHODS

We performed a retrospective analysis of 26 patients suffering from head and neck sarcomas, who received postoperative or definitive radiation therapy between 2003 and 2012. Median age was 64 years (19-88) and 69 % were male. Tumor locations were skull (including skin) in 31 %, paranasal sinus/orbita in 27 % and neck (including pharynx/larynx) in 42 %. Median tumor size was 4.6 cm (1-12 cm). 22 patients (85 %) presented in primary situation. Stage at presentation (UICC 7(th) for soft tissue sarcomas) was as follows: Ia:4 %, IIa:50 %, IIb:15 %, III:31 %. All except one patient suffered from high grade lesions (G2/3 FNCLCC), predominantly angiosarcoma (35 %), MFH (19 %) and synovial sarcoma (15 %). Surgery was performed in 21 pts (81 %), resulting in free margins in 10 (38 %), microscopically positive margins in 6 (23 %) and gross residual disease in 5 (19 %). Median dose to the primary tumor region was 66Gy (45-72Gy) in conventional fractionation, using 3D-CRT in 65 %, IMRT in 27 % and electrons in 8 %. 50 % of the patients also received sequential chemotherapy.

RESULTS

Median follow up was 39 months (8-136). We observed three local recurrences, transferring into estimated 3- and 5-year local control rates of 86 %. One additional patient failed distantly, resulting in 3- and 5-year freedom from treatment failure rates of 82 %. Four patients have deceased, transferring into 3- and 5-year overall survival rates of 88 % and 82 %, respectively. Only two of the four deaths were sarcoma related. Maximum acute toxicity (CTCAE 3.0) was grade 1 in 27 % of the patients, grade 2 in 50 % and grade 3 in 23 %. Severe acute toxicity was mainly represented by mucositis and dysphagia. Maximum late toxicity was grade 1 in 31 %, grade 2 in 15 % and grade 3 in 19 % of the patients. Severe late toxicity included skin ulceration (n = 1), dysphagia with persistent tube dependency (n = 1), persistent sinusitis (n = 1) and hearing loss (n = 2).

CONCLUSION

Excellent local control and overall survival rates can be achieved with postoperative or definitive radiation therapy with acceptable acute and late toxicities in patients suffering from sarcomas of the head and neck region.

Carbon Ion irradiation in the treatment of grossly incomplete or unresectable malignant peripheral nerve sheaths tumors: acute toxicity and preliminary outcome

Background

To report our early experience with carbon ion irradiation in the treatment of gross residual or unresectable malignant peripheral nerve sheath tumors (MPNST).

Methods

We retrospectively analysed 11 patients (pts) with MPNST, who have been treated with carbon ion irradiation (C12) at our institution between 2010 and 2013. All pts had measurable gross disease at the initiation of radiation treatment. Median age was 47 years (29-79). Tumors were mainly located in the pelvic/sacral (5 pts) and sinunasal/orbital region (5 pts). 5 pts presented already in recurrent situation, 3 pts had been previously irradiated, and in 3 pts MPNST were neurofibromatosis type 1 (NF1) associated. Median cumulative dose was 60 GyE. Treatment was carried out either as a combination of IMRT plus C12 boost (4 pts) or C12 only (7 pts).

Results

Median follow-up was 17 months (3-31 months). We observed 3 local progressions, translating into estimated 1- and 2-year local control rates of 65%. One patient developed distant failure, resulting in estimated 1- and 2-year PFS rates of 56%. Two patients have died, therefore the estimated 1- and 2-year OS rates are 75%. Acute radiation related toxicities were generally mild, no grade 3 side effects were observed. Severe late toxicity (grade 3) was scored in 2 patients (trismus, wound healing delays).

Conclusion

Carbon ion irradiation yields very promising short term local control and overall survival rates with low morbidity in patients suffering from gross residual or unresectable malignant peripheral nerve sheath tumors and should be further investigated in a prospective trial.

External beam radiation therapy for orthopaedic pathology

External beam radiation therapy is essential in the management of a wide spectrum of musculoskeletal conditions, both benign and malignant, including bony and soft-tissue sarcomas, metastatic tumors, pigmented villonodular synovitis, and heterotopic ossification. Radiation therapy, in combination with surgery, helps reduce the functional loss from cancer resections. Although the field of radiation therapy is firmly rooted in physics and radiation biology, its indications and delivery methods are rapidly evolving. External beam radiation therapy mainly comes in the form of four sources of radiotherapy: protons, photons, electrons, and neutrons. Each type of energy has a unique role in treating various pathologies; however, these energy types also have their own distinctive limitations and morbidities.

Radiation therapy in management of sporadic and neurofibromatosis type 1-associated malignant peripheral nerve sheath tumors

INTRODUCTION

Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft tissue sarcomas in which complete surgical resection is the mainstay of therapy. However, the recurrence rate is high and few options remain for refractory or metastatic MPNST. This study examines the outcomes of adjuvant radiation therapy in MPNST in patients with and without neurofibromatosis type 1 (NF1) and reviews the literature on use of radiation for MPNST.

METHODS

A retrospective review of 33 MPNST patients between 1990 and 2012 evaluated at the NIH. All diagnoses were pathologically confirmed at the NCI. Clinical presentation, treatment, and survival were analyzed.

RESULTS

Thirty-three patients were included 18 NF1-associated, 15 sporadic tumors. Tumor location included extremity (58%), trunk (36%), and head/neck (6%). Histologic grade showed 25 high-grade tumors compared to 7 low-grade tumors. Twenty patients were treated with radiation therapy (median total dose of 58.5 Gy with 1.8 Gy/fraction). A median survival of all patients was 46.5 months and 43.7% overall 5-year survival. Prognostic factors include extent of resection, tumor location, and histology grade. Radiation was not found to be a prognostic factor for overall survival.

CONCLUSION

This study is consistent with previous studies regarding the role of radiation in the management of MPNST. Prospective evaluation of adjuvant radiation will allow to more fully define the role of radiation in MPNST.

Interobserver variability of clinical target volume delineation in soft-tissue sarcomas

PURPOSE

The present observational study reports the results of a multi-institutional dummy-run designed to estimate the consistency of interobserver variability in clinical target volume delineation in two different cases of soft-tissue sarcomas in which postoperative and preoperative radiotherapy were prescribed, respectively. The purpose of this work was to quantify interobserver variability in routine clinical practice.

PATIENTS AND METHODS

Two different cases of soft-tissues sarcomas were chosen: a case of postoperative and a case of preoperative radiation therapy. Participating centres were requested to delineate clinical target volumes according to their experience in both cases. Descriptive statistic was calculated for each variable (volume, diameters) separately for two cases. Box-whiskers plots were used for presentation of clinical target volume. A Shapiro-Wilk's test was performed to evaluate the departures from normality distribution for each variable. The comparison between relative variations of diameters was evaluated using the Student's t test.

RESULTS

Several variations affecting both volumes and diameters were observed. Main variations were observed in the craniocaudal and laterolateral diameters. Each case showed similar dispersion, indicating a lack of reproducibility in volumes definition.

CONCLUSIONS

This observational study highlighted that, in the absence of specific instructions or guidelines, the interobserver variability can be significant both in postoperative and preoperative radiotherapy of soft-tissue sarcomas.

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.

Long-term clinical outcome of patients with soft tissue sarcomas treated with limb-sparing surgery and postoperative radiotherapy

BACKGROUND

To evaluate long-term local control, survival, radiation side effects and functional outcome after limb-sparing surgery followed by postoperative radiotherapy (RT) for soft tissue sarcoma (STS).

MATERIAL AND METHODS

Between 1995 and 2010, 118 patients with STS of an extremity were treated with limb-sparing surgery and postoperative RT. Follow-up was complete for all patients. Acute and late radiation related toxicities were scored using CTCAE v4.0.

RESULTS

Median follow-up was 93 months. RT dose was 60 Gy in 92.4% of the patients; 5.1% received 66 Gy; 2.5% 50-56 Gy. Actuarial local recurrence rates at five and 10 years were 9% and 12%. Five- and 10-year overall survival rates were 69% and 51%. Acute radiation toxicities occurred in 91% of the patients; 19% were grade 3, 2% grade 4. Late radiation toxicities were reported in 71% of the patients: 50% grade 1, 18% grade 2, and 3% grade 3. Limb and joint function after treatment were good, 19% having mild limitation of motion, 1.5% moderate, and 2.5% severe limitations.

CONCLUSION

Limb-sparing surgery with 60 Gy postoperative radiotherapy for patients with STS provides excellent local control and high survival rates with acceptable toxicity and functional outcomes.

Dosimetric comparison between VMAT with different dose calculation algorithms and protons for soft-tissue sarcoma radiotherapy

BACKGROUND

To appraise the potential of volumetric modulated arc therapy (VMAT, RapidArc) and proton beams to simultaneously achieve target coverage and enhanced sparing of bone tissue in the treatment of soft-tissue sarcoma with adequate target coverage.

MATERIAL AND METHODS

Ten patients presenting with soft-tissue sarcoma of the leg were collected for the study. Dose was prescribed to 66.5 Gy in 25 fractions to the planning target volume (PTV) while significant maximum dose to the bone was constrained to 50 Gy. Plans were optimised according to the RapidArc technique with 6 MV photon beams or for intensity modulated protons. RapidArc photon plans were computed with: 1) AAA; 2) Acuros XB as dose to medium; and 3) Acuros XB as dose to water.

RESULTS

All plans acceptably met the criteria of target coverage (V95% >90-95%) and bone sparing (D(1 cm3) <50 Gy). Significantly higher PTV dose homogeneity was found for proton plans. Near-to-maximum dose to bone was similar for RapidArc and protons, while volume receiving medium/low dose levels was minimised with protons. Similar results were obtained for the remaining normal tissue. Dose distributions calculated with the dose to water option resulted ~5% higher than corresponding ones computed as dose to medium.

CONCLUSION

High plan quality was demonstrated for both VMAT and proton techniques when applied to soft-tissue sarcoma.

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.

Treatment outcome of conservative surgery plus postoperative radiotherapy for extremity soft tissue sarcoma

PURPOSE

To evaluate the treatment outcome and prognostic factor of postoperative radiotherapy for extremity soft tissue sarcoma (STS).

MATERIALS AND METHODS

Forty three patients with extremity STS were treated with conservative surgery and postoperative radiotherapy from January 1981 to December 2010 at Korea University Medical Center. Median total 60 Gy (range, 50 to 74.4 Gy) of radiation was delivered and 7 patients were treated with chemotherapy.

RESULTS

The median follow-up period was 70 months (range, 5 to 302 months). Twelve patients (27.9%) sustained relapse of their disease. Local recurrence occurred in 3 patients (7.0%) and distant metastases developed in 10 patients (23.3%). The 5-year overall survival (OS) was 69.2% and disease free survival was 67.9%. The 5-year local relapse-free survival was 90.7% and distant relapse-free survival was 73.3%. On univariate analysis, no significant prognostic factors were associated with development of local recurrence. Histologic grade (p = 0.005) and stage (p = 0.02) influenced the development of distant metastases. Histologic grade was unique significant prognostic factor for the OS on univariate and multivariate analysis. Severe acute treatment-related complications, Common Terminology Criteria for Adverse Events (CTCAE) grade 3 or 4, developed in 6 patients (14.0%) and severe late complications in 2 patients (4.7%).

CONCLUSION

Conservative surgery with postoperative radiotherapy achieved a satisfactory rate of local control with acceptable complication rate in extremity STS. Most failures were distant metastases that correlate with tumor grade and stage. The majority of local recurrences developed within the field. Selective dose escalation of radiotherapy or development of effective systemic treatment might be considered.

Risk factors for local recurrence and metastasis in soft tissue sarcomas of the extremity

OBJECTIVES

We reviewed our institution's experience in treating soft tissue sarcomas of the extremity to identify factors associated with local recurrence, metastasis, and overall survival, to identify patients who may benefit from intensification of therapy.

METHODS

A retrospective analysis was performed for patients who underwent both limb-sparing surgery and external beam radiotherapy for extremity sarcoma. Those who had gross residual disease or who presented with recurrent or metastatic disease were excluded. The Kaplan-Meier product limit and multivariate Cox regression were used to estimate local failure-free probability, distant failure-free probability, and overall survival along with associations with patient, tumor, and treatment characteristics.

RESULTS

One hundred eighty-eight patients were included in the analysis. Twenty-five (13%) and 46 (24%) experienced local and distant recurrence, respectively. Patients with high/intermediate-grade tumors [hazard ratio (HR)=5.63, 95% confidence interval (CI): 1.27-24.89, P=0.023] or with multifocally positive margins (HR=4.27, 95% CI: 1.20-15.24, P=0.026) were more likely to fail locally. Those with a preceding local recurrence (HR=8.58, 95% CI: 3.87-19.04, P<0.0001), high/intermediate-grade tumors (HR=5.68, 95% CI: 1.28-25.25, P=0.023), or no secondary reexcision (HR=2.5, 95% CI: 1.09-5.74, P=0.031) were more likely to develop metastasis. Patients with local recurrence (HR=3.6, 95% CI: 1.77-7.29, P<0.001), metastasis (HR=16.0, 95% CI: 7.93-32.31, P<0.0001), or without secondary reexcision (HR=3.2, 95% CI: 1.27-8.09, P=0.014) had decreased overall survival.

CONCLUSIONS

Patients whose tumor grade or margin status put them at high risk for local failure should be considered for intensification of therapy. Those with a local recurrence should be considered for increased surveillance or systemic therapy, as local failure is associated with subsequent metastasis and decreased survival.

Effects of extensive circumferential periosteal stripping on the microstructure and mechanical properties of the murine femoral cortex

Extensive periosteal stripping (PS) is a risk factor for post-radiation pathologic fracture following surgery for extremity soft tissue tumors. The purpose of this study was to determine the effects of PS on bone structure and mechanical properties. Thirty-one skeletally mature mice underwent PS, with circumferential removal of periosteum from an 8-mm segment of the mid-diaphysis of the left femur. Thirty-one control mice underwent sham surgery in which the femur was isolated without manipulation of the periosteum. At 2, 6, 12, or 26 weeks following surgery, the left femora were examined by micro-CT to quantify cortical thickness (CtTh), cross-sectional area (CSA), bone volume (BV), and polar moment of inertia (PMI). Three-point mechanical bend testing was performed and peak load, stiffness, and energy to failure were determined. PS resulted in significantly decreased CtTh, CSA, BV, and PMI at all time points. Peak load, stiffness, and energy to failure were significantly reduced at 2, 6, and 12 weeks. There were no significant differences in mechanical properties at 26 weeks. In this mouse model, extensive circumferential PS resulted in sustained changes in bone structure that were still evident after 6 months, accompanied by reductions in bone strength that persisted for at least 3 months.

Incidence and Severity of Lymphoedema following Limb Salvage of Extremity Soft Tissue Sarcoma

Background and Purpose. Lymphoedema is a serious complication following limb salvage for extremity soft tissue sarcomas (STSs) for which little is known. We aimed to evaluate its incidence, its, severity and its associated risk factors. Material and Method. Patient and tumor characteristics, treatment modalities and complications and functional outcomes (MSTS 1987, TESS), and lymphoedema severity (Stern) were all collected from prospective databases. Charts were retrospectively abstracted for BMI and comorbidities. Results. There were 289 patients (158 males). Mean age was 53 (16-88). Followup ranged between 12 and 60 months with an average of 35 and a median of 36 months. Mean BMI was 27.4 (15.8-52.1). 72% had lower extremity tumors and 38% upper extremity. Mean tumor size was 8.1 cm (1.0-35.6 cm). 27% had no adjuvant radiation, 62% had 50 Gy, and 11% received 66 Gy. The incidence of lymphoedema was 28.8% (206 none, 58 mild, 22 moderate, 3 severe, and 0 very severe). Mean MSTS score was 32 (11-35) and TESS was 89.4 (32.4-100). Radiation dose was significantly correlated with tumor size > 5 cm (P = 0.0001) and TESS score (P = 0.001), but not MSTS score (P = 0.090). Only tumor size > 5 cm and depth were found to be independent predictors of significant lymphoedema. Conclusion. Nine percent of STS patients in our cohort developed significant (grade ≥ 2) lymphoedema. Tumor size > 5 cm and deep tumors were associated with an increased occurrence of lymphoedema but not radiation dosage.

Pattern of local recurrence after conservative surgery and radiotherapy for soft tissue sarcoma

Purpose: Over the past three decades our centre has adopted a policy of conservative surgery followed by adjuvant radicaldose radiotherapy for medium-and high-grade soft tissue sarcomas. For all cases of local recurrence following this treatment we aimed to define the spatial relationship between sites of recurrence and the positions of the phase 1 and 2 radiotherapy volumes.

Patients: We identified 25 cases of local recurrence recorded on our soft tissue sarcoma database between 1986 and 1999 inclusive. We excluded patients with macroscopic residual disease following surgery. Most patients were treated with a phase I volume corresponding to the entire muscle compartment (50 Gy in 25 fractions over 5 weeks) and a phase II volume corresponding to the tumour bed (10 Gy in five fractions). Six of the patients were treated according to a hyperfractionated regimen.

Methods: For each case we reviewed the diagnostic imaging, planning radiographs and prescription sheets. We audited whether treatment had been given according to protocol and defined whether recurrence had arisen in the phase 1 volume, phase 2 volume or ‘out of field’.

Results: Four (16%) patients recurred within the phase I volume, 17 (68%) recurred within the phase II volume and four (16%) outside the irradiated volume including one marginal recurrence. In six patients there had been deviation from our radiotherapy protocol (usually unavoidable) including all three true out of field recurrences.

Discussion: The majority of recurrences occur in the phase 2 volume. Prospective multi-centre data collection and, ideally, a prospective randomised trial are required to formulate an improved treatment policy with respect to radiotherapy margins and dose.

Post-Operative Radiotherapy for Soft Tissue Sarcoma of the Anterior Compartment of the Thigh: Should the Sartorius Muscle be Included?

PURPOSE

The clinical target volume (CTV) of post-operative radiotherapy for soft tissue sarcoma of the limbs conventionally includes the whole of the transverse cross-section of the affected anatomical compartment. In the anterior thigh sartorius appears to lie within its own fascial compartment and can be safely excluded. We investigated the potential impact of omitting sartorius from the anterior muscle compartment on patients with soft tissue sarcoma of the thigh.

PATIENTS AND METHODS

We used the planning CT data from six patients who had previously received post-operative radiotherapy for soft tissue sarcoma of the thigh. The anterior compartments were outlined twice, initially including and then excluding the sartorius muscle. The volumes of the anterior compartment (i.e., the CTVs), both with and without sartorius, and the corresponding planning target volumes (PTVs) were calculated. Treatment plans were prepared for each PTV. For both volumes the unirradiated normal tissue corridor was outlined on each CT slice. The volume and circumference of the unirradiated corridor were then calculated.

RESULTS

For all six patients there was an important improvement in normal tissue sparing by excluding sartorius. The mean reduction in volume of the anterior compartment when sartorius was excluded was 10% (95% Confidence Interval 8-12%), whilst the mean decrease in PTV was 11% (95% CI 7-14%). There was a substantial increase in the volume of the unirradiated normal tissue corridor, with a mean value of 77% (95% CI 41-114%) when sartorius was excluded. In addition, the percentage increase in the size of the unirradiated normal tissue corridor, expressed as a percentage of the whole leg circumference, was 10% (95% CI 8-13%). When sartorius was included in the anterior compartment, the circumference of the unirradiated corridor was less than one-third of the whole leg circumference in four of the six patients. When sartorius was excluded, the circumference of the unirradiated corridor was greater than one-third of the leg circumference over the entire length of the target volume in all patients.

DISCUSSION

It is essential to know the anatomy of the sartorius muscle to be able to exclude it from the anterior compartment. The increase in the size of the normal tissue corridor when sartorius is excluded should deliver clinical advantage by decreasing the normal tissue adverse effects.