Comparison of conventional radiotherapy and intensity-modulated radiotherapy for post-operative radiotherapy for primary extremity soft tissue sarcoma

The IMRiS Trial: A Phase 2 Study of Intensity Modulated Radiation Therapy in Extremity Soft Tissue Sarcoma

PURPOSE

Primary soft tissue sarcoma (STS) is rare, with many tumors occurring in extremities. Local management is limb-sparing surgery and preoperative/postoperative radiation therapy (RT) for patients at high risk of local recurrence. We prospectively investigated late normal tissue toxicity and limb function observed after intensity modulated RT (IMRT) in extremity STS.

METHODS AND MATERIALS

Patients with extremity STS, age ≥16 years. Two treatment cohorts: IMRT 50 Gy in 25 × 2 Gy fractions (preoperative) or 60/66 Gy in 30/33 × 2 Gy fractions (postoperative). The primary endpoint was the rate of grade ≥2 late soft tissue fibrosis (subcutaneous tissue) at 24 months after IMRT (Radiation Therapy Oncology Group late radiation morbidity scoring).

RESULTS

One hundred sixty-eight patients were registered between March 2016 and July 2017. Of those, 159 (95%) received IMRT (106, 67% preoperative RT; and 53, 33% postoperative RT) with a median follow-up of 35.2 months (IQR, 32.9-36.6); 62% men, median age 58 years. Of 111 patients assessable for the primary endpoint at 24 months, 12 (10.8%; 95% CI, 5.7%-18.1%) had grade ≥2 subcutaneous fibrosis. The overall rate at 24 months of Radiation Therapy Oncology Group late skin, bone, and joint toxicity was 7 of 112 (6.3%), 3 of 112 (2.7%), and 10 of 113 (8.8%), respectively, and for Stern's scale edema was 6 of 113 (5.3%). More wound complications were observed with preoperative than postoperative RT (29.2% vs 3.8%). Overall survival at 24 months was 84.6%, and the local recurrence event rate at 24 months was 10%.

CONCLUSIONS

The rate of grade ≥2 subcutaneous fibrosis at 24 months after IMRT was 10.8%, consistent with other recent trials of IMRT and lower than historically reported rates in patients treated with 3-dimensional conformal RT. This trial provides further evidence for the benefits of IMRT in this patient population.

Complications and Risk Factors in Patients with Soft Tissue Sarcoma of the Extremities Treated with Radiotherapy

INTRODUCTION

Soft tissue sarcomas of the extremities (ESTSs) pose significant challenges in treatment and management due to their diverse nature and potential complications. This study aimed to assess complications associated with multimodal treatments involving surgery and radiotherapy (RT) and to identify potential risk factors.

METHODS

We retrospectively analyzed nonmetastatic ESTS patients treated with surgery and pre- or post-operative RT between 2007 and 2020 in Strasbourg, France. Complications, including wound complications (WCs), lymphedema, acute and chronic RT-related complications, and fractures, were meticulously evaluated.

RESULTS

A total of 169 patients diagnosed with localized ESTSs were included, with a median age of 64 years (range 21-94 years). ESTSs primarily occurred proximally (74.6%) and in the lower limbs (71%). The median follow-up was 5.5 years. WCs occurred in 22.5% of patients, with proximal and lower extremity tumors being significant risk factors. Acute RT-related complications included radiodermatitis, with grade ≥ 2 occurring in 43.1% of patients, which was associated with superficial tumors. Three patients had an edema grade ≥ 2. Chronic complications included telangiectasias (21.7%) and fibrosis (38.7%), with higher rates associated with larger PTVs and higher RT doses, respectively. Fractures occurred in 5 patients, mainly in the tibia (40%).

CONCLUSIONS

Multimodal treatment of ESTSs demonstrated excellent tolerance, with manageable side effects. Numerous risk factors have been highlighted, providing insights for optimizing treatment strategies and enhancing patient care in this rare disease.

Novel Postoperative Hypofractionated Accelerated Radiation Dose-Painting Approach for Soft Tissue Sarcoma

Purpose

Hypofractionated radiation therapy (RT) offers benefits in the treatment of soft tissue sarcomas (STS), including exploitation of the lower α/β, patient convenience, and cost. This study evaluates the acute toxicity of a hypofractionated accelerated RT dose-painting (HARD) approach for postoperative treatment of STS.

Methods and Materials

This is a retrospective review of 53 consecutive patients with STS who underwent resection followed by postoperative RT. Standard postoperative RT dosing for R0/R1/gross disease with sequential boost (50 Gy + 14/16/20 Gy in 32-35 fractions) were replaced with dose-painting, which adapts dose based on risk of disease burden, to 50.4 and 63, 64.4, 70 Gy in 28 fractions, respectively. The first 10 patients were replanned with a sequential boost RT approach and dosimetric indices were compared. Time-to-event outcomes, including local control, regional control, distant control, and overall survival, were estimated with Kaplan-Meier analysis.

Results

Median follow-up was 25.2 months. Most patients had high-grade (59%) STS of the extremity (63%) who underwent resection with either R1 (40%) or close (36%) margins. Four patients experienced grade 3 acute dermatitis which resolved by the 3-month follow-up visit. The 2-year local control, regional control, distant control, and overall survival were 100%, 92%, 68%, and 86%, respectively. Compared with the sequential boost plan, HARD had a significantly lower field size (total V50 Gy; P = .002), bone V50 (P = .031), and maximum skin dose (P = .008). Overall treatment time was decreased by 4 to 7 fractions, which translated to a decrease in estimated average treatment cost of $3056 (range, $2651-$4335; P < .001).

Conclusions

In addition to benefits in cost, convenience, and improved biologic effect in STS, HARD regimen offers a safe treatment approach with dosimetric advantages compared with conventional sequential boost, which may translate to improved long-term toxicity.

Longitudinal Costs of Image-Guided Intensity-Modulated Radiation Therapy Versus Three-Dimensional Conformal Radiation: Lessons From Phase III PARCER Trial for Shaping Resource-Stratified Guidelines in Low- and Middle-Income Countries

PURPOSE

The PARCER trial provided level I evidence for image-guided intensity-modulated radiation therapy (IG-IMRT) in patients with cervical cancer. Further information regarding long-term financial impact is imperative for adoption into the National Cancer Grid of India cervical cancer resource-stratified guidelines.

METHODS

Patient data from the PARCER trial were analyzed to evaluate the cost implications of transitioning to IG-IMRT. Lacking differences in outcomes between the three-dimensional conformal radiation (3D-CRT) and IG-IMRT, differences in treatment costs, adverse event incidence, and toxicity management costs were examined. The overall financial impact was estimated by adding the treatment costs, toxicity management, and wage loss. This was extrapolated nationally to determine if a transition to IG-IMRT would be feasible for the Indian health care system.

RESULTS

Of the 300 patients in the PARCER trial, 93 faced grades ≥2 adverse events (3D-CRT = 59, IG-IMRT = 34). Patients in the 3D-CRT and IG-IMRT arms spent an average of 2.39 years and 1.96 years in toxicity, respectively. The average toxicity management and the yearly financial impact per patient were, respectively, 1.50 and 1.44 times higher for 3D-CRT patients compared with IG-IMRT patients. Extrapolation to the national level showed that treatment with 3D-CRT led to a 2.88 times higher cost ratio when compared with treatment with IG-IMRT.

CONCLUSION

Although the initial costs of IG-IMRT are high, on the basis of longitudinal data, it is financially inefficient to treat with 3D-CRT. Resource-stratified guidelines should include longitudinal health intervention costs rather than solely initial costs for policy decisions to implement advanced radiation technology.

Prognostic Factors in Extremity Soft Tissue Sarcomas Treated with Radiotherapy: Systematic Review of the Literature

Soft tissue sarcomas of the extremities are rare tumors with various prognostic factors. Their management is debatable due to their inconsistent results within the literature and the lack of large prospective studies. The objective of this systematic review is to analyze the available scientific data on prognostic factors concerning the characteristics of the patients, the disease and the treatments performed, as well as their potential complications, on studies with a median follow-up of 5 years at minimum. A search of articles following the "PRISMA method" and using the PubMed search engine was conducted to select the most relevant studies. Twenty-five articles were selected, according to preestablished criteria. This review provides a better understanding of the prognosis and disease outcome of these tumors. Many factors were described comparing the frequency of occurrence according to the studies, which remain heterogeneous between them. Significant factors that could orient patients to radiotherapy were highlighted. These positive prognostic factors provide valuable insight to optimize radiotherapy treatments for patients treated for soft tissue sarcoma of the extremities.

Toxicity, normal tissue and dose-volume planning parameters for radiotherapy in soft tissue sarcoma of the extremities: A systematic review of the literature

BACKGROUND

Patients with soft tissue sarcoma of the extremities (STSE) are left with high incidence of toxicities after Radiotherapy (RT). Understanding the normal tissue dose relationship with the development of long-term toxicities may enable better RT planning in order to reduce treatment toxicities for STSE. This systematic review of the literature aims at reporting the incidence of acute and late toxicities and identifying RT delineation guidance the normal tissues structures and dose-volume parameters for STSE.

METHODS

A literature search of PUBMED-MEDLINE for studies that reported data on RT toxicity outcomes, delineation guidelines and dose-volume parameters for STSE from 2000 to 2022. Data has been tabulated and reported.

RESULTS

Thirty of 586 papers were selected after exclusion criteria. External beam RT prescriptions ranged from 30 to 72 Gy. The majority of studies reported the use of Intensity Modulated RT (IMRT) (27%). Neo-adjuvant RT was used in 40%. The highest long-term toxicities were subcutaneous and lymphoedema, reported when delivering 3DCRT. IMRT had a lower incidence of toxicities. Normal tissue outlining such as weight-bearing bones, skin and subcutaneous tissue, corridor and neurovascular bundle was recommended in 6 studies. Nine studies recommended the use of dose-volume constraints, but only one recommended evidence-based dose-volume constraints.

CONCLUSION

Although the literature is replete with toxicity reports, there is a lack of evidence-based guidance on normal tissue and dose-volume parameters and strategies to reduce the normal tissues irradiation when optimising RT plans for STSE are poor compared to other tumour sites.

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.

Combining a Customized Immobilization System with an Innovative Use of the ExacTrac System for Precise Volumetric Modulated Arc Therapy of Challenging Forearm Sarcomas

High-precision image-guided radiation therapy (RT) for tumors abutting the appendicular skeleton may mean technical difficulties and concerns among practitioners. This technical note addresses the specific challenge for normofractionated image-guided RT of a tumor target in a forearm through an unconventional use of a treatment verification system usually devoted to stereotactic RT.

Low rate of function-limiting side effects with high-dose adjuvant radiotherapy in high-grade soft tissue extremity sarcomas: a retrospective single-center analysis over 10 years

Background

Over the years, radiotherapy has been established as a tool to improve local control for high-grade sarcomas. Although the European Society for Medical Oncology guidelines has taken notice of a shift toward a neoadjuvant radiotherapy approach, the American Society for Radiation Oncology guidelines clearly favor a neoadjuvant approach, citing debilitating long-term adverse effects when radiotherapy is applied postoperatively. In this study, we examined these irradiation-associated adverse events for adjuvant radiotherapy and focused on the prognostic factors for disease outcome, including local control.

Methods

In this retrospective study, data for 106 patients with extremity soft-tissue sarcomas diagnosed between 1997 and 2021, of which 40 received adjuvant radiotherapy, were collected from the clinical and radiological information systems of a high-volume sarcoma treatment center. These data were then analyzed for radiation-associated side effects as well as predictive factors for overall survival, disease-free survival, local control, and surgical complications.

Results

Radiotherapy was beneficial to patients improving local control, especially for high-grade sarcomas, even when those were resected with negative margins. Side effects due to radiotherapy occurred in 87.5% of the patients, and these effects primarily included radiation dermatitis in 67.5%; however, only 40.0% had any adverse event of ≥ grade 2 according to Common Terminology Criteria for Adverse Events. Long-term function-limiting side effects occurred in 45.0% of the patients; 10% exhibited ≥ grade 2 function-limiting adverse events. Greater time between surgery and adjuvant radiotherapy was beneficial for the patients, whereas joint infiltrating sarcomas were associated with more severe long term, function-limiting adverse events. 28.3% of the patients experienced a recurrence at any location (median time 18.35 months) and in 16% the recurrence was local (median time 16.11 months), resulting in 1, 3, and 5 year disease-free survival rates of 74.1, 58.9, and 38.5% and local control rates of 78.7, 61.6, and 42.8% were observed, respectively.

Conclusion

Recurrences may be avoided with high-dose radiation, especially for high-grade G2 and G3 sarcomas, even after complete R0 resection. This resulted in a low rate of severe long-term function-limiting adverse events. Thus, adjuvant radiotherapy should be seriously considered when planning patient treatment, especially when treating patients that present with high-grade sarcomas.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-022-04423-1.

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.

IMRiS phase II study of IMRT in limb sarcomas: Results of the pre-trial QA facility questionnaire and workshop

INTRODUCTION

Soft tissue sarcomas of the extremities (STSE) are rare malignancies. We report current UK practice for immobilisation of soft tissue sarcoma of STSE, as part of the initial study set-up within the IMRiS trial, a phase II study of intensity modulated radiotherapy (IMRT) in primary bone and soft tissue sarcoma.

METHODS

A facility questionnaire (FQ) was circulated to 29 IMRiS centres investigating the variation in immobilisation devices, planning techniques, and imaging protocols. A workshop was held to address concerns raised by centres. It focused on STSE immobilisation and patient set-up. Robustness of patient set-up at each centre was evaluated based on the following criteria: evidence of local set-up audit, calculation of margins based on set-up audit results, imaging frequency, and number of patients treated per centre per annum.

RESULTS

Twenty-seven (93%) questionnaires were returned. 30% (8/27) of responders routinely treated STSE with IMRT. The remaining 70% (19/27) had little or no experience with IMRT for STSE. Vacuum bags were the most frequent immobilisation device (9/27), followed by thermoplastic shells (7/27). Nine centres had audited their local set-up; however, only 4 had calculated margins in response to the results. Ten centres were classified as having high level of robustness.

CONCLUSIONS

Immobilisation devices and planning techniques for STSE are inconsistent across centres. Robustness of set-up is an important tool to ensure quality of results in a multicentre trial setting with such different levels of experience. The IMRiS trial Quality Assurance programme encourages centres to assess robustness of set-up through local audit and subsequent calculation of treatment margins.

IMPLICATIONS FOR PRACTICE

This is the first study that used robustness criteria to tailor QA support to individual centres.

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.

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.

Neoadjuvant image-guided helical intensity modulated radiotherapy of extremity sarcomas - a single center experience

Background

Advanced radiotherapy (RT) techniques allow normal tissue to be spared in patients with extremity soft tissue sarcoma (STS). This work aims to evaluate toxicity and outcome after neoadjuvant image-guided radiotherapy (IGRT) as helical intensity modulated radiotherapy (IMRT) with reduced margins based on MRI-based target definition in patients with STS.

Methods

Between 2010 to 2014, 41 patients with extremity STS were treated with IGRT delivered as helical IMRT on a tomotherapy machine. The tumor site was in the upper extremity in 6 patients (15%) and lower extremity in 35 patients (85%). Reduced margins of 2.5 cm in longitudinal direction and 1.0 cm in axial direction were used to expand the MRI-defined gross tumor volume, including peritumoral edema, to the clinical target volume. An additional margin of 5 mm was added to receive the planning target volume. The full total dose of 50 Gy in 2 Gy fractions was sucessfully applied in 40 patients. Two patients received chemotherapy instead of surgery due to systemic progression. All patients were included into a strict follow-up program and were seen interdisciplinarily by the Departments of Orthopaedic Surgery and Radiation Oncology.

Results

Thirty eight patients that received total RT total dose and subsequent resection were analyzed for outcome. After a median follow-up of 38.5 months cumulative OS, local PFS and systemic PFS at 2 years were determined at 78.2, 85.2 and 54.5%, respectively. Two of 6 local recurrences were proximal marginal misses. Negative resection margins were achieved in 84% of patients. The rate of major wound complications was comparable to previous IMRT studies with 36.8%. RT was overall tolerable with low toxicity rates.

Conclusions

IMRT-IGRT offers neoadjuvant treatment for extremity STS with reduced safety margins and thus low toxicity rates. Wound complication rates were comparable to previously reported frequencies. Two reported marginal misses suggest a word of caution for reduction of longitudinal safety margins.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1207-2) contains supplementary material, which is available to authorized users.

Clinical outcomes of limb salvage surgery with postoperative intensity-modulated radiation therapy for soft-tissue sarcoma and metastasis

OBJECTIVE

The primary aim of intensity-modulated radiation therapy (IMRT) for treating soft tissue sarcoma of an extremity is the reduction of morbidity and maintenance of local control.

METHODS

We evaluated the outcomes and toxicity of adjuvant IMRT following function-preserving surgery to treat patients with soft tissue sarcoma and metastasis of the extremities. We retrospectively reviewed prospective databases at Kure Medical Center and Aichi Medical University between 2013 and 2016 and identified 10 patients with lower extremity soft tissue sarcoma who underwent both limb-sparing surgery and postoperative IMRT at one of our institutions.

RESULTS

There were 7 men and 3 women (mean age, 67.2 years; range, 48-87 years) included in the study. Of these, four patients were continuously disease-free, two showed no evidence of disease, and four died due to disease. The average functional score was 82% (range, 53-100%). Among the 10 patients, 2 (22%) had grade 1-2 edema and 1 (11%) had grade 2 joint stiffness. Another patient developed grade 2 acute dermatitis. There were no severe complications such as infection, tissue necrosis, fracture, or nerve palsy.

CONCLUSION

Although the number of patients in this study was small, our results show that adjuvant IMRT following function-preserving surgery for soft tissue sarcoma of the extremity can be valuable for treating unmanageable tumors.

Global Health Perspective in Sarcomas and Other Rare Cancers

Sarcomas, rare and heterogenous malignancies that comprise less than 1% of all cancers, have poor outcomes in the metastatic and refractory setting. Their management requires a multidisciplinary approach that consists of medical and surgical oncologists, radiation oncologists, and pathologists as well as ancillary support. In addition to systemic treatments, most patients will require surgical resection and radiation therapy, which mandates the use of the latest technologies and specialized expertise. Management guidelines have been developed in high-income countries, but their applicability in low-income countries, where resources may be limited, remains a challenge. In this article, we propose the best possible evidence-based practices specifically for income-constrained settings to overcome this challenge. In addition, we review the different methods that can be used in low-income countries to access new and expensive treatments, which often times carry prohibitive costs for these areas.

A retrospective cohort study to assess adjuvant concurrent chemoradiation (CCRT) compared to adjuvant radiation therapy (RT) in the treatment of grade 2 and 3 extremity soft tissue sarcomas

PURPOSE

To evaluate the efficacy and tolerance of adjuvant concurrent chemoradiation (CCRT) as treatment of grade 2 and 3 (G2-3) localized extremity soft tissue sarcomas (STS) by comparing CCRT with standard adjuvant radiation therapy (RT).

PATIENTS AND METHODS

This monocentric retrospective study included non-pediatric patients (>16years) treated by adjuvant RT with or without chemotherapy (CT) after conservative resection of non-recurrent G2-3 extremity STS.

RESULTS

A total of 80 patients were treated between 1990 and 2012: 51 by RT and 29 by CCRT. Of the 29 CCRT patients, 25 received doxorubicin monotherapy (75mg/m²/3weeks). The CCRT group contained a greater proportion of grade 3 extremity STS (p<0.001). Median follow up was 68months (9-284). Multivariate analysis revealed greater local control in the CCRT group (1 local recurrence vs 8 in the RT group; HR=0.082, 95% CI 0.011-0.321) and incomplete resection as the major risk factor of local recurrence (HR=25.2, 95% CI 4.767-133.226). The two groups exhibited no differences in distant failure-free survival (HR=1.469, 95% CI 0.668-3.228), disease-free survival (HR=1.096, 95% CI 0.519-2.315) or overall survival (HR=1.378, 95% CI 0.498-3.814). Grade 3 was an adverse prognostic factor for overall survival (HR=3.11, 95% CI 1.04-9.32). Our analyses also revealed that CCRT tended to increase the risk of both grade ≥3 acute dermatitis (14 events vs 6 in the RT group; OR=6.99, 95% CI 2.28-21.47) and grade ≥2 late toxicity (6 events vs 3 in the RT group; p=0.0572).

CONCLUSION

CCRT could improve local control as part of a limb-preservation strategy. However, with a limited number of patients, CCRT showed no improvement in either distant control or survival and increased toxicity.

Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial soft tissue sarcoma. Its rarity precludes large prospective studies. Clinical diagnosis requires an high index of suspicion. Effective management requires an appreciation of tumor biology and the nature of the characteristic infiltrative growth pattern. DFSP tends to recur locally, with a low risk of dissemination. Aggressive surgical resection with widely negative margins is essential to management. Radiotherapy may be indicated in special circumstances. Understanding the molecular pathogenesis has resulted in use of tyrosine kinase inhibitor therapy for patients with locally advanced disease or in metastatic disease. DFSP patients require long-term follow-up.

[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.

Dosimetric comparison of 3-dimensional conformal radiation therapy and intensity modulated radiation therapy and impact of setup errors in lower limb sarcoma radiation therapy

PURPOSE

This study compared dosimetric data between 3-dimensional conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT) plans in a population of patients with lower limb sarcoma immobilized with an in-house device and quantified the impact of systematic and random errors on these techniques. The dosimetric effects of displacements on target coverage and organs at risk (OARs) were considered.

METHODS AND MATERIALS

Plans were created for 11 postoperative patients using both 3DCRT and IMRT. The techniques were compared dosimetrically. Population-based systematic and random errors were applied and the results compared with the initial plans.

RESULTS

Higher target D95, D2, D98, and D50 and the best homogeneity index resulted with IMRT compared with 3DCRT. Systematic errors increased target D2 in IMRT. Random errors decreased target homogeneity in IMRT. Maximum bone dose was higher in IMRT than in 3DCRT. Neither error type increased OAR dose for either technique.

CONCLUSIONS

IMRT could become the favored lower limb sarcoma radiation therapy technique because of superior target coverage and homogeneity. Offline imaging can adequately correct for systematic errors in these patients when an in-house immobilization device is used.

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

Postoperative intensity-modulated radiation therapy provides favorable local control and low toxicities in patients with soft tissue sarcomas in the extremities and trunk wall

Purpose

To investigate the efficacy and toxicity of postoperative intensity-modulated radiation therapy (IMRT) for patients with soft tissue sarcomas (STSs) in the extremities and trunk wall.

Patients and methods

Eighty patients with localized STSs in the extremities and trunk wall treated with function-conserving surgery and postoperative IMRT were analyzed. The primary locations were in the extremities in 51 patients and in the trunk wall in 29 patients. The margins were positive in nine patients and negative in 71 patients. The median dose of IMRT was 64 Gy.

Results

At a median follow-up time of 38 months, eight patients developed local recurrences. The 5-year local control (LC) rate was 88.1%. The patients with negative margins exhibited much better LC than did those with positive margins (90% vs 64.8%, P=0.023). Multivariate analysis revealed that positive margin was an independent risk factor for LC. The 5-year distant metastasis-free survival, disease-free survival, and overall survival rates were 75.2%, 72.6%, and 83.6%, respectively. Large tumor size (>5 cm) was significantly associated with poor overall survival. Edema and joint stiffness were observed in 17.6% and 9.8% of patients with extremity STSs, respectively.

Conclusion

IMRT provides excellent LC and low toxicity for patients with STSs in the extremities and trunk wall.

The optimal tomotherapy treatment planning parameters for extremity soft tissue sarcomas

BACKGROUND AND PURPOSE

To determine the optimum combination of treatment parameters between pitch, field width (FW) and modulation factor (MF) for extremity sarcomas in tomotherapy.

MATERIALS AND METHODS

Six patients previously treated for extremity sarcomas (3 arms and 3 legs) with tomotherapy were included in this study. 288 treatment plans were recalculated, corresponding to all combinations between 2 FW (2.5 and 5 cm), 4 MF (1.5, 2, 2.5 and 3) and 6 pitches (0.215, 0.287, 0.43 and 3 off-axis pitches). The treatment parameters (MF, FW or pitch) are modified between each plan, and the calculation is relaunched for 400 iterations, without modifying the optimisation constraints of the plan under which the patient has been treated.

RESULTS

We suggest eliminating the 0.43 pitch and never combining a 0.215 pitch with an MF ≤ 2. We also do not recommend using an MF = 1.5 unless treatment time is an absolute priority over plan quality. We did not see any advantage in using Chen off-axis pitches, except for targets far from the axis (>15 cm) treated with a high pitch. A combination of MF = 2/FW = 5 cm/pitch = 0.287 gives plans of acceptable quality, combined with reduced treatment times. These conclusions are true only for extremity sarcomas treated in 2 Gy/fraction.

CONCLUSIONS

We have shown that the choice of pitch/MF/FW combination is crucial for the treatment of extremity sarcomas in tomotherapy: some produce good dosimetric quality with a reduced irradiation time, while others may increase the time without improving the quality.

Dosimetric feasibility of magnetic resonance imaging-guided tri-cobalt 60 preoperative intensity modulated radiation therapy for soft tissue sarcomas of the extremity

PURPOSE

The purpose of this study was to investigate the dosimetric differences of delivering preoperative intensity modulated radiation therapy (IMRT) to patients with soft tissue sarcomas of the extremity (ESTS) with a teletherapy system equipped with 3 rotating (60)Co sources and a built-in magnetic resonance imaging and with standard linear accelerator (LINAC)-based IMRT.

METHODS AND MATERIALS

The primary study population consisted of 9 patients treated with preoperative radiation for ESTS between 2008 and 2014 with LINAC-based static field IMRT. LINAC plans were designed to deliver 50 Gy in 25 fractions to 95% of the planning target volume (PTV). Tri-(60)Co system IMRT plans were designed with ViewRay system software.

RESULTS

Tri-(60)Co-based IMRT plans achieved equivalent target coverage and dosimetry for organs at risk (long bone, skin, and skin corridor) compared with LINAC-based IMRT plans. The maximum and minimum PTV doses, heterogeneity indices, and ratio of the dose to 50% of the volume were equivalent for both planning systems. One LINAC plan violated the maximum bone dose constraint, whereas none of the tri-(60)Co plans did.

CONCLUSIONS

Using a tri-(60)Co system, we were able to achieve equivalent dosimetry to the PTV and organs at risk for patients with ESTS compared with LINAC-based IMRT plans. The tri-(60)Co system may be advantageous over current treatment platforms by allowing PTV reduction and by elimination of the additional radiation dose associated with daily image guidance, but this needs to be evaluated prospectively.

Comparison of local recurrence with conventional and intensity-modulated radiation therapy for primary soft-tissue sarcomas of the extremity

PURPOSE

The use of intensity-modulated radiation therapy (IMRT) in the treatment of soft tissue sarcoma (STS) of the extremity is increasing, but no large-scale direct comparison has been reported between conventional external-beam radiation therapy (EBRT) and IMRT.

METHODS

Between January 1996 and December 2010, 319 consecutive adult patients with primary nonmetastatic extremity STS were treated with limb-sparing surgery and adjuvant radiotherapy (RT) at a single institution. Conventional EBRT was used in 154 patients and IMRT in 165 with similar dosing schedules. Median follow-up time for the cohort was 58 months.

RESULTS

Treatment groups were comparable in terms of tumor location, histology, tumor size, depth, and use of chemotherapy. Patients treated with IMRT were older (P = .08), had more high-grade lesions (P = .05), close (< 1 mm) or positive margins (P = .04), preoperative radiation (P < .001), and nerve manipulation (P = .04). Median follow-up was 90 months for patients treated with conventional EBRT and 42 months for patients treated with IMRT. On multivariable analysis adjusting for patient age and tumor size, IMRT retained significance as an independent predictor of reduced LR (hazard ratio = 0.46; 95% CI, 0.24 to 0.89; P = .02).

CONCLUSION

Despite a preponderance of higher-risk features (especially close/positive margin) in the IMRT group, IMRT was associated with significantly reduced local recurrence compared with conventional EBRT for primary STS of the extremity.

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.

A new method of lower extremity immobilization in radiotherapy

We developed a new method for immobilization of the fix lower extremities by using a thermoplastic mask, a carbon fiber base plate, a customized headrest, and an adjustable angle holder. The lower extremities of 11 patients with lower extremity tumors were immobilized by this method. CT simulation was performed for each patient. For all 11 patients, the device fit was suitable and comfortable and had good reproducibility, which was proven in daily radiotherapy.

Perioperative irradiation in extremity soft tissue sarcoma

Adjuvant radiotherapy constitutes an important component of the treatment of soft tissue sarcomas. Extremity soft tissue sarcomas constitute a large proportion of this rare mesenchymal tumor. Questions regarding timing, techniques and toxicity come into play about optimizing adjuvant radiotherapy. This article will discuss recent trends and outcomes of perioperative, that is, preoperative and postoperative, irradiation.

Multimodality management of extremity soft tissue sarcomas-an Indian perspective

Soft-tissue sarcomas are a rare and heterogeneous group of tumors. The last few decades have seen rapid strides in the management of these complex lesions. The presence of a soft-tissue sarcoma in the extremity is no longer an indication for amputation. Function preserving alternatives for local control in these lesions are the norm without compromising on overall disease survival. Good functional and oncological results can be achieved with a combination of excision of the tumor and where required, suitable adjuvant therapies. These lesions are best managed at specialty centres where the requisite multidisciplinary care can be offered to the patient to optimise results. This article outlines the current understanding and emphasises the multimodality management of these challenging tumors. We also present Indian data of the incidence and oncologic outcomes of these lesions and suggest a treatment algorithm.

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.

Application of IMRT in adjuvant treatment of soft tissue sarcomas of the thigh-Preliminary results

BACKGROUND

Fracture of the femur is the most frequent late complication in patients with soft tissue sarcomas (STS) who receive external beam radiotherapy after limb-sparing surgery.

AIM

To reduce the risk of bone fracture following radiotherapy of STS of the thigh, we minimized the dose to the femur and to surrounding normal tissues by applying intensity modulated radiation therapy (IMRT). We report preliminary results of post-surgery IMRT of the thigh in patients with STS in this extremity.

MATERIALS AND METHODS

10 adult patients undergoing post-operative radiotherapy of STS of the thigh were treated using IMRT. Clinical IMRT plans with simultaneous integrated boost (SIB) and 3-phase three-dimensional conformal radiotherapy (3D-CRT) were designed to adequately treat the planning target volume and to spare the femur to the largest extent possible. Dose distributions and dose-volume histograms were compared.

RESULTS

For either technique, a comparable target coverage was achieved; however, target volume was better covered and critical structures were better spared in IMRT plans. Mean and maximum doses to OAR structures were also significantly reduced in the IMRT plans. On average, the mean dose to the femur in 3D-CRT plans was about two times higher than that in IMRT plans.

CONCLUSION

Compared with 3D-CRT, the application of IMRT improves the dose distribution within the concave target volumes and reduces dose to the OAR structures without compromising target coverage.

Management of extremity soft tissue sarcomas

Soft-tissue sarcomas are a rare and heterogeneous group of tumors. The last few decades have seen rapid strides in surgery with function preserving alternatives for local control in these lesions becoming the norm without compromising on overall disease survival. Good functional and oncological results can be achieved with a combination of excision of the tumor, and where required, suitable adjuvant therapies. These lesions are best managed at specialty centres where the requisite multidisciplinary care can be offered to the patient to optimise results. This overview is intended as a review of current understanding and the multimodality management of these challenging tumors.