Advanced-technology radiation therapy in the management of bone and soft tissue sarcomas.

BACKGROUND: For patients with sarcomas, radiotherapy can be used as neoadjuvant, adjuvant, or primary local therapy, depending on the site and type of sarcoma, the surgical approach, and the efficacy of chemotherapy. METHODS: The authors review the current status of advanced technology radiation therapy in the management of bone and soft tissue sarcoma. RESULTS: Advances in radiotherapy have resulted in improved treatment for bone and soft tissue sarcomas. Intensity-modulated radiation therapy (IMRT) uses modifications in the intensity of the photon-beam from a linear accelerator across the irradiated fields to enhance dose conformation in three dimensions. For proton-beam radiation therapy, the nuclei of hydrogen atoms are accelerated in cyclotrons or synchrotrons, extracted, and transported to treatment rooms where the proton beam undergoes a series of modifications that conform the dose in a particular patient to the tumor target. Brachytherapy and intraoperative radiation therapy have generally been used to treat microscopic residual disease in patients with sarcomas. These technologies deliver dose to tumor cells with irradiation of limited volumes of normal tissue. Patients who may benefit from technically advanced radiotherapy include those with skull base and spine/paraspinal sarcomas, Ewing's sarcoma, and retroperitoneal/extremity sarcomas. CONCLUSIONS: Advances in radiation therapy technology, particularly IMRT, proton-beam or other charged-particle radiation therapy, brachytherapy, and intraoperative radiation therapy, have led to improved treatment for patients with bone and soft tissue sarcomas.     

Surgical considerations for management of distal extremity soft tissue sarcomas

PURPOSE OF REVIEW: This review focuses on the surgical management of soft tissue sarcomas of the hands and the feet. With recent advances in limb salvage surgery and radiotherapy delivery, local control of soft tissue sarcoma in the extremity has become optimized, and the associated functional results of this treatment have taken on extreme importance. Techniques to limit the amount of normal tissue resected and to reconstruct the resulting defects are critical to the final functional result. RECENT FINDINGS: Several features of soft tissue sarcoma unique to the hand and foot have been reported. Certain histologic subtypes of soft tissue sarcoma have been noted to arise preferentially in the hand and the foot, such as epithelioid sarcoma, clear cell sarcoma, and synovial sarcoma. Patients with hand and foot sarcomas have been described as having improved overall survival, but this is likely a result of the smaller size of tumors arising in these locations. Reconstruction of bone defects using various techniques, vascular reconstruction, tendon transfers, and soft tissue reconstruction using regional flaps in the hand and free flaps in the foot have resulted in good functional outcomes. Amputation and early prosthetic fitting still have a role in management of some soft tissue sarcomas, most frequently in the foot. SUMMARY: Limb salvage remains the standard of care for extremity soft tissue sarcomas. Given the fact that patients have good oncologic and functional outcomes with limb salvage in tumors in the hand and foot, surgical oncologists should have this goal for each patient.     

Amputation for extremity soft tissue sarcoma does not increase overall survival: A retrospective cohort study

To determine if amputation increases survival when compared to limb salvage surgery in patients with a soft tissue sarcoma (STS) of the extremity when there is often a misconception among physicians and patients that ablative surgery eliminates local recurrence and increases overall survival. This retrospective cohort study assessed 278 patients with STS and compared 18 patients who had undergone amputations for soft tissue sarcomas of the extremities to a comparative cohort of 260 patients who underwent limb salvage surgery during the same time period. Our limb salvage surgery (LSS) rate was 94% overall for soft tissue sarcomas with a median follow-up of 3.1 years. Patients undergoing amputations either had tumors that involved a critical neurovascular bundle (in particular nerve rather than vessel resection was more responsible for a decision toward ablation), or underlying bone or had neoplasms whose large size would require such an enormous resection that a functional limb would not remain. In comparing prognostic effects, mainly death due to sarcoma, distant metastasis and local recurrence, it was found that there was no statistically significant difference between patients undergoing amputation to those undergoing limb salvage surgery (p > 0.05). While amputations do not increase overall survival in soft tissue sarcomas of the extremity as compared to LSS, they are still a valuable option in a surgeon's arsenal. In particular, amputations can provide improved local control and symptomatic treatment in patients who might not be candidates for limb salvage surgery.     

Sarcomas of soft tissue and bone

Sarcomas arise primarily from mesenchymal structures at any site in the body, even within visceral stroma and neurovascular bundles. Sarcomas have been associated with prior radiation therapy, toxic exposures, and genetic conditions and soft tissue sarcomas have been distinguished from bone sarcomas. For localized soft tissue sarcoma, tumor grade is the most important prognostic variable. Low-grade tumors are generally cured by wide surgical excision, but there is a significant rate of both local recurrence and development of distant metastasis in high-grade lesions. The treatment of soft tissue sarcoma histologic subtypes is generally similar grade-for-grade, with the exception of rhabomyosarcoma, Kaposi's sarcoma, and mesothelioma. Tumor location strongly influences resectability. Radiation therapy has been used successfully in conjunction with conservative surgery to improve local control rates for soft tissue sarcomas, particularly in extremity lesions. Currently, adjuvant chemotherapy remains unproven for most adult soft tissue sarcomas, but is established in the treatment of rhabdomyosarcomas, osteosarcomas, and Ewing's sarcomas.     

Immunotherapy: A New (and Old) Approach to Treatment of Soft Tissue and Bone Sarcomas

Soft tissue and bone sarcomas are a rare and heterogeneous form of cancer. With standard of care treatment options including surgery, radiation, and chemotherapy, the long‐term survival is still low for high‐risk soft tissue sarcoma patients. New treatment strategies are needed. Immunotherapy offers a new potential treatment paradigm with great promise. Immunotherapy of soft tissue sarcomas dates back to Dr. Coley's first use of toxins in the late 1800s. A variety of strategies of immunotherapy have been tried in soft tissue and bone sarcomas, including various vaccines and cytokines, with limited success. Results of these early clinical trials with vaccines and cytokines were disappointing, but there are reasons to be optimistic. Recent advances, particularly with the use of adoptive T‐cell therapy and immune checkpoint inhibitors, have led to a resurgence of this field for all cancer patients. Clinical trials utilizing adoptive T‐cell therapy and immune checkpoint inhibitors in soft tissue and bone sarcomas are under way. This paper reviews the current state of evidence for the use of immunotherapy, as well as current immunotherapy strategies (vaccines, adopative T‐cell therapy, and immune checkpoint blockade), in soft tissue and bone sarcomas. By understanding the tumor microenviroment of sarcomas and how it relates to their immunoresponsiveness, better immunotherapy clinical trials can be designed, hopefully with improved outcomes for soft tissue and bone sarcoma patients.

Implications for Practice

Immunotherapy is a promising treatment paradigm that is gaining acceptance for the management of several cancers, including melanoma, renal cell carcinoma, prostate cancer, and lung cancer. There is a long history of immunotherapy in the treatment of soft tissue and bone sarcomas, although with little success. It is important to understand past failures to develop future immunotherapy treatment strategies with an improved possibility of success. This article reviews the history of and current state of immunotherapy research in the treatment of soft tissue and bone sarcomas, with particular regard to vaccine trials, adoptive T‐cell therapy, and immune checkpoint blockade.     

Surveillance in patients with sarcoma of the extremities.

AIM: To evaluate the efficiency of our follow-up regime for patients with sarcoma of the extremities. METHODS: We have reviewed our follow-up policy in 480 patients with non-metastatic bone or soft tissue sarcomas and with more than 5 years of follow-up. RESULTS: We detected 24% of the soft tissue sarcoma recurrences and 38% of the bone tumour recurrences. We detected 67% of the pulmonary metastases before they became symptomatic. Only 11% of those patients who developed metastases were cured, as were only 26% of those who developed local recurrence. CONCLUSIONS: This study shows that our surveillance programme detects most metastases, but only about one third of the local recurrences.     

Retrospective analysis of metastatic sarcoma patients

Numerous studies have reported the survival of metastatic sarcoma patients who have undergone either a lung metastasectomy or chemotherapy. However, little is known with regards to the clinical course of patients with bone or soft tissue sarcomas who have succumbed to disease. This study aimed to analyze the metastatic patterns of sarcoma patients and to describe the clinical course after the detection of distant metastasis. We reviewed the clinical records of 255 patients with a diagnosis of sarcoma who were referred to our institution, and found 63 patients who succumbed due to metastasis. We examined the clinical features of the initially detected distant metastases, the subsequent clinical course up to the time of patient death and the survival time of patients who died of lung metastasis. Of the 63 patients who died of distant metastasis, 52 (83%) developed lung metastasis as the first metastatic site, while 22 (35%) developed extra-pulmonary metastasis. The majority (77%; 49 of 63 patients) died of primary metastasis. While all 18 bone sarcoma patients died of lung metastasis, 11 of the 45 soft tissue sarcoma patients died of extra-pulmonary metastasis. Six patients died of brain metastasis. The survival of the patients with lung metastasis was only approximately 6 months following the cessation of treatment, regardless of the type of treatment used. These results indicate that planned follow-up and treatment of sarcomas require a precise knowledge of tumor clinical behavior, particularly of the preponderant activity.     

Incidence, épidémiologie des sarcomes et biologie moléculaire. Résultats préliminaires de l’étude EMS en Rhône-Alpes

Sarcomas comprise a heterogeneous group of mesenchymal neoplasms. They can be grouped into 3 general categories, soft tissue sarcoma, visceral and primary bone sarcoma, which have different staging and treatment approaches. Soft tissue sarcomas are typically classified on the basis of genetic alterations and light-microscopic examination of hematoxylineosin-stained tissue, in which recognizable morphological characteristics of normal tissues are identified. Sarcomas are further characterized by histologic grade. The 3 most important prognostic variables are grade, size, and location of the primary tumor. This review includes a discussion of both soft tissue sarcomas (unclassified sarcoma, liposarcoma, leiomyosarcoma, synovial sarcoma, dermatofibrosarcoma protuberans, angiosarcoma, Kaposi sarcoma, gastrointestinal stromal tumor, rhabdomyosarcoma, …) and primary bone sarcomas (osteosarcoma, Ewing sarcoma and chondrosarcoma). The approach to a patient with a sarcoma begins with a biopsy that obtains adequate tissue for diagnosis without interfering with subsequent optimal definitive surgery. Subsequent treatment depends on the specific type of sarcoma. Due to the absence of clear knowledge for incidence rate, we conducted in 2005 and 2006 an exhaustive analysis of all diagnosed cases in the Rhône-Alpes region. Because sarcomas are relatively uncommon yet comprise a wide variety of different entities, second opinion was systematically performed for all included cases.     

The role of high-dose therapy and autologous stem cell transplantation for pediatric bone and soft tissue sarcomas

The prognosis for children with bone and soft tissue sarcomas has significantly improved since the advent of effective multiagent chemotherapy, aggressive surgery for local disease and more precise delivery of radiotherapy doses. However, in a small proportion of patients that present with high-risk disease, long-term outcome has not substantially increased, with disease-free survival rates still in the order of 20-30%. It is therefore clear that novel therapies are needed for children with these tumors. Based on the highly chemosensitive nature of the majority of pediatric sarcomas, several small studies have been conducted to investigate the potential role of high-dose chemotherapy followed by hematopoietic stem cell reconstitution. This review will provide an overview of the current literature concerning the use of high-dose therapy with stem cell transplantation for the three main pediatric sarcomas--Ewing sarcoma, rhabdomyosarcoma and osteosarcoma.     

Limb sparing surgery in soft tissue sarcoma of extremities: An Indian Perspective

This is a retrospective study of 57 patients with extremity soft tissue sarcomas treated at Gujarat Cancer Research Institute, Gujarat, India from January 2005 to December 2007. It aims to review the feasibility of limb sparing surgery for extremity soft tissue sarcoma in Indian population. Twenty-eight percent (28%) of tumors were located in the upper limbs and 72% in the lower extremities. The goal of treatment was limb salvage if feasible. The treatment consisted of amputation in 17 (30%) and local wide excision i.e. limb salvage surgery (LSS) in 40 (70%) patients. The most common histology was pleomorphic sarcoma (21%). Sixty-four percent (64%) of the patients were treated with surgery alone, 32% with surgery plus radiation and 4% with surgery plus systemic chemotherapy. Inadequate margins were present in 12% of the patients. All the patients were followed up for at least 2 years. Recurrence in the form of local and distant occurred in 39% of the patients. Local recurrence occurred in 18% of the patients who underwent LSS and in 35% of those who underwent amputation. Pulmonary metastasis was detected in 16% of patients. The 2 year mortality was 10.5% with the most common etiology being lung metastasis and the most common histology being leiomyosarcoma. We concluded that limb salvage surgery for soft tissue sarcoma is feasible in the Indian population (70%) although the rate is lower than that of world literature at 90%. Keywords: soft tissue sarcoma, wide excision, amputation, limb salvage surgery, Indian population.     

Möglichkeiten der plastischen Chirurgie in der Behandlung von Weichteilsarkomen

Background

The therapy of choice for locally limited soft tissue sarcomas involves complete surgical resection of the tumor. The goal of surgical therapy is the achievement of negative surgical margins (R0 resection). In locally advanced soft tissue sarcomas that have already infiltrated critical anatomical structures, the achievement of R0 status can be associated with a high surgical morbidity and result in functional impairment of the affected extremities or truncal wall. Plastic surgery can reduce this surgical morbidity by using a variety of modern techniques.

Objective

The aim of this article is to illustrate the various treatment options of plastic surgery in the multimodal therapy of patients with soft tissue sarcoma.

Material and methods

This article is based on a review of the current literature and evaluation of an in-house patient database.

Results

Several plastic surgery treatment options can be implemented in the curative and palliative therapy of patients with soft tissue sarcoma of the extremities and truncal wall. Large soft tissue defects can be covered by local pedicled or free flaps, whereas bone defects can be reconstructed by free bone transfer. Motor reconstruction surgery can partially restore functional impairment of extremities after nerve or muscle resection. In palliative disease stages soft tissue coverage after surgical debulking of exulcerated tumors can improve the quality of life of affected patients.

Discussion

Reconstructive plastic surgery techniques can restore functional impairments and cover soft tissue defects so that amputation of extremities can be avoided or complete tumor resection from the truncal wall can be made possible. In palliative disease situations plastic surgery can improve the quality of life.     

Diagnosis and management of synovial sarcoma

Synovial sarcoma accounts about 9% of soft tissue sarcomas, most commonly develops in the extremity of young adults, is considered high grade and contains a characteristic translocation (X;18;p11;q11). While surgery and radiation therapy have achieved excellent local control, distant metastasis remains the principal problem limiting survival. Although ifosfamide based chemotherapy has been associated with an improved survival in patients with synovial sarcoma, the search for less toxic and more targeted systemic therapies is ongoing.     

Appraising the current role of chemotherapy for the treatment of sarcoma

Sarcomas are a heterogeneous group of relatively rare mesenchymal neoplasms. They can be grouped into two general categories: soft tissue sarcoma (STS) and primary bone sarcoma, which are treated differently. Because sarcomas are relatively rare and complex with a wide variety of different histopathologic subtypes, evaluation by multidisciplinary teams who have expertise in the field is recommended. Treatment guidelines for the use of chemotherapy in patients with STS and bone sarcoma have been published by the National Comprehensive Cancer Network. The role of adjuvant chemotherapy in resected STS remains controversial. Although chemotherapy improves disease-free survival, the long-term overall survival benefit remains unproven. Chemotherapy is typically used as palliative treatment for most subtypes of metastatic STS. In contrast, chemotherapy has a proven role in the treatment of primary bone tumors and Ewing sarcoma, but it has not demonstrated efficacy in the treatment of chondrosarcoma. The standard chemotherapy regimens used in sarcoma are associated with significant toxicity, including long-term complications. Less intense and less toxic regimens are the focus of ongoing clinical research. Newer cytotoxic agents with an improved safety profile, such as trabectedin and palifosfamide, are currently in development. Future research needs to focus on identification of subpopulations of patients that are most likely to benefit from chemotherapy.     

Progress in the diagnosis and treatment of rhabdomyosarcoma and related soft tissue sarcomas

Advances in the diagnosis and treatment of rhabdomyosarcoma and related soft tissue sarcomas continue in the Intergroup Rhabdomyosarcoma Study Group (IRSG) and European cooperative groups. The use of molecular biology techniques in soft tissue sarcomas are redefining the classic pathology of these small blue cell tumors. Improvements in imaging, radiotherapy, and surgery, in part, deserve credit for the better survival seen in all cooperative trials. These advances confound the interpretation of consecutively run chemotherapy trials using historical comparisons. The IRSG has reported improvement in the prognosis of both nonmetastatic and metastatic embryonal rhabdomyosarcoma as attributable to three, three-drug regimens that use cyclophosphamide at 2.2 g/m2 in either maintenance or induction and maintenance therapy. Patients of any age with metastatic, nonembryonal, and those over 10 years of age with metastatic embryonal rhabdomyosarcoma continue to have a poor prognosis, which even megatherapy has failed to change. The doublet of ifosfamide and etoposide in combination with vincristine, actinomycin D, and cyclophosphamide at 2.2 g/m2 achieved a remarkable 3-year survival of 58% in patients with metastatic rhabdomyosarcoma and undifferentiated soft tissue sarcoma. The topoisomerase I inhibitor, topotecan, has recently been found by the IRSG to have a 57% overall response rate in patients with metastatic alveolar rhabdomyosarcoma. Topotecan has completed testing with cyclophosphamide in a phase II window study in newly diagnosed patients with metastatic disease and has been incorporated into a randomized trial in intermediate risk patients in IRSG-V. Molecular studies in IRSG-V will be applied in the detection of occult bone marrow metastases and the evaluation of resection margins at initial and second-look surgery. Long-term follow-up will be required in patients with gross residual sarcoma randomized to conventional and hyperfractionated radiotherapy in IRSG-IV to assess late effects. Although older patients with unfavorable histology and metastatic disease continue to have a poor prognosis, the overall 5-year survival of children and adolescents with nonmetastatic and metastatic rhabdomyosarcoma is approaching 80%. As molecular discoveries advance the diagnosis and detection of rhabdomyosarcoma, it is hoped that the futuristic molecular based treatment strategies in development and early testing will further improve survival in high-risk patients with metastatic soft tissue sarcoma.     

Survival of patients with localized high-grade soft tissue sarcoma with multimodality therapy. A matched control study

Ten of 16 consecutive patients (63%) with Stages III-IVA soft tissue sarcoma presenting between 1975 and 1978 and treated with surgery, radiotherapy and adjuvant chemotherapy have remained disease-free with a median follow-up of three years (range, 28-68 months). Survival at three years was 86%. However, in the American Joint Committee (AJC) soft tissue sarcoma staging system published in 1977, Grade 3 soft tissue sarcomas were associated with a three-year survival of 35% and almost 90% of the patients destined to fail did so within three years of diagnosis (8). To determine if the observed improvement in survival resulted merely from lesions with favorable prognostic determinants at diagnosis, study patients were matched for stage, histologic type and location of the primary lesion with controls generated from these 1215 carefully reviewed sarcoma patients collected from the data base of the Task Force on Soft Tissue Sarcomas of the AJC. Only control cases whose histology had been reviewed and who had been treated with surgery (with or without radiotherapy) were included in the analysis. Cases survived significantly longer than controls at three years (p less than 0.001) and, in fact, disease-free survival of cases (63%) was superior to overall survival of controls (27%) (p less than 0.01). Our data support the conclusion that patients with high-grade soft tissue sarcoma treated by an experienced multimodality team have a three-year disease-free survival of approximately 63%. The impact of each component of multimodality therapy cannot be determined, and improved survival may result, in addition, from improved diagnostic and staging techniques currently available.     

SEOM clinical guidelines for the management of adult soft tissue sarcomas

Soft tissue sarcomas are uncommon tumors of mesenchimal cell origin. Criteria for suspicion is a soft tissue mass that is increasing in size, and has a size greater than 5 cm or is located under the deep fascia. Diagnosis and management of these patients should preferably be performed by a specialist multidisciplinary team in a referral center. Assessment of a patient with a suspect of sarcoma should include magnetic resonance and biopsy performed prior to surgery. Primary local therapy for patients with localized sarcoma is based on wide surgical resection with a tumor-free tissue margin, in association in most cases with radiotherapy. Adjuvant chemotherapy constitutes an option that could be considered in high-risk sarcomas of the extremities. When metastasis are present, surgery of pulmonary lesions, in some selected patients, and chemotherapy are current available options.     

Multidisiciplinary “limb salvage” treatment of soft tissue and skeletal sarcomas

Sixty-five patients with soft tissue sarcomas and 40 patients with skeletal sarcomas were treated pre-operatively with infra-arterial Doxorubicin and radiation therapy (3500 rad in 10 fractions). The tumors were widely excised and in the case of skeletal sarcomas, the bone was replaced with a cadaver allograft or metal endoprosthesis in an attempt to achieve limb salvage. Chemotherapy consisting of Adriamycin and Methotrexate was administered post-operatively. These patients have been followed from 6 to 70 months with a median follow-up for soft tissue and skeletal tumors of 24 and 30 months respectively. In the soft tissue sarcoma group there have been 2 local recurrences; actuarial overall and disease-free survival at 3 years was 64 and 61%, respectively. In the skeletal sarcoma group there have been only 2 recurrences and the actuarial survival and disease-free survival of 75 and 55% at 2 years, respectively. In the soft tissue sarcoma group there have been 33 thigh lesions, 13 of which have required periosteal stripping. Five of the patients with thigh lesions have developed femoral fractures. All of these patients had post-operative chemotherapy and four of the five patients had periosteal stripping. In the skeletal sarcoma group, eleven of the twenty-one cadaver allografts have either fractured or become unstable requiring replacement with metallic endoprostheses that have been used exclusively for the past two years. Ninty-seven of the total group of 105 patients achieved limb salvage to the last follow-up or time of death with an acceptable complication rate. Longer follow-up is mandatory to determine the late effects of this combined modality regimen.     

Concepts in limb-sparing treatment of adult soft tissue sarcomas

Pretreatment assessment of patients with soft tissue sarcomas of the extremities requires careful attention to a biopsy approach that will establish the precise diagnosis and will not compromise the subsequent definitive operative procedure. Also, staging procedures are required to evaluate the status of both local and distant sites. Limb-sparing surgery for high grade extremity soft tissue sarcomas is a feasible and appropriate approach in approximately 90% of patients with such lesions. Wide gross surgical margins around the sarcoma are the optimal operative approach. Circumstantial evidence is convincing that local treatment failure can be reduced by adjuvant regional radiation treatment when surgical margins are narrow, and end results appear to be equal to those obtained by more extensive surgical resection alone. Adjuvant radiation following operation with optimal gross surgical margins has not been established as adding benefit. Although some groups treating soft tissue sarcomas do use intraarterial chemotherapy in conjunction with these other modalities, there is, as yet, no convincing evidence that this aspect of the multimodality treatment adds to local and/or systemic disease control. The efficacy of adjuvant systemic chemotherapy for high grade soft tissue sarcomas remains to be established within the context of prospective clinical trials.     

New concepts for the treatment of pediatric nonrhabdomyosarcoma soft tissue sarcomas

Nonrhabdomyosarcoma soft tissue sarcomas form a group of rare tumors with a different biology and clinical behavior. The recently established European Pediatric Soft Tissue Sarcoma Study Group is organizing a new study devoted specifically to these tumors that were formerly treated according to the principles derived from experience with rhabdomyosarcoma, which is a clearly distinct entity. The new study includes two prospective trials, one for synovial sarcoma and the other for adult-type nonrhabdomyosarcoma soft tissue sarcomas. While surgery remains the mainstay of treatment, the role of adjuvant therapy is not yet clear and our understanding of the biology and natural history of nonrhabdomyosarcoma soft tissue sarcomas is still incomplete. This review presents the latest data on nonrhabdomyosarcoma soft tissue sarcoma treatment and outcome, and the rationale behind a risk-adapted treatment program that investigates the role of full-dose ifosfamide-doxorubicin chemotherapy in improving the response rate of patients with unresectable disease, the chances of avoiding adjuvant chemotherapy in low-risk synovial sarcomas, and the possible role of chemotherapy in high-risk adult-type soft tissue sarcomas.     

Response of sarcomas of bone and of soft tissue to neutron beam therapy

A total of 51 patients were treated at Fermilab for sarcoma of bone (25 patients) and soft tissue (26 patients). Neutrons were delivered in twice weekly fractions over 6-7 weeks to total doses between 18 and 26 Gy. Long-term local control (greater than 2 years) was achieved in 24 patients (47%). Overall local control rates were 44% in the bone sarcomas and 50% in the soft tissue tumors. Chondrosarcoma appeared relatively more responsive with 9 out of 16 (56%) controlled, compared to osteogenic sarcoma with 2 out of 9 (22%) controlled. Among the soft tissue tumors, liposarcoma (5/7 controlled) and neurogenic sarcoma (3/3 controlled) appear to be more responsive than other tumors. The overall survival rate was 40% in the entire series. These results are comparable with international experience in neutron therapy of sarcomas of bone and soft tissues. Out of 263 soft tissue sarcomas treated with neutrons only to full dosage throughout the world, 152 (58%) were locally controlled. Similarly out of 74 sarcomas of bone so treated, 44 (60%) were controlled.