Is pre-operative radiotherapy superior to postoperative radiotherapy in the treatment of soft tissue sarcoma?

Body composition predictors of therapy response in patients with primary extremity soft tissue sarcomas

Background Recent studies have suggested that the quantity and quality of adipose tissue and muscle, assessed on non-contrast computed tomography (CT), may serve as imaging biomarkers of survival in patients with and without neoplasms. Purpose To assess body composition measures that could serve as predictors of therapy response in patients with extremity soft tissue sarcomas treated with radiation therapy and surgery. Material and Methods The study was IRB-approved. Sixty patients had a history of extremity soft tissue sarcoma and underwent FDG-PET/CT prior to radiation therapy and surgical resection. Cross-sectional areas and CT attenuation (HU) of abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and psoas muscle were assessed on non-contrast CT. Clinical information on predictors of tumor recurrence and post-surgical wound infections were recorded. Cox proportional hazard models were used to determine longitudinal associations between body composition and tumor recurrence/wound infections. Results Twenty-three tumor recurrences occurred over a follow-up period of 43 ± 35 months. Higher SAT and lower psoas attenuation were associated with tumor recurrence which remained significant after adjustment for covariates ( P ≤ 0.01). There were 13 post-surgical wound infections. Higher VAT and SAT attenuation were associated with post-surgical wound infections ( P < 0.04); however, VAT attenuation lost significance after adjustment for covariates. Conclusion Abdominal adipose tissue and psoas muscle attenuation assessed on non-contrast CT may predict tumor recurrence and post-surgical infections in patients with extremity soft tissue sarcomas.

Skin elasticity as a measure of radiation fibrosis: is it reproducible and does it correlate with patient and physician-reported measures?

Current means of measuring RT-induced fibrosis are subjective. We evaluated the DermaLab suction cup system to measure objectively skin deflection as a surrogate for fibrosis. Sixty-nine patients with E-STS were treated with limb-sparing surgery and 50-66 Grays (Gy) of RT. Using a “scleroderma” DermaLab Suction Cup, the skin stiffness was measured by two clinicians. The National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) scale, the Musculoskeletal Tumor Rating Scale (MSTS) and Toronto Extremity Salvage Score (TESS) questionnaires were completed for each patient. Levels of agreement between measurers were estimated using the Kappa (κ) coefficient and the concordance correlation coefficient (CCC). All sixty-nine patients were included. The level of agreement between measurers for NCI-CTCAE grading was moderate (range κ = 0.41-0.59). The CCC for the elasticity measurements were higher, with CCC = 0.82 for fibrotic skin and CCC = 0.84 for normal skin. The elasticity measurements were significantly higher when MSTS scores were <30 and or TESS scores were <90. Suction Cup measurement of skin elasticity is more reproducible than CTCAE grading and shows promise in generating reproducible measurements for radiation-induced skin fibrosis. Furthermore, it correlates well with the MSTS and TESS.

Leiomyosarcoma of the cephalic vein

A 78-year-old man presented with a mass on his right forearm. A 5 x 4 x 3 cm³ mass was excised en bloc with extensions along the course of the cephalic vein and its tributaries. Histological analysis revealed the mass to be a high-grade leiomyosarcoma arising within the cephalic vein. The tumour was controlled locally and distally until the patient died 10 months later, from an unrelated illness. This is the first reported case of a venous leiomyosarcoma of the cephalic vein.

Treatment of soft tissue sarcoma: a European approach

This article discusses the treatment of adult soft tissue sarcoma (excluding gastrointestinal stromal tumor), analyzing the principles underlying treatment and the results of surgery, radiotherapy, and chemotherapy. The focus is on the European approach in particular, and ongoing studies are summarized.

Tumors of the peripheral nerves and plexuses

Peripheral nerve tumors are a diverse group of lesions histologically and in their clinical behavior. The genetic disorders neurofibromatosis type 1 and 2 and schwannomatosis are significant risk factors for the development of peripheral nerve tumors. An understanding of these disorders is important in allowing appropriate management. Active treatment of peripheral nerve tumors is reserved for lesions that are malignant or causing neurologic dysfunction, pain, compressive symptomatology, or cosmetic concern. The mainstay of treatment is surgical intervention, the nature of which will vary with the type of tumor and anatomical location. In the case of malignant tumors, adjuvant chemotherapy and radiotherapy are commonly used. Developments in the understanding of the genetics and molecular biology of peripheral nerve tumors are opening up potentially exciting new avenues of treatment. The prognosis of benign peripheral nerve tumors is excellent, with a recurrence rate of just 5% or less after successful surgery. Malignant tumors have proven to be more challenging, with a much higher recurrence rate and a 5-year survival rate of 64%.

Model of radiation-impaired healing of a deep excisional wound

Despite many well-recognized benefits, administration of ionizing radiation before surgical resection of malignancies is associated with a high risk of wound-healing complications. Most animal models investigating techniques to improve wound healing use a superficial wound. The goal of this study was to develop a novel model of radiation-impaired healing using a deep excisional wound, which is closer to the clinical situation. In the first part of this study, female Lewis rats were exposed to 0, 12, 15, or 18 Gy single-fraction radiation to the buttocks. Three weeks later, deep wounds were created by excision of the gluteus maximus muscle. Irradiated wounds had a lower rate of healing of the surgically created defect than unirradiated wounds (p<0.001), but there was no significant difference between the different doses of radiation. Impaired healing was still evident at 12 weeks. The second part of this study investigated the ability of porcine small-intestinal submucosa (SIS) to improve healing in this animal model. At 6 weeks, wounds implanted with SIS showed improved healing at all doses of radiation compared with unimplanted irradiated wounds. However, higher doses of radiation were still associated with a lower rate of healing. SIS induced a cellular response that was not evident in defects that did not receive SIS, suggesting that SIS has the potential to stimulate repair. This reproducible model of radiation-impaired wound healing closely resembles the clinical setting. The results indicate that this model can be used to investigate new biomaterials as possible therapeutic agents to enhance wound healing.

Diagnosis and treatment options for nerve sheath tumors

The purpose of this review is to discuss the contemporary diagnosis and treatment options for nerve sheath tumors. Common nerve sheath tumors include schwannomas, neurofibromas and malignant nerve sheath tumors. Nerve sheath tumors can be associated with genetic disorders such as neurofibromatosis and schwannomatosis. There is great variation in terms of tumor location, clinical presentation and treatment strategy. Magnetic resonance imaging is the diagnostic study of choice for nerve sheath tumors and surgery has become the mainstay of treatment for most symptomatic lesions. Progress in microsurgical techniques has resulted in significant improvement in surgical outcome, with preservation of neurologic function. Complete resection of benign nerve sheath tumors is the goal of surgical intervention and this results in cure. In contrast, malignant nerve sheath tumors remain a major challenge with poor outcomes overall. Progress in multidisciplinary research may ultimately lead to novel therapeutic strategies.

Evaluation of clinical utility of BTC-2000 for measuring soft tissue fibrosis

PURPOSE

To evaluate whether mechanical tissue parameters, specifically laxity (in millimeters) and energy absorption (millimeters of mercury multiplied by millimeters) as measured by the BTC-2000, could discriminate levels of fibrosis severity among patients treated for extremity soft tissue sarcoma by surgery alone; preoperative radiotherapy (RT) and surgery; and surgery followed by postoperative RT.

METHODS AND MATERIALS

A total of 41 patients were treated for extremity soft tissue sarcoma by surgery alone (n = 11); preoperative RT (50 Gy in 2-Gy daily fractions) and surgery (n = 15); and surgery followed by postoperative RT (66 Gy in 2-Gy daily fractions; n = 15). Serial fibrosis measurements were evaluated at equal intervals from the midpoint of the surgical incision along the length of the incision. On the basis of the average of these measurements, differences among the three groups were analyzed using analysis of variance.

RESULTS

Pair-wise statistically significant differences were found among the three treatment groups for both laxity and energy absorption as determined by the average of all measurements. The treatment difference remained statistically significant even after adjusting for differences based on the untreated contralateral limb and anatomic site (p <0.001 and p = 0.002 for laxity and energy absorption, respectively).

CONCLUSION

The biomechanical tissue parameters of laxity and energy absorption discriminated fibrosis severity in patients treated with different RT doses. The BTC-2000 may provide a useful quantitative measure of soft tissue fibrosis.

Effect of radiation and cell implantation on wound healing in a rat model

BACKGROUND AND OBJECTIVES

Having shown that intra-dermal injection of fibroblasts decreases the effect of radiation on healing of superficial wounds, we now test the effect of fibroblasts and syngeneic marrow stromal cells on irradiated deep and superficial wounds.

METHODS

Wistar rats received bilateral buttock irradiation followed by partial excision of the gluteus muscle bilaterally. In Protocol 1, one irradiated wound was treated with 1.2 x 10(7) autologous cells injected intra-dermally. In Protocol 2, the experimental side was treated with a fibrin and autologous cell implant (1.2 x 10(7) cells). Twenty-one days later, wound mechanical characteristics were tested. In Protocol 3, the effect of pooled marrow stromal cells on healing of superficial irradiated wounds in Lewis rats was similarly tested.

RESULTS

The fibrin-fibroblast implant (Protocol 2) had no effect on wound mechanics. Superficial injection of fibroblasts (Protocol 1) significantly improved wound breaking strength when compared to the control group (mean +/- SEM, breaking strength: treated 504.6 +/- 37.0 g vs. control 353.4 +/- 35.2 g, P = 0.005). The dermal injection of marrow stromal cells also resulted in marked increases in breaking strength (mean +/- SEM, breaking strength: treated 338.5 +/- 39.9 g vs. control 187.1 +/- 12.0 g, P < 0.01). In both Protocols 1 and 3, ultimate tensile strength and toughness were increased in the side receiving cell transplantation.

CONCLUSIONS

Cell implantation holds promise for decreasing the effect of radiation on healing of irradiated wounds.

Radiation therapy for soft tissue sarcoma

Sarcomas are relatively uncommon tumors of mesenchymal origin. They may arise anywhere within the musculoskeletal system and are typically classified by clinical behavior into benign, borderline, or malignant. This article focuses primarily on the role of radiation for malignant soft tissue sarcoma and selected borderline tumors.

Radiation therapy for low-grade soft tissue sarcoma

One hundred eight patients with low-grade soft tissue sarcoma treated at the authors' institution from 1984 to 1999 were reviewed retrospectively. Low-grade sarcomas were defined as those designated as Grade I of III or Grade I or II of IV. Patients who presented with recurrent tumors or who had multiple procedures at outside institutions were excluded. The patient's gender, age at diagnosis, histologic diagnosis, site and depth of primary involvement, and specimen size at resection were noted. Involvement of periosteum, bone, and neurovascular structures also was recorded. The decision to use radiation therapy was made case-by-case. Indications for preoperative radiation therapy included tumor adjacent to the neurovascular bundle or bone where a marginal surgical margin was anticipated. Indications for postoperative radiation therapy included followup resection of an unsuspected malignancy. Patients were evaluated according to treatment rendered. Sixty-six patients were treated with surgery alone, whereas 42 patients had excision of the tumor in conjunction with radiation therapy. The overall local control rate was 97.2% (105 of 108). There were no statistically significant differences in local recurrence, wound complication, fibrosis, or survival between the two groups. Patients treated with radiation therapy had an increased incidence of postoperative lymphedema. Kaplan-Meier 10-year survival rates were approximately 90% for both groups.

Wound complications following pre-operative radiotherapy for soft tissue sarcoma

AIMS

We analysed wound complications in 43 patients with soft tissue sarcoma who were treated with combined pre-operative radiotherapy and surgery.

METHODS

All patients received the same protocol of pre-operative radiotherapy at our institution.

RESULTS

Thirty-six (84%) patients developed acute skin toxicity following radiotherapy. After wide local excision, 15 patients required primary soft tissue reconstruction with vascularized muscle transfer and four patients underwent free skin flap to enable wound closure as part of their primary surgery. Nineteen patients (44%) developed post-operative wound complications including 10 (23%) patients who required an additional surgical procedure. Four (27%) patients developed flap necrosis in a group of 15 who underwent primary vascularized soft tissue transfer. All required a second vascularized muscular flap. One elderly patient, who had grade 3 acute radiation skin toxicity, had an arterial graft and total hip arthroplasty for a femoral artery aneurysm and an avascular necrosis of the hip, respectively. In our series, age (> or = 40 years) was the only impact factor influencing wound complication after surgery following radiotherapy (P=0.06).

CONCLUSIONS

Site of tumour, radiation field size, surgical resection volume, grade of acute radiation toxicity, co-morbidity, and smoking were not demonstrated to have predictive value in wound complication following pre-operative radiotherapy. Although previous papers suggested that vascularized soft tissue transfer could be useful reducing wound morbidity, our results could not confirm this.

Is radiotherapy important for low-grade soft tissue sarcoma of the extremity?

Radiotherapy and limb-preserving surgery has replaced amputation and compartmental resection for treatment of soft tissue sarcomas. However, the role of radiotherapy in low-grade tumors remains unclear. This study reviews the outcomes of 132 patients who received multimodality treatment for low-grade soft tissue sarcoma. Large primary tumors (> 5 cm) and the absence of radiotherapy correlated with local recurrence. Radiotherapy was most effective in patients operated on with marginal margins. Patients who were treated with wide surgical margins or had small tumors (< or =5 cm) showed no benefit with adjuvant radiotherapy. Size greater than 5 cm and local recurrence correlated with metastasis. Radiotherapy appears to be important in the management of low-grade soft tissue sarcoma. The principles of local treatment for low-grade soft tissue sarcoma should be the same as for high-grade tumors with a combination of surgery and adjuvant radiotherapy. In a subset of patients with small and widely excised tumors, consideration may be given to withholding radiotherapy. Local recurrence and metastasis from low-grade soft tissue sarcoma may occur as long as 1 decade after primary tumor resection. Long-term review of patients with low-grade tumors may be indicated.