Current results of brachytherapy for soft tissue sarcoma

Midterm Results of High-Dose-Rate Intraoperative Brachytherapy in the Treatment of Soft Tissue Sarcomas

INTRODUCTION

According to the literature only sparse data are available on the use of high-dose-rate intraoperative brachytherapy (IOHDR-BT) as a boost to external-beam irradiation (EBRT) in combination with a wide resection in patients with high-grade soft tissue sarcomas (STS).

MATERIALS AND METHODS

Applying a retrospective study design, we investigated all patients who between 2010 and 2016 underwent marginal resection of a high-grade STS and intraoperative radiotherapy, followed by EBRT. We included only patients with a traceable follow-up time of at least two years. Of 89 patients, 35 met our inclusion criteria and showed an average follow-up of four years.

RESULTS

We found an overall 2-year local control rate of 94.3%. The local recurrence rate for R0 resections was 6%, whereas recurrences occurred in 13% of R1 resections and in 100% of R2 resections. One affected patient received only intraoperative radiotherapy. The recurrence rate by tumour entity was 36% for LPS, 11% for myxofibrosarcoma and 17% for undifferentiated pleomorphic sarcoma.

CONCLUSION

The treatment regimen consisting of limb-preserving surgery, IORT and pre- or postoperative radiotherapy consistently shows excellent local control rates.

Brachytherapy in the Treatment of Soft-Tissue Sarcomas of the Extremities-A Current Concept and Systematic Review of the Literature

INTRODUCTION

Evidence on the use of brachytherapy in soft-tissue sarcoma (STS) is sparse. Therapy regimens are determined more by local interdisciplinary tumor conferences than by standardized protocols. Patient-specific factors complicate the standardized application of therapy protocols. The individuality of the treatment makes it difficult to compare results.

MATERIALS AND METHODS

A comprehensive literature search was conducted, whereby the literature from a period of almost 44 years (1977-2021) was graded and included in this systematic review. For this purpose, PubMed was used as the primary database. Search string included "soft-tissue sarcoma", "brachytherapy", and "extremity." Four independent researchers reviewed the literature. Only full-text articles written in English or German were included.

RESULTS

Of the 175 identified studies, 70 were eligible for analysis based on the inclusion and exclusion criteria. The key points to compare were local complications, recurrence rate and correlation with margins of resection, and the use of brachytherapy regarding tumor grading.

CONCLUSION

Brachytherapy represents an important subset of radiotherapy techniques used in STSs, whose indications and applications are constantly evolving, and for which a local control rate of 50% to 96% has been reported as monotherapy, depending on risk factors. However, the best benefit is seen in the combination of further resection and brachytherapy, and most authors at many other centers agree with this treatment strategy.

Soft-tissue Sarcomas

This article discusses the epidemiology, diagnosis, and management of primary soft-tissue sarcomas (STS). These musculoskeletal tumors are a rare and heterogeneous group of malignancies, which are best managed by multidisciplinary teams in specialist sarcoma referral centers. Historically, the standard for local control of these tumors has been amputation. Evolutions in multimodality treatment have seen a shift toward preservation of the limb. Advances in limb-sparing surgery have seen the quality of life in sarcoma patients to improve drastically; however, unplanned surgical excision of STS remains a major treatment dilemma in the control of local disease.

Isolated limb perfusion for unresectable extremity sarcoma: results of 2 single-institution phase 2 trials

BACKGROUND

Controversy has surrounded the role of isolated limb perfusion (ILP) for unresectable extremity sarcomas. However, there remains a group of sarcoma patients for whom amputation is the only potential treatment. Because systemic therapies are limited, the authors evaluated ILP in an effort to provide a limb-salvage option.

METHODS

Since 1995, patients with unresectable extremity sarcomas were entered in 2 prospective trials using ILP. Study 1 used tumor necrosis factor (TNF) and melphalan in the perfusion circuit at hyperthermic temperatures (39-41°C). Study 2 used doxorubicin at normothermic temperatures. All ILPs were performed using the standard, previously described technique.

RESULTS

Seventeen patients were entered into study 1; there were 10 (58%) partial responses, 1 (6%) near complete response (CR), 1 (6%) CR, and 5 (30%) no response/minor response. Fourteen patients died of their disease, with a median follow-up of 17 months. Seven (41%) patients maintained their limb intact until the time of death. Twelve patients were entered into study 2; there were no partial or CRs and 2 (20%) minor responses. With a median follow-up of 35 months, there are 3 patients alive (2 with their extremity intact and 1 with an amputation). Six patients developed myonecrosis with creatine phosphokinase levels up to 54,000 U/dL.

CONCLUSIONS

Although doxorubicin is active systemically, TNF and melphalan appear to have greater activity and less toxicity during ILP. Future clinical trials are needed to clearly identify the role for ILP in patients with unresectable extremity sarcomas. Cancer 2011. © 2011 American Cancer Society.

Image-guided percutaneous (125)I seed implantation as a salvage treatment for recurrent soft tissue sarcomas after surgery and radiotherapy

The purpose of this study was to evaluate the safety and efficacy of percutaneous iodine-125 ((125)I) seed implantation using computed tomography (CT) or ultrasound guidance in the treatment of recurrent soft tissue malignancies after surgery and radiotherapy. From February 2002 to September 2009, 18 patients with recurrent soft tissue sarcomas were treated under ultrasound or CT guidance. The actuarial median number of (125)I seeds implanted was 35 (range, 6-129), and the actuarial D90 of the implanted (125)I seeds ranged from 107.9 to 204.4 Gy (median, 147.1 Gy). The activity of the seeds ranged from 0.4 to 0.8 mCi (median, 0.7 mCi). Follow-up times ranged from 4 to 78 months (median, 20 months). The median local control was 41 months (95% CI, 15.9-66.1 months). The 1-, 2-, 3-, 4-, and 5-year local controls were 78.8%, 78.8%, 78.8%, 26.3%, and 0%, respectively. The median survival was 32 months (95% CI, 16-48 months). The actuarial 1-, 2-, 3-, 4-, and 5-year survivals were 76.6%, 61.3%, 39.4%, 39.4%, and 39.4%, respectively. Seven (7) patients (38.9%) experienced recurrence after seed implantation. Six (6) patients (33.3%) died of distant metastases and 1 died of stroke. Two (2) patients developed ulceration, 1 case caused by recurrence and another by a reaction of the skin to radiation. Percutaneous (125)I seed implantation for recurrent soft tissue malignancies under CT or ultrasound guidance is safe and is associated with high efficacy and low morbidity.

Imaging applications in multicatheter brachytherapy for soft tissue sarcomas

Multicatheter brachytherapy can be applied as a monotherapy or in combination with external beam radiotherapy as an adjuvant treatment for soft tissue sarcoma. Successful application of brachytherapy in the treatment of soft tissue sarcoma requires implementation of multiple imaging modalities during preoperative and postoperative planning. Preoperative imaging is essential in planning local therapy for soft tissue sarcoma in that it defines the proximity of the tumor to adjacent critical structures, predicts the likelihood of close or positive surgical margins, and aids in defining the target volume for a brachytherapy implant. In the postoperative setting, imaging is utilized to assess the accuracy of target volume coverage and integrity of the implant, as well as in three-dimensional treatment planning.

Surgery combined with brachytherapy in patients with retroperitoneal sarcomas

Purpose

The primary aim of this work was to analyze feasibility of combined treatment of retroperitoneal sarcomas (RS): surgery (S) and intraoperative brachytherapy (IOBRT). The secondary aim was to analyze results and complications after this treatment.

Material and methods

84 patients with retroperitoneal sarcomas were qualified for combined treatment (S and IOBRT) between June 1998 and September 2006. 65 of the patients (77.4%) had local recurrences. Sarcomas with intermediate and high grade of histological malignancy (G2, G3 – 76.2%) were the most frequent within the all surgically treated patients. Resection ability (R0/R1) in analyzed group of patients was estimated as 85% (74 cases). After intraoperative evaluation, 57 (67.8%) patients were qualified for IOBRT. Since 2000, in 34 patients (60%) an adjuvant postoperative external beam radiation therapy (EBRT) in dose of 50 Gy was applied. Median follow-up of the surviving patients was 40 months.

Results

On the basis of the univariate analysis, relevant aspects negatively influencing overall survival rate within the RS group treated with IOBRT were as follows: surgery of sarcoma recurrence (p = 0.002), higher grade of histological malignancy (p = 0.05), histological type different than liposarcoma (p = 0.05) as well as no adjuvant EBRT (p = 0.05). On the basis of multivariate analysis one can ascertain that relevant factors negatively influencing LRFS in RS patients treated with IOBRT were: surgery due to recurrence of sarcoma (p = 0.008) and lack of EBRT (p = 0.01).

Conclusions

Combined treatment (surgery and brachytherapy) was possible to be carried out on 68% of RS patients. The overall number of complications was quite high, however acceptable, taking into consideration the application of extensive, multi-organ treatments in case of sarcoma recurrences in this localization. The results suggest that the method of treatment will improve the final outcome when most of patients will be qualified for treatment of primary sarcomas in experienced centre.

The histopathologic evaluation of soft tissue changes in rabbit extremity after different dose-fractionation schemes of interstitial high dose rate (HDR) brachytherapy

BACKGROUND

The use of HDR in the treatment of soft tissue sarcoma had been on the rise. However, there was limited study to evaluate the effect of different fractionation schemes on soft tissue and the optimal HDR scheme.

AIMS

We aimed to assess the histopathologic changes on soft tissue after different HDR brachytherapy doses.

METHODS

The subjects were divided into three groups. Each group included 10 limbs. Group A had only an applicator without radiation, group B received a total of 24 Gy at 6 Gy per fraction, twice a day, and group C received a total of 13.5 Gy in a single fraction. The histopathologic findings were grouped into soft tissue pathology-1 (edema, inflammation, endothelial proliferation, necrosis) and soft tissue pathology-2 (atrophy, calcification, vascular hyalinization, fibrosis) (STP-1-2).

RESULTS

The highest mean grade values of STP-1 and STP-2 were observed in group C (0.95 and 1.45) in comparison to group A (0.45 and 0.85) and group B (0.65 and 0.9). The difference in STP-1 was found significant only between groups A and C and the difference in STP-2 was found both between groups A and C and groups B and C.

CONCLUSION

In our experimental study it was shown that the fractionated interstitial HDR had both lower rate and severity of toxicity in comparison to a single high dose fraction. Before using a single fractionated regimen in the clinic, the increased morbidity related to the irreversible early toxicities or progressive late toxicities should be kept in mind.

Management of locally recurrent soft-tissue sarcoma after prior surgery and radiation therapy

PURPOSE

The aim of this study was to evaluate outcome and treatment toxicity after wide local re-excision (WLE), with or without additional radiation therapy, for patients with isolated first local recurrence of soft-tissue sarcoma arising within a previously irradiated field.

METHODS

A retrospective review was performed of 62 consecutive patients. All patients underwent prior resection and external beam radiation. For recurrent disease, 25 patients were treated with WLE alone, and 37 patients were treated with WLE and additional radiation (45- 64 Gy). In 33 patients, the radiation was delivered via an afterloaded brachytherapy, single-plane implant.

RESULTS

The 5-year disease specific and distant metastasis-free survival rates were 65% and 73%, respectively. Local control (LC) at 5 years was 51%, and on multivariate analysis, a positive surgical resection margin (p< 0.001) was associated with a lower rate of LC. Reirradiation was not associated with improved LC; however complications requiring outpatient or surgical management were more common in patients who had undergone reirradiation (80% vs. 17%, p < 0.001). Amputation was also more common in the subgroup of patients who underwent extremity reirradiation (35% with radiation vs. 11% without, p = 0.05), although only one amputation was performed to resolve a treatment complication.

CONCLUSION

Conservative surgery alone results in LC in a minority of patients who have failed locally after previous excision and external beam radiation. Although selection biases and small patient numbers confound the analysis, local treatment intensification with additional radiation does not clearly improve outcome after surgical excision alone, and is associated with an increase in complications.

Radiotherapy and wound healing

Radiotherapy is an invaluable weapon when treating cancer. However, the deleterious effects of radiation, both immediate and long-term, may have a significant effect on local tissues. Problematic wound healing in radiation-damaged tissue constitutes a major problem that is frequently overlooked during the management of patients who require radiotherapy, or have had radiotherapy in the past. Poor wound healing may lead to chronic ulceration, pain, secondary infection and psychological distress and compromise the outcome of general or reconstructive surgery. We discuss the pathophysiology of poor wound healing following radiotherapy, specific problems for radiation-damaged tissue and potential treatments to improve wound healing of irradiated tissues.

Preoperative radiotherapy for soft tissue sarcoma: the Peter MacCallum Cancer Centre experience

AIM

Radiotherapy has been shown to improve local control in combination with limb-sparing or conservative surgery in the management of localised soft tissue sarcoma. Our centre's treatment protocol is to offer preoperative external beam radiotherapy (50.4Gy in 28 fractions) followed by surgery four to six weeks later. The aim of this study is to review the treatment outcome and toxicity of patients treated with this protocol.

METHODS

Consecutive patients with localised extremity or truncal soft tissue sarcoma who presented between January 1996 and December 2000 and treated with preoperative radiotherapy followed by limb-sparing surgery were reviewed. Patients with recurrent disease or metastatic disease at diagnosis and patients below the age of 16years were excluded. Local and distant recurrence, overall survival and treatment toxicity were analyzed.

RESULTS

Sixty-seven cases were identified (41 males and 26 females). The median age was 52years (range 17 to 82). The majority (79%) had tumours located in the lower limb. The most common histological diagnoses were malignant fibrous histiocytoma and liposarcoma. The median follow-up was 4.1years (range 0.6 to 6.9). There were six local recurrences, two of which were successfully salvaged. Twenty patients developed distant metastases. The estimated 5-year actuarial local recurrence free, distant recurrence free and overall survival were 93%, 68% and 73% respectively. Acute radiotherapy toxicity and wound complications were acceptable and late toxicity was uncommon.

CONCLUSION

Preoperative radiotherapy followed by surgery provides effective local control in the management of soft tissue sarcoma.

Surgery Combined With Intraoperative Brachytherapy in the Treatment of Retroperitoneal Sarcomas

BACKGROUND

The purpose of this study was to analyze the results of treatment of retroperitoneal soft tissue sarcomas (RSTS) by surgery combined with intraoperative brachytherapy (IOBRT).

METHODS

Seventy adult patients with RSTS were considered for combined treatment (surgery plus IOBRT) between June 1998 and February 2004. There were 64 (91%) recurrent tumors, and 93% of tumors exceeded 5 cm. IOBRT was performed with high-dose-rate Gammamed 12 with iridium 192 (IOBRT time range, 20-87 minutes; median, 56 minutes).

RESULTS

After intraoperative re-evaluation, 24 patients (34%) were found to be ineligible for IOBRT because of multiple intraperitoneal recurrences, macroscopically nonradical resection, poor general condition, and technical aspects. Thirty-seven patients underwent IOBRT immediately after surgery during the same general anesthesia procedure. Nine patients underwent delayed IOBRT within 1 to 3 days after the primary operation. Ten (21.5%) of 46 patients underwent reoperation because of surgical complications. One patient died in the postoperative period. After IOBRT, 24 patients (52%) underwent adjuvant external beam radiotherapy (EBRT) to a total dose of 50 Gy. Over a median follow-up time of 20 months, the estimated 5-year overall survival and local recurrence-free survival rates in IOBRT patients were 55% and 51%, respectively. Application of adjuvant EBRT showed a favorable local control rate.

CONCLUSIONS

The scheduled combined treatment (surgery plus IOBRT) was possible to perform in 66% of RSTS cases that received surgical treatment. The complication rate was high, but we consider it acceptable because of the necessity for extensive aggressive surgical treatment in regionally advanced RSTS. EBRT seems to be an indispensable part of treatment that provides better local control.

Nerve tolerance to high-dose-rate brachytherapy in patients with soft tissue sarcoma: a retrospective study

Background

Brachytherapy, interstitial tumor bed irradiation, following conservative surgery has been shown to provide excellent local control and limb preservation in patients with soft tissue sarcomas (STS), whereas little is known about the tolerance of peripheral nerves to brachytherapy. In particular, nerve tolerance to high-dose-rate (HDR) brachytherapy has never been properly evaluated. In this study, we examined the efficacy and radiation neurotoxicity of HDR brachytherapy in patients with STS in contact with neurovascular structures.

Methods

Between 1995 and 2000, seven patients with STS involving the neurovascular bundle were treated in our institute with limb-preserving surgery, followed by fractionated HDR brachytherapy. Pathological examination demonstrated that 6 patients had high-grade lesions with five cases of negative margins and one case with positive margins, and one patient had a low-grade lesion with a negative margin. Afterloading catheters placed within the tumor bed directly upon the preserved neurovascular structures were postoperatively loaded with Iridium-192 with a total dose of 50 Gy in 6 patients. One patient received 30 Gy of HDR brachytherapy combined with 20 Gy of adjuvant external beam radiation.

Results

With a median follow-up of 4 years, the 5-year actuarial overall survival, disease-free survival, and local control rates were 83.3, 68.6, and 83.3%, respectively. None of the 7 patients developed HDR brachytherapy-induced peripheral neuropathy. Of 5 survivors, 3 evaluable patients had values of motor nerve conduction velocity of the preserved peripheral nerve in the normal range.

Conclusion

In this study, there were no practical and electrophysiological findings of neurotoxicity of HDR brachytherapy. Despite the small number of patients, our encouraging results are valuable for limb-preserving surgery of unmanageable STS involving critical neurovascular structures.

A novel technique using customised templates for the application of fractionated interstitial HDR brachytherapy to the tumour bed in soft-tissue sarcomas located in the extremities

AIMS

Postoperative interstitial brachytherapy of limbs is challenging, because it is difficult to deliver a conformal dose to the tumour bed. We developed and assessed a new surgical fixation system for positioning guiding tubes in interstitial brachytherapy in order to achieve favourable geometry.

MATERIALS AND METHODS

A 28-year-old patient was treated with postoperative interstitial brachytherapy boost followed by external radiotherapy after the 11th recurrence of a desmoid tumour in the forearm. On the basis of preoperative imaging data, customised resorbable templates made of polydioxanone (PDS) were cut to fit in the space left by the resected tumour. These were strategically positioned in the tumour bed during surgery. In order to hold the brachytherapy-guiding tubes parallel for the duration of treatment, they were passed through a series of holes bored into the templates.

RESULTS

Fixing the guiding tubes with PDS templates resulted in a fixed geometry, and thus in an optimal dose distribution with only little additional dose optimisation needed by the brachytherapy treatment planning system. An optimised dose to the tumour bed, and a reduction of dose to critical normal tissues, is achievable with this template system for sarcomas located between osseous structures.

CONCLUSION

The PDS templates offer a more rigid fixation of the guiding tubes in relation to the surrounding anatomy even after the operation cavity has been closed. A tailored dose distribution can be achieved, thus reducing possible side-effects. Additionally, because of the self-resorbable nature of the material, a re-operation for template removal is not necessary. The potential advantages of this method are being further investigated.