High dose rate interstitial brachytherapy in soft tissue sarcoma: technical aspects and results

Brachytherapy for Organ and Function Preservation in Soft-Tissue Sarcomas in Adult and Paediatric Patients

Adjuvant radiotherapy is an integral component in the management of soft-tissue sarcomas. Brachytherapy is a very convenient and conformal way of delivering adjuvant radiotherapy in such tumours, which spares the surrounding normal tissue. Randomised studies have established the efficacy of brachytherapy in the adjuvant setting, with a 5-year local control of 80-85%. High dose rate, low dose rate and pulsed dose rate have shown equivalent local control, but high dose rate has gained popularity owing to patient convenience, radiation safety and flexibility in dose optimisation. Freehand insertion perioperative brachytherapy (intraoperative placement and postoperative treatment) is the most commonly used technique in soft-tissue sarcomas, with intraoperative radiotherapy and radioactive seed placement being the less commonly used techniques. Brachytherapy can be used as monotherapy or in combination with external beam radiotherapy, such as in cases of close/positive margins for safe dose escalation. Although the quantum of side-effects with external beam radiotherapy has considerably reduced with the evolution of technology and the introduction of intensity modulation (intensity-modulated radiotherapy), brachytherapy still scores better in terms of dose conformality, especially in recurrent tumours (previously irradiated) and when used to treat paediatric and geriatric patients.

American Brachytherapy Society (ABS) consensus statement for soft-tissue sarcoma brachytherapy

PURPOSE

Growing data supports the role of radiation therapy in the treatment of soft tissue sarcoma (STS). Brachytherapy has been used for decades in the management of STS and can be utilized as monotherapy or as a boost to external beam radiation. We present updated guidelines from the American Brachytherapy Society regarding the utilization of brachytherapy in the management of STS.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in STS and STS brachytherapy created an updated clinical practice guideline including step-by-step details for performing STS brachytherapy based on a literature review and clinical experience.

RESULTS

Brachytherapy monotherapy should be considered for lower-recurrence risk patients or after a local recurrence following previous external beam radiation; a brachytherapy boost can be considered in higher-risk patents meeting implant criteria. Multiple dose/fractionation regimens are available, with determination based on tumor location and treatment intent. Techniques to limit wound complications are based on the type of wound closure; wound complication can be mitigated with a delay in the start of brachytherapy with immediate wound closure or by utilizing a staged reconstruction technique, which allows an earlier treatment start with a delayed wound closure.

CONCLUSIONS

These updated guidelines provide clinicians with data on indications for STS brachytherapy as well as guidelines on how to perform and deliver high quality STS brachytherapy safely with minimal toxicity.

Does an Algorithmic Approach to Using Brachytherapy and External Beam Radiation Result in Good Function, Local Control Rates, and Low Morbidity in Patients With Extremity Soft Tissue Sarcoma?

BACKGROUND

High-dose-rate brachytherapy (HDR-BT) and external-beam radiation therapy (EBRT) are two modalities used in the treatment of soft tissue sarcoma. Previous work at our institution showed early complications and outcomes for patients treated with HDR-BT, EBRT, or a combination of both radiation therapy modalities. As the general indications for each of these approaches to radiation therapy differ, it is important to evaluate the use of each in an algorithmic way, reflecting how they are used in contemporary practice at sites that use these treatments. QUESTION/PURPOSES: (1) To determine the proportions of intermediate- and long-term complications associated with the use of brachytherapy in the treatment of primary high-grade extremity soft tissue sarcomas; (2), to characterize the long-term morbidity of the three radiation treatment groups using the Radiation Therapy Oncology Group/ European Organization for Research and Treatment of Cancer (RTOG/EORTC) Late Radiation Morbidity Scoring Scheme; (3) to determine whether treatment with HDR-BT, EBRT, and HDR-BT+EBRT therapy, in combination with limb-salvage surgery, results in acceptable local control in this high-risk group of sarcomas.

METHODS

We retrospectively studied data from 171 patients with a diagnosis of high-grade extremity soft tissue sarcoma treated with limb-sparing surgery and radiation therapy between 1990 and 2012 at our institution, with a mean followup of 72 months. Of the 171 patients, 33 (20%) were treated with HDR-BT, 128 (75%) with EBRT, and 10 (6%) with HDR-BT+EBRT. We excluded 265 patients with soft tissue sarcomas owing to axial tumor location, previous radiation to the affected extremity, incomplete patient records, patients receiving primary amputation, recurrent tumors, pediatric patients, low- and intermediate-grade tumors, and rhabdoid histology. Fifteen patients (9%) were lost to followup for any reason including died of disease or other causes during the first 12 months postoperatively. This included four patients who received HDR-BT (12%), 11 who received EBRT (9%), and none who received HDR-BT+EBRT (0%) with less than 12 months followup. Determination of radiation therapy technique for each patient was individualized in a multidisciplinary forum of sarcoma specialists. Anticipated close or positive surgical margins and a low likelihood of complex soft tissue procedures were factors that encouraged use of brachytherapy, whereas the anticipated need for secondary procedures and/or soft tissue coverage encouraged use of EBRT alone. Combination therapy was used when the treatment volume exceeded the treatment field of the brachytherapy catheters or when the catheters were used to boost a close or positive surgical margin. Local recurrence, complications, and morbidity outcomes scores (RTOG) were calculated based on chart review. Between-group comparisons pertaining to the proportion of patients experiencing complications, morbidity outcomes scores, and local recurrence rates were not performed because of dissimilarities among the patients in each group at baseline.

RESULTS

The HDR-BT treatment group showed a high incidence of intermediate-term complications, with the three most common being: deep infection (33%, 11 of 33); dehiscence and delayed wound healing (24%, eight of 33); and seroma and hematoma (21%, seven of 33). The EBRT group showed a high incidence of intermediate- and long-term complications with the three most common being: chronic radiation dermatitis (35%, 45 of 128); fibrosis (27%, 35 of 128); and chronic pain and neuritis (13%, 16 of 128). The RTOG scores for each treatment group were: HDR-BT 0.8 ± SD 1.2; EBRT 1.9 ± 2.0; and HDR-BT+EBRT 1.7 ± 1.7. Overall, 142 of 169 (84%) patients were free from local recurrence: 27 (82%) in the HDR-BT group, 108 (86%) in the EBRT group, and seven (70%) in the combination therapy group.

CONCLUSIONS

In this single-institution study, an algorithmic approach to using HDR-BT and EBRT in the treatment of patients with high-grade soft tissue sarcomas can yield acceptable complication rates, good morbidity outcome scores, and a high degree of local control. Based on these results, we believe HDR-BT is best for patients with an anticipated close margin, a positive surgical margin, and for patients who are unlikely to receive a complex soft tissue procedure. Conversely, if a secondary procedure and/or soft tissue coverage are likely to be used, EBRT alone may be reasonable. Finally, combination therapy might be considered when the treatment volume exceeded the treatment field capacity for HDR-BT or when the catheters were used to boost a close or positive surgical margin.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Malignant soft tissue sarcoma of the shoulder treated by surface mould brachytherapy boost in an adjuvant setting

Purpose

Soft tissue sarcomas of the extremities account for half of all soft tissue sarcomas. Radiotherapy and surgery have been the standard modalities in the treatment of this type of cancer. Brachytherapy can be used as the sole therapy, if the target volume is localized and easily accessible. This work reports three cases of shoulder soft tissue sarcomas with positive deep resected margins, treated with a combination of external beam radiotherapy and surface mould brachytherapy boost technique.

Material and methods

Between January and June 2014, three patients received brachytherapy with sites close to the shoulder, and post-surgery involved deep resected margins. Each mould was made on a base of thermoplastic, over which dental wax was coated and catheters implanted. The target volume was defined as the tissue covering the tumor bed with lateral margins of 2-2.5 cm and depth of 1-1.5 cm. Treatment planning was computed tomography-based and dose prescribed was 85-100% isodose. Treatments has been delivered twice daily, six hours interval, and a review of reactions evaluated.

Results

Volume receiving more than 150% of the prescribed dose has been limited to less than 2%, and that above 200% to be inside the mould. Brachytherapy equivalent dose at 2 Gy per fraction (EQD₂) of these patients was 24 and 28.6 Gy. Maximum dose to organ at risk (OAR) (2 cc of OAR) ranged between 55-87% of prescribed dose, with a median dose being 80%. All cases had only grade 1 post-radiotherapy skin immediate reactions, which resolved within four weeks. In all patients, no treatment failures were noted at nearly 2-years post-irradiation.

Conclusions

Surface mould brachytherapy in soft tissue sarcomas could be a useful alternative to interstitial brachytherapy, especially where the target volume is superficially extensive with underlying critical structures, and where catheter placement may be difficult, such as the shoulder.

Evidence and clinical outcomes of adult soft tissue sarcomas of the extremities treated with adjuvant high-dose-rate brachytherapy - a literature review

The treatment strategies for adult soft tissue sarcomas of the extremities place an emphasis on local control, maintenance of limb function, and quality of life. Surgery is the mainstay of treatment for soft tissue sarcomas. Radiotherapy and chemotherapy are also both important treatments used in these patients to optimize the outcomes of limb sparing surgery. Compared to external beam radiation therapy, brachytherapy has the advantage of delivering a concentrated dose to the tumor, whilst sparing the normal tissues. Consequently, early and late complications such as bone fractures and subcutaneous fibrosis are potentially avoided by using brachytherapy. The evidence and clinical outcomes of HDR brachytherapy in soft tissue sarcomas of the extremities are described in this paper by means of a literature review.

American Brachytherapy Society (ABS) consensus statement for sarcoma brachytherapy

PURPOSE

To present recommendations for the use of brachytherapy (BT) in patients with soft tissue sarcoma (STS).

METHODS

A group of practitioners with expertise and experience in sarcoma BT formulated recommendations for BT in STS based on clinical experience and literature review.

RESULTS

The indications for adjuvant BT are discussed. There is no consensus on the use of BT alone or in combination with external beam radiation therapy (EBRT), but factors that influence the selection of this modality include tumor grade and size, prior surgeries, and tumor recurrence. Low-dose-rate, high-dose-rate, and pulsed-dose-rate radiation are all acceptable BT modalities to use for STS. Recommendations are made for patient selection, techniques, dose rates, and dosages. Outcome data and toxicity data are reviewed.

CONCLUSIONS

BT is a useful component of the treatment of STS. The advantages of BT are the targeted dose distribution, low integral dose, and short treatment times. Ultimately the clinician should select the modality or combination of modalities that are most familiar to the treatment team and suitable to the patient.

Early complications of high-dose-rate brachytherapy in soft tissue sarcoma: a comparison with traditional external-beam radiotherapy

BACKGROUND

Radiotherapy and surgery are routinely utilized to treat extremity soft tissue sarcoma. Multiple radiation modalities have been described, each with advantages and disadvantages, without one modality demonstrating clear superiority over the others.

QUESTIONS/PURPOSES

We determined the overall initial complication rate in patients receiving surgery and radiotherapy, which specific complications were found when comparing different modalities, and whether combination therapy increased the overall rate of complications compared with surgery and single-modality radiotherapy.

PATIENTS AND METHODS

We retrospectively reviewed the records of 190 patients who received external-beam radiotherapy (141 patients), high-dose-rate brachytherapy (37 patients), or both (12 patients). We evaluated 100 men and 90 women (mean age, 57 years; range, 18-94 years) for tumor size and subtype, comorbidities, stage, grade, margin of resection, type of adjuvant treatment, and complications. Minimum followup was 3 months (mean, 40 months; range, 3-155 months).

RESULTS

The most frequent early complications in the high-dose-rate brachytherapy cohort were infection, cellulitis, and seroma and/or hematoma. In the external-beam radiotherapy cohort, chronic edema, fibrosis, and chronic radiation dermatitis were more frequently encountered. The total number of early complications and overall incidence of major complications requiring further surgery were similar among the three cohorts, but a larger number of patients in the high-dose-rate brachytherapy group required subsequent surgery for infection compared with the external-beam radiotherapy group.

CONCLUSIONS

High-dose-rate brachytherapy decreases radiation exposure and allows shorter duration of treatment compared with traditional external-beam radiotherapy but has a higher perioperative wound complication rate.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

Adjuvant high dose rate brachytherapy for soft tissue sarcomas: initial experience report

Purpose

Adjuvant high-dose-rate brachytherapy (HDRBT) offers advantages over low dose rate brachytherapy (LDRBT), although there are little data on local tumor control and treatment related toxicity. We report outcome in patients with primary, recurrent, and metastatic extremity and superficial trunk soft tissue sarcoma.

Material and methods

Eleven patients (12 sites) with intermediate or high grade sarcoma were treated with adjuvant HDRBT following surgical resection. Patients were treated at 3.4 Gy fractions delivered twice daily to a total dose of 34 Gy (1 patient received 9 fractions).

Results

With median follow-up of 20.8 months, 1 patient developed a local recurrence. 2-year local control and overall survival are 89% and 71%, respectively. Wound complications occurred in 3 sites. Two of the wound complications developed in the area of previous external beam radiotherapy (EBRT).

Conclusion

Surgical resection followed by HDRBT is associated with excellent early local tumor control and acceptable wound complication.

Tratamento radioterápico adjuvante nos sarcomas de extremidades de alto grau

OBJETIVO: Avaliar as terapias utilizadas em nossa instituição no tratamento dos sarcomas de extremidades de alto grau, mediante análise da sobrevida global do tratamento multidisciplinar. MATERIAIS E MÉTODOS: Estudo retrospectivo com 36 pacientes, no período de 1993 a 2007, em estádios IIb/III, submetidos a radioterapia externa após cirurgia com ou sem reforço de dose com braquiterapia. RESULTADOS: Trinta e seis pacientes foram submetidos a tratamento cirúrgico seguido de radioterapia externa, sendo que quatro pacientes (11%) receberam reforço de dose com braquiterapia e sete pacientes (19%) receberam quimioterapia. A dose mediana de radioterapia foi de 50 Gy (IC95%: 47-53 Gy), sendo realizado reforço de dose em quatro pacientes com braquiterapia, com dose variando de 16,2-35 Gy. A quimioterapia foi indicada em sete pacientes (19%) com margens positivas. Quinze pacientes apresentaram recidiva local e/ou a distância (42%) e todos faleceram. Vinte e um pacientes (58%) encontram-se sem evidência clínica e radiológica de recidiva local e/ou a distância. O seguimento mediano é de 88 meses (IC95%: 74-102). A taxa de sobrevida global para sete anos foi de 80%. CONCLUSÃO: Concluímos que a associação cirurgia + radioterapia apresenta-se como tratamento eficaz e com ótimas respostas e melhora da sobrevida global na possibilidade de associação da braquiterapia.

Perioperative hyperfractionated high-dose rate brachytherapy for the treatment of soft tissue sarcomas: multicentric experience

BACKGROUND

Low-dose rate brachytherapy is a well-established adjuvant treatment for soft tissue sarcomas (STS). The experience with high-dose rate brachytherapy (HDR BT) in this indication is limited. The purpose of our study was to evaluate the viability of perioperative hyperfractionated HDR BT for STS.

METHODS

Forty-five patients with primary (17 cases) or recurrent (28 cases) STS were treated with resection and HDR BT between 1998 and 2007. Eleven patients were treated with HDR BT alone (mean dose 40 Gy; 30-54 Gy) and 34 were treated with a combination of HDR BT (mean dose 24 Gy; 15-30 Gy) and external beam radiotherapy (EBRT) (40-50 Gy). Hyperfractionation, 3 Gy twice daily, was used for HDR BT with plastic tubes. Adjuvant chemotherapy was indicated for patients with high risk of dissemination.

RESULTS

Local control (LC) was achieved in 17 patients (100%) treated for primary tumor and in 18 of 28 patients (64%) treated for recurrence; this difference was statistically significant (p = 0.004). Distant metastases occurred in seven patients (15.6%). The 5-year overall survival was 70%; the 5-year local control was 74%. LC was significantly better for extremities sarcomas in comparison with trunk tumors, for patients treated with EBRT and BT in comparison with BT alone, and for doses >65 Gy.

CONCLUSIONS

Our study suggests that perioperative HDR BT is a promising method for achieving high biological doses with good LC in the postoperative radiotherapy of STS and that combination of BT and EBRT provides better tumor control than BT alone.

Adjuvant high-dose-rate and low-dose-rate brachytherapy with external beam radiation in soft tissue sarcoma: a comparison of outcomes

PURPOSE

To compare outcomes of patients treated with low-dose-rate (LDR) adjuvant brachytherapy (BT) + external beam radiation therapy (EBRT) vs. high-dose-rate (HDR) adjuvant BT + EBRT.

METHODS AND MATERIALS

Thirty-seven patients with soft tissue sarcoma (STS) were treated with pre- or postoperative external beam irradiation and postoperative LDR or HDR BT.

RESULTS

There was no significant difference in the 2-year local control rates (90% with LDR boost vs. 94% for HDR). The rate of National Cancer Institute (NCI) grades 2-4 wound-healing complications was 40% in the LDR group vs. 18% in the HDR group (p = 0.14). On univariate analysis, only suboptimal geometry of the implant predicted for increasing complication rate in the LDR group. In the HDR group, BT dose per fraction, total BT dose, and total biologically equivalent dose (BED3) radiation dose were significant.

CONCLUSIONS

HDR and LDR boost BT results in acceptable local control for STS. There is a suggestion that HDR may have lower incidence of severe (grade > or = 3) acute toxicity than LDR.

Adjuvant High Dose Rate Brachytherapy in the Management of Soft Tissue Sarcoma

OBJECTIVES

Although brachytherapy has been used in the management of soft tissue sarcoma for decades, there is little published data regarding dose and toxicity. We performed an interim analysis of our high dose-rate experience to establish dosing guidelines.

METHODS

We analyzed our first 12 soft tissue sarcoma patients treated with high dose-rate brachytherapy as tumor bed boost (in conjunction with beam therapy), seeking an association between treatment factors and wound-healing complications. In the process of our analysis, we devised a dosimetric method to retrospectively quantify delivered dose. Our findings were used to formulate dosing guidelines; the first 5 cases treated along these guidelines are also presented.

RESULTS

Despite the small number of cases, we were able to demonstrate a correlation (P < 0.01) between wound healing and brachytherapy dose (fractional or total biologically equivalent dose). We found no relationship between wound healing and patient age, diabetes, width of excised skin, cross-sectional area of implant, sequencing of therapy, or surgery-to-brachytherapy interval.

CONCLUSION

There appears to be a relationship between dose and disturbed wound healing that should be respected to avoid unnecessary toxicity. An objective technique for defining target volume and quantifying dose is proposed for meaningful analysis of dose/effect relationships.

Perioperative high-dose-rate brachytherapy in soft tissue sarcomas of the extremity and superficial trunk in adults: initial results of a pilot study

PURPOSE

This study was undertaken to determine the feasibility of perioperative high-dose-rate brachytherapy (PHDRB) as an alternative to standard low-dose-rate brachytherapy in adult patients with soft tissue sarcomas.

METHODS AND MATERIALS

Twenty-five adult patients with soft tissue sarcomas of the extremities or the superficial trunk were treated with surgical resection and PHDRB (16, 24, or 32Gy) for negative, close/microscopically positive, or grossly involved surgical resection margins, respectively. External beam radiation therapy (45Gy) was added postoperatively. Adjuvant chemotherapy with ifosfamide and doxorubicin was given to patients with high-grade tumors.

RESULTS

Resection margins were negative in 6 patients (24.0%), close/microscopically positive in 18 (72.0%), and grossly involved in 1 (4.0%). One patient (4.0%) with wound dehiscence needed reoperation. Three patients failed in the anatomical region treated, but relapse sites were not adjacent to the area treated with PHDRB. After a median followup of 23.2 months (range 2.8-48.0), the 4-year local and regional control rates were 100% and 80.5%, respectively. Four-year overall survival was 78.2%.

CONCLUSIONS

Locoregional control and survival results are encouraging for this high-risk patient population. PHDRB results seem to be similar to those obtained with low-dose-rate brachytherapy.

Surgically (laparotomy/laparoscopy) guided placement of high dose rate interstitial irradiation catheters (LG-HDRT): Technique and outcome

OBJECTIVE

To describe and evaluate the technique and the clinical outcome of a new modality for the treatment of women with persistent or recurrent pelvic malignancies utilizing surgically (laparotomy or laparoscopic) guided high dose rate (HDR) catheters to complete high dose rate interstitial irradiation therapy (LG-HDRT).

METHODS

Between 6/2000 and 6/2004, 14 women with histologic evidence of postradiation persistent (3 patients) or recurrent (11 patients) pelvic disease underwent LG-HDRT. Five patients (36%) received treatment for a 2nd, 3rd or 4th recurrence. Preoperative clinical and radiologic evaluation to exclude evidence of extrapelvic disease was routine. Initial intraoperative evaluation included intraabdominal inspection and or biopsy to determine the extent of disease. A two "team" approach was used to place the 100 cm Teflon after loading HDR catheters. Each catheter had its open ends closed with bone wax prior to placement. Using a 14 gauge intravenous catheter as a guide, each HDR catheter was individually placed transvaginally. The tumor bed (treatment volume) was marked circumferentially with clips to facilitate treatment planning. Dosimetry was typically completed on the day of surgery and HDR therapy was started within the initial 24 postoperative hours. The catheters were removed transvaginally, without anesthesia following completion of therapy.

RESULTS

Mean patient age was 63.1 years and weight was 138.2 lb. Squamous cell cancer of the vagina or cervix was the most common (64%) diagnosis. The mean time from initial diagnosis to LG-HDRT was 67.9 months. The procedure was completed laparoscopically in 71% of patients, with 4 patients requiring laparotomy (3 conversions from laparoscopy). The mean duration of surgery was 94.9 min and the mean hospital stay was 4.8 days. Only 2 patients (14%) were discharged prior to the completion of therapy. The mean number of catheters placed was 6.1 and the mean dose delivered was 20 Gy over a mean of 5 fractions. There were no major intraoperative complications. Postradiation complications were limited to DVT (1), bladder bleeding (1), </=grade 2 gastrointestinal disturbances (3) and vulvovaginal desquamation (1). Overall posttreatment survival (mean 20.75 months) has been excellent with only 2 local recurrences and one patient dead of disease.

CONCLUSION

The efficacy of this treatment technique as demonstrated by the superb rate of local control (86%) and mean overall survival of 20.75 months compares favorably with other radiation or surgical treatment modalities in this population. Combined with the relative absence of morbidity, even when treating women following multiple recurrences suggests that LG-HDRT a viable treatment option for many women with local, postradiation persistent or recurrent pelvic cancer.

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.

Perioperative Hyperfractionated High-Dose Rate Brachytherapy Combined with External Beam Radiotherapy in the Treatment of Soft Tissue Sarcomas

Aims and background

Low-dose rate brachytherapy alone or in combination with external beam radiotherapy represents a well-established adjuvant treatment in soft tissue sarcomas following surgical resection. The experience with high-dose radiotherapy in this indication is limited. The purpose of our study was an evaluation of the viability of perioperative hyperfractionated high-dose rate brachytherapy in combination with external beam radiotherapy for primary and recurrent soft tissue sarcomas.

Patients and methods

From February 1998 through June 2002, 10 adult patients with soft tissue sarcomas were treated by interstitial perioperative high-dose rate brachytherapy and external beam radiotherapy. TNM classification was pT2bpN0pM0 in 9 patients and pT1bpN0pM0 in 1 patient. Grade of differentiation was G1 (2 patients), G2 (n = 1), G3 (n = 5), G4 (n = 2). Surgical margins were negative in 7 cases, close in 2 cases and positive in 1 case. The tumor was localized in an extremity in all cases. Hyperfractionation 3 Gy twice daily at 10 mm from the plane of sources was used for brachytherapy, with total doses 18–30 Gy. The patients received external beam radiotheapy with doses 40–50 Gy after brachytherhapy. Follow-up periods were between 24–71 months (median, 46).

Results

Local control of the disease was achieved in all 10 patients. Distant metastases occurred in 2 cases. One patient was disease free after salvage surgery and chemotherapy, and one patient died of lung disease progression 14 months after brachytherapy. In one case, subcutaneous fistula occurred after radiotherapy and was cured by an excision. Six patients experienced grade 1 or 2 fibrosis and 1 case a mild peripheral neuropathy was recorded.

Conclusions

Our study on a small number of patients suggests that perioperative hyperfractionated high-dose rate brachytherapy with doses 8 × 3 Gy in combination with external beam radiotherapy 40–50 Gy is a promising method to achieve high biological doses in the postoperative radiotherapy of soft tissue sarcomas without severe late morbidity and warrants further research.

Current results of brachytherapy for soft tissue sarcoma

Perioperative brachytherapy results in a better local control rate than surgery alone for extremity soft tissue sarcoma. Brachytherapy enables the delivery of a high radiation dose to a limited volume of tissue, allows the reduction of radiation treatment time, enables direct visualization of the tumor bed and surrounding critical structures, and costs less than external beam radiotherapy. The literature seems to regard the effectiveness of brachytherapy as comparable to that of external beam radiotherapy, and the side effect profile is acceptable. Traditional low-dose-rate brachytherapy methods require extended periods of patient isolation, but recent technologic advances may obviate this necessity. Newer high-dose-rate (HDR) brachytherapy delivery methods allow for the fractionation of radiation delivery and outpatient treatment in some cases. Furthermore, with HDR brachytherapy, the radiation dose distribution can be tailored around critical anatomic structures. Although the application of HDR brachytherapy to soft tissue sarcoma is relatively new, it seems to result in a satisfactory local control rate and may replace traditional low-dose-rate techniques.

[Brachytherapy in soft tissue sarcomas]

Soft tissue sarcomas are rare tumors with a high risk or local recurrence and a risk of distant metastases. Standard treatment advocated is the combination of conservative resection and external radiotherapy. Brachytherapy is an integrated part of the multidisciplinary treatment. Brachytherapy can increase local control with good functional results. Primary exclusive brachytherapy has been used and is effective and safe in high grade sarcomas (randomized trial of MSKCC). Brachytherapy seems to be important as part of the treatment of central localization (shoulder, groin) and sarcomas with positive resection margins, but its relation with external radiotherapy has to be defined. Brachytherapy used with special guidelines allows to obtain an improved local control with an acceptable level of complication.