Low-dose neoadjuvant external beam radiation therapy for soft tissue sarcoma

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Nutritional Predictors of Wound Infection in Patients with Lower Extremity Soft Tissue Sarcoma

BACKGROUND

Soft tissue sarcoma (STS) frequently requires high-risk surgery that predisposes patients to complex wounds. Past studies have identified a variety of tumor characteristics as risk factors for wound infection (WI); however, physiologic characteristics have not yet been studied in this population. Thus, the objective of this study is to identify any nutritional indicators and physiologic characteristics associated with the development of WI.

PATIENTS AND METHODS

633 patients from a large tertiary care center institution were identified with lower extremity STS removed from 1992 to 2017. The primary outcomes of interest were WI at patient's surgical site within 90 days of surgery and additional procedure due to wound infection. Patients' laboratory values, comorbidities, and other characteristics were assessed using multivariable analysis to determine risk factors for WI. Receiver operator characteristic (ROC) curves were used for analysis of plasma glucose and albumin levels to determine a useful risk threshold. Significance was determined to be p < 0.05.

RESULTS

Postoperative plasma glucose levels were significantly higher among patients with WI compared with those without (p < 0.001) and showed predictivity in ROC analysis (AUC 0.77, 95% CI 0.72-0.82). Preoperative albumin (p < 0.001) and prognostic nutritional index score (p = 0.002) were significantly lower among patients with WI. Partial thromboplastin time (PTT), international normalized ratio (INR), white blood cell count (WBC), and platelet count values had no effect on WI. Smoking elevated risk for WI (OR 1.64, p < 0.01). Significant risk factors were the same when assessed for those with WI undergoing additional procedures.

CONCLUSIONS

Postoperative plasma glucose levels, preoperative albumin levels, and smoking status are useful nutritional variables in predicting WI in STS excisional procedures.

Low-dose preoperative radiation, resection, and reduced-field postoperative radiation for soft tissue sarcomas

BACKGROUND AND OBJECTIVES

Radiotherapy (RT) enables conservative surgery for soft tissue sarcoma (STS). RT can be delivered either pre-operatively (PreRT) or postoperatively (PORT), yet in some patients, neither approach is fully satisfactory (e.g., urgent surgery or wound healing risk prevents PreRT, yet PORT alone cannot cover the entire surgical field). We hypothesized that, in such situations, low-dose PreRT (LD-PreRT) would decrease the risk of intraoperative tumor seeding and thus permit PORT to a reduced volume (covering the high-risk tumor bed but not all surgically manipulated tissues).

METHODS

We identified a single-institution retrospective cohort of 78 patients treated with LD-PreRT (10-30 Gy), resection, and PORT between 1980 and 2018.

RESULTS

At a median follow-up of 8.2 years, 8-year overall survival (OS) was 65.9%, disease-free survival (DFS) 50.5%, and local control (LC) 76.7%; in 45 patients with extremity/superficial trunk (E/ST) STS, 8-year LC was 80.9%. Both before and after propensity score adjustment, there were no differences in OS, DFS, or LC between this cohort and a separate cohort of 394 STS (221 E/ST-STS) patients treated with surgery and PORT alone.

CONCLUSIONS

In patients for whom neither PreRT nor PORT alone is optimal, LD-PreRT may prevent intraoperative tumor seeding and enable PORT to a reduced volume while preserving oncologic outcomes.

Retroperitoneal soft tissue sarcoma: low-dose neoadjuvant radiation therapy followed by surgery with or without intraoperative radiotherapy and adjuvant radiation therapy

BACKGROUND

We describe the clinical history, outcome, and toxicity of five patients with high-grade retroperitoneal soft tissue sarcoma (RSTS) who were treated with neoadjuvant low-dose radiotherapy (RT) followed by resection with or without intraoperative radiotherapy (IORT), followed by adjuvant RT. We aim to provide additional evidence for the various treatment options that exist for this rare tumor entity.

METHODS

Most patients presented with mild abdominal symptoms. Diagnosis was confirmed by biopsy. Additional imaging was done by sonography, magnetic resonance imaging (MRI), and/or positron emission tomography (PET)/computed tomography (CT). All patients were treated with neoadjuvant RT of 19.8 Gy in 1.8-Gy fractions followed by resection and postoperative RT up to 45 Gy with a median interval between resection and start of postoperative RT of 5 weeks. Two patients received additional IORT. Median follow-up was 61 months.

RESULTS

One patient developed a local recurrence that was diagnosed 30 months after the start of the first therapy. He was treated with a salvage resection and had no evidence of disease at the last follow-up. Another patient developed a right-sided RSTS on the contralateral side from the primary radiation field with pelvic bone infiltration 56 months after the start of RT. He was treated again by RT and resection and was without evidence of disease at last follow-up. Radiotherapy was well tolerated without major toxicity.

CONCLUSION

The treatment of RSTS by low-dose neoadjuvant RT, resection with IORT and adjuvant RT seems to be a feasible and effective treatment approach. Further studies comparing neoadjuvant with adjuvant RT are necessary to find the best treatment option.

Utilization pattern and survival outcomes of adjuvant therapies in high-grade nonretroperitoneal abdominal soft tissue sarcoma: A population-based study

BACKGROUND

Nonretroperitoneal abdominal soft tissue sarcoma (NRA-STS) is a rare disease with limited data supporting its management. Our study aimed to reveal the utilization patterns of adjuvant therapy and its potential survival benefits using the National Cancer Data Base.

MATERIALS

The analysis included patients with resected high-grade NRA-STS. Chi-square analysis was used to evaluate distribution of patient and tumor-related factors within treatment groups. The Kaplan-Meier and Cox proportional hazards model were utilized to evaluate overall survival according to treatment approach. Multivariate analysis was used to determine the impact of these factors on patients' outcome. Matched propensity score analysis was implemented to control for imbalance of confounding variables.

RESULTS

At median follow-up of 49 months, 5-year overall survival improved from 46% without adjuvant radiation therapy to 52% (P = 0.009) with radiotherapy delivery with a 30% reduction in hazard of death (95% confidence interval = 0.58-0.84). On multivariate analysis, age <50, tumor <8 cm, negative margins and radiotherapy delivery were significant predictors of improved survival. Chemotherapy was not associated with significant survival improvement (Hazard Ratios [HR]: 0.89, P = 0.28).

CONCLUSION

Adjuvant radiotherapy was associated with improved survival in high-grade NRA-STS. Chemotherapy was not associated with a survival improvement; however, further studies are needed to refine treatment strategies.

Surgical Treatment of Primary Osteosarcoma of the Sacrum: A Case Series of 26 Patients

STUDY DESIGN

Twenty-six patients were treated surgically for sacral osteosarcomas in our center. The oncological and functional results are analyzed.

OBJECTIVE

To describe the general characteristics and evaluate the outcome of surgical treatment of primary osteosarcoma of the sacrum.

SUMMARY OF BACKGROUND DATA

A very few reports have addressed the technique and outcome of surgical treatment of primary sacral osteosarcoma. The survival rate of such cases is low.

METHODS

The clinical data of 26 patients treated surgically for sacral osteosarcomas from June 2000 to December 2013 at our hospital were retrospectively reviewed.

RESULTS

There were 15 males and 11 females with a median age of 28 years (range, 12-68 years). Distal metastasis occurred in 13 patients (50%), and local recurrence occurred in 10 patients (38.5%, including 6 patients with additional distal metastasis). The 1-year and 5-year survival rates were 92.3% and 38.7%, respectively. Adequate and inadequate surgical margins were obtained in 16 and 10 cases, respectively. Patients with adequate margins had a significantly lower recurrence rate (P = 0.015) and higher event-free survival rate (P = 0.04) than those with inadequate margins. However, the overall survival rate did not differ significantly between patients with adequate and inadequate margins (P = 0.22). Only seven cases showed a good response based on necrosis rate (>90%). Patients with a better response to chemotherapy had better event-free and overall survival rates.

CONCLUSION

Adequate surgical margins are achievable in most cases of sacral osteosarcomas. Adequate margins can significantly improve the recurrence rate and event-free survival rate compared with inadequate margins. However, sacrectomy is still a challenging surgical technique. Adequate margins are also difficult to obtain in sacrectomy. In addition, only a few patients had a good response to chemotherapy. These reasons lead to a low 5-year survival rate in primary sacral osteosarcoma patients.

LEVEL OF EVIDENCE

4.

Risk factors for significant wound complications following wide resection of extremity soft tissue sarcomas

BACKGROUND

Wound complications following resection of a localized soft tissue sarcoma have been associated with lower extremity location, large tumor volume, and use of preoperative radiation. Some of these wounds, however, show the potential for healing with local wound care and nonsurgical techniques. We are unaware of any published data establishing factors associated with nonhealing wounds that ultimately are treated with local or free vascularized tissue transfer.

QUESTIONS/PURPOSES

The purpose of this study was to determine the variables associated with development of a significant wound complication defined as one that underwent a secondary procedure using local or free tissue transfer after resection of a localized soft tissue sarcoma.

METHODS

Using our institution's cancer center database, we identified 140 patients who underwent resection of a localized extremity soft tissue sarcoma at our institution between 1997 and 2010. Thirty-two patients were excluded who underwent immediate planned vascularized tissue transfer, along with 26 patients who did not receive radiation, and an additional three patients were excluded who were followed for less than 1 month. This left 79 patients, including 18 treated with postoperative external beam radiotherapy and 61 with preoperative external beam radiotherapy. Of patients receiving radiation treatment before surgery, 13 received no additional radiation treatment, 33 underwent intraoperative radiation with electrons (IOERT) to sites considered at high risk for local recurrence, and an additional 15 had perioperative brachytherapy. Univariate and multiple regression analyses were performed using frequency of local or free tissue transfer at 3 weeks or greater postoperatively owing to wound-related complications as a dependent variable.

RESULTS

Lower extremity location and vascular involvement were associated with use of delayed vascularized tissue coverage for wound-healing problems. Patients in this series who underwent preoperative external beam radiotherapy coupled with dose-escalated IOERT or chemotherapy had a similar rate of flap use compared with patients treated with postoperative radiation.

CONCLUSIONS

Patients with tumors of the lower extremity involving major neurovascular structures and for whom radiation therapy is planned should be counseled specifically because they appear to be at increased risk for use of delayed local or free vascularized tissue transfer for a nonhealing wound following resection of a localized extremity soft tissue sarcoma.

Perioperative irradiation in extremity soft tissue sarcoma

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