Patterns of Radiotherapy Use and Outcomes in Head and Neck Soft-Tissue Sarcoma in a National Cohort

Comparison of Definitive Radiotherapy-Based Treatment and Surgical-Based Treatment for Locally Advanced Head and Neck Soft Tissue Sarcoma

Background: Head and neck soft-tissue sarcomas are rare but aggressive malignancies. Definitive radiotherapy might be an alternative treatment choice in patients unfit for surgery with preservation of organ function and facial morphology. Whether definitive radiotherapy is comparable with surgery has not been fully demonstrated. In this study, we compared the prognosis of patients with radiotherapy-based treatment and with surgery-based treatment. Methods: From May 2014 to February 2021, patients with locally advanced head and neck soft-tissue sarcoma treated with either definitive radiotherapy-based treatment or radical surgery-based treatment were retrospectively enrolled. Clinical outcomes including tumor response, patients' survival and acute treatment-related toxicities were evaluated. Kaplan-Meier curves with log-rank test were used to compare survival data. Cox regression analysis was used to explore prognostic factors. Results: A total of 24 patients (12 males and 12 females, 3 to 61 years old) were eligible for analysis. The median follow-up time was 49 (range: 6-96) months. In 16 patients receiving definitive radiotherapy-based treatment, 6 reached complete response. The survival curve showed that there was no statistically significant difference in overall survival (OS), distant metastasis-free survival (DMFS), loco-regional relapse-free survival (LRRFS) and progression-free survival (PFS) between the two groups of patients (p = 0.35, p = 0.24, p = 0.48, p = 0.1, respectively). COX regression analysis showed that older age was associated with poor DMFS. There was no significant difference in grade 3-4 toxicities between the two groups. Conclusions: In cases of contradictions to surgery, refusal to surgery or failure to complete resection, chemoradiotherapy might be an alternative treatment option.

Is there a place for definitive radiotherapy in the treatment of unresectable soft-tissue sarcoma? A systematic review

BACKGROUND

Definitive external beam radiotherapy (EBRT) is an unusual treatment of unresectable soft-tissue sarcomas (STS). Recent technical innovations and physical advantages of particle therapies may improve results of this therapeutic option. The role of this review was to report the clinical results of photon- and particle-based EBRT in unresectable STS.

MATERIAL AND METHODS

We performed a systematic review of the literature on Pubmed database to identify studies investigating the efficacy and safety of EBRT. The primary endpoint was local control (LC) and secondary endpoints were progression-free survival (PFS), overall survival (OS) and adverse events in a subset of patients with gross disease STS.

RESULTS

We identified 29 studies involving 1409 patients (pts) evaluating photon (n = 18; 956 pts), proton (n = 1; 21 pts), carbon ion (n = 2; 152 pts), neutron (n = 7; 259 pts) or pion (n = 1; 21 pts) therapy. Definitive EBRT achieves valuable 5-year LC rates of 28-73% with photon and 52-69% with particle therapies. Most local failures (66-100%) occurred within 3 years. Long-term disease control can be achieved in a fraction of patients, with 5-year PFS and OS of 0-39% and 24.7-63%, respectively. The rate of severe adverse events was highly variable with photons, <15% in proton and carbon ion therapy, whereas 25 to 50% of patients treated with neutrons and pions presented severe AE. While a dose higher or equal 64 Gy seem to improve the prognosis, delivering a dose higher or equal 68 Gy dramatically increases severe adverse events.

CONCLUSION

Definitive EBRT with dose 64-66 Gy seems to be a safe and efficient treatment for unresectable STS. Future clinical trials should assess the potential of biomarkers of response, thus identifying patients that could benefit from local treatment.

Long-term outcomes after definitive radiotherapy with modern techniques for unresectable soft tissue sarcoma

INTRODUCTION

The use of definitive radiotherapy (dRT) in unresectable soft-tissue sarcomas (STS) is still controversial and recent data are scarce. We report clinical results of this therapeutic option.

METHODS

We retrospectively included STS patients treated between 2009 and 2020, with dRT for unresectable or with a measurable residual disease after R2 surgery. Response rate, local failure (LF), progression-free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

116 patients with localized/locally advanced STS were treated from 2009 to 2020, with a median age of 71 years (range 18-92). Most tumors were deep-seated (96.6%), grade 2-3 (85.1%), located in the trunk or extremities (74.2%). Helical tomotherapy, volumetric modulated arc therapy, or stereotactic radiotherapy was performed in 39.7%, 19% and 8.6% of patients, respectively. The median equivalent dose in 2 Gy fractions (EQD2) was 60 Gy (IQR 52-65). At first follow-up, 66 (58.9%) and 25 (22%) patients had stable disease and partial response. After a median follow-up of 54.8 months (IQR 40.3-95.4), 3-year LF, PFS and OS were 43.2%, 16.6% and 34%, respectively. Median OS was 21.4 months (95%CI 14-26). The multivariate analysis identified grade 3 and AJCC T3-T4 stage to be associated with both shorter PFS and OS (all p<0.001). Macroscopically incomplete resection and EQD2 ≥64Gy were associated with better OS (p=0.016 and p=0.007). Acute and late severe adverse events occurred in 24 (19.7%) and 5 (4.3%) patients.

CONCLUSION

In unresectable STS patients, definitive modern radiotherapy is a safe and effective treatment yielding long term control in selected patients.

Radiation Therapy in Adult Soft Tissue Sarcoma-Current Knowledge and Future Directions: A Review and Expert Opinion

Simple Summary

Radiation therapy (RT) is an integral part of the treatment of adult soft-tissue sarcomas (STS). Although mainly used as perioperative therapy to increase local control in resectable STS with high risk features, it also plays an increasing role in the treatment of non-resectable primary tumors, oligometastatic situations, or for palliation. This review summarizes the current evidence for RT in adult STS including typical indications, outcomes, side effects, dose and fractionation regimens, and target volume definitions based on tumor localization and risk factors. It covers the different overall treatment approaches including RT either as part of a multimodal treatment strategy or as a sole treatment and is accompanied by a summary on ongoing clinical research pointing at future directions of RT in STS.

Abstract

Radiation therapy (RT) is an integral part of the treatment of adult soft-tissue sarcomas (STS). Although mainly used as perioperative therapy to increase local control in resectable STS with high risk features, it also plays an increasing role in the treatment of non-resectable primary tumors, oligometastatic situations, or for palliation. Modern radiation techniques, like intensity-modulated, image-guided, or stereotactic body RT, as well as special applications like intraoperative RT, brachytherapy, or particle therapy, have widened the therapeutic window allowing either dose escalation with improved efficacy or reduction of side effects with improved functional outcome. This review summarizes the current evidence for RT in adult STS including typical indications, outcomes, side effects, dose and fractionation regimens, and target volume definitions based on tumor localization and risk factors. It covers the different overall treatment approaches including RT either as part of a multimodal treatment strategy or as a sole treatment, namely its use as an adjunct to surgery in resectable STS (perioperative RT), as a primary treatment in non-resectable tumors (definitive RT), as a local treatment modality in oligometastatic disease or as palliative therapy. Due to the known differences in clinical course, general treatment options and, consequently, outcome depending on lesion localization, the main part of perioperative RT is divided into three sections according to body site (extremity/trunk wall, retroperitoneal, and head and neck STS) including the discussion of special applications of radiation techniques specifically amenable to this region. The review of the current evidence is accompanied by a summary on ongoing clinical research pointing at future directions of RT in STS.