Regional hyperthermia for soft tissue sarcoma - a survey on current practice, controversies and consensus among 12 European centers

PURPOSE

To analyze the current practice of regional hyperthermia (RHT) for soft tissue sarcoma (STS) at 12 European centers to provide an overview, find consensuses and identify controversies necessary for future guidelines and clinical trials.

METHODS

In this cross-sectional survey study, a 27-item questionnaire assessing clinical subjects and procedural details on RHT for STS was distributed to 12 European cancer centers for RHT.

RESULTS

We have identified seven controversies and five consensus points. Of 12 centers, 6 offer both, RHT with chemotherapy (CTX) or with radiotherapy (RT). Two centers only offer RHT with CTX and four centers only offer RHT with RT. All 12 centers apply RHT for localized, high-risk STS of the extremities, trunk wall and retroperitoneum. However, eight centers also use RHT in metastatic STS, five in palliative STS, eight for superficial STS and six for low-grade STS. Pretherapeutic imaging for RHT treatment planning is used by 10 centers, 9 centers set 40-43 °C as the intratumoral target temperature, and all centers use skin detectors or probes in body orifices for thermometry.

DISCUSSION

There is disagreement regarding the integration of RHT in contemporary interdisciplinary care of STS patients. Many clinical controversies exist that require a standardized consensus guideline and innovative study ideas. At the same time, our data has shown that existing guidelines and decades of experience with the technique of RHT have mostly standardized procedural aspects.

CONCLUSIONS

The provided results may serve as a basis for future guidelines and inform future clinical trials for RHT in STS patients.

Update on Dosing and Fractionation for Neoadjuvant Radiotherapy for Localized Soft Tissue Sarcoma

OPINION STATEMENT

Neoadjuvant radiotherapy (RT) over 5-6 weeks with daily doses of 1.8-2.0 Gy to a total dose of 50-50.4 Gy is standard of care for localized high-grade soft tissue sarcomas (STS) of the extremities and trunk wall. One exception is myxoid liposarcomas where the phase II DOREMY trial applying a preoperative dose of 36 Gy in 2 Gy fractions (3-4 weeks treatment) has achieved excellent local control rates of 100% after a median follow-up of 25 months.Hypofractionated preoperative RT has been investigated in a number of phase II single-arm studies suggesting that daily doses of 2.75-8 Gy over 1-3 weeks can achieve similar oncological outcomes to conventional neoadjuvant RT. Prospective data with direct head-to-head comparison to conventional neoadjuvant RT investigating oncological outcomes and toxicity profiles is eagerly awaited.For the entire group of retroperitoneal sarcomas, RT is not the standard of care. The randomized multi-center STRASS trial did not find a benefit in abdominal recurrence-free survival by the addition of preoperative RT. However, for the largest histological subgroup of well-differentiated and grades I and II dedifferentiated liposarcomas, the STRASS trial and the post-hoc propensity-matched STREXIT analysis have identified a possible benefit in survival by preoperative RT. These patients deserve to be informed about the pros and cons of preoperative RT while the longer follow-up data from the STRASS trial is awaited.

Stereotactic radiotherapy for soft tissue and bone sarcomas: real-world evidence

Introduction:

Selected patients with locally advanced or metastatic soft tissue and bone sarcomas (STBS) may benefit from intensive local treatment, such as stereotactic radiotherapy (SRT). This study aimed to summarize the utilization and outcomes of SRT in STBS and to identify predictive factors for progression and survival.

Materials and methods:

Consecutive patients with advanced STBS who underwent STBS in a sarcoma tertiary center were identified. We collected tumor- and treatment-related factors. Endpoints comprised time to local progression (TTLP), local progression-free survival (LPFS), time to progression, progression-free survival, and overall survival (OS). The Cox proportional-hazards model was used to identify prognostic factors.

Results:

We identified 141 patients who underwent 233 SRTs. Median follow-up was 21 months. Local and distant progression occurred after 19 and 163 SRTs, respectively. SRT for lung metastases was predictive for better TTLP and LPFS (hazard ratio, HR = 0.12, p = 0.007 and HR = 0.42, p = 0.002, respectively). Bone sarcoma (HR for TTLP = 3.18, p = 0.043; HR for LPFS = 1.99, p = 0.028) and lower administered dose (HR for TTLP = 0.98, p = 0.007; HR for LPFS = 0.99, p = 0.012) were predictive for worse TTLP and LPFS. SRT for oligometastases (HR = 0.46, p = 0.021) and lung metastases (HR = 0.55, p = 0.046) was predictive for better OS, whereas diagnosis of bone sarcoma (HR = 2.05, p = 0.029) was predictive for worse OS.

Conclusion:

SRT provides excellent local control in STBS patients without significant toxicity. Patients with oligometastatic disease, lung metastases, and soft tissue sarcomas benefit the most from SRT. The dose escalation moderately enhances local control; however, it does not translate into better survival.

Definitive Radiotherapy in the Management of Non-Resectable or Residual Retroperitoneal Sarcomas: Institutional Cohort Analysis and Systematic Review

Background:

There is currently no consensus on optimal management of patients with primary or recurrent non-resectable/residual retroperitoneal sarcomas (RPS). The objective of this study was to document the outcomes of patients with primary or recurrent non-resectable/residual RPS treated in our center with definitive radiotherapy (RT) and to perform a systematic review on the topic.

Methods:

A retrospective analysis of consecutive RPS patients treated in our center between 2000 and 2019 was performed. All consecutive patients who underwent definitive conformal RT with image guidance for primary or recurrent non-resectable or macroscopically residual RPS were included. Additionally, a systematic review compliant with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was performed.

Results:

The study enrolled 14 patients who met the aforementioned criteria. Data on clinicopathological characteristics, RT and response to treatment were assessed. RT allowed achieving prolonged local control of the disease, i.e. no local progression of the disease for more than 12 months after RT in 10 patients. Local control lasted more than 24 months in 6 cases, with minimal or no toxicity. A systemic review of 11 studies revealed concordance of our results with previous reports of primary or recurrent non-resectable/residual RPS.

Conclusions:

RT provided satisfactory local disease control with acceptable treatment tolerance in patients with primary or recurrent non-resectable/residual RPS and represents a valuable treatment modality in the selected group of patients. Additional RT modalities i.e. BT, particle therapy, MRI-guided RT, or GRID/Lattice RT may be introduced to improve local control and further minimize toxicity.

The Management of Radiation-Induced Sarcomas: A Cohort Analysis from a Sarcoma Tertiary Center

(1) Background: Radiation-induced sarcomas (RIS) are rare diseases with poor prognoses. The aim of the study was to analyze outcomes and identify factors affecting survival in a cohort of patients with RIS. (2) Methods: We included consecutive patients with RIS that we found in the available electronic medical records of a sarcoma tertiary center. We analyzed patients’ RIS characteristics, management of RIS, the occurrence of local recurrence and distant metastases, the date of disease progression, the date of death, and the date of the last follow-up. (3) Results: Fifty-eight patients met the inclusion criteria. The most frequent sites of RIS development were the thorax and pelvis. The majority of RIS were poorly differentiated, high-grade tumors. Forty patients underwent surgery or radiotherapy with curative intent. The others were referred to palliative chemotherapy. Median progression-free survival and overall survival were 15 and 21 months, respectively. Treatment with curative intent and tumor localization on breasts and upper extremities were associated with a lower risk of death in univariate analysis. (4) Conclusions: The study confirms the poor prognosis of RIS. Treatments with locally curative intent at the tumor site are of prognostic value. Secondary radiotherapy is rarely used in RIS.

Radiotherapy in the Management of Pediatric and Adult Osteosarcomas: A Multi-Institutional Cohort Analysis

Background: Due to the rarity of osteosarcoma and limited indications for radiotherapy (RT), data on RT for this tumor are scarce. This study aimed to investigate the utilization of RT for osteosarcomas in the recent 20 years and to identify factors related to patients’ response to radiation. Methods: We performed a retrospective analysis of patients irradiated for osteosarcoma treatment. We planned to assess differences in the utilization of RT between the periods of 2000–2010 and 2011–2020, identify the risk factors associated with local progression (LP), determine whether RT-related parameters are associated with LP, and calculate patients’ survival. Results: A total of 126 patients with osteosarcoma who received 181 RT treatments were identified. We found a difference in RT techniques between RT performed in the years 2000–2010 and that performed in the years 2011–2020. LP was observed after 37 (20.4%) RT treatments. Intent of RT, distant metastases, and concomitant systemic treatment affected the risk of LP. Five-year overall survival was 33% (95% confidence interval (26%–43%)). Conclusions: RT for osteosarcoma treatment has evolved from simple two-dimensional palliative irradiation into more conformal RT applied for new indications including oligometastatic and oligoprogressive disease. RT may be a valuable treatment modality for selected patients with osteosarcoma.

Neoadjuvant Treatment Options in Soft Tissue Sarcomas

Due to the heterogeneity of soft tissue sarcomas (STS), the choice of the proper perioperative treatment regimen is challenging. Neoadjuvant therapy has attracted increasing attention due to several advantages, particularly in patients with locally advanced disease. The number of available neoadjuvant modalities is growing continuously. We may consider radiotherapy, chemotherapy, targeted therapy, radiosensitizers, hyperthermia, and their combinations. This review discusses possible neoadjuvant treatment options in STS with an emphasis on available evidence, indications for each treatment type, and related risks. Finally, we summarize current recommendations of the STS neoadjuvant therapy response assessment.