Postoperative intensity-modulated radiation therapy provides favorable local control and low toxicities in patients with soft tissue sarcomas in the extremities and trunk wall

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.

Separation Surgery and Postoperative Intensity-Modulated Radiation Therapy for a High-Grade Myxofibrosarcoma Involving the Spine: A Case Report

BACKGROUND Myxofibrosarcoma involving the spine is a rare and intractable disease. Although wide surgical resection is the mainstay of treatment, it is often difficult to complete marginal en-bloc resection due to adjacent neurovascular components in the spine. Separation surgery, a partial resection to achieve circumferential separation and high-dose irradiation such as postoperative intensity-modulated radiation therapy, has received much attention as a new therapy for spinal tumors. However, little evidence regarding separation surgery with intensity-modulated radiation therapy for a spinal myxofibrosarcoma exists. CASE REPORT We present a case of a 75-year-old man with progressive myelopathy. Radiological examination revealed severe spinal cord compression due to an unknown widespread multiple tumor in the cervical and thoracic spine. Computed tomography-guided biopsy showed high-grade sarcoma. Positron emission tomography detected no other tumors in the body. Separation surgery was therefore performed with posterior stabilization. Hematoxylin and eosin staining showed storiform cellular infiltrates and pleomorphic cell nuclei. Histopathology identified high-grade myxofibrosarcoma. Postoperative intensity-modulated radiation therapy of 60 Gy in 25 fractions was completed without any adverse effects. The patient had greatly improved neurological function, was capable of walking with a cane, and had no recurrence for at least 1 year after surgery. CONCLUSIONS We reported a case of an unresectable high-grade myxofibrosarcoma of the spine successfully treated with the combination of separation surgery and postoperative intensity-modulated radiation therapy. This combination therapy is a relatively safe and effective treatment option in patients with impending neurological damage by unresectable sarcomas when total en-bloc resection is challenging due to the size, location, or adhesion.

Fluorescence guidance improves the accuracy of radiological imaging-guided surgical navigation

BACKGROUND

Imaging-based navigation technologies require static referencing between the target anatomy and the optical sensors. Imaging-based navigation is therefore well suited to operations involving bony anatomy; however, these technologies have not translated to soft-tissue surgery. We sought to determine if fluorescence imaging complement conventional, radiological imaging-based navigation to guide the dissection of soft-tissue phantom tumors.

METHODS

Using a human tissue-simulating model, we created tumor phantoms with physiologically accurate optical density and contrast concentrations. Phantoms were dissected using all possible combinations of computed tomography (CT), magnetic resonance, and fluorescence imaging; controls were included. The data were margin accuracy, margin status, tumor spatial alignment, and dissection duration.

RESULTS

Margin accuracy was higher for combined navigation modalities compared to individual navigation modalities, and accuracy was highest with combined CT and fluorescence navigation (p = 0.045). Margin status improved with combined CT and fluorescence imaging.

CONCLUSIONS

At present, imaging-based navigation has limited application in guiding soft-tissue tumor operations due to its inability to compensate for positional changes during surgery. This study indicates that fluorescence guidance enhances the accuracy of imaging-based navigation and may be best viewed as a synergistic technology, rather than a competing one.

Real-world clinical outcomes with daily image-guided IMRT in extremity soft tissue sarcomas

PURPOSE

We report the clinical outcomes of patients with soft tissue sarcomas (STS) arising in extremities treated with image-guided intensity modulated radiotherapy (IG-IMRT) at our institute. Local control of the tumors treated with RT was the primary end point of this study. Analyzing overall survival and long-term toxicities were the secondary objectives.

METHODS AND MATERIALS

The database of the patients with STS who received wide local excision and IG-IMRT at our institution from January 2012 to December 2020 was reviewed. Radiation was offered either preoperatively or postoperatively as part of multi-modality treatment.

RESULTS

Thirty-three consecutive patients were identified and included for analysis. Twenty-eight patients (84.8%) received postoperative adjuvant radiotherapy. Dedicated MRI simulation studies were performed in 31 patients (93.9%) in the treatment position. RapidArc IMRT technique was used in 31 patients (93.9%). A total of 2954 images were acquired during 991 treatment sessions. Errors exceeding 1 mm in the x, y and z directions were corrected online before the treatment. With a median follow-up of 36 months, two patients (6.1%) developed local recurrence. The 3-year local control was 90.9% (95% CI, 0.76 - 0.98), and the 5-year overall survival was 71.7% (95% CI, 0.44 - 0.88). One patient (3.03%) sustained a pathological fracture during the follow-up period.

CONCLUSION

Our results showed that IMRT with daily imaging offered excellent local control with acceptable long-term toxicity, as well as being feasible and practical to implement in our routine clinical practice.

Soft tissue sarcomas of the upper extremities: Maximizing treatment opportunities and outcomes

Soft tissue sarcomas (STS) are rare tumors; they do not even equate to 1% of all malignant tumor cases. One-fifth of all STS occur in the upper extremities, where epithelioid sarcoma, synovial sarcoma, clear cell sarcoma and malignant fibrohistiocytoma are the most frequent subtypes. Surgical resection is the cornerstone of treatment. However, accomplishment of optimal oncological and functional results of STS of the upper extremities may represent a challenge for hand surgeons, due to the complex anatomy. In several cases, preoperative therapies are needed to facilitate tumor resection and improve the oncological outcome. Oligometastatic disease may also be a challenging scenario as curative strategies can be applied. Radiotherapy and chemotherapy are commonly used for this purpose albeit with conflicting evidence. Novel drug combinations have also been approved in the metastatic setting, further improving the quality of life and survival of eligible patients. Thus, prior to any approach, every case should be individually discussed in sarcoma centers with specialized multidisciplinary tumor boards. The aim of the present review was to gather the multidisciplinary experiences of the available therapeutic strategies for STS of the upper extremities.

Comparison of outcome and toxicity of postoperative intensity-modulated radiation therapy with two-dimensional radiotherapy in patients with soft tissue sarcoma of extremities and trunk

BACKGROUND

To compare the survival outcomes and late toxicities of postoperative intensity-modulated radiation therapy (IMRT) with two-dimensional radiotherapy (2D-RT) for patients with soft tissue sarcoma (STS) of extremities and trunk.

METHODS

274 consecutive patients with nonmetastatic STS of extremities and trunk treated with postoperative IMRT (n = 187) and 2D-RT (n = 87) were analyzed. Survival was calculated by using Kaplan-Meier method. Independent prognostic factors were identified using Cox stepwise regression analysis for variables with a P-value <0.1 in univariate analysis.

RESULTS

With a median follow-up time of 58.1 months, 30 local recurrences, 66 distant metastases, and 40 deaths occurred. Compared to 2D-RT group, the IMRT group had higher 5-year local recurrence-free survival (LRFS) (91.1% vs 80.8%; P = 0.029), distant metastasis-free survival (DMFS) (80.0% vs 69.7%; P = 0.048), disease-free survival (DFS) (75.2% vs 59.2%; P = 0.021), and overall survival (OS) (90.2% vs 81.0%; P = 0.029). Multivariate analysis showed IMRT was an independent favorable factor for LRFS, DMFS, DFS, and OS. For late toxicities, the patients in IMRT group enjoyed lower incidences of ≥Grade 2 joint stiffness (3.9% vs 12.3%; P = 0.041) and ≥Grade 3 fractures (0.0% vs 3.4%; P = 0.25) than those in 2D-RT group. ≥Grade 2 Edema was similar between these two groups (4.8% vs 9.2%; P = 0.183).

CONCLUSIONS

When compared with conventional techniques, postoperative IMRT seems to provide better LRFS, DMFS, DFS, and OS and less late toxicities in patients with STS of extremities and trunk, which should be offered as a preferred treatment.

Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial soft tissue sarcoma. Its rarity precludes large prospective studies. Clinical diagnosis requires an high index of suspicion. Effective management requires an appreciation of tumor biology and the nature of the characteristic infiltrative growth pattern. DFSP tends to recur locally, with a low risk of dissemination. Aggressive surgical resection with widely negative margins is essential to management. Radiotherapy may be indicated in special circumstances. Understanding the molecular pathogenesis has resulted in use of tyrosine kinase inhibitor therapy for patients with locally advanced disease or in metastatic disease. DFSP patients require long-term follow-up.