Prognostic relevance of ¹⁸F-FDG PET uptake in patients with locally advanced, extremity soft tissue sarcomas undergoing neoadjuvant isolated limb perfusion with TNF-α and melphalan

Malignant tumours of the foot and ankle

Tumours of the foot and ankle constitute about 4-5% of all musculoskeletal tumours with the majority of them being benign. Diagnosis of malignant soft tissue or bone tumours is frequently delayed because of the relatively low prevalence and uncommon presentation at the foot and ankle. Suspicious lesions or lumps should be subjected to CT, MRI and biopsy. Subfascial location, lump size more than 5 cm, increase in size, painful and recurrent tumours should raise the suspicion of malignancy and lead to patient referral to a designated tumour centre. Neoadjuvant and adjuvant systemic chemotherapy and/or radiation therapy, isolated limb perfusion (ILP) and hyperthermia for malignant tumours have to be discussed in a multidisciplinary tumour board. With the advances in local and free tissue transfer, limb-sparing techniques have increasingly replaced primary amputations thus preserving lower limb function as much as possible without compromising on the principles of oncologic resection.

Maximum standardized uptake value on 18F-fluorodeoxyglucose positron emission tomography/computed tomography improves outcome prediction in retroperitoneal liposarcoma

While ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) has been investigated in extremity sarcomas, there is no evidence on its usefulness in retroperitoneal sarcoma. This study was designed to evaluate the usefulness of ¹⁸F-FDG PET/CT in predicting aggressiveness of retroperitoneal liposarcoma. Patients experienced surgery for retroperitoneal liposarcoma from November 2007 to February 2018 and underwent preoperative ¹⁸F-FDG PET/CT were included. Preoperative maximum standardized uptake value (SUV_max) was calculated. To evaluate the predictability of SUV_max for Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade 3, receiver operating characteristics (ROC) curve analysis was performed. To analyze whether SUV_max can be a risk factor for prognosis, multivariable Cox regression was performed including potential risk factors regarding operation and histopathology. A total of 133 patients were included. ROC curve showed area under the curve of 0.877 (P < 0.001), with a cut-off point of 4.5 SUV_max showing 85.7% sensitivity and 78.3% specificity. Cox analyses showed that SUV_max > 4.5 was a significant factor for recurrence-free survival (HR = 2.148, CI 1.301-3.546, P = 0.003) and overall survival (HR = 5.052, CI 1.854-13.766, P = 0.002). SUV_max is highly predictive of FNCLCC grade 3 and SUV_max > 4.5 can be used as a prognostic factor before obtaining the histopathology.

Diagnosis and treatment of soft-tissue sarcomas of the extremities and trunk

The relatively low incidence and often atypical clinical presentation of soft-tissue sarcomas (STS) impedes early and adequate diagnosis. Patients may report on recently enlarged soft-tissue swellings, infrequently complain of painful lesions, or even have no symptoms at all.

A thorough diagnostic work-up is essential in order to distinguish between benign soft-tissue tumours and STSs. Patient history, clinical features and radiological findings all help in assessing the underlying pathology. ‘Worrying’ features such as recent increase in size, deep location relative to the fascia, a tumour exceeding 4 cm in size, and invasive growth patterns seen on imaging should prompt verification by biopsy.

Even though acquisition of biopsy material may be incomplete, one should bear in mind some essential rules. Regardless of the biopsy technique applied, the most direct route to the lump in question should be identified, contamination of adjacent structures should be avoided and a sufficient amount of tissue acquired.

Treatment of STS is best planned by a multidisciplinary team, involving experts from various medical specialities. The benchmark therapy consists of en bloc resection of the tumour, covered by a safety margin of healthy tissue. Depending on tumour histology, grade, local extent and anatomical stage, radiotherapy, chemotherapy and isolated hyperthermic limb perfusion may be employed.

Due to the complexity of treatment, any soft-tissue swelling suspected of malignancy is best referred directly to a sarcoma centre, where therapeutic management is carefully planned by an experienced multidisciplinary team.

Cite this article: EFORT Open Rev 2017;2:421-431. DOI: 10.1302/2058-5241.2.170005

Prognostic value of 18F-FDG PET-CT-based functional parameters in patients with soft tissue sarcoma: A meta-analysis

BACKGROUND

Considering the clinical importance of high 5-year mortality, we performed a meta-analysis of maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) from F-FDG PET-CT for overall survival (OS) and progression-free survival (PFS) in patients with soft tissue sarcoma.

METHODS

The search and selection of eligible articles was conducted on PubMed and EMBASE. We applied hazard ratio (HR) and odd ratio (OR) to measure the correlation between SUVmax, MTV, and TLG with PFS and OS. The SUVmax was analyzed through subgroup in terms of histological grade and HR of posttreatment SUVmax was also assessed.

RESULTS

Eleven studies with 582 patients were included. The pooled HRs of pretreatment SUVmax were 2.40 (95% CI: 1.38-4.17) for OS and 2.20 (95% CI: 1.47-3.30) for PFS. The HRs in terms of OS were 3.20 (95% CI: 1.71-5.98) based on MTV and 5.20 (95% CI: 2.34-11.56) based on TLG. Meanwhile, the predict results of pretreatment SUVmax on OR remained significant and the HRs of posttreatment SUVmax were 2.25 (95% CI: 1.33-3.80) for OS and 2.87 (95% CI: 1.81-4.55) for PFS.

CONCLUSIONS

The pretreatment SUVmax, MTV, and TLG of F-FDG PET-CT showed significant prognostic value for OS and the PET-CT can be used in identifying high-risk patients about progression and survival. The analysis for posttreatment SUVmax suggested PET-CT as a promising equipment in monitoring therapy response.

Positron emission tomography (18)F-fluorodeoxyglucose uptake and prognosis in patients with bone and soft tissue sarcoma: A meta-analysis

PURPOSE

To investigate the prognostic significance of (18)F-FDG PET imaging in patients with bone and soft tissue sarcoma, a meta-analysis was conducted.

METHODS

Comprehensive literature searches were performed in PubMed, Embase, Web of Science and Cochrane Library. Pooled hazard ratio (HR) values were calculated to assess the correlations of pre-chemotherapy SUV (SUV1), post-chemotherapy SUV (SUV2), SUV Ratio, total lesion glycolysis (TLG) and metabolic tumor volume (MTV) with event-free survival (EFS) and overall survival (OS).

RESULTS

Twenty-three studies with 1261 patients were identified. The combined HRs for EFS were 1.84 (95% CI: 1.54-2.20) for SUV1, 2.92 (95% CI: 2.15-3.97) for SUV2, 1.90 (95% CI: 1.43-2.52) for SUV Ratio, 3.01 (95% CI: 1.36-6.67) for TLG and 2.32 (95% CI: 1.44-3.75) for MTV. The pooled HRs for OS were 1.85 (95% CI: 1.49-2.30) for SUV1, 2.00 (95% CI: 1.39-2.88) for SUV2, 2.20 (95% CI: 1.18-4.10) for SUV Ratio, 6.19 (95% CI: 2.17-17.66) for TLG and 2.67 (95% CI: 1.52-4.68) for MTV. Besides, high SUV1 was found to be significantly associated with higher rate of metastasis (RR 5.55, 95% CI: 2.75-11.18) and local recurrence (RR 1.87 95% CI: 1.28-2.72).

CONCLUSION

(18)F-FDG PET parameters of SUV1, SUV2, SUV Ratio, TLG and MTV may have effective prognostic significance for patients with bone and soft tissue sarcoma. (18)F-FDG PET imaging may be a promising tool to help predict survival outcomes of these patients.

Histological response assessment following neoadjuvant isolated limb perfusion in patients with primary, localised, high-grade soft tissue sarcoma

PURPOSE

Histological response assessment following neoadjuvant treatment can help identify patients at a higher risk for systemic disease progression. Our goal was to evaluate whether mitotic count and the amount of viable tumour following neoadjuvant isolated limb perfusion (ILP) for primary, locally advanced, non-metastatic, high-grade extremity soft tissue sarcoma correlate with prognosis.

PATIENTS AND METHODS

This study is a retrospective analysis of 61 patients who underwent neoadjuvant ILP followed by surgical resection with curative intent between 2001 and 2011. Non-parametric analyses were carried out with the Mann-Whitney U and the Wilcoxon signed-rank test. Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank test.

RESULTS

The median follow-up was 44 months for all patients and 55 months for survivors. The amount of viable tumour after ILP had no correlation with overall (OS) (P = 0.227) or event-free (EFS) (P = 0.238) survival probability. Patients with a low mitotic count after ILP had a significantly higher OS (P < 0.001), EFS (P = 0.002) and post-relapse survival probability (P = 0.030) compared to patients with an intermediate or high mitotic count.

CONCLUSIONS

The mitotic count following ILP for primary, high-grade, locally advanced, non-metastatic soft tissue sarcoma appears to significantly correlate with prognosis. If these results are validated in a prospective setting, they could provide a rationale for the design of adjuvant systemic chemotherapy trials with the goal of improving the prognosis of patients with an intermediate or high mitotic count after ILP.