Calculating Tumor Volume Using Three-Dimensional Models in Preoperative Soft-Tissue Sarcoma Surgical Planning: Does Size Matter?

This feasibility study aims to explore the use of three-dimensional virtual surgical planning to preoperatively determine the need for reconstructive surgery following resection of an extremity soft-tissue sarcoma. As flap reconstruction is performed more often in advanced disease, we hypothesized that tumor volume would be larger in the group of patients that had undergone flap reconstruction. All patients that were treated by surgical resection for an extremity soft-tissue sarcoma between 1 January 2016 and 1 October 2019 in the University Medical Center Groningen were included retrospectively. Three-dimensional models were created using the diagnostic magnetic resonance scan. Tumor volume was calculated for all patients. Three-dimensional tumor volume was 107.8 (349.1) mL in the group of patients that had undergone primary closure and 29.4 (47.4) mL in the group of patients in which a flap reconstruction was performed, p = 0.004. Three-dimensional tumor volume was 76.1 (295.3) mL in the group of patients with a complication following ESTS treatment, versus 57.0 (132.4) mL in patients with an uncomplicated course following ESTS treatment, p = 0.311. Patients who had undergone flap reconstruction had smaller tumor volumes compared to those in the group of patients treated by primary closure. Furthermore, a larger tumor volume did not result in complications for patients undergoing ESTS treatment. Therefore, tumor volume does not seem to influence the need for reconstruction. Despite the capability of three-dimensional virtual surgical planning to measure tumor volume, we do not recommend its utilization in the multidisciplinary extremity soft-tissue sarcoma treatment, considering the findings of the study.

Hyperbaric oxygen therapy for radiation-induced tissue injury following sarcoma treatment: A retrospective analysis of a Dutch cohort.

BACKGROUND AND OBJECTIVES: Sarcomas are commonly managed by surgical resection combined with radiotherapy. Sarcoma treatment is frequently complicated by chronic wounds and late radiation tissue injury (LRTI). This study aims to gain insight in the use and results of hyperbaric oxygen therapy (HBOT) for radiation-induced complications following sarcoma treatment. METHODS: All sarcoma patients treated between 2006 and 2017 in one of the five centers of the Institute for Hyperbaric Oxygen in the Netherlands were included for retrospective analysis. RESULTS: Thirty patients were included, 18 (60.0%) patients were treated for chronic wounds and 12 (40.0%) for LRTI. Two patients with chronic wounds were excluded from analysis as HBOT was discontinued within five sessions. In 11 of 16 (68.8%) patients treated for chronic wounds, improved wound healing was seen. Nine of 12 (75.0%) patients treated for LRTI reported a decline in pain. Reduction of fibrosis was seen in five of eight patients (62.5%) treated for LRTI. CONCLUSIONS: HBOT is safe and beneficial for treating chronic wounds and LRTI in the sarcoma population. Awaiting further prospective results, we recommend referring to HBOT centers more actively in patients experiencing impaired wound healing or symptoms of delayed radiation-induced tissue injury following multimodality sarcoma treatment.

PET segmentation of bulky tumors: Strategies and workflows to improve inter-observer variability.

BACKGROUND: PET-based tumor delineation is an error prone and labor intensive part of image analysis. Especially for patients with advanced disease showing bulky tumor FDG load, segmentations are challenging. Reducing the amount of user-interaction in the segmentation might help to facilitate segmentation tasks especially when labeling bulky and complex tumors. Therefore, this study reports on segmentation workflows/strategies that may reduce the inter-observer variability for large tumors with complex shapes with different levels of user-interaction. METHODS: Twenty PET images of bulky tumors were delineated independently by six observers using four strategies: (I) manual, (II) interactive threshold-based, (III) interactive threshold-based segmentation with the additional presentation of the PET-gradient image and (IV) the selection of the most reasonable result out of four established semi-automatic segmentation algorithms (Select-the-best approach). The segmentations were compared using Jaccard coefficients (JC) and percentage volume differences. To obtain a reference standard, a majority vote (MV) segmentation was calculated including all segmentations of experienced observers. Performed and MV segmentations were compared regarding positive predictive value (PPV), sensitivity (SE), and percentage volume differences. RESULTS: The results show that with decreasing user-interaction the inter-observer variability decreases. JC values and percentage volume differences of Select-the-best and a workflow including gradient information were significantly better than the measurements of the other segmentation strategies (p-value<0.01). Interactive threshold-based and manual segmentations also result in significant lower and more variable PPV/SE values when compared with the MV segmentation. CONCLUSIONS: FDG PET segmentations of bulky tumors using strategies with lower user-interaction showed less inter-observer variability. None of the methods led to good results in all cases, but use of either the gradient or the Select-the-best workflow did outperform the other strategies tested and may be a good candidate for fast and reliable labeling of bulky and heterogeneous tumors.

Volume of interest delineation techniques for 18F-FDG PET-CT scans during neoadjuvant extremity soft tissue sarcoma treatment in adults: a feasibility study.

BACKGROUND: This study explores various volume of interest (VOI) delineation techniques for fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT) scans during neoadjuvant extremity soft tissue sarcoma (ESTS) treatment. RESULTS: During neoadjuvant treatment, hyperthermic isolated limb perfusion (HILP) and preoperative external beam radiotherapy (EBRT), 11 patients underwent three 18F-FDG PET-CT scans. The first scan was made prior to the HILP, the second after the HILP but prior to the start of the EBRT, and the third prior to surgical resection. An automatically drawn VOIauto, a manually drawn VOIman, and two gradient-based semi-automatically drawn VOIs (VOIgrad and VOIgrad+) were obtained. Maximum standardized uptake value (SUVmax), SUVpeak, SUVmean, metabolically active tumor volume (MATV), and total lesion glycolysis (TLG) were calculated from each VOI. The correlation and level of agreement between VOI delineation techniques was explored. Lastly, the changes in metabolic tumor activity were related to the histopathologic response. The strongest correlation and an acceptable level of agreement was found between the VOIman and the VOIgrad+ delineation techniques. A decline (VOIman) in SUVmax, SUVpeak, SUVmean, TLG, and MATV (all p < 0.05) was found between the three scans. A > 75% decline in TLG between scan 1 and scan 3 possibly identifies histopathologic response. CONCLUSIONS: The VOIgrad+ delineation technique was identified as most reliable considering reproducibility when compared with the other VOI delineation techniques during the multimodality neoadjuvant treatment of locally advanced ESTS. A significant decline in metabolic tumor activity during the treatment was found. TLG deserves further exploration as predictor for histopathologic response after multimodality ESTS treatment.

Histopathological tumor response following neoadjuvant hyperthermic isolated limb perfusion in extremity soft tissue sarcomas: Evaluation of the EORTC-STBSG response score.

INTRODUCTION: This study aims to evaluate the applicability and prognostic value of the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) histopathological response score in extremity soft tissue sarcoma (ESTS) patients treated with neoadjuvant hyperthermic isolated limb perfusion (HILP) and delayed surgical resection. METHODS: Patients treated between 1991 and 2016 were included. The histopathological tumor response was established in accordance with the EORTC-STBSG response score. The distribution of patients was assorted according to the 5-tier histopathological response score for tumor grade, histological subtype and HILP regimen. Predictors for local recurrence free survival (LRFS) and overall survival (OS) were identified through Kaplan-Meier and Cox regression analyses. RESULTS: Ninety-one patients were included and their resection specimens were reanalyzed. Which resulted in 11 Grade A (12.1%), ten Grade B (11.0%), 15 Grade C (16.5%), 22 Grade D (24.2%) and 33 Grade E (36.3%) responses found among the series. The histopathological response was significantly influenced by the HILP regimen used, p = 0.033. Median follow-up was 65.0 (18.0-157.0) months. The histopathological response was not associated with LRFS nor OS. Resection margins, HILP regimen and adjuvant radiotherapy were associated with LRFS. Patients' age, tumor grade, tumor size and histological subtype were predictors for OS. CONCLUSIONS: The EORTC-STBSG response score is applicable for determining the histopathological response to neoadjuvant ESTS treatment. However, this response does not seem to predict LRFS nor OS in locally advanced ESTS.

Hyperthermic isolated limb perfusion, preoperative radiotherapy, and surgery (PRS) a new limb saving treatment strategy for locally advanced sarcomas.

BACKGROUND: This feasibility study presents the results of a new intensive treatment regimen for locally advanced extremity soft tissue sarcomas (ESTS), consisting of hyperthermic isolated limb perfusion (HILP), preoperative external beam radiotherapy (EBRT), and surgical resection. METHODS: From 2011 to 2016, 11 high grade locally advanced ESTS patients underwent this treatment regimen. Preoperative EBRT (12 × 3 Gy) started <4 weeks following the HILP (TNF-α and melphalan) and the surgical resection was planned to take place <2 weeks following the end of the EBRT. RESULTS: All patients completed the treatment. After a median follow-up of 32 (23-50) months, the limb was saved in 10 patients (91%), 1 patient (9%) developed a local recurrence, 5 patients (45%) developed distant metastases, and 3 patients (27%) died of their disease. During follow-up two patients (18%) developed a pathologic fracture of the treated limb and three patients (27%) developed a major wound complication requiring surgical intervention. The median overall treatment time (OTT) was 56 (49-69) days. CONCLUSIONS: This intensive treatment regimen is feasible and safe in locally advanced ESTS, and it achieves oncological results that are comparable with conventional HILP treatment. In addition, the major wound complication risk is comparable and the OTT is reduced.

Identification of predictors for wound complications following preoperative or postoperative radiotherapy in extremity soft tissue sarcoma.

INTRODUCTION: In extremity soft tissue sarcoma (ESTS), external beam radiotherapy (EBRT) has been used in addition to limb-sparing surgery (LSS). This study aims to identify predictors for major wound complication (MWC) development following EBRT and LSS in ESTS. METHODS: This retrospective study includes ESTS patients treated with EBRT and LSS between 2005 and 2017. Two groups were formed; Group I included preoperatively irradiated patients, whereas Group II included patients who underwent postoperative EBRT. Multivariate logistic regression analyses were performed to create a prediction model for MWC development. RESULTS: One hundred twenty-seven patients were included, 58 patients (45.7%) in Group I and 69 patients (54.3%) in Group II. Some differences in baseline characteristics were found between the groups, e.g. in tumor size and grade, histological subtype and total RT dose. Twenty-three patients (39.7%) in Group I and 14 patients (20.3%) in Group II developed a MWC (p = 0.02). Preoperative EBRT was identified as independent predictor for MWC development, OR 2.75 (95%CI 1.21-6.26), p = 0.02. Furthermore, a trend towards an increased MWC risk was shown for patients' age (OR 1.02 (0.99-1.04)), delayed wound closure (OR 3.20 (0.64-16.02)) and negative surgical margins (OR 2.26 (0.72-7.11)). The area under the curve (AUC) of the model was 0.68 (0.57-0.79). CONCLUSIONS: This study corroborates the increased MWC risk following preoperative EBRT in ESTS. It remains important to carefully weigh the MWC risk against the expected long-term functional outcome, and to consider the liberal use of primary plastic surgical reconstructions in an individualized multidisciplinary tumor board prior to treatment.

Amputations for extremity soft tissue sarcoma in an era of limb salvage treatment: Local control and survival.

BACKGROUND: Despite multimodality limb salvage treatment (LST) for locally advanced extremity soft tissue sarcoma (ESTS), some patients still need an amputation. Indications for amputation and oncological outcome for these patients are described. METHODS: Between 1996 and 2016, all patients who underwent an amputation for ESTS were included. Patients who underwent an amputation as primary or as non-primary treatment formed Group I and II, respectively. RESULTS: Thirty-nine patients were included, 16 in Group I (41%) and 23 in Group II (59%). Tumor size or local recurrence which could not be treated with LST were the two main reasons for amputation. Local recurrence free survival (LRFS) (P = 0.396), distant metastases free survival (DMFS) (P = 0.965), disease-specific survival (DSS) (P = 0.745), and overall survival (OS) (P = 0.718) were comparable for both groups. Ten-year LRFS was 90.0% versus 83.7%; DMFS was 31.0% versus 42.2%; DSS was 52.2% versus 44.1%; and OS was 44.2% versus 41.6%, for group I and II respectively. CONCLUSIONS: Oncological outcome seems to be comparable between patients who underwent a primary or a non-primary amputation for ESTS. With the on-going possibilities concerning prosthesis and rehabilitation programs, it remains important to decide in a multidisciplinary sarcoma team meeting which treatment suits best for each individual patient.