Update on musculoskeletal applications of magnetic resonance-guided focused ultrasound

Magnetic resonance-guided focused ultrasound (MRgFUS) is a noninvasive, incisionless, radiation-free technology used to ablate tissue deep within the body. This technique has gained increased popularity following FDA approval for treatment of pain related to bone metastases and limited approval for treatment of osteoid osteoma. MRgFUS delivers superior visualization of soft tissue targets in unlimited imaging planes and precision in targeting and delivery of thermal dose which is all provided during real-time monitoring using MR thermometry. This paper provides an overview of the common musculoskeletal applications of MRgFUS along with updates on clinical outcomes and discussion of future applications.

Desmoid Tumors: Current Perspective and Treatment

OPINION STATEMENT

Desmoid tumors are rare tumors with a tendency to infiltrate locally. The lack of a standard treatment approach makes choosing the most appropriate treatment for patients challenging. Most experts recommend watchful observation for asymptomatic patients as spontaneous regression of tumor is observed in up to 20% of patients. Upfront resection of the desmoid tumor has fallen out of favor due to high morbidity and high relapse rates associated with the tumor. Systemic therapy has evolved over several decades. Where chemotherapy, hormonal therapy, and non-steroidal anti-inflammatory drugs were used over the last several decades, tyrosine kinase inhibitors came to the forefront within the last decade. Most recently, gamma-secretase inhibitors have shown significant clinical benefit in patients with desmoid tumors, bringing forth an entirely new mechanistic approach. Several Wnt pathway inhibitors are also under development. Invasive approaches like cryoablation have also shown clinical benefit in patients with extra-abdominal desmoid tumors in recent years. The recent approval of nirogacestat has ushered in a new era of treatment for patients diagnosed with desmoid tumors. Several new molecules are expected to be approved over the coming years.

MR-guided focused ultrasound therapy of extra-abdominal desmoid tumors: a multicenter retrospective study of 105 patients

OBJECTIVE

To assess the safety and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for the treatment extra-abdominal desmoids.

METHODS

A total of 105 patients with desmoid fibromatosis (79 females, 26 males; 35 ± 14 years) were treated with MRgFUS between 2011 and 2021 in three centers. Total and viable tumors were evaluated per patient at last follow-up after treatment. Response and progression-free survival (PFS) were assessed with (modified) response evaluation criteria in solid tumors (RECIST v.1.1 and mRECIST). Change in Numerical Rating Scale (NRS) pain and 36-item Short Form Health Survey (SF-36) scores were compared. Treatment-related adverse events were recorded.

RESULTS

The median initial tumor volume was 114 mL (IQR 314 mL). After MRgFUS, median total and viable tumor volume decreased to 51 mL (95% CI: 30-71 mL, n = 101, p < 0.0001) and 29 mL (95% CI: 17-57 mL, n = 88, p < 0.0001), respectively, at last follow-up (median: 15 months, 95% CI: 11-20 months). Based on total tumor measurements (RECIST), 86% (95% CI: 75-93%) had at least stable disease or better at last follow-up, but 50% (95% CI: 38-62%) of remaining viable nodules (mRECIST) progressed within the tumor. Median PFS was reached at 17 and 13 months for total and viable tumors, respectively. NRS decreased from 6 (IQR 3) to 3 (IQR 4) (p < 0.001). SF-36 scores improved (physical health (41 (IQR 15) to 46 (IQR 12); p = 0.05, and mental health (49 (IQR 17) to 53 (IQR 9); p = 0.02)). Complications occurred in 36%, most commonly 1st/2nd degree skin burns.

CONCLUSION

MRgFUS reduced tumor volume, reduced pain, and improved quality of life in this series of 105 patients with extra-abdominal desmoid fibromatosis.

CLINICAL RELEVANCE STATEMENT

Imaging-guided ablation is being increasingly used as an alternative to surgery, radiation, and medical therapy for the treatment of desmoid fibromatosis. MR-guided high-intensity focused ultrasound is an incisionless ablation technique that can be used to reduce tumor burden effectively and safely.

KEY POINTS

• Desmoid fibromatosis was treated with MR-guided high-intensity focused ultrasound in 105 patients. • MR-guided focused ultrasound ablation reduced tumor volume and pain and improved quality of life. • MR-guided focused ultrasound is a treatment option for patients with extra-abdominal desmoid tumors.

Multifocal Desmoid-Type Fibromatosis: Case Series and Potential Relationship to Neuronal Spread

Multifocal desmoid-type fibromatosis (DTF) is very rare and usually regional. We report three cases that initially appeared to be multifocal, but subsequent detailed imaging revealed unsuspected tracking along nerves in two cases. This neural spread is reminiscent of neuromuscular choristoma (NMC), a rare developmental lesion in which mature skeletal muscle cells, or rarely smooth muscle cells, infiltrate and enlarge peripheral nerves. NMC is frequently associated with DTF. These two cases suggest that DTF spread along nerves and appeared as distinct multifocal lesions while actually being contiguous. The third case was felt to represent true multifocal tumor development, possibly due to tumor seeding at the time of chest surgery. The relationship of DTF to NMC is discussed.

Desmoid-type fibromatosis: Current therapeutic strategies and future perspectives

Desmoid tumors (DT) are rare, slow-growing, locally invasive soft tissue tumors that often pose significant therapeutic challenges. Traditional management strategies including active surveillance, surgery, radiotherapy, and systemic therapy which are associated with varying recurrence rates and high morbidity. Given the challenging nature of DT and the modest outcomes associated with current treatment strategies, there has been a growing interest in the field of γ-secretase inhibitors as a result of its action on the Wnt/β-catenin signaling pathway. In this review article, we will shed the light on the pathogenesis and molecular biology of DT, discuss its symptoms and diagnosis, and provide a comprehensive review of the traditional therapeutic approaches. We will also delve into the mechanisms of action of γ-secretase inhibitors, its efficacy, and the existing preclinical and clinical data available to date on the use of these agents, as well as the potential challenges and future prospects in the treatment landscape of these tumors.

Role of Surgery in the Treatment of Abdominal Desmoid Fibromatosis: A Single-Center Experience

With increasing multidisciplinary management and emphasis on masterly inactivity for abdominal fibromatosis (AF), the indications for surgery are evolving. This retrospective analysis looked at outcomes following surgery. Two groups of patients who underwent surgery for AF between November 2011 and August 2021 were identified-intra-abdominal fibromatosis (IAF) and abdominal wall fibromatosis (AWF). All treatment-related details and follow-up data were gathered from a database and analyzed. Sixteen patients underwent surgery for IAF. R0 resection (wide margin) was achieved in 13 patients (81.2%). Over a median follow-up period of 51.7 (range 5-103) months, 5 patients developed recurrence (31.2%). The conditional probabilities of OS and DFS at 5 years were 80% (95% CI 58.7-100) and 42.2% (95% CI 20.3-87.8), respectively. Ten patients with AWF underwent surgery. R0 resection was achieved at 70% (7/10). Over a median follow-up period of 54.8 (range 12.9-96.7) months, 2 patients (20%) developed recurrence. The conditional probabilities of OS and DFS at 5 years were 88.9% (95% CI 70.6-100) and 77.8% (95% CI 54.9-87.8), respectively. Surgery has a vital role in the management of AF presenting with progressive/symptomatic lesions, especially when watchful waiting is not an option, and must be considered as one of the first-line active therapy. Timely curative surgery avoids disease progression and its morbidity with acceptable recurrence rates and provides durable remissions.

Desmoid Tumors in the Active Surveillance Era: Evaluation of Treatment Options and Pain Relief in a Single-Center Retrospective Analysis

In patients with desmoid tumors (DTs), active surveillance has been increasingly preferred over surgery, while treatment (including pharmacological therapy, radiotherapy, and/or surgery) is performed in cases with confirmed disease progression. This study aimed to evaluate event-free survival and pain management according to different treatment strategies. We evaluated event-free survival, including recurrence after initial surgical treatment or changes in the therapeutic management after initial non-surgical treatment and pain management according to different treatment strategies. All patients referred for DT in 2001-2021 at our institutions were stratified into four groups: those treated surgically prior to 2012 (SGPre12) or after 2012 (SGPost12), those treated pharmacologically (MG), and those under active surveillance (ASG). An event was defined as recurrence after initial surgical treatment or a change in therapeutic management. Overall, 123 patients were included in the study: 28 in SGPre12, 41 in SGPost12, 38 in MG, and 16 in ASG. Pharmacological treatment resolved painful symptoms in 16/27 (60%) patients (p = 0.0001). The median follow-up duration was 40 months (IQR 23-74). Event-free survival at 1, 3, and 5 years was: 85%, 70%, and 62% in SGPre12; 76%, 58%, and 49% in SGPost12; 49%, 31%, and 31% in MG; and 45%, 45%, and 45% in ASG. Our findings support the role of active surveillance as initial management, as demonstrated by the fact that about half the patients did not experience any progression, while surgery can be reserved as a first-line approach for selected patients. In terms of pain relief, medical therapy led to symptom resolution in more than half the cases.

Case Report: Desmoid tumor response to magnetic resonance-guided high intensity focused ultrasound over 4 years

Desmoid tumors are a rare form of cancer, which show locally aggressive invasion of surrounding tissues and may occur anywhere in the body. Treatment options comprise conservative watch and wait strategies as tumors may show spontaneous regression as well as surgical resection, radiation therapy, nonsteroidal anti-inflammatory drugs (NSAID), chemotherapy, or local thermoablative approaches for progressive disease. The latter comprises cryotherapy, radiofrequency, microwave ablation, or thermal ablation with high intensity focused ultrasound (HIFU) as the only entirely non-invasive option. This report presents a case where a desmoid tumor at the left dorsal humerus was 2 times surgically resected and, after recurrence, thermally ablated with HIFU under magnetic resonance image-guidance (MR-HIFU). In our report, we analyze tumor volume and/or pain score during standard of care (2 years) and after HIFU treatment over a 4-year follow-up period. Results showed MR-HIFU treatment led to complete tumor remission and pain response.

Postoperative lumbar fusion paraspinal desmoid tumor case report

Desmoid tumors are rare soft tissue tumors with slow growth and high recurrence rates. They typically arise sporadically in the abdominal wall or retroperitoneum, with a few rare cases reported after trauma and surgery. Postoperative desmoid tumors in adults are very rare with only 7 reported cases involving the paraspinal location. This is the first reported case of a male patient with a postoperative paraspinal desmoid tumor.

Management of unresectable and recurrent intra-abdominal desmoid tumors treated with ultrasound-guided high-intensity focused ultrasound: A retrospective single-center study

To assess the efficacy and safety of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation for treatment of unresectable and recurrent intra-abdominal desmoid tumors. From June 2014 to March 2020, 15 patients with consecutive unresectable and recurrent diseases that pathologically proven to be intra-abdominal desmoid tumors had undergone the treatment of US-guided HIFU ablation. All patients underwent contrast-enhanced magnetic resonance imaging before and after HIFU treatment. Nonperfused volume ratio was used to evaluate the effect of HIFU therapy. Intraprocedural and postprocedural adverse effects and complications are recorded to assess the safety of the therapy. Outcome of HIFU ablation has been investigated through serial contrast-enhanced imaging examinations during follow up. Out of 15 patients 14 of them have successfully completed the whole therapy, 1 patient is ineffective and gives up further treatment. The mean nonperfused volume ratio is 71.1% (95% confidence interval, 3% to 88.2%). During a mean follow up of 29 months (range from 8 to 61 months), the mean tumor volume was reduced by 59% (95% confidence interval, +49% to -100%). No tumor spreads along the treated area in all patients except one. Complications have occurred in 5 patients (33.3%), including bowel rupture (1 case), intra-abdominal abscess (1 case), slight injury to the femoral nerve (1 case), and bone injury (2 cases), the bowel rupture patient underwent surgery; the others have been cured during the follow up. US-guided HIFU ablation is an effective treatment modality for patients suffered from unresectable and recurrent intra-abdominal desmoid tumors.

Biclonal Desmoid-Type Fibromatosis With Two Beta-Catenin Mutations: Evidence for the Recruitment of Normal Myofibroblasts

Sporadic aggressive fibromatosis, or desmoid-type fibromatosis, is characterized by oncogenic mutations in CTNNB1. The clonal cell is a myofibroblast-like cell, and it has been hypothesized that the recruitment of normal myofibroblasts could contribute significantly to the tumor. We describe a case in which a CTNNB1 p.T41A mutation was present at a mutant allele frequency of 30%, suggesting that a significant proportion of the tumor myofibroblasts may have been recruited from normal precursor pools. In addition, a small subclone with a p.S45F mutation (allele frequency of 2%) was identified in the tumor. This case provides additional evidence that myofibroblasts recruited by a tumor from a normal precursor pool contribute significantly to the tumor; such recruitment could impact response to treatment and long-term outcomes.

Intraabdominal sporadic desmoid tumors and inflammation: an updated literature review and presentation and insights on pathogenesis of synchronous sporadic mesenteric desmoid tumors occurring after surgery for necrotizing pancreatitis

Sporadic intra-abdominal desmoid tumors are rare and known to potentially occur after trauma including previous surgery, although knowledge of the underlying pathogenetic mechanism is still limited. We reviewed the recent literature on sporadic intraabdominal desmoids and inflammation as we investigated the mutational and epigenetic makeup of a case of multiple synchronous mesenterial desmoids occurring after necrotizing pancreatitis. A 62-year-old man had four mesenteric masses up to 4.8 cm diameter detected on CT eighteen months after laparotomy for peripancreatic collections from necrotizing pancreatitis. All tumors were excised and diagnosed as mesenteric desmoids. DNA from peripheral blood was tested for a multigene panel. The tumour DNA was screened for three most frequent β-catenin gene mutations T41A, S45F and S45P. Expression levels of miR-21-3p and miR-197-3-p were compared between the desmoid tumors and other wild-type sporadic desmoids. The T41A CTNNB1 mutation was present in all four desmoid tumors. miR-21-3p and miR-197-3p were respectively upregulated and down-regulated in the mutated sporadic mesenteric desmoids, with respect to wild-type lesions. The patient is free from recurrence 34 months post-surgery. The literature review did not show similar studies. To our knowledge, this is the first study to interrogate genetic and epigenetic signature of multiple intraabdominal desmoids to investigate potential association with abdominal inflammation following surgery for necrotizing pancreatitis. We found mutational and epigenetic features that hint at potential activation of inflammation pathways within the desmoid tumor.

Evaluation of outcomes in the management of primary sporadic desmoid-type fibromatosis at a specialist soft tissue sarcoma unit

Background

Desmoids are rare fibroblastic tumours whose treatment in any individual case presents a persistent challenge. We endeavoured to evaluate various clinicopathological factors contributing to tumour behaviour.

Methods

This is a retrospective review of 95 primary truncal sporadic fibromatosis managed between 2011 and 2020. We studied progression rate for wait and watch (WW) and recurrence rate for the surgically treated group as adverse events. Relevant event-free survivals and potential risk factors were analysed over a median follow-up of 27 months.

Results

66 patients (69.5%) received watchful surveillance and 28 upfront surgery. 2-year progression-free survival in WW group (88.9%) was higher than RFS in the surgical group (77.1%) p = 0.02. Adverse event rate compared favourably, 28.8% in WW and 28.6% in surgical group. At final follow-up, rate of stable disease for WW was 47%, and the regression rate was 24.2%. On Cox regression analysis, meantime to progress was 14 ± 2.0 months, with larger tumour size as a significant prognostic indicator (p = 0.05). Surgical group's mean time to recurrence was 13.8 ± 2.76 months, with tumour location a significant contributing factor (p = 0.05).

Conclusions

This study confirms to the safety of both treatment approaches. Adverse event rates remained comparable, but event-free survival was longer for the watchful surveillance group.

Evolving strategies for management of desmoid tumor

Desmoid tumors (DTs) are rare soft tissue mesenchymal neoplasms that may be associated with impairments, disfigurement, morbidity, and (rarely) mortality. DT disease course can be unpredictable. Most DTs are sporadic, harboring somatic mutations in the gene that encodes for β-catenin, whereas DTs occurring in patients with familial adenomatous polyposis have germline mutations in the APC gene, which encodes for a protein regulator of β-catenin. Pathology review by an expert soft tissue pathologist is critical in making a diagnosis. Magnetic resonance imaging is preferred for most anatomic locations. Surgery, once the standard of care for initial treatment of DT, is associated with a significant risk of recurrence as well as avoidable morbidity because spontaneous regressions are known to occur without treatment. Consequently, active surveillance in conjunction with pain management is now recommended for most patients. Systemic medical treatment of DT has evolved beyond the use of hormone therapy, which is no longer routinely recommended. Current options for medical management include tyrosine kinase inhibitors as well as more conventional cytotoxic chemotherapy (e.g., anthracycline-based or methotrexate-based regimens). A newer class of agents, γ-secretase inhibitors, appears promising, including in patients who fail other therapies, but confirmation in Phase 3 trials is needed. In summary, DTs present challenges to physicians in diagnosis and prognosis, as well as in determining treatment initiation, type, duration, and sequence. Accordingly, evaluation by a multidisciplinary team with expertise in DT and patient-tailored management are essential. As management strategies continue to evolve, further studies will help clarify these issues and optimize outcomes for patients.

Surgical management of abdominal desmoids: a systematic review and meta-analysis

BACKGROUND

Desmoid tumours are benign fibromatous tumours arising from dysregulated myofibroblast proliferation within musculoaponeurotic structures. They can occur sporadically but more commonly are associated with genetic syndromes such as familial adenomatous polyposis [1] (FAP). Mutations in either the Wnt, β-catenin or APC genes are 'key' triggers for the development of these tumours [5]. Classically, these tumours do not metastasise; however, they are associated with significant morbidity and mortality due to their infiltrative pattern and/or local invasion. Historically, surgical resection was the cornerstone of treatment. There remains paucity of data regarding outcomes following the surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity.

OBJECTIVES

The aim of this review was to assess the current evidence for surgical management of abdominal desmoid tumours in terms of success, recurrence and morbidity.

METHODS

A systematic search of articles in PubMed, EMBASE and The Cochrane Library databases was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the period from January 2000 to November 2020.

RESULTS

Twenty-three studies were included, of which, 749 patients had surgical resection (696 for primary and 53 for recurrent desmoids), 243 patients (18.8%) were medically managed and 353 patients (27.3%) underwent surveillance. Median follow-up was 51.4 months (range 1-372). Six-hundred and ninety-six of the 749 resections (92.9%) underwent primary desmoid resection, with the remaining 53 (7.1%) undergoing resection for recurrence. One-hundred and two surgically managed patients (19%) developed a (re)recurrence, with mesenteric involvement the commonest site for recurrence (55%). When comparing recurrence post-surgery to progression following medical therapy, there was a trend towards better outcomes with surgery, with 25% of surgical patients having a recurrence versus 50.5% having progression with medical therapy [OR 0.40 (95% CI 0.06-2.70), p = 0.35]. Major morbidity following surgery was 4.4% (n = 33) with 2% (n = 14) mortality within 30 days of resection.

CONCLUSION

The management of desmoids has considerable heterogeneity. Surgical resection for abdominal desmoids remains a valid treatment option in highly selective cases where negative margins can be obtained, with low major morbidity and/or mortality.

Current management and recent progress in desmoid tumors

Desmoid tumors are rare soft tissue tumors that can have aggressive infiltrative growth and relapse locally. Desmoid tumors can impact functionality and cause treatment-related morbidity and mortality. Here, the authors review current management strategies and avenues for further investigation. As part of the evolution of therapy away from primary surgical approaches to less invasive options, image-guided ablation has been accepted as less morbid and include cryoablation and high-intensity focused ultrasound. Systemic therapy options currently include hormonal agents, nonsteroidal anti-inflammatory drugs, tyrosine kinase inhibitors, and anthracycline-based regimens. Hormonal agents and nonsteroidal anti-inflammatory drugs have benign side effect profiles but generally limited efficacy. Anthracycline-based therapies are limited by the risk of secondary malignancies and cardiomyopathy. Tyrosine kinase inhibitors are well studied, and sorafenib is now one of the most utilized therapies, though limited by its side effect profile. Nirogacestat (PF-0308401) is an investigational small molecule gamma-secretase (GS) inhibitor that has demonstrated efficacy in phase 1 and II trials. A phase III trial investigating patients with desmoid tumors or aggressive fibromatosis is estimated to be completed December 2021 (NCT03785964). In addition to nirogacestat, the gamma-secretase inhibitor AL102 is being investigated for the treatment of patients with progressing desmoid tumors in the phase II/III RINGSIDE trial. Finally, the beta-catenin inhibitor Tegavivint (BC2059) is being investigated in a phase 1 open-label trial in patients with a proven primary or recurrent desmoid tumor that is unresectable and symptomatic or progressive.

Focused Ultrasound for Pediatric Diseases

Focused ultrasound (FUS) is a noninvasive therapeutic technology with multiple pediatric clinical applications. The ability of focused ultrasound to target tissues deep in the body without exposing children to the morbidities associated with conventional surgery, interventional procedures, or radiation offers significant advantages. In 2021, there are 10 clinical pediatric focused ultrasound studies evaluating various musculoskeletal, oncologic, neurologic, and vascular diseases of which 8 are actively recruiting and 2 are completed. Pediatric musculoskeletal applications of FUS include treatment of osteoid osteoma and bone metastases using thermal ablation and high-intensity FUS. Pediatric oncologic applications of FUS include treatment of soft tissue tumors including desmoid tumors, malignant sarcomas, and neuroblastoma with high-intensity FUS ablation alone, or in combination with targeted chemotherapy delivery. Pediatric neurologic applications include treatment of benign tumors such as hypothalamic hamartomas with thermal ablation and malignant diffuse intrinsic pontine glioma with low-intensity FUS for blood brain barrier opening and targeted drug delivery. Additionally, low-intensity FUS can be used to treat seizures. Pediatric vascular applications of FUS include treatment of arteriovenous malformations and twin-twin transfusion syndrome using ablation and vascular occlusion. FUS treatment appears safe and efficacious in pediatric populations across many subspecialties. Although there are 7 Food and Drug Administration-approved indications for adult applications of FUS, the first Food and Drug Administration approval for pediatric patients with osteoid osteoma was obtained in 2020. This review summarizes the preclinical and clinical research on focused ultrasound of potential benefit to pediatric populations.

Percutaneous Cryoablation Provides Disease Control for Extra-Abdominal Desmoid-Type Fibromatosis Comparable with Surgical Resection

PURPOSE

The aim of this study was to determine outcomes and prognostic factors for patients with primary and locally recurrent extra-abdominal desmoid tumors who underwent percutaneous cryoablation, and to compare with patients treated with surgery.

METHODS

Group characteristics were compared using Fisher's exact test, and propensity score matching was performed using the nearest-neighbor approach. Kaplan-Meier and log-rank analyses were used to evaluate the variation in first local recurrence and disease control, while multivariate Cox regression was used to identify factors associated with first local recurrence. All statistical tests were two-sided and a p-value of 0.05 was considered statistically significant.

RESULTS

Twenty-two cryoablation patients were matched with 33 surgical patients (n = 55). Median follow-up after cryoablation was 16.3 months versus 14.9 months after surgery. Two-year local recurrence-free survival (LRFS) was 59% after cryoablation and 71% after surgery, and median LRFS was 26.6 months after cryoablation but was not reached after surgery. Two-year disease control for all patients was 85%, however median disease control was not reached in either the cryoablation or surgery groups. There was no significant difference in LRFS or disease control between matched cryoablation and surgical patients. No local recurrences occurred after the first cryoablation in patients with zero or one of the following risk factors: tumor size > 5 cm, age ≤ 25 years, or locally recurrent disease. All patients with two or more of these risk factors recurred locally after the first cryoablation.

CONCLUSION

Percutaneous cryoablation of primary and locally recurrent extra-abdominal desmoid tumors provides freedom from first local recurrence and long-term disease control comparable with surgery.

Musculoskeletal Applications of Magnetic Resonance-Guided Focused Ultrasound

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive therapy that uses focused sound energy to thermally ablate focal pathology within the body. In the United States, MRgFUS is approved by the Food and Drug Administration for the treatment of uterine fibroids, palliation of painful bone metastases, and thalamotomy for the treatment of essential tremor. However, it has also demonstrated utility for the treatment of a wide range of additional musculoskeletal (MSK) conditions that currently are treated as off-label indications. Advantages of the technology include the lack of ionizing radiation, the completely noninvasive technique, and the precise targeting that offer unprecedented control of the delivery of the thermal dose, as well as real-time monitoring capability with MR thermometry. In this review, we describe the most common MSK applications of MRgFUS: palliation of bone metastases, treatment of osteoid osteomas, desmoid tumors, facet arthropathy, and other developing indications.

Pseudoaneurysm within a desmoid tumor in an extremity: report of 2 cases

Desmoid tumor is considered a benign neoplasm, yet substantial morbidity can result from local invasion of structures adjacent to the tumor or from complications related to its treatment. We report two patients with extremity desmoid tumor who were each found at MRI to have an unsuspected pseudoaneurysm within their tumor after prior treatments (surgery and systemic therapy in one, surgery alone in the other). Such a pseudoaneurysm probably results from weakening of an arterial wall by adjacent desmoid tumor, as well as from local trauma. Due to the potential risk for life-threatening rupture of a pseudoaneurysm, one patient underwent surgical repair and the other, coil embolization. To our knowledge the presence of pseudoaneurysm has been reported within a few cases of abdominal desmoid tumor but not within an extremity desmoid tumor. This diagnosis has not been reported to have been made at MRI, either.

Surgical management of a giant abdominal wall desmoid tumour

Desmoid tumours are clonal fibroblastic proliferations in soft tissues, characterised by infiltrative growth and local recurrence, but not metastasis. Various treatment strategies for desmoid tumours exist, varying from observation, medical and systemic therapy to radiotherapy and surgery. A 25-year-old woman with a background of familial adenomatous polyposis was referred with an enlarging abdominal desmoid tumour measuring 40×40×40 cm despite repeated radiofrequency ablation, surgical debulking and hormone therapy. The patient had a two-stage operation. The first stage involved excision of the desmoid tumour with full-thickness abdominal wall. The abdominal wall was not closed, and a topical negative pressure seal was applied. After 2 days, she underwent the second stage: reconstruction of the abdominal wall defect with a large porcine mesh which was covered with anterolateral thigh flaps. Postoperative complications included ileus and a fall which required further surgery. The patient was discharged 1 month after the first operation. Abdominal MRI scans were performed at 3 and 7 months postdischarge and showed no recurrence of diseaseBackground.

Management of serious complications in intra-abdominal desmoid-type fibromatosis

Background

Desmoid fibromatosis (DF) is a rare and locally infiltrative monoclonal fibroblastic proliferation arising from connective tissues, with lack of metastatic potential. About 10% of all DF cases are intra‐abdominally sited. Complications in this site, due to the locally infiltrative nature of the disease, may be severe and potentially life threatening. However, data on incidence, management, and outcome of these complications are limited.

Aim

Data of patients with sporadic or FAP‐related intra‐abdominal DF treated at Istituto Nazionale dei Tumori (INT) in Milano from 2005 to 2020 who developed a serious complication during the course of their disease were retrospectively collected and analyzed with a descriptive statistics.

Methods and Results

Out of 72 intra‐abdominal DF, 8 cases were identified (M/F: 5/3, median age: 35 years, FAP‐related/sporadic: 2/6): 3 with bowel obstruction, 5 with bowel perforation. In 4 cases the serious complication was the first evidence of disease; in the other 4 cases it occurred at a time interval from diagnosis in the range of 4–44 months (during an active surveillance program in one case and during chemotherapy in the other 3 cases). A surgical treatment was feasible and successful in 5 cases. In 3 surgically unmanageable patients, all progressing and experiencing acute complications while on chemotherapy, a non‐surgical approach with intensive supportive treatment and with a prompt change of chemotherapy regimen was implemented, being successful in two, the other patient dying due to a concomitant progressive lymphoma thereafter.

Conclusion

In this series of intra‐abdominal DF, the incidence of serious complications was 11%. Most patients were successfully treated with surgery. When surgery was deemed to be unfeasible, a conservative management with intensive supportive care and a careful choice of chemotherapy was adopted, ensuring a favorable outcome in most.

Ultrasound-Guided Vacuum-assisted Biopsy Versus Surgical Resection in Patients With Breast Desmoid Tumor

BACKGROUND

Recent studies suggest that desmoid tumors can be managed more conservatively rather than undergoing wide surgical resection (SR). Ultrasound-guided vacuum-assisted biopsy (UGVAB) is a minimally invasive technique. This retrospective study aimed to compare the outcome in patients with breast desmoid tumor (BDT) who received UGVAB alone versus SR.

MATERIALS AND METHODS

The pathology database was searched for patients diagnosed with BDT ≤ 3 cm from 2007 to 2019. All patients underwent breast ultrasound examination and were then performed UGVAB alone or local SR. The Kaplan-Meier method with a log-rank test was used as a univariate analysis to compare the relapse-free survival (RFS) rates between UGVAB and SR groups. Cox regression analysis was used for multivariate analysis.

RESULTS

A total of 39 patients were included. The median follow-up was 41 mo (range, 5-110 mo). The incidence of tumor recurrence was 23.1% (9/39). The 3-y cumulative RFS was 83.1% and 95.8% in the UGVAB and SR group, respectively, which was not significantly different between the two groups (P = 0.131, log-rank test). Multivariate analysis also revealed that treatment strategy (UGVAB versus SR) was not associated with an increased risk of relapse events (P = 0.274).

CONCLUSIONS

Small desmoid tumors (≤3 cm) after UGVAB alone did not have a significantly compromised RFS compared with those who underwent SR. UGVAB may be an alternative and relatively conservative method for the diagnosis and local control of BDT with a smaller size. A prospective, randomized study with large sample size is needed to confirm this observation.

Desmoid Tumors Characteristics, Clinical Management, Active Surveillance, and Description of Our FAP Case Series

(1) Background: desmoid tumors (DTs) are common in patients with familial adenomatous polyposis (FAP). An active surveillance approach has been recently proposed as a valuable alternative to immediate treatment in some patients. However, no clear indication exists on which patients are suitable for active surveillance, how to establish the cut-off for an active treatment, and which imaging technique or predictive factors should be used during the surveillance period. (2) Results: we retrospectively analyzed 13 FAP patients with DTs. A surveillance protocol consisting of scheduled follow-up evaluations depending on tumor location and tissue thickening, abdominal computed tomography (CT) scan/Magnetic resonance imaging (MRI) allowed prompt intervention in 3/11 aggressive intra-abdominal DTs, while sparing further interventions in the remaining cases, despite worrisome features detected in three patients. Moreover, we identified a possible predictive marker of tumor aggressiveness, i.e., the "average monthly growth rate" (AMGR), which could distinguish patients with very aggressive/life-threatening tumor behavior (AMGR > 0.5) who need immediate active treatment, from those with stable DTs (AMGR < 0.1) in whom follow-up assessments could be delayed. (3) Conclusion: surveillance protocols may be a useful approach for DTs. Further studies on larger series are needed to confirm the usefulness of periodic CT scan/MRI and the value of AMGR as a prognostic tool to guide treatment strategies.

Desmoid tumour of the distal forearm involving the distal radioulnar joint

A 32-year-old woman presented with progressive pain and swelling of the left wrist for 6 months. Physical examination revealed a firm, tender, oval swelling over the left wrist. X-rays showed a pressure effect on the distal radius and ulna. Magnetic Resonance Imaging (MRI) revealed a well-defined, asymmetrical, dumbbell-shaped soft-tissue lesion involving the interosseous region of the distal forearm and extending until the distal radioulnar joint (DRUJ). Core needle biopsy confirmed the diagnosis of desmoid tumour. Marginal excision of the tumour was done. At the 2-year follow-up, the patient was doing well and had painless and improved left wrist motion. Desmoid tumour involving the DRUJ has not been previously reported. We, through this case, report new observation and discuss the epidemiology, investigation of choice, treatment modalities, and the need for a regular follow-up for appendicular desmoid tumours.

Desmoid-type fibromatosis of the chest wall: a case report

Desmoid-type fibromatosis (DF), also known as deep fibromatosis or desmoid tumor, is an extremely rare neoplasm that develops from fascia and musculoaponeurotic tissue. These tumors are characterized by slow progressive growth, local invasion, and local recurrence after surgical excision, but they lack metastatic potential. DF accounts for 3.5% of all fibrous tumors, with an annual incidence of approximately 2–4/million. Until now, only a small number of cases have been found in the chest wall. Herein, we present a rare case of chest wall DF in a 43-year-old female, which was discovered accidentally due to a thoracic wall mass that extended outward from the sternum. Computed tomography scans revealed a subcutaneous soft tissue mass anterior to the sternum, which was considered to be a mesenchymal tumor or an inflammatory lesion. The patient underwent surgical excision of the mass. The mass was completely removed and all margins were negative. According to the pathological results, the patient was finally diagnosed as DF. Postoperative radiotherapy was suggested subsequently, especially considering the locally aggressive and infiltrative nature of the tumor. However, this was rejected by the patient, and biannual re-examination was recommended instead. Despite the absence of postoperative radiotherapy, there was no evidence of local recurrence 2 years later. We consider regular postoperative follow-up may be able to replace postoperative radiotherapy, and if there exist an opportunity to completely resect the mass, surgical is a worthwhile choice.

A Large Sporadic Intra-abdominal Desmoid-Type Fibromatosis in a Young Male: A Case Report

Desmoid type fibromatosis (DTF) is a rare benign tumor of connective tissue origin. While these tumors are typically not malignant, they can exhibit aggressive growth patterns causing mass effect on surrounding organs. These tumors typically present in the extremities and abdominal wall, rarely occurring in the mesentery, and abdominal organs. Due to the rarity of this tumor and the variable size and origin, it is difficult to provide exact prognosis, recurrence, and treatment efficacy regarding desmoid tumors arising from the ileocolic mesentery. We present a case of a young male with a sporadic 31 × 25 × 12 cm DTF arising from the ileocolic mesentery that was complicated by mass effect on bowel and intra-abdominal organs requiring surgical intervention. On presentation, the patient exhibited weight gain and abdominal pressure. Abdominal distension without tenderness on palpation was noted on physical examination. The tumor biopsy confirmed the diagnosis of DTF. No evidence of familial adenomatous polyposis or Gardner syndrome was identified. The tumor was surgically excised and intimately associated with the bowel requiring ileocolonic resection with primary anastomosis. At 3-months follow up, surveillance MRI showed no residual or recurrent lesion. A multi-disciplinary approach to this patient's diagnosis and treatment allowed for an accurate diagnosis, efficient treatment, and follow up plan.

Lower Rate of CTNNB1 Mutations and Higher Rate of APC Mutations in Desmoid Fibromatosis of the Breast: A Series of 134 Tumors

Desmoid fibromatosis (DF) is a rare, locally aggressive, nonmetastasizing fibroblastic/myofibroblastic tumor with a tendency to recur and an unpredictable clinical course. A "wait-and-see" policy is the new standard of care. DF are characterized by activating alterations of the wnt/β-catenin pathway: CTNNB1 or adenomatous polyposis coli gene (APC) mutations (these mutations being mutually exclusive). Desmoid-type fibromatosis of the breast (DFB) is rare with an incidence of 0.2% of breast tumors. The diagnosis of DFB is difficult, as it must be distinguished from metaplastic carcinoma and other spindle cell lesions. Sequencing of 128 DFB identified a lower rate of CTNNB1 mutations using Sanger (65.6%) or Sanger+next-generation sequencing (77.7%) and a higher rate of APC mutations (11.8%) than in all-site DF. By excluding patients with familial adenomatous polyposis (n=2), the rate of APC mutations in DFB was high (10.7%). The distribution of CTNNB1 mutations in DFB was different from all-site DF, with a higher rate of T41A (68.9%), a lower rate of S45F (5.7%), and a similar rate of S45T (12.6%). By combining the 2 molecular techniques in a 2-step manner (Sanger, then next-generation sequencing), we increased the detection rate of CTNNB1 mutations and lowered the rate of wild-type tumors from 34.4% to 9.8%, therefore improving the diagnosis of DFB. The identification of the exon 3 CTNNB1 mutation in breast spindle cell lesions is a highly specific tool for the diagnosis of DFB, in addition to extensive immunohistochemical analysis. Our study also underlines the importance of APC in DFB tumorigenesis. These findings have significant implications for patient care and management.

Is mutation analysis of β-catenin useful for the diagnosis of desmoid-type fibromatosis? A systematic review

BACKGROUND

An accurate diagnosis is crucial to determine the treatment modality for desmoid-type fibromatosis, although the histopathological diagnosis is occasionally difficult to make. Many desmoid-type fibromatosis have been reported to have hotspot mutation of β-catenin gene (CTNNB1). In the present study, we performed a systematic review to verify the usefulness of CTNNB1 mutation analysis in the diagnosis of desmoid-type fibromatosis.

METHODS

A literature search from January 1990 to August 2017 was conducted. Three reviewers independently assessed and screened the literature for eligibility and determined the final articles to be evaluated. Data regarding the sensitivity, specificity, accuracy and usefulness of CTNNB1 mutation analysis in the diagnosis of desmoid-type fibromatosis were recorded. We rated each report according to the Grading of Recommendations Development and Evaluation approach.

RESULTS

The search yielded 90 studies, seven of which were included after the first and second screenings. The positive rate of CTNNB1 mutation in desmoid-type fibromatosis was 86.8%, but the cohort of six of the seven reports was already diagnosed histopathologically as desmoid-type fibromatosis. Therefore, the usefulness of CTNNB1 mutation analysis in a cohort that is difficult to diagnose histopathologically is not clear in this review. Nevertheless, CTNNB1 mutation showed very high specificity in desmoid-type fibromatosis, indicating the usefulness of CTNNB1 mutation analysis in its diagnosis in combination with histological examination.

CONCLUSION

Because the lack of data precludes any useful comparison with histological diagnosis, the evidence level is low. However, considering its specificity, CTNNB1 mutation analysis may be useful in cases in which the histopathological diagnosis is difficult.

Radiotherapy in desmoid fibromatosis: a 10-year experience from a tertiary care centre

Aim of the study:

To assess the relapse-free survival (RFS) and the factors influencing local recurrence in patients with desmoid fibromatosis (DF) treated at our centre and to determine the role of post-operative radiotherapy (RT) in improving local control.

Methods:

A retrospective analysis of 51 patients treated for DF from January 2004 to December 2013 was undertaken. The RFS was calculated using the Kaplan–Meier curve. Univariate analysis was done to assess correlation with tumour size, site, the extent of surgery, margin status and adjuvant RT with RFS.

Results:

The median age was 28 years with a male:female ratio of 1:3. The most common location of the tumour was anterior abdominal wall (47%). The median tumour size was 10 cm. Wide local excision was done in most patients. Complete resection with negative margin was achieved in eight patients. Post-operative RT was indicated for 43 patients of whom 19 received RT. At a median follow-up of 37 months, RFS in the complete resection with margin negative group was 100%. RFS for the patients with positive or close margins who received RT was 79% and for those who did not receive RT, it was 87%.

Conclusions:

Complete excision with negative margins gives the best local control in DF. The benefit of post-operative RT could not be ascertained.

Recent Advances in Desmoid Tumor Therapy

The desmoid tumor is a locally aggressive proliferative disease within the family of soft-tissue sarcomas. Despite its relatively good prognosis, the clinical management of desmoid tumors requires constant multidisciplinary evaluation due to its highly variable clinical behavior. Recently, active surveillance has being regarded as the appropriate strategy at diagnosis, as indolent persistence or spontaneous regressions are not uncommon. Here, we review the most recent advances in desmoid tumor therapy, including low-dose chemotherapy and treatment with tyrosine kinase inhibitors. We also explore the recent improvements in our knowledge of the molecular biology of this disease, which are leading to clinical trials with targeted agents.

The value of the black fiber sign on T1-weighted images for predicting stability of desmoid fibromatosis managed conservatively

OBJECTIVES

It is challenging to know at the first which patients with desmoid fibromatosis (DF) are better suited to conservative or aggressive treatment. To investigate whether the low signal intensity bundles on T1- or T2-weighted images (WI), termed the "black fiber sign (BFS)," can predict non-progressive behavior in the conservative approach.

METHODS

This retrospective study included 59 patients with primary DF managed with wait-and-see approach from 2005 to 2018 and serial MR images were analyzed. Three observers blinded to the patient information verified the presence or absence of BFS on baseline T1 or T2WI. The likelihood of progression-free survival (PFS) after ascertaining the presence or absence of the BFS was estimated using the Kaplan-Meier method and analyzed with the log-rank test.

RESULTS

PFS was significantly higher in cases with BFS than without BFS on T1WI (p < 0.01), but there was no significant difference in PFS between cases with and without BFS on T2WI. Multivariable Cox proportional hazards analysis revealed that the absence of BFS on T1WI was a high-risk factor for progression (hazard ratio, 14.9; p < 0.01). Drastic tumor regression was apparent with significantly increased low-signal area in cases with BFS on T1WI. Intra- and interobserver reliabilities of BFS on T1WI were in almost-perfect agreement (κ > 0.8).

CONCLUSION

Our retrospective observational data support that presence of BFS in baseline MRI may be a predictor for progression-free survival of DF. BFS on T1WI is easily identifiable and can be utilized clinically in patients with DF.

KEY POINTS

• We proposed a new imaging marker for prediction of desmoid fibromatosis progression. • The absence of black fiber sign predicted a high risk of disease progression.

Usefulness of surgical treatment for asymptomatic patients with extra-peritoneal desmoid-type fibromatosis: a systematic review and meta-analysis

Objective

The purpose of this systematic review is to assess and compare the efficacy of surgical treatment for patients with asymptomatic extra-peritoneal desmoid-type fibromatosis to the wait-and-see policy by evaluating (1) the exacerbation rate (exacerbation; recurrence after surgery or progressive disease following non-surgical treatment) and (2) treatment-associated complications in extra-peritoneal desmoid-type fibromatosis.

Methods

We evaluated documents published between 1 January 1990 and 31 August 2017. The risk of bias in the selected literature was analyzed using the Cochrane Collaboration Risk of Bias Tool. Quality of evidence was evaluated using Grading of Recommendation, Assessment, Development and Evaluation approach.

Results

One prospective cohort study, four case–control studies and five case series studies were identified. Meta-analysis was performed to evaluate the exacerbation rate after treatment on one prospective cohort study and four case–control studies. In comparing surgical and non-surgical treatments, the exacerbation rate was significantly higher in the surgical treatment group (odds ratio: 1.32, 95% confidence interval 1.01–1.73, P = 0.05). However, in the case series study, the recurrence rate was 23.4% for the surgical treatment group, while the progressive disease rate was 28.1% for the non-surgical treatment group. The postoperative complication rates associated with surgical treatment in the two studies were 20.8 and 17.2%, respectively.

Conclusions

When considering the exacerbation rate, non-surgical treatment might be appropriate for asymptomatic patients with extra-peritoneal desmoid-type fibromatosis. However, if patients with tumor-related symptoms opt for surgery, including those who face difficulties due to the presence of tumors, it is important to fully explain to them the possibility that the recurrence rate and treatment-associated functional failures may increase depending on the site of occurrence.

[Magnetic resonance imaging of desmoid-type fibromatosis: Current evaluation criteria]

The management of desmoid-type fibromatosis has considerably evolved these last years, toward first-line active surveillance then systemic or local symptomatic treatment in case of aggressive tumor. Magnetic resonance imaging is the modality of choice in each of these treatment settings. It needs multiparametric approach taking into account mainly the tumor size, and T2-weighted signal that is correlated with histological composition and clinical behavior. A volumetric approach should be favored for the evaluation of tumor size change. The interest of paramagnetic contrast injection and tumor enhancement requires further investigation.

Familial Adenomatous Polyposis and Desmoid Tumor Treated with Multivisceral Transplantation and Kidney Autotransplantation: Case Report and Literature Review

Introduction

Desmoid tumours (DT) are commonly associated with Gardener's syndrome. Their surgical resection may be complicated by their close proximity to major vessels, multiple organ involvement, and frequent local recurrence. Multivisceral transplantation (MVTx) is an alternative treatment for patients with intestinal and liver failure. In patients with DT closely associated with renal structures but without end-stage kidney disease, concomitant excision of the patient's own kidney, ex vivo tumour resection with nephron-sparing surgery, or autotransplantation has been proposed.

Case Presentation

A 36-year-old Caucasian female weighing 60 kg with Gardener's syndrome with a history of abdominal surgery was presented to our department with progressive abdominal distention associated with paroxysmal pain. With the use of CT, the patient was diagnosed with a mass arising from the mesenterial region. The patient had normal kidney function and nonalcoholic steatohepatitis. The patient was indicated for MVTx.

Management and Outcome

After 16 months on the waiting list, the patient received a multivisceral graft from a deceased donor. Following the restoration of graft vascular flow, the patient's right kidney was removed and the DT dissected ex vivo before autotransplantation into the right pelvic fossa. The patient received immunosuppressive, antithrombotic, and antibiotic treatment. There was no acute rejection, though the patient experienced pulmonary infection, dysphagia, and oesophageal reflux with fungal infection. The patient had required temporary dialysis for acute renal failure for 75 days. One year after the surgery, nausea and violent vomiting caused delayed gastric emptying caused by spastic pylorus. Clinical improvement was achieved using gastric peroral endoscopic myotomy (G-POEM).

Conclusion

MVTx with kidney autotransplantation is a feasible treatment option in patients with familiar adenomatous polyposis complicated by an abdominal DT. Precise tumour dissection with nephron-sparing surgery was carried ex vivo. G-POEM was used to relieve MVTx-related gastroparesis. The patient had no disease reoccurrence after one-year follow-up.

Modeling open surgery in mice to explore peritoneal damage, carbon dioxide humidification and desmoidogenesis

Background

The exposure of the peritoneum to desiccation during surgery generates lasting damage to the mesothelial lining which impacts inflammation and tissue repair. We have previously explored open abdominal surgery in mice subjected to passive airflow however, operating theatres employ active airflow. Therefore, we sought an engineering solution to recapitulate the active airflow in mice. Similarly, to the passive airflow studies we investigated the influence of humidified-warm carbon dioxide (CO₂) on this damage in the context of active airflow. Additionally, we addressed the controversial role of surgery in exacerbating desmoidogenesis in a mouse model of familial adenomatous polyposis.

Methods

An active airflow mouse-operating module manufactured to produce the equivalent downdraft airflow to that of a modern operating theatre was employed. We quantified mesothelial cell integrity by scanning electron microscopy (SEM) sampled from the peritoneal wall that was subjected to mechanical damage or not, with and without the delivery of humidified-warm CO₂. To explore the role of open and laparoscopic surgery in the process of desmoidogenesis we crossed Apc^min/+ C57Bl/6 mice with p53^+/− mice to generate animals that developed desmoid tumors with 100% penetrance.

Results

One hour of active airflow generates substantial damage to peritoneal mesothelial cells and their microvilli as measured at 24 h post intervention, which is significantly greater than that generated by passive airflow. Use of humidified-warm CO₂ mostly protects the mesothelium that had not experienced additional mechanical (surgical) damage at 24 h. Maximal damage was evident in all treatment groups regardless of flow or use of gas. At day 10 mechanically-damaged peritoneum remains in mice but is essentially repaired in the gas-treated groups. Regarding desmoidogenesis, operating procedures did not increase the frequency of desmoid tumors but their frequency correlated with time following surgery but not age of mice.

Conclusions

Active airflow generates more peritoneal damage than passive airflow and is reduced significantly by the use of humidified-warm CO₂. Introduced peritoneal damage is largely repaired in mice by day 10 with gas. Desmoid tumor incidence is not increased substantially by surgery itself but rises over time following surgery compared to non-surgery mice.

The initiation, design, and establishment of the Desmoid Tumor Research Foundation Patient Registry and Natural History Study

Desmoid tumors are locally invasive sarcoma, affecting 5-6 individuals out of 1,000,000 per year. The desmoid tumors have high rates of recurrence after resection and can lead to significant deterioration of the quality of life of patients. There is a need for a better understanding of the desmoid tumors' patient experience from first symptoms through diagnosis, disease monitoring, and clinical treatment options. With the National Organization of Rare Disorders, the Desmoid Tumor Research Foundation Natural History Study was designed to be collected through the registry. This article describes the protocol for the Desmoid Tumor Research Foundation Natural History Study and some initial findings. The Desmoid Tumor Research Foundation Natural History Study Advisory Committee developed a series of questionnaires and longitudinal surveys, in addition to those from the National Organization of Rare Disorders for all of the rare diseases. These 13 surveys are designed to uncover initial symptoms, diagnosis process, disease monitoring, quality of life, treatments, as well as socioeconomic information. Since launching the Desmoid Tumor Research Foundation Registry and Natural History Study (https://dtrf.iamrare.org), more than 300 desmoid tumor patients have consented to the Desmoid Tumor Research Foundation Natural History Study and completed the Participant Profile. The majority of the respondents are between the ages of 21 and 50 years (76%), female (81.2%), White (91.5%), and live in the United States (47.1%). The majority of tumors are in the lower or upper extremity, (22.9%) followed closely by abdominal desmoid tumors (21.5%). Most are willing to donate specimens (89.9%) and participate in trials (97.2%). Ongoing efforts are addressing the demographic differences between the respondents and non-respondents and any selection bias based on access to the registry and study. The Desmoid Tumor Research Foundation Natural History Study is built on the largest desmoid tumors registry and has recruited more desmoid tumors participants since launching in September 2017. It will serve to fill desmoid tumors knowledge gaps and assist other researchers in their recruitment efforts for additional studies.

Local Control and Analgesic Efficacy of Percutaneous Cryoablation for Desmoid Tumors

OBJECTIVE

Cryoablation is being more and more often used to treat desmoid tumors. We report our experience of cryoablation as a local and analgesic treatment for inoperable or recurring desmoid tumors.

METHODS

This study includes 34 patients who underwent percutaneous cryoablation of 41 desmoid tumors between July 2012 and September 2016. All patients underwent pain assessment using a visual analog scale (VAS) and preoperative imaging. All cryoablation procedures were performed using the same cryoablation system. Patients received clinical and radiological follow-up at 6 months post-procedure, with pain-rating and adverse events being recorded. A long-term follow-up was achieved until 31 December 2018. Disease-free survival at 3 years was also recorded. Radiological tumor response was determined by tumor measurements using RECIST 1.1.

RESULTS

Twelve patients benefitted from curative treatment on 100% of the tumor volume, but 22 patients received debulking treatment because of the risk of neighboring structures. Two patients had a postoperative hematoma grade 2 of the CIRSE classification system for complications, and two patients had grade 4 complications involving palsy of the common fibular nerve. Disease-free survival at 3 years was 42.2%. The mean VAS pain scores were 5.7 and 2.4 at pretreatment and 6 months, respectively, showing a mean reduction of 3.3 (p < 0.001). At 6 months, all measured tumor dimensions were significantly lower than pretreatment.

CONCLUSION

Cryoablation is an effective therapeutic option for the local treatment and for the analgesic management of desmoid tumors.

Evidence-based MR imaging follow-up strategy for desmoid-type fibromatosis

OBJECTIVES

To propose a follow-up strategy for desmoid-type fibromatosis (DF) based on tumor growth behavior and the signal on T2-weighted MRI.

METHODS

We retrospectively reviewed 296 MRI studies of 34 patients with histologically proven DF. In each study, tumor volume and T2 signal relatively normal striated muscle were assessed. Volume variation and monthly growth rates were analyzed to determine lesion growth behavior (progressing versus stable/regressing lesions). Growth behavior was correlated with T2 signal, tumor location, β-catenin status, treatment strategy, and follow-up duration. Interobserver variability of volume measurements and interobserver measurement variation ratio were assessed.

RESULTS

There were 25 women and 9 men with a mean age of 39.9 ± 19 (4-73) years. Mean follow-up time in the patients included was 55 ± 41 (12-148) months. In progressing lesions, the mean average monthly growth ratio was 10.9 ± 9.2 (1.1-42.5) %. Interobserver variability of volume measurements was excellent (ICC = 0.96). Mean interobserver measurement variation ratio was 20.4 ± 23.6%. The only factor correlated with tumor growth behavior was T2 signal ratio (p < 0.0001). Seventeen out of 34 (50%) patients presented a signal change over the threshold of 1 during follow-up. There were five occurrences of secondary growth after a period of stability with a mean delay until growth of 38.2 ± 44.2 (17-116) months.

CONCLUSION

DF growth rate was quantitatively assessed. A threshold for volume variation detection was established. DF growth behavior was significantly related to T2 signal. An evidence-based follow-up strategy is proposed.

KEY POINTS

• In progressing desmoid fibromatosis, the mean average monthly growth ratio was 10.9 ± 9.2%. • Lesions with muscle/tumor T2 signal ratios lower than 1 tended to be stable or regress over time. • Given the interobserver measurement variability and MRI in-plane spatial resolution, a variation higher than 42.6% in tumor volume is required to confirm punctual progression.

Clinical features and treatment outcome of desmoid-type fibromatosis: based on a bone and soft tissue tumor registry in Japan

BACKGROUND

Treatment modality of desmoid-type fibromatosis (DF) has changed from surgery with a wide surgical margin to conservative treatment. In this study, tumor characteristics of DF, transition of the treatment modality, and clinical outcome of surgical treatment were analyzed based on data obtained from the bone and soft tissue tumor registry established in Japan.

METHODS

Data were collected as registration data and follow-up data. Five hundred and thirty registered cases of DF were identified, including 223 cases with follow-up data with or without surgical treatment.

RESULTS

The number of registered patients increased gradually. The frequency of surgical treatment was gradually reduced year by year. The 3-year local recurrence free survival (LRFS) was 77.7%, with tumor location and size tending to correlate with LRFS. Interestingly, there was no significant difference in LRFS between wide and marginal margin (P = 0.34).

CONCLUSIONS

The treatment modality has shifted from surgical to conservative treatment, with risk factors for surgical treatment similar to those noted in previous studies. The National registry system is crucial for a rare disease such as DF, and in the future, a population based registry system should be established to better comprehend the actual status of DF.

Enhanced T-lymphocyte infiltration in a desmoid tumor of the thoracic wall in a young woman treated with intratumoral injections of the oncolytic peptide LTX-315: a case report

Background

Desmoid tumors are intermediary malignant, fibrous lesions occurring in various soft tissues. Surgical treatment is relentlessly challenging because of the propensity for local aggressive behavior and high risk of recurrence. Consequently, a wide range of oncological drugs and radiation therapy are being used; however, outcomes are unpredictable. We investigated whether local treatment with an oncolytic peptide could be beneficial in a patient with an unresectable desmoid tumor.

Case presentation

In a young 29-year-old Caucasian woman who was diagnosed with a retromammary desmoid tumor infiltrating deeply into the anterior thoracic wall, surgery was considered excessively mutilating, and observation was recommended. The lesion progressed, however, and caused debilitating pain, despite nonsteroidal anti-inflammatory medication. Subcutaneous injections of human interferon-α (Multiferon®) resulted in reduced growth kinetics but had to be terminated because of development of symptomatic pneumonitis. Frequently used oncological treatment was withheld because of the toxicity profile, and the patient was instead included in a phase I study investigating transdermal intratumoral injection of LTX-315, an oncolytic peptide that induces anticancer immune responses (ClinicalTrials.gov, NCT01986426). A marked increase of CD8⁺ tumor-infiltrating T cells in the lesion was complemented by upregulation of immune gene signature (including effector T-cell, T-helper type 1 cell, chemokine, and cytokine genes). These changes were followed by gradual symptom relief and long-term disease stabilization, indicating clinical benefit. LTX-315 was well tolerated until termination in week 16 after a serious allergic reaction.

Conclusions

Our patient was treated with repeated intratumoral injections of LTX-315, resulting in tumor regression accompanied by upregulation of immune genes and T-cell infiltration. Local application of immunotherapy, minimizing systemic side effects, represents a novel treatment modality in desmoid tumors that should be tested in further clinical trials.

Breast desmoid tumor management in France: toward a new strategy

PURPOSE

Desmoid tumors (DTs) are rare tumors that originate from myofibroblastic tissue. Recently, initial wait and see was recommended (ESMO guidelines Ann Oncol 2017) in the most frequent locations. This study investigates the outcome of breast desmoid tumor (BDT) according to the initial strategy.

METHOD

Data from all consecutive patients treated from a BDT in four referral centers were collected. Only intra-mammary desmoid tumors were included. A pathological review and a molecular analysis (CTNNB1 gene mutation) were performed (National re-reading network of sarcomas-RRePS). Patients were grouped according to initial strategy: surgery group (SG) and active surveillance group (ASG).

RESULTS

A total of 63 patients (61 women, 2 men) met the inclusion criteria. Median age was 50 years (16-86). CTNNB1 mutation was found in 61% (n = 36). SG included 46 patients (73%) (41 partial mastectomies, 2 mastectomies, and 3 mastectomies associated to parietectomies). Surgical margins were positive in 15 patients (33.3%). Median follow-up of SG was 24.9 (0.5-209) months; and 4 patients (8.7%) developed recurrence. ASG included 17 patients (27%). Their median follow-up was 42.2 (0-214) months, and 15 patients (88.2%) did not require any additional treatment. Six patients (35%) had a spontaneous regression, 9 patients (52%) were stable, and 2 patients presented a significant progression that was treated by partial mastectomy.

CONCLUSION

This study supports an initial nonsurgical approach to BDTs followed by surgery based on tumor growth in select cases, which is consistent with current ESMO recommendations.

Desmoid-type fibromatosis arising in a bifid rib chest wall

Desmoid-type fibromatosis is a rare soft tissue tumor and the chest wall is one of the common sites of its extra-abdominal occurrence. A bifid rib is one of the congenital rib abnormalities. We report a case of desmoid-type fibromatosis arising in a chest wall's bifid rib. A 42-year-old female complained of right chest pain without remarkable medical, traumatic, or familial history. Chest-computed tomography revealed a chest wall tumor located adjacent to a bifid costal cartilage of third rib. We performed chest wall resection of second and third ribs. Pathologically, the tumor was diagnosed a desmoid-type fibromatosis of the chest wall. We surmise mechanical stimulation due to the bifid rib may be related to the occurrence of the tumor. In case of desmoid-type fibromatosis without somatic gene mutation, traumatic history, wound, implants, or use of female hormonal agents, we should search also local congenital abnormality.

Soft Tissue Cancer Management: Isolated Limb Infusion for Sarcoma

Background

Sarcoma is a heterogeneous group of malignancies comprising almost 80 subtypes of bone and soft tissue cancers. Previously, all subtypes were managed identically. Advancements in biological and genetic studies have revealed that sarcoma subtypes display varying characteristics and therefore require tailored treatments. Locally advanced soft tissue malignancies of both the trunk and the extremities can present significant challenges for treatment. At present, a negative surgical resection margin is the only definitive treatment despite attempts to use neoadjuvant and adjuvant therapies. In patients with locally advanced non-resectable soft tissue sarcoma (STS), the current practice would advocate amputation. However, studies suggest that limb salvage may be possible with radiotherapy or regional chemotherapy using isolated limb perfusion or isolated limb infusion (ILI). An ideal treatment modality for non-resectable STS would strive for preservation of anatomy and functionality as well as improve quality of life. The aim of the study was to investigate the efficacy of isolated limb infusion as an alternative treatment modality for non-resectable locally advanced STS.

Methods

The efficacy of ILI was retrospectively investigated in 10 patients with STS. All patients received ILI with melphalan and actinomycin at the North Estonia Medical Centre Foundation, Tallinn, Estonia from September 1, 2014 to May 31, 2018. The procedures were performed in a lower extremity in 8 patients and in an upper extremity in 2 patients. The 6-month overall response rate was 78% and the overall limb salvage rate was 100%. The distant metastatis-free survival was longer for responders than for non-responders.

Results and Conclusions

ILI is an alternative treatment modality for regional disease control and limb preservation in patients with cutaneous and soft tissue malignant neoplasms of the extremities. The short-term response rates are encouraging and the median overall survival shows good results in this highly complex patient population.

Clinical prognostic factors for pediatric extra-abdominal desmoid tumor: analyses of 66 patients at a single institution

Background and purpose

Pediatric desmoid tumor (PDT) is rare and has a high local recurrence rate. The purpose of the present study was to analyze clinical risk factors of local recurrence in PDT patients.

Materials and methods

We reviewed clinical data of 66 PDT patients from 2004 to 2015. All patients underwent macroscopically complete resection, and some recurrent tumors were prescribed radiotherapy. Factors such as sex, age at presentation, location, and proximity to nerves or vasculature were analyzed. The local recurrence rate and recurrence-free survival were analyzed with these factors.

Results

All patients in the present study were children and had extra-abdominal tumors. The median follow-up time was 6.6 years. Thirty-six (55%) patients had local recurrence. Age, sex, tumor site, tumor size, and proximity to nerves/vasculature had a significant impact on prognosis in univariate analysis. Radiotherapy decreased the local recurrence rate. In multivariate analysis, younger age, tumor location in buttocks, larger tumor, and proximity to important nerves/vasculature were independent risk factors for poor prognosis.

Conclusions

Favorable therapeutic strategies could be selected according to the preoperative prognostic risk factors. Radiotherapy should be considered for local recurrence of PDT.

Recurrent Desmoid Tumor of the Neck: A Case Report of a Benign Disease with Aggressive Behavior

We present a case of a desmoid tumor recurrence in a patient with a history of a resected desmoid tumor of the right neck area with free surgical margins six months earlier. The neoplasm was found to invade the parapharyngeal space, and wide excision was performed including most of the sternocleidomastoid muscle (SCM), the thrombosed internal jugular vein (IJV), and the infiltrated spinal accessory nerve (SAN). The histopathologic findings displayed free microscopic margins, with close margins at the site of the parapharyngeal space extension. After 3 months, there was no sign of tumor recurrence. After 6 months, local tumor recurrence was identified on clinical examination and imaging. The decision of the Oncology Board was further treatment with radiotherapy (RT). Response to treatment was satisfactory, and the patient was on close follow-up for twelve months. Desmoid tumors are very rare benign neoplasms of mesenchymal origin with negligible mortality but high morbidity, due to their high recurrence rates, local tissue infiltration, and unpredictable disease course and response to treatment. No universally acceptable treatment protocols have been introduced to date. Appropriate patient counseling and close follow-up are warranted in all cases.

HIFU for Bone Metastases and other Musculoskeletal Applications

High-intensity focused ultrasound (HIFU) is a totally noninvasive procedure that has shown promising results in the management of numerous malignant and nonmalignant conditions. Under magnetic resonance or ultrasound guidance, high-intensity ultrasound waves are focused on a small, well-defined target region, inducing biologic tissue heating and coagulative necrosis, thus resulting in a precise and localized ablation. This treatment has shown both great safety and efficacy profiles, and may offer a multimodal approach to different diseases, providing pain palliation, potential local tumor control, and, in some cases, remineralization of trabecular bone. In musculoskeletal field, HIFU received FDA approval for treating bone metastasis, but its application has also been extended to other conditions, such as osteoid osteoma, desmoid tumor, low-flow vascular malformation, and facet joint osteoarthritis. This article illustrates the basic principles of HIFU and its main effects on biologic tissues with particular attention on bone, provides a step-by-step description of the HIFU procedure, and discusses the commonly treated conditions, in particular bone metastases.