Positron emission tomography as a surrogate marker for evaluation of treatment response in patients with desmoid tumors under therapy with imatinib

Diagnostic Superiority of Dual-Time Point [18F]FDG PET/CT to Differentiate Malignant from Benign Soft Tissue Tumors

[18F]FDG PET/CT is used in the workup of indeterminate soft tissue tumors (STTs) but lacks accuracy in the detection of malignant STTs. The aim of this study is to evaluate whether dual-time point [18F]FDG PET/CT imaging (DTPI) can be useful in this indication. In this prospective study, [18F]FDG PET/CT imaging was performed 1 h (t1) and 3 h (t2) after injection. Tumor uptake (SUVmax) was calculated at each time point to define a retention index (RI) corresponding to the variation between t1 and t2 (%). Sixty-eight patients were included, representing 20 benign and 48 malignant tumors (including 40 sarcomas). The RI was significantly higher in malignant STTs than in benign STTs (median: +21.8% vs. -2%, p < 0.001). An RI of >14.3% predicted STT malignancy with a specificity (Sp) of 90% and a sensitivity (Se) of 69%. An SUVmaxt1 of >4.5 was less accurate with an Sp of 80% and an Se of 60%. In a subgroup of tumors with at least mild [18F]FDG uptake (SUVmax ≥ 3; n = 46), the RI significantly outperformed the diagnostic accuracy of SUVmax (AUC: 0.88 vs. 0.68, p = 0.01). DTPI identifies malignant STT tumors with high specificity and outperforms the diagnostic accuracy of standard PET/CT.

Mesenchymal Tumors of the Breast: Fibroblastic/Myofibroblastic Lesions and Other Lesions

Mesenchymal breast tumors are a rare and diverse group of tumors that present some of the most challenging cases for multidisciplinary breast cancer teams. As a result of overlapping morphologies and a lack of large-scale studies on these tumors, practices are often heterogeneous and slow to evolve. Herein, we present a non-systematic review that focuses on progress, or lack thereof, in the field of mesenchymal breast tumors. We focus on tumors originating from fibroblastic/myofibroblastic cells and tumors originating from less common cellular origins (smooth muscle, neural tissue, adipose tissue, vascular tissue, etc.).

Clinical outcomes of medical treatments for progressive desmoid tumors following active surveillance: a systematic review

Approximately 80% of desmoid tumors (DTs) show spontaneous regression or disease stabilization during first-line active surveillance. Medical treatment can be considered in cases of disease progression. This systematic review aimed to evaluate the effectiveness and toxicity of each medical treatment by reviewing only the studies that included progressive disease as the inclusion criterion. We searched the EMBASE, PubMed, and CENTRAL databases to identify published studies for progressive DTs. The disease control rates of the medical treatments, such as low-dose chemotherapy with methotrexate plus vinblastine or vinorelbine, imatinib, sorafenib, pazopanib, nilotinib, anlotinib, doxorubicin-based agents, liposomal doxorubicin, hydroxyurea, and oral vinorelbine for progressive DTs were 71-100%, 78-92%, 67-96%, 84%, 88%, 86%, 89-100%, 90-100%, 75%, and 64%, respectively. Low-dose chemotherapy, sorafenib, pazopanib, nilotinib, anlotinib, and liposomal doxorubicin had similar toxicities. Sorafenib and pazopanib were less toxic than imatinib. Doxorubicin-based chemotherapy was associated with the highest toxicity. Hydroxyurea and oral vinorelbine exhibited the lowest toxicity. Stepwise therapy escalation from an initial, less toxic treatment to more toxic agents is recommended for progressive DTs. Sorafenib and pazopanib had limited on-treatment side effects but had the possibility to induce long-term treatment-related side effects. In contrast, low-dose chemotherapy has some on-treatment side effects and is known to have very low long-term toxicity. Thus, for progressive DTs following active surveillance, low-dose chemotherapy is recommended in young patients as long-term side effects are minor, whereas therapies such as sorafenib and pazopanib is recommended for older patients as early side effects are minor.

Desmoid-type fibromatosis: imaging features and course

Desmoid-type fibromatosis (DF) is a soft tissue tumor characterized by infiltrative growth and a tendency toward local recurrence, while it exhibits self-limiting behavior and shows spontaneous regression. With its unpredictable behavior, a change in treatment strategies from initial surgery to nonsurgical management has been proposed, and active surveillance is currently widely chosen as the initial treatment strategy for DF. We reviewed the imaging features of DF regarding its clinical course, focusing on regression cases, postoperative cases, and imaging changes after systemic treatment.

Differentiation of intra-abdominal desmoid tumor from peritoneal seeding based on CT and/or 18F-FDG PET-CT in patients with history of cancer surgery

PURPOSE

To investigate differential imaging features of intra-abdominal desmoid tumors and peritoneal seeding in patients with history of cancer surgery.

METHODS

Thirty-two patients who had a single pathologically proven intra-peritoneal lesion that developed after cancer surgery were enrolled between January 2000 and June 2019. There were 16 desmoid tumors and 16 peritoneal seeding lesions. Portal phase CT and/or ¹⁸F-FDG PET findings were analyzed by two radiologists in consensus for the following items: location, size, shape, margin, contour, homogeneity, necrosis, adjacent organ invasion, calcification, intra-lesional fat, peritoneal infiltration, mass effect, and degree of enhancement. Hounsfield units (HU) and maximum standardized uptake values (SUV_max) of the lesions were measured. Imaging findings were compared using the Chi square test, Fisher's exact test, and student t test.

RESULTS

Desmoid tumors frequently showed well-defined margins (9/16) and smooth contours (12/16), whereas peritoneal seeding had ill-defined margins (13/16) and lobulated contours (11/16) (P = 0.028 and 0.013, respectively). Intra-lesional fat was found more frequently in desmoid tumors (7/16) than peritoneal seeding (1/16) (P = 0.014). Desmoid tumors showed iso-attenuation (13/16) compared to psoas muscle in portal phase, while peritoneal seeding depicted high attenuation (12/16) (P = 0.002). Mean HU was significantly lower in desmoid tumors (64.3) than peritoneal seeding lesions (95.1) (P = 0.001). However, the mean SUV_max of desmoid tumors (4.1) did not significantly differ from peritoneal seeding lesions (5.2) (P = 0.519).

CONCLUSION

Several CT features including iso-attenuation in portal phase and presence of intra-lesional fat can be helpful in differentiating desmoid tumors from peritoneal seeding in patients with history of intra-abdominal cancer surgery.

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.

Current Update on Desmoid Fibromatosis

OBJECTIVE

The purpose of this article is to review the etiopathogenesis, molecular cytogenetics, histopathology, clinical features, and multimodality imaging features of desmoid fibromatosis. Recent advances in the management of desmoid fibromatosis will also be discussed.

CONCLUSIONS

Desmoid fibromatosis is a rare soft tissue neoplasm with a high incidence of local recurrence. Imaging plays an important role in the diagnosis and management of this disease.

An update on the management of sporadic desmoid-type fibromatosis: a European Consensus Initiative between Sarcoma PAtients EuroNet (SPAEN) and European Organization for Research and Treatment of Cancer (EORTC)/Soft Tissue and Bone Sarcoma Group (STBSG)

Desmoid-type fibromatosis is a rare and locally aggressive monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Currently, there is no established or evidence-based treatment approach available for this disease. Therefore, in 2015 the European Desmoid Working Group published a position paper giving recommendations on the treatment of this intriguing disease. Here, we present an update of this consensus approach based on professionals' AND patients' expertise following a round table meeting bringing together sarcoma experts from the European Organization for Research and Treatment of Cancer/Soft Tissue and Bone Sarcoma Group with patients and patient advocates from Sarcoma PAtients EuroNet. In this paper, we focus on new findings regarding the prognostic value of mutational analysis in desmoid-type fibromatosis patients and new systemic treatment options.

Aggressive fibromatosis response to tamoxifen: lack of correlation between MRI and symptomatic response

Background

One of the commonly used systemic agents for the treatment of aggressive fibromatosis is the anti-oestrogen drug tamoxifen. However, data on efficacy and optimum methods of response assessment are limited, consisting mainly of small case series and reports.

Methods

A retrospective database was used to identify consecutive patients diagnosed with aggressive fibromatosis (AF) and treated with tamoxifen plus/minus non-steroidal anti-inflammatory drugs at our tertiary referral centre between 2007 and 2014. MRI and symptom changes were recorded.

Results

Thirty-two patients (13 male 19 female, median age 41 years) were included. Median duration of treatment with tamoxifen was 316 days. Of 9 patients with progressive disease by RECIST 1.1 (28%): 4 patients experienced worsening symptoms; 3 patients had improved symptoms and 2 had no change in symptoms. Of 22 patients with stable disease (69%): 11 had no change in symptoms; 6 had improved symptoms and 5 patients had worsening symptoms. One patient achieved a partial response with improved symptoms.

Conclusions

No relationship was identified between symptomatic benefit and response by RECIST 1.1 on MRI. Prospective studies in AF should incorporate endpoints focusing on patient symptoms.

Fibromatosis Associated With Neuromuscular Choristoma: Evaluation by FDG PET/CT

Neuromuscular choristoma (NMC) is a rare benign peripheral nerve lesion consisting of mature skeletal muscle fibers admixed with nerve fascicles. Aggressive fibromatosis frequently develops in association with NMC, often after surgery or biopsy, but the exact pathogenesis is not known. We present a case of NMC complicated by aggressive fibromatosis evaluated by F-FDG PET/CT and examine the relationship of metabolic activity and MRI signal characteristics.

Desmoid-type fibromatosis

Desmoid-type fibromatosis is a rare, locally infiltrative, mesenchymal neoplasm that is associated with high rates of local recurrence but lacks the potential to metastasise. The disease affects younger individuals, with a peak age of 30 years, and is the most common cause of an anterior abdominal wall mass in young women of childbearing age. It may, however, involve nearly every body part, including the extremities, head and neck, trunk, and abdominal cavity; as such, desmoid-type fibromatosis may present to a range of general and subspecialty radiologists. These rare tumours have a widely variable clinical presentation and unpredictable natural history, hence input from a soft-tissue tumour centre is recommended, although much of the imaging may be performed at the patient's local hospital. The consensus for treatment has changed over the past decade, with most centres moving away from primary radical surgery towards a front-line 'watch-and-wait' policy. Therefore, imaging has an increasingly important role to play in both the diagnosis and follow-up of these patients. This review will discuss the typical imaging characteristics of these lesions and suggest diagnostic and follow-up magnetic resonance imaging protocols, with details of suitable sequences and scanning intervals.

Musculoskeletal desmoid tumours: Pre- and post-treatment radiological appearances

This study was aimed to illustrate the pre- and post-treatment imaging findings of musculoskeletal desmoid tumours and describe current treatment methods. Imaging of histologically proven cases of desmoid tumours at St. Vincent's Hospital, Melbourne, were obtained via picture archiving communication system (PACS) and then assessed by two musculoskeletal radiologists. Suitable imaging both pre- and post-treatment were then obtained from PACS. All imaging chosen were de-identified. Ninety-two patients were found to have histologically proven cases of desmoid tumours between January 2000 and December 2013. Six patients with extra-abdominal tumours were selected, where pre- and post-treatment imaging was available. Desmoid tumours can occur in many areas of the body. Treatment of desmoids are varied. Although wide-margin surgery has been the traditional form of treatment, it still cannot guarantee absence of tumour recurrence despite microscopically tumour-free margins. Other forms of treatment such as non-steroidal anti-inflammatory drugs, radiotherapy, chemotherapy, tyrosine kinase inhibitors and also the conservative 'watch and wait' approach have been suggested, which show varying results.

Systemic treatment approaches for sporadic desmoid-type fibromatosis: scarce evidence and recommendations

Desmoid-type fibromatosis (DF) is a rare disease characterized by a monoclonal, fibroblastic proliferation and a variable and often unpredictable clinical course. Although histologically benign, DF is locally invasive and associated with a high local recurrence rate, but lacks any metastatic potential. As there is no established or evidence-based treatment approach available as of today, an individualized treatment strategy is fundamental in the light of highly variable clinical presentations, anatomic locations, and biological behaviors. Surgery with negative margins has been the cornerstone of DF treatment; however, an overall reassessment of the management of DF patients has taken place in the last few years, and preservation of function and quality of life has become a priority in these patients. Evidence is scarce for systemic treatment; different pharmacological options can be proposed and will be reviewed here. To better define possible therapeutic strategies, a consensus approach has been initiated, bringing together sarcoma experts from the European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) with patient advocates from Sarcoma Patients EuroNet (SPAEN). As a prerequisite, patients should be discussed in a multidisciplinary setting in centers/networks with specific expertise and experience in this disease.

The preoperative maximum standardized uptake value measured by 18F-FDG PET/CT as an independent prognostic factor of overall survival in endometrial cancer patients

PURPOSE

The aim of this study was to determine if the preoperative maximum standardized uptake value (SUVmax) measured by 18F-FDG PET/CT in the primary tumor has prognostic value in the group of patients with endometrial cancer.

PATIENTS, MATERIALS, AND METHODS

A total of one hundred one consecutive endometrial cancer patients, age range 40-82 years (mean 62 years) and FIGO I-IV stage, who underwent 18-FDG-PET/CT within two weeks prior radical surgery, were enrolled to the study. The maximum SUV was measured and compared with the clinicopathologic features of surgical specimens. The relationship between SUVmax and overall survival was analyzed.

RESULTS

The mean preoperative SUVmax was 14.34; range (3.90-33.80) and was significantly lower for FIGO I than for higher stages (P = 0.0012), as well as for grade 1 than for grade 2 and 3 (P = 0.018), deep myometrial invasion (P = 0.0016) and for high risk group (P = 0.0004). The analysis of survival ROC curve revealed SUVmax cut-off value of 17.7 to predict high risk of recurrence. Endometrial cancer patients with SUVmax higher than 17.7 characterized by lower overall survival.

CONCLUSION

The preoperative SUVmax measured by 18F-FDG PET/CT is considered as an important indicator reflecting tumor aggressiveness which may predict poor prognosis. High value of SUVmax would be useful for making noninvasive diagnoses and deciding the appropriate therapeutic strategy for patients with endometrial cancer.

New strategy for monitoring targeted therapy: molecular imaging

Targeted therapy is becoming an increasingly important component in the treatment of cancer. How to accurately monitor targeted therapy has been crucial in clinical practice. The traditional approach to monitor treatment through imaging has relied on assessing the change of tumor size by refined World Health Organization criteria, or more recently, by the Response Evaluation Criteria in Solid Tumors. However, these criteria, which are based on the change of tumor size, show some limitations for evaluating targeted therapy. Currently, genetic alterations are identified with prognostic as well as predictive potential concerning the use of molecularly targeted drugs. Conversely, considering the limitations of invasiveness and the issue of expression heterogeneity, molecular imaging is better able to assay in vivo biologic processes noninvasively and quantitatively, and has been a particularly attractive tool for monitoring treatment in clinical cancer practice. This review focuses on the applications of different kinds of molecular imaging including positron emission tomography-, magnetic resonance imaging-, ultrasonography-, and computed tomography-based imaging strategies on monitoring targeted therapy. In addition, the key challenges of molecular imaging are addressed to successfully translate these promising techniques in the future.