MR-Guided Laser Ablation in Desmoid Tumor Treatment: An Alternative Approach for Cases with Cold Hypersensitivity

Desmoid tumors are rare benign connective tissue neoplasms that originate from connective tissues, including musculoaponeurotic structures, and may also occur in locations such as the mesentery [1]. These tumors are locally invasive, with recurrence rates of up to 77% despite aggressive treatments [2]. Current options include surgery, radiation, hormonal therapy, and systemic agents, with variable efficacy [3]. Ablation technologies like laser interstitial thermal therapy (LITT) and cryoablation offer alternative treatments [4]. LITT, particularly when guided by magnetic resonance (MR) imaging, allows precise ablation with real-time thermometry [5]. This report highlights the use of MR-guided laser ablation in a patient with severe cold hypersensitivity, contraindicating cryoablation. A 40-year-old woman with familial adenomatous polyposis (FAP) presented with recurring chest wall desmoid tumors. Diagnosed in 2004 with a 2.3 × 5.0 cm tumor, she initially managed the disease conservatively. Tumor progression led to Imatinib therapy in 2017, which provided temporary symptom relief. By 2018, imaging revealed tumor growth (4.6 cm), and surgery was deemed inappropriate due to extensive chest wall involvement, posing significant morbidity. Severe cold hypersensitivity precluded cryoablation, prompting MR-guided (1.5 T MRI- Philips Healthcare, Ingenia, Best, Netherlands) laser ablation. Between 2018 and 2023, the patient underwent 11 MR-guided laser ablation sessions targeting various chest wall and breast lesions (Fig. 1). Laser energy was delivered using a 980-nm diode laser system (Visualase system, Medtronic, Minneapolis, MN) via a diffusing fiber placed in direct contact with tumor tissue. Saline cooling prevented carbonization, and MR thermometry enabled precise monitoring of heat deposition (Fig. 2). Treatment cycles (20–25 W for 1–2 min) were performed before retracting the fiber approximately 2 cm to cover tumor lengths between 2 and 10 cm. Identical protocols were used for ablation in the chest and breast regions. Procedures lasted 4–6 h due to the iterative pull-back technique and single-fiber use. Post-procedure imaging, conducted immediately after each session, confirmed complete ablation without enhancement at the ablation zone. Initially, the patient stayed overnight for pain control, transitioning to same-day discharge. Follow-up MRIs every 3–6 months assessed the treatment response. Out of the 11 MR-guided laser ablations, each session provided significant symptom relief and reduced tumor burden. Some lesions required additional treatments to manage recurrence or residual disease (Fig. 3). Over time, the recurrence rate decreased, resulting in prolonged asymptomatic intervals of approximately 1–2 years. The patient tolerated the procedures well, reporting significant pain relief and improved quality of life. Mild, transient localized erythema was the only adverse effect observed, resolving within 24 h. Post-procedure recovery was generally uneventful, with same-day discharge or brief observation periods. This case demonstrates the utility of MR-guided laser ablation for desmoid tumors in patients with contraindications to other treatments like cryoablation. Compared to CT-guided ablation, MR guidance offers superior visualization and thermal precision in complex anatomical regions. Hormonal therapy, NSAIDs, and tyrosine kinase inhibitors are noninvasive options but have limited efficacy. Chemotherapy and radiation therapy provide alternatives but carry risks of toxicity and secondary malignancies [3]. The iterative pull-back technique enabled precise ablation of tumors up to 10 cm in length. While effective, procedural duration highlights the need for advancements in fiber technology to reduce treatment time. Tumor response was monitored via MR imaging and clinical outcomes. Incorporating RECIST criteria in future studies could standardize evaluations. Despite limitations, such as a single-patient design and lack of comparative data, MR-guided laser ablation provided substantial clinical benefit and represents a promising option for complex cases.

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