The overall goal of this procedure is to destroy a tumor and an appropriate margin of normal tissue around the tumor in a safe and minimally invasive manner. This is accomplished by first reviewing a patient's images and overall health to determine plan of care and candidacy for ablation. Using imaging guidance strategically place applicators into the tumor, then apply enough thermal energy to destroy the tumor and an appropriate margin of normal tissue.
Finally, with immediate and serial follow-up imaging, confirm that the tumor has been completely destroyed. Ultimately, results can be obtained that show complete destruction of the tumor in situ you with only minimal associated invasiveness and few complications. The main advantage of this technique over other methods such as surgical resection, is that image guided tumor ablation is less invasive.
As a result, it is associated with fewer complications and a much more rapid recovery time, and yet in certain patients can be just as effective as surgery. While thermal ablation can be used to treat many tumors in the liver, it can also be used to treat tumors in other locations such as a kidney, lung, and bone. Several energy sources are available for thermal ablation.
High temperature sources include radiofrequency, electrical, current microwaves, lasers, and focused ultrasound. Generally, individuals that are new to this technique will struggle because the technique that you apply varies from case to case. Although in every case your overarching goal is gonna be tumor destruction the way that you meet that goal, the techniques that you lose are very heterogeneous, and that can be a challenge.
This case presents a 50-year-old woman with a history of retroperitoneal MAU sarcoma that was previously resected. She had both liver and lung metastases, which had responded well to chemotherapy with the exception of a single hepatic lesion that was chemo refractory. This was biopsied with ultrasound guidance to determine that it was in fact residual metastatic disease.
A multidisciplinary discussion determined that the best treatment for this lesion would be image guided tumor ablation. The main considerations during this discussion were the patient's young age, her lack of comorbidities and her lack of other chemotherapeutic options. Because of the proximity of the pancreas and bowel, it was felt that hydrodisection would be necessary to increase the safety of this technique.
Thermal ablation is indicated after a multifactorial assessment of both tumor and patient related factors, including tumor type, size, location, and vocality, as well as patient comorbidities and overall health. Next, perform a pre ablation planning ultrasound to determine optimal patient positioning and a suitable approach for applicator placement to confirm that the thermal ablation is technically feasible with an, with an emphasis on safety and efficacy, determine the number of applicators needed to complete the treatment and their optimal placement. Also, assess the need for adjuvant techniques, The most appropriate ablation modalities, dependent upon many different factors.
This includes the size of the tumor, the location of the tumor within the organ, the presence or absence of adjacent structures that would be vulnerable to injury, and the associated need for precision. In general, we use radiofrequency ablation to treat lesions within the liver and cryoablation to treat lesions within the kidney. However, there are many exceptions to this rule.Here.
The procedure is performed under general anesthesia in a CT imaging suite. In some cases, ablation can be performed with deep sedation or even conscious sedation. IV access is needed for image-guided tumor ablation, and in some cases an arterial line may be needed for blood pressure monitoring.
Sterile preparation, including scrubbing of the insertion site with chlorhexidine and establishment of a sterile field, is necessary to reduce the risk of post-procedural infection. In addition, a single dose of antibiotics can be administered at the time of the ablation in patients with certain risk factors. A more prolonged course of antibiotics may be necessary for radio frequency ablation.
Verify equipment including ground pad placement, ground pads should be placed correctly to minimize the likelihood of skin burns. It is critical to ensure accurate and appropriate placement of the image. Guided applicators, since this often includes multiple applicator placements, particularly for larger tumors, navigate the many factors carefully consider a CT scan in some patients with larger tumors in which positioning of the applicators relative to each other is important.
Proceed to hydrodissection when applicable. Place a needle into the space between the tumor and the adjacent vulnerable structure, followed by infusion of an appropriate fluid into the space. This is an effective method for protecting adjacent structures that may be vulnerable to thermal damage when performing the percutaneous ablation.
Use D five W since it is non ionic and isotonic mixing about 1%weight per volume. IOHEXOL allows visualization of the fluid on CT for a safe and effective procedure. Utilize a multimodality approach with ultrasound and CT to effectively and precisely monitor the growing ablation zone.
A contrast enhanced CT immediately after the ablation session indicates efficacy of treatment as well as any early complications. Importantly, it establishes a post-procedure baseline. The interval and optimal for follow-up evaluation varies depending on tumor type and patient factors, and may include either CT or MRI imaging preferably with contrast.
For liver tumors like this one, we would perform a contrast enhanced abdominal CT 1, 3, 6, 12, 18, and 24 months after the procedure with further follow-up to be based upon the patient's underlying disease. Ultrasound gives us a real time evaluation of the developing ablation zone, while CT gives us a more global picture of where the applicators are located in their proximity to the adjacent structures. The combination of the two really gives us a superior assessment of both the ablation zone and the safety and lets us assess the likelihood of collateral damage.
Hydrodissection with D five W was used to create a physical and electrical barrier between the ablation zone and any adjacent tissues. This barrier protects the adjacent tissue from thermal damage, which decreases post-procedural pain in patients who receive RF ablation In the liver Image guided tumor ablation is a safe and effective therapy for many patients who have tumors that are refractory to surgery or have failed chemotherapy or radiotherapy.
