Immunotherapy differs from traditional cancer treatment by stimulating your body’s natural defense mechanisms against cancer cells, using various approaches designed to boost your immunity and stop them from growing further. At Mayo Clinic experts use various strategies to stimulate this immune response in order to combat cancer cells before they spread and spread further.
Carrie Kumpel understood the risks involved with participating in human trials, yet wanted to explore histotripsy – an innovative treatment which uses sound waves to break apart liver tumors – using histotripsy.
Radiofrequency ablation (RFA)
Radiofrequency ablation (RFA) offers an alternative to surgical resection for treating certain malignant tumors. RFA uses a needle-shaped electrode to deliver heat energy directly into the tumor mass and cause thermal coagulative necrosis that leads to cell death and destruction of tumors. It has proven successful when applied to benign and malignant neoplasms found in liver, kidney, or lung tissue, or patients not suitable for surgery due to poor functional status, advanced disease or co-morbidities.
RFA may be performed percutaneously or laparoscopically. Laparoscopic RFA has lower rates of complications but may be difficult for obese or critically ill patients to complete successfully. Depending on the type of tumor being treated, repeat procedures may be necessary in order to successfully eradicate it.
Your doctor will use an ultrasound or CT scan to locate the tumor. A small needle will then be inserted into your skin near it and attached to a microelectrode that sends out safe electric current through it, heating up tissue and blocking pain signals from reaching the brain. This process is repeated until all symptoms have subsided or until all areas become numb and no longer experience pain.
If your doctor prescribes RFA, you will be required to fast for several hours prior to the procedure and avoid taking blood thinners before. Someone must accompany you afterward for transport home.
This procedure has proven highly successful at eliminating small tumor masses that cannot be surgically resected, though local recurrence rates tend to be higher for larger neoplasms or those near major vessels. Furthermore, this form of ablation is less successful against metastatic liver neoplasms that recur.
Under sedation, this procedure can be carried out as either an outpatient procedure or with a short hospital stay. Chemoembolization uses catheters to deliver chemotherapy agents directly into tumor sites for delivery via chemotherapy treatments; using this approach increases chances of cure by shrinking tumor size and improving response to chemotherapy agents.
Presently, no long-term studies compare radiofrequency ablation (RFA) with surgical resection in treating malignant tumors; however, short-term studies demonstrate its efficacy against certain cancers such as pancreatic neuroendocrine tumors and hepatocellular carcinoma. Although these results are promising, further research needs to be conducted into how RFA therapy could be improved – one possible strategy could include creating a model which predicts size and shape of lesion that would enable clinicians to better plan and treat their patients.
High-intensity focused ultrasound (HIFU)
High-intensity focused ultrasound (HIFU) offers noninvasive, painless solutions for certain conditions. Unlike radiofrequency ablation, which damages surrounding tissues during treatment, HIFU does not use sound waves to heat and destroy tumors or abnormalities using soundwave therapy instead. It has been successfully used for treating various conditions like uterine fibroids, tremors and bone metastases; and is also an attractive choice for prostate cancer patients who would rather forgo surgery and radiation therapies.
HIFU is an outpatient procedure and does not require sedation. When lying on your back, a radiologist will place the HIFU probe either within your back passage (rectum) or skin. Before beginning any HIFU therapy session, you will be instructed not to consume food or liquid for six hours beforehand.
Your urologist will use the Focal One system’s ultrasound probe to scan your prostate and generate a three-dimensional image on screen, enabling them to locate areas requiring destruction with HIFU energy beams and then precisely plan each beam’s direction and intensity using Focal One’s planning features.
Once HIFU energy beams reach their target area, they quickly raise tissue temperature through ablation – this process is known as ablation. Once this happens, they continue to destroy small sections of cancerous tissue while moving onto another part of the prostate gland.
HIFU can offer several advantages, including minimal side effects and infection risks, while increasing effectiveness of other treatments such as radiotherapy and chemotherapy.
HIFU can also influence immune response. It is thought that HIFU ablation releases antigenic cell debris that is then taken up by antigen-presenting cells and activated dendritic cells, leading to antitumor immune response as well as reduced immunosuppressive cytokines, leading to possible local control of tumor growth.
Though HIFU has proven itself effective, it isn’t available in every hospital yet. Most often you must go through a clinical trial to access this treatment or travel to a specialist centre; additionally it may not suit all forms of prostate cancer and your doctor will help decide if this therapy is the appropriate choice for your condition; alternative treatments may be more suitable in certain instances.
Ultrasound-assisted drug delivery
Ultrasound-assisted drug delivery is a non-invasive therapy that enables direct drug delivery directly to target tissue. This technique utilizes ultrasound waves to encase drug-carrying nanoparticles with ultrasound energy before their release at their targeted site, and enable use of drugs otherwise ineffective in penetrating blood-brain barriers. Ultrasound-assisted drug delivery has already proven itself useful in treating Alzheimer’s disease, cardiovascular conditions, infections, as well as cancer treatments – among others.
Ultrasound-assisted drug delivery works through two mechanisms, namely acoustic cavitation and hyperthermia. Mechanical energy released by ultrasound radiation interaction with tissues is transformed into thermal energy via friction effects; sonoporation induces cell membrane permeability enhancement allowing more nanoparticles carrying therapeutics into tumor tissue, increasing local concentration while simultaneously decreasing systemic dosage needs for effective treatment.
Ultrasound-mediated BBB disruption is another means of using HIFU to deliver drugs effectively into the brain. Both preclinical and clinical studies have demonstrated how ultrasound can open the BBB and deliver drugs into it, but the optimal combination of ultrasound with drug carrier remains to be established – one which provides sufficient mechanical disruption of the BBB while still permitting efficient release of drug through delivery channels; additionally, selecting appropriate parameters ensures only therapeutic dose reaches target tissue.
HIFU-based blood-brain barrier disruption has been shown to enhance chemotherapy drugs’ bioavailability. Many chemotherapies cannot cross the blood-brain barrier and therefore do not reach their targets within the brain, leading to neurotoxicity – thus making developing technologies to overcome it an important goal.
Ultrasound-assisted drug delivery offers an effective alternative to more invasive procedures like resection or biopsy. Using this approach, doctors can precisely localize and treat lesion while limiting unintended damage to surrounding tissues. In addition, treatment can often be completed under local anesthesia, thus decreasing patient discomfort and recovery times.
Furthermore, this method is safe and relatively cost-effective; therefore it could become widely adopted as a new form of therapy for cancer patients who do not qualify for surgery or traditional therapies; additionally it can be combined with conventional therapies to increase their effectiveness.
Researchers recently demonstrated that ultrasound-assisted resection of prostate tumors led to improved overall survival rates and reduced biochemical recurrence rates compared with surgical excision alone. Furthermore, HIFU combined with cryotherapy has proven itself effective at preventing return of prostate cancer after radical prostatectomy.
