Phase I study of cancer lesion-targeted microwave coagulation therapy for localized prostate cancer: A pilot clinical study protocol

Clinical guidelines for microwave ablation of spinal metastases

Spinal metastases are the most common source of morbidity in patients with cancer. Recently, microwave ablation has produced satisfactory results in the management of spinal metastases. However, there is still controversy in terms of clinical treatment, such as indication, power, time, and temperature. To standardize the application of microwave ablation technology and reduce the risk of surgical-related complications in spinal metastases, in this report, we aimed to summarize the current evidence and clinical experience of microwave ablation and developed a clinical guideline, initiated by the Musculoskeletal Tumor Group of the Committee for Minimally Invasive Therapy in Oncology of the Chinese Anti-Cancer Association. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used in to rate the quality of evidence and the strength of recommendations, and the Reporting Items for Practice Guidelines in Healthcare (RIGHT) checklist was strictly followed to report the guideline. Finally, 15 evidence-based recommendations were formulated based on the 15 most concerned clinical questions among orthopedic surgeons, oncologists, and interventional radiologists in China. This guideline aims to promote the science-based normalization of microwave ablation for the treatment of spinal metastases.

Microwave for focal therapy of prostate cancer: Non-clinical study and exploratory clinical trial

OBJECTIVE

The objective of this non-clinical study and clinical trial (phase II) was to examine the safety and efficacy of microwave tissue coagulation (MTC) for prostate cancer and assess its use in lesion-targeted focal therapy.

METHODS

In the non-clinical study using Microtaze®-AFM-712 (Alfresa-pharma Corporation) with an MTC-needle, MTC was performed by a transperineal approach to canine prostatic-targeted tissue under real-time ultrasound guidance. Using various MTC-output and irradiation-time combinations, the targeted and surrounding tissues (rectum, bladder, and fat) were examined to confirm the extent of coagulative necrosis or potential cell death, and to compare intra-operative ultrasound and pathology findings. The exploratory clinical trial was conducted to examine the safety and efficacy of MTC. Five selected patients underwent transperineal MTC to clinically single magnetic resonance imaging (MRI)-visible lesions with Gleason score 3+4 or 4+4. Prostate-specific antigen (PSA), MRI, and Expanded Prostate Cancer Index Composite questionnaire findings were compared before and 6 months after surgery.

RESULTS

The region of coagulative necrosis was predictable by monitoring of ultrasonically visible vaporization; thus, by placing the MTC-needle at a certain distance, we were able to perform a safe procedure without adverse events affecting the surrounding organs. Based on the non-clinical study, which used various combinations of both output and irradiation time, MTC with 30-W output for 60-sec irradiation was selected for the prostate. Based on the predictable necrosis, the therapeutic plan (where to place the MTC-needle to achieve complete ablation of the target and how many sessions) was strictly determined per patient. There were no serious adverse events in all patients and only temporary urinary symptoms related to MTC-therapy were observed. Furthermore, satisfaction of having undergone treatment was very high. All pre-operative MRI-visible lesions disappeared, and PSA decreased 55% 6 months after surgery.

CONCLUSION

MTC may be an option for lesion-targeted focal therapy for prostate cancer.

Future perspective of focal therapy for localized prostate cancer

Objective

To summarize the recent literature discussing focal therapy for localized prostate cancer.

Methods

A thorough literature review was performed using PubMed to identify recent studies involving focal therapy for the treatment of localized prostate cancer.

Results

In an effort to decrease the morbidity associated with prostate cancer treatment, many urologists are turning to focal therapy as an alternative treatment option. With this approach, the cancer bearing portion of the prostate is targeted while leaving the benign tissue untouched. Multiparametric magnetic resonance imaging remains the gold standard for visualization during focal therapy, but new imaging modalities such as prostate specific membrane antigen/positron emission tomography and contrast enhanced ultrasound are being investigated. Furthermore, several biomarkers, such as prostate cancer antigen 3 and prostate health index, are used in conjunction with imaging to improve risk stratification prior to focal therapy. Lastly, there are several novel technologies such as nanoparticles and transurethral devices that are under investigation for use in focal therapy.

Conclusion

Focal therapy is proving to be a promising option for the treatment of localized prostate cancer. However, further study is needed to determine the true efficacy of these exciting new technologies.

A review of antenna designs for percutaneous microwave ablation

Microwave (MW) antenna is a key element in microwave ablation (MWA) treatments as the means that energy is delivered in a focused manner to the tumor and its surrounding area. The energy delivered results in a rise in temperature to a lethal level, resulting in cell death in the ablation zone. The delivery of energy and hence the success of MWA is closely dependent on the structure of the antennas. Therefore, three design criteria, such as expected ablation zone pattern, efficiency of energy delivery, and minimization of the diameter of the antennas have been the focus along the evolution of the MW antenna. To further improve the performance of MWA in the treatment of various tumors through inventing novel antennas, this article reviews the state-of-the-art and summarizes the development of MW antenna designs regarding the three design criteria.

Ablative options for prostate cancer management

This review provides an overview of the available ablative options for prostate cancer (PCa) management. It contemplates the ablative concepts and the role of prostate ablation in different settings, from primary treatment to repeat ablation, and as an alternative to radiorecurrent disease. Improvements in prostate imaging have allowed us to ablate prostate lesions through thermal, mechanical, and vascular-targeted sources of energy. Partial gland ablation (PGA) has an emerging role in the management of localized PCa because toxicity outcomes have been proven less harmful compared with whole-gland treatments. Although long-term oncological outcomes are yet to be consolidated in comparative studies, recent large series and prospective studies in PGA have reported encouraging results. A second ablation after disease recurrence has demonstrated low toxicity, and future studies must define its potential to avoid radical treatments. PGA is an attractive option for PCa management in different scenarios because of its low-toxicity profile. As expected, recurrence rates are higher than those seen in whole-gland procedures. Long-term oncological outcomes of primary and salvage options are required to endorse it among the standard treatments.