High-intensity focused ultrasound as a treatment option in renal cell carcinoma

Renal preservation therapy for renal cell carcinoma

Renal preservation therapy has been a promising concept for the treatment of localized renal cell carcinoma (RCC) for 20 years. Nowadays partial nephrectomy (PN) is well accepted to treat the localized RCC and the oncological control is proved to be the same as the radical nephrectomy (RN). Under the result of well oncological control, minimal invasive method gains more popularity than the open PN, like laparoscopic partial nephrectomy (LPN) and robot assisted laparoscopic partial nephrectomy (RPN). On the other hand, thermoablative therapy and cryoablation also play an important role in the renal preservation therapy to improve the patient procedural tolerance. Novel modalities, but limited to small number of patients, include high-intensity ultrasound (HIFU), radiosurgery, microwave therapy (MWT), laser interstitial thermal therapy (LITT), and pulsed cavitational ultrasound (PCU). Although initial results are encouraging, their real clinical roles are still under evaluation. On the other hand, active surveillance (AS) has also been advocated by some for patients who are unfit for surgery. It is reasonable to choose the best therapeutic method among varieties of treatment modalities according to patients' age, physical status, and financial aid to maximize the treatment effect among cancer control, patient morbidity, and preservation of renal function.

High intensity focused ultrasound treatment of small renal masses: Clinical effectiveness and technological advances

The review summarises the technological advances in the application of high-intensity focused ultrasound for small renal masses presumed to be cancer including the systematic review of its clinical application. Current progress in the area of magnetic resonance image guided ultrasound ablation is also appraised. Specifically, organ tracking and real time monitoring of temperature changes during the treatment are discussed. Finally, areas of future research interest are outlined.

Kidney cancer: energy ablation

PURPOSE OF REVIEW

Solid renal tumours with a diameter 4 cm or less are frequently found during routine radiologic investigations. Since a significant number of patients are elderly and frail, there is a growing interest in effectively treating these patients by minimally invasive energy-ablative surgery.

RECENT FINDINGS

Such tumours may be treated by either freezing (cryoablation) or by heat (radio-frequency ablation or high-intensity focused ultrasound). In addition, percutaneous methods are available, but percutaneous focused ultrasound is not feasible as yet with the technique available. All percutaneous techniques lack effective monitoring of ablation, however, and oncological follow-up commonly relies on radiologic measurements only. Not surprisingly, the effectiveness of all percutaneous procedures is significantly lower, with a high recurrence and re-treatment rate as compared with open or laparoscopic procedures. Long-term results in larger series are missing, but it seems that laparoscopic cryoablation is most effective in respect to oncological results, but requires more technical efforts and surgical skills as compared with radio-frequency ablation or focused ultrasound.

SUMMARY

There is currently no ideal energy-ablative energy source on the horizon, but cryoablation seems to produce the most durable result. Focused ultrasound, however, may have the greatest potential for further developments.

Renal cell carcinoma: Current status and emerging therapies

Renal cell carcinoma (RCC) accounts for about 3% of all adult malignancies and its incidence is increasing. Smoking, obesity, and end-stage renal disease are important risk factors. Localized RCC may be cured with surgical excision. However, over one-third of patients eventually develop metastatic disease. While chemotherapy and radiation therapy are relatively ineffective for RCC, immunotherapy modestly extends survival and may lead to tumor regression and long-term survival in a small minority of patients. Recently, research into the pathology of genetic syndromes associated with RCC has led to remarkable advances in our understanding of the pathogenesis of sporadic RCC. Rational therapeutic agents developed from this understanding have established new treatment paradigms for this disease.