Surgical management of renal tumors

Effects of radiofrequency radiation in the presence of gold nanoparticles for the treatment of renal cell carcinoma

Introduction: The most common type of kidney cancer is renal cell carcinoma (RCC), which accounts for more than 80% of all kidney cancers.

Objectives: The aim of this study was to evaluate the effects of radiofrequency (RF) radiation in the presence of gold nanoparticles (GNPs) for the treatment of RCC.

Materials and Methods: Human embryonic kidney (HEK) cancer cells were divided into 6 groups. Various tests were performed on HEK cells in the presence of RF and GNPs. In order to investigate the radiation effects on the cells’ survival, MTT [3-(4,5-dimethylthiazol–2-yl)-2,5-iphenyltetrazolium bromide] assay was performed at different days during and post-irradiation period. The repeated measure analysis of variance (ANOVA) method was used for statistical analysis of the cells’ survival using SPSS version 16.0. A significant level of 0.05 was considered to the tests.

Results: Using the ANOVA test, a significant decrease in cell’s survival was seen in the RF exposed group 3 compared to the control group (P=0.035). While, differences were not significant between RF exposed group 2 and the control group (P>0.05). A significant decrease in cell’s survival in the RF exposed groups 5 (P=0.025) and 6 (P=0.018) at the presence of GNP compared to the control group was seen.

Conclusion: Results of this study showed that, this method can be efficiently used for RCC treatment as an alternative to nephrectomy. More follow up in vivo studies on mammalians are needed to investigate the potential of the presented method for clinical applications.

Diffusion-weighted magnetic resonance imaging in cystic renal masses

INTRODUCTION

We aimed to introduce the diagnostic value of diffusion-weighted (DWI) magnetic resonance imaging (MRI) for distinguishing benign and malignant renal cystic masses.

METHODS

Abdominal DWI-MRIs of patients with Bosniak categories 2F, 3, and 4 cystic renal masses were evaluated retrospectively. Cystic masses were assigned as benign or malignant according to histopathological or followup MRI findings and compared with apparent diffusion coefficient (ADC) values.

RESULTS

There were 30 patients (18 males and 12 females, mean age was 59.23 ± 12.08 years [range 38-83 years]) with cystic renal masses (eight Bosniak category 2F, 12 Bosniak category 3, 10 Bosniak category 4). Among them, 14 cysts were diagnosed as benign and 16 as malignant by followup imaging or histopathological findings. For the malignant lesions, the mean ADC values were lower than for benign lesions (p=0.001). An ADC value of ≤2.28 ×10^-6 mm²/s or less had a sensitivity of 75% and a specificity of 92.86% for detecting malignancy.

CONCLUSIONS

ADC can improve the diagnostic performance of MRI in the evaluation of complex renal cysts when used together with conventional MRI sequences.

Application of contrast-enhanced ultrasonography after radiofrequency ablation for renal cell carcinoma: is it sufficient for assessment of therapeutic response?

PURPOSE

To assess the efficacy of contrast-enhanced ultrasonography (CEUS) with Sonovue in the evaluation of therapeutic response to radiofrequency ablation (RFA) of renal cell carcinoma (RCC).

MATERIALS AND METHODS

In a recent 3 years, 63 patients (mean age, 60 years; range 26-81 years) with 64 RCCs were treated by RFA. The lesions had a diameter between 1.8 and 9.8 cm (average diameter, 3.1 cm). The indications for RFA treatment included chronic renal insufficiency (n = 10), presence of solitary kidney (n =3), bilateral renal carcinoma (BRCC) (n =2), advanced age (n =12), significant medical comorbidity (n =29) or refusal of conventional therapy (n =7). Tumors were treated by laparoscopy-assisted (n =41), open surgical (n =18) or percutaneous US guidance (n =4). Follow-up CEUS and contrast-enhanced CT were performed 1 month after treatment to assess the necrotic area. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor.

RESULTS

On the 1-month CEUS and CT imaging after RFA, 62 of 64 tumors (96.9%) were successfully ablated with one session, and residual tumors were found in two RCCs. One of the two tumors was subjected to additional RFA treatment. We could not obtain a complete ablation in the other tumor of a patient with solitary kidney. The diagnostic concordance between the CEUS and 1-month follow-up CT was 100%. Sixty-one patients survived in the follow-up phase which ranged from 2 to 34 months. One patient with solitary kidney died of systemic disease progression and one patient was lost to follow-up. Of the 61 tumors without residual on both CT and CEUS after RFA, four had suspicious findings of recurrence on follow-up CEUS, and two of them were confirmed by subsequent CT examination. With CT as the reference imaging procedure in the assessment of renal tumor ablation, the sensitivity, specificity, positive predictive value, and negative predictive value of CEUS for detecting recurrence during follow-up were 100%, 96.6%, 50%, and 100%.

CONCLUSION

Despite its limitation of false-positive value, CEUS is potentially effective in assessing the therapeutic response to RFA of RCC.

MRI of the kidney-state of the art

Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted.

Intact specimen extraction in laparoscopic nephrectomy procedures: Pfannenstiel versus expanded port site incisions

OBJECTIVES

Laparoscopic nephrectomy is considered the standard of care for most Stage T1 and T2 renal tumors. Most centers perform intact extraction rather than morcellation. The extraction incision location varies, with no consensus on the best site. We compared the operative and perioperative parameters after transperitoneal laparoscopic nephrectomy procedures with intact specimen extraction through a Pfannenstiel (PFN) or expanded port site (EPS) incision.

METHODS

The consecutive charts of 150 patients (March 2001 to October 2003) undergoing laparoscopic radical nephrectomy (LRN), laparoscopic nephroureterectomy, or laparoscopic donor nephrectomy with intact specimen extraction were reviewed. The specimens were extracted by way of a PFN or an EPS incision. Two analyses were completed. The first included only LRN, and the second included LRN, laparoscopic nephroureterectomy, and laparoscopic donor nephrectomy.

RESULTS

In the LRN-only analysis, the PFN group had a shorter hospital stay (2.84 versus 3.37 days, P <0.05). This group also used significantly less morphine (23.7 versus 47.3 mg, P <0.006). The PFN group in the second analysis also used less morphine (26.3 versus 51.1 mg, P <0.002). Four extraction site complications were found; 1 patient in the PFN group developed cellulitis, and 3 patients in the EPS group developed an incisional hernia.

CONCLUSIONS

This evidence suggests reduced morbidity with intact specimen extraction through a PFN incision compared with an EPS incision during laparoscopic nephrectomy procedures. Our practice has been modified on the basis of these data, and all specimens are now removed through a PFN incision when suitable. Urologists should consider PFN incisions for specimen extraction with laparoscopic nephrectomy procedures.

Nonoperable Recurrent Renal Cell Carcinoma: Management with Embolization and CT-Guided RF Ablation

We report the case of a 59-year-old male who underwent embolization and computed-tomography-guided radiofrequency ablation of a recurrent renal cell carcinoma that developed after radical nephrectomy in contiguity to the inferior vena cava. The alternative of a new operation was rejected because of the proximity of the tumor to the vessel and percutaneous approach seemed to be the better solution.

Renal cell carcinoma: Current status and future prospects

The incidence of renal cell carcinoma (RCC) is increasing. Despite improvements in the management of localized RCC, most patients are diagnosed with advanced RCC, which is often refractory and associated with a poor prognosis. Although surgery is the only curative treatment for localized RCC, improved diagnostic methods facilitating early detection and characterization of renal tumors have enabled more effective use of less invasive treatments. Adrenal-sparing radical total nephrectomy, and laparoscopic radical and total nephrectomy are increasingly being performed in preference to radical nephrectomy. However, standard treatments for advanced RCC are largely unsuccessful. Radiotherapy is often used to control symptoms associated with RCC in patients unsuitable for surgery. Immunotherapy with cytokines is the standard systemic treatment for advanced RCC, and is associated with prolonged survival in a subset of patients, but is generally poorly tolerated. An increased knowledge of the underlying pathophysiology of RCC has resulted in the identification of molecular pathways involved in tumor growth. Promising new agents designed to target these pathways are in development.