Dear Patients,

The minimal invasive image-guided therapy of renal cell carcinoma has gained a lot of important in the last few years. This is being performed in some cases as an alternative therapy and in other cases as neoadjuvant therapy to conventional surgical resection. This method can in special cases of resectable tumor replace the surgical treatment, for e.g., in cases of contraindication for general anaesthesia or in cases of unwillingness of the patient to undergo an operation.
The tumor cell necrosis can be induced through percutaneous thermotherapy oder transarterial embolisation.
The neoadjuvant embolisation is the most frequently used method. It is performed as preoperative prophylaxis for prevention of intraoperative haemorrhage and for symptomatic treatment of haematuria. Other indications are palliative or neoadjuvant embolisation in terms of local or extrarenal metastases which could be treated either with palliative percutaneous thermoablation or with radical resection. In this method the artery supplying the tumor is explored using a suitable angiography catheter and occluded with particles or coils [1,2] (table 1). The same technique also allows application of chemotherapeutic drugs with high local affect and low systemic adverse reactions. This is followed by application of embolisat which leads to ischaemic necrosis of the tumor (Fig. 1, 2). There are different methods of thermotherapy, for e.g, radiofrequency ablation (RFA) [3,4], Laser-induced interstitial thermotherapy (LITT) (5), focused ultrasound microwave and kryotherapy [6]. All these methods cause coagulation necrosis of the tumor through extreme changes in temperature. In the last 10 years RFA has established itself as the most frequent thermoablation method [3, 4, 7, 8]. The results of RFA depends on the tumor size and its position. A complete coagulation necrosis can be achieved in 90-100% of cases of renal cell carcinoma of size 3 cm or less, but only about 70% in cases of tumor of size from 3 to 5 cm (fig. 3) (table 2).
The central position of the tumors which are larger than 3 cm are completely necrosed. Heavy generators can produce higher energy and therefore can achieve a larger necrosis volume [7, 8].
In summary, interventional radiology is gaining importance as primary therapy in small as well as large primary tumors but also for metastases therapy. There are large scale scientific studies being done to study its effectiveness.

Fig. 1. Palliative TACE of renal cell carcinoma (left) at stage T3N1M1. A) Selektive angiography of artery supplying the tumor showing pathological vessels. B) Visualisation after chemoembolisation. Intensive Lipiodol uptake in the vascular lacuna within the tumor.

Fig. 2. Symptomatic chemoembolisation of renal cell carcinoma in a patient with liver metastases and pain due to capsular infiltration. The patient also recieved systemic chemotherapy and hepatic chemoperfusion. A) Selective angiography to visualise the tumor-supplying artery. B) Visualisation after chemoembolisation showing the lipiodol drops in the vessels.

Fig. 3. Renal cell carcinoma in a patient with single kidney, after nephrectomy. A) CT-guided RFA in prone position. The RF catheter lies within the tumor (arrow). B) MRI - T1 wieghted image after application of contrast media after successful ablation. The tumor shows a central hypointense area - scar tissue without contrast enhancement (arrow).

Table 1. Indications for different modalities of interventional treatment of renal cell carcinoma

Table 2. Results of RFA of renal cell carcinoma according to tumor size [8]

References

1. Heye S, Maleux G, Van Poppel H, Oyen R, Wilms G. Hemorrhagic complications after nephron-sparing surgery: angiographic diagnosis and management by transcatheter embolization.AJR Am J Roentgenol. 2005 May; 184(5):1661-4.

2. Thomas J, Perabo FG, Bachmann R, Steiner G, Schild H, Muller SC. Superselective embolization of arterial bleeding as a late complication 3 months after nephron sparing surgery for renal cell carcinoma. ScientificWorldJournal. 2004 Jun 7; 4 Suppl 1:350-2.

3. Sabharwal R, Vladica P. Renal tumors: technical success and early clinical experience with radiofrequency ablation of 18 tumors. Cardiovasc Intervent Radiol. 2006 Mar-Apr; 29(2):202-9.

4. Varkarakis IM, Allaf ME, Inagaki T, Bhayani SB, Chan DY, Su LM, Jarrett TW, Kavoussi LR, Solomon SB. .Percutaneous radio frequency ablation of renal masses: results at a 2-year mean followup. J Urol. 2005 Aug; 174(2):456-60

5. de Jode MG, Vale JA, Gedroyc WM. MR-guided laser thermoablation of inoperable renal tumors in an open-configuration interventional MR scanner: preliminary clinical experience in three cases. J Magn Reson Imaging. 1999 Oct; 10(4):545-9.

6. Rehman J, Landman J, Lee D, Venkatesh R, Bostwick DG, Sundaram C, Clayman RV. Needle-based ablation of renal parenchyma using microwave, cryoablation, impedance- and temperature-based monopolar and bipolar radiofrequency, and liquid and gel chemoablation: laboratory studies and review of the literature. J Endourol. 2004 Feb; 18(1):83-104.

7. Boss A, Clasen S, Kuczyk M, Anastasiadis A, Schmidt D, Claussen CD, Schick F, Pereira PL. Radiofrequency ablation of renal cell carcinomas using MR imaging: initial results. Rofo. 2005 Aug; 177(8):1139-45

8. Gervais DA, Arellano RS, Mueller PR. Percutaneous radiofrequency ablation of renal cell carcinoma. Eur Radiol. 2005 May; 15(5):960-7

 

Document Date: 2006/05/18   Author: Ahmed Koujan

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