Percutaneous imaging-guided radiofrequency ablation of small renal cell carcinoma: techniques and outcomes of 24 treatment sessions in 18 consecutive patients.

PURPOSE: To evaluate the early clinical experience associated with percutaneous imaging-guided radiofrequency ablation (RFA) in patients with renal cell carcinoma (RCC). METHODS: Eighteen consecutive patients with RCC were treated with percutaneous RFA sessions (24 sessions for 19 solitary RCC in 18 patients: 15 patients underwent a single RFA session, 3 had 2 sessions and one 3 sessions). Treatment indications were localized, solid renal mass <4.5 cm, comorbidities precluding surgery, high operation risk, and refusal to perform surgery. During 23 sessions, RFA was performed using computed tomography (CT) guidance and in one session it was guided by ultrasonography. The average patient age was 76.8±7.6 years (range 64-89), and the average renal mass size 3.3 ±0.7 cm (range 2.0-4.5). Follow-up imaging was performed at 3- and 6-month intervals and yearly thereafter. Successful treatment was defined as lack of enhancement of the treated region on follow-up CT studies. RESULTS: RFA was technically successful in all patients. After the last imaging control, 17 of the 19 tumors were completely necrotic according to the imaging criteria (the secondary clinical success rate was 89.5%). Thirteen tumors were not visible on the first follow-up imaging control (the primary clinical success rate was 68.4% - 13 of 19). In 4 of the 6 patients residual tumors were successfully re-ablated, while in 2 patients repeated RFAs were not performed at the time of writing this report. Five patients (20.8%) developed treatmentrelated complications, including mild pain, large perirenal abscess, mild perirenal hematoma and transient elevation of the white blood cell count. The mean follow-up period was 25.3±16.8 months (range 1-51). CONCLUSION: RFA is effective and safe treatment option of exophytic RCC <5 cm in diameter in patients not suitable for surgery due to serious concomitant diseases or advanced age.

Risk of deterministic effects during endovascular aortic stent graft implantation.

Since the 1990s, stent graft implantation for aortic pathology has become an alternative to extensive surgical procedures in some patients. Indeed, many patients with such pathology are now treated endovascularly. Only limited data concerning the risk of a deterministic effect during aortic stent graft implantation are available Accordingly, 179 consecutive patients treated in our institute between October 2002 and July 2008 with endovascular aortic stent grafts were included in this study. Dosimetric data (kerma area product (KAP) and cumulative dose at the interventional reference point (CD(irp))) from radiograph reports were analysed for 172 patients. On a group of 19 patients, GAFCHROMIC XR type dosimetric films were also used to verify the automatic measurements. Readings from the integrated KAP meter were found to be too high and were therefore corrected - KAP to dose area product (DAP) and CD(irp) to entrance skin dose (ESD). Median DAP was 153 Gy cm² (35-700 Gy cm²) and median ESD was 0.44 Gy (0.12-2.73 Gy). Recorded dosimetric quantities were found to be good predictors of the skin dose and highlighted 4 patients (2.3%) who received skin doses that might cause possible deterministic effects. Endovascular stent graft implantation is less invasive than a surgical procedure and is widely used; mid-term results are encouraging. In a small number of patients, deterministic effects can occur even in departments with well-trained staff. Operators should inform the patients of possible skin injury after receiving high doses of ionising radiation and proper support must be available should that occur.

Infrapopliteal run-off and the outcome of femoropopliteal percutaneous transluminal angioplasty.

BACKGROUND: The outcome of percutaneous transluminal angioplasty (PTA) of peripheral arterial lesions is influenced by several factors, including the haemodynamic conditions. Our study tested: (a) whether infrapopliteal run-off after completed PTA influenced the time course of restenosis/reocclusion of the femoropopliteal arterial segment, and (b) whether worsening of infrapopliteal run-off influenced the long-term femoropopliteal patency after PTA. PATIENTS AND METHODS: Among 245 patients treated by femoropopliteal PTA we enrolled 176 patients who consented to regular follow-up. Concomitant infrapopliteal PTA was performed whenever feasible. The technical success of PTA and the patency of calf arteries were assessed by angiography. Infrapopliteal run-off was scored by a modification of the Society for Vascular Surgery criteria. The treated patients' limbs were divided into a group with good infrapopliteal run-off and a group with compromised run-off. Follow-up examination of the femoropopliteal arterial segment was performed by vascular ultrasonography (US) 1, 6 and 12 months after PTA, and an adverse outcome was defined by a > or = 50 % stenosis, i.e., at least doubling of the maximal systolic velocity, or occlusion - evidenced by the absence of flow. The patency of calf arteries was re-assessed by US 12 months after PTA. RESULTS: One month after femoropopliteal PTA 19 / 83 (23 %) of patients with compromised run-off developed the combined end-point of restenosis or reocclusion in comparison to 10 / 93 (11 %) with good run-off (p = 0.03). After 6 months the incidence of restenosis/reocclusion had increased in both groups at an approximately equal rate, but the differences were no longer significant: 39 / 80 (49 %) in the compromised run-off group vs. 36 / 83 (43 %) in the good run-off group after 6 months, p = 0.49, and 42 / 73 (57 %) vs. 38 / 73 (52 %) after 12 months, p = 0.51. However, in patients' limbs with good periprocedural run-off that deteriorated into compromised run-off in the year after PTA, femoropopliteal restenosis/reocclusion occurred more often than in limbs which retained good run-off: 10 / 14 (71 %) vs. 18 / 51 (35 %), p = 0.02. CONCLUSIONS: Compromised postprocedural infrapopliteal run-off predisposes to early restenosis/reocclusion after femoropopliteal PTA. Deterioration of infrapopliteal run-off in the year after femoropopliteal PTA is accompanied by worsening of long-term femoropopliteal patency.

Patient peak skin doses from cardiac interventional procedures.

Interventional cardiac procedures not only lead to significant effective doses for the patient but also can potentially cause deterministic effects on the patient's skin. Information about the peak (maximal) skin doses (PSD) received by patients during percutaneous transluminal coronary angioplasty procedures were collected from three cardiac catheter rooms. Cumulative dose at the interventional reference point (CD(IRP)) was collected for 161 patients and for 16 patients PSD was determined using Gafchromic dosimetry films. The comparison showed that CD(IRP) readings give a useful but conservative estimation of patient peak skin dose as it can lead to a significant overestimation. The median and third quartile values of CD(IRP) were 0.64 and 0.92 Gy, respectively. The 2 Gy threshold for deterministic effects was exceeded in nine patients. A good correlation was found between CD(IRP) and kerma area product measurements while the correlation with fluorography time was very weak.