R. Del Vescovo

Experimental assessment of CT-based thermometry during laser ablation of porcine pancreas.

Laser interstitial thermotherapy (LITT) is employed to destroy tumors in organs, and its outcome strongly depends on the temperature distribution inside the treated tissue. The recent introduction of computed tomography (CT) scan thermometry, based on the CT number dependence of the tissue with temperature, overcomes the invasiveness of other techniques used to monitor temperature during LITT. The averaged CT number (ROI = 0.02 cm(2)) of an ex vivo swine pancreas is monitored during LITT (Nd:YAG laser power of 3 W, treatment time: 120 s) at different distances from the applicator (from 4 to 30 mm). The averaged CT number shows a clear decrease during treatment: it is highest at 4 mm from the applicator (mean variation in the whole treatment of -0.256 HU s(-1)) and negligible at 30 mm, since the highest temperature increase is present close to the applicator (i.e., 45 °C at 4 mm and 25 °C at 6 mm). To obtain the relationship between CT numbers and pancreas temperature, the reference temperature was measured by 12 fiber Bragg grating sensors. The CT number decreases as a function of temperature, showing a nonlinear trend with a mean thermal sensitivity of -0.50 HU °C(-1). Results here reported are the first assessment of pancreatic CT number dependence on temperature, at the best of our knowledge. Findings can be useful to further investigate CT scan thermometry during LITT on the pancreas.

Monitoring of temperature increase and tissue vaporization during laser interstitial thermotherapy of ex vivo swine liver by computed tomography

Laser interstitial thermotherapy (LITT) is a minimally invasive technique used to thermally destroy tumour cells. Being based on hyperthermia, LITT outcome depends on the temperature distribution inside the tissue. Recently, CT scan thermometry, based on the dependence of the CT number (HU) on tissue temperature (T) has been introduced during LITT; it is an attractive approach to monitor T because it overcomes the concerns related to the invasiveness. We performed LITT on nine ex vivo swine livers at three different laser powers, (P=1.5 W, P=3 W, P=5 W) with a constant treatment time t=200 s; HU is averaged on two ellipsoidal regions of interest (ROI) of 0.2 cm2, placed at two distances from the applicator (d=3.6 mm and d=8.7 mm); a reference ROI was placed away from the applicator (d=30 mm). The aim of this study is twofold: 1) to evaluate the effect of the T increase in terms of HU variation in ex vivo swine livers undergoing LITT; and 2) to estimate the P value for tissue vaporization. To the best of our knowledge, this is the first study focused on the HU variation in swine livers undergoing LITT at different P. The reported findings could be useful to assess the effect of LITT on the liver in terms of both T changes and tissue vaporization, with the aim to obtain an effective therapy.

DyCoH: an innovative tool to Dynamic Contrast Enhancement analysis

Contrast-Enhancement (CE) is an innovative approach, used in radiological framework, to evaluate the vascularization of the diseases. This non-invasive method determines the nature of a diseases, analysing the perfusions dynamic of contrast media in the tissues. In this paper we present an innovative tool named DyCoH (Dynamic Contrast Enhancement). This software, being specifically designed for this type of analysis, provides to medical doctor, in a very user-friendly framework, all the information needed to perform the CE analysis. DyCoH produces four inspectionable colour-maps that radiologists can use to identify the most relevant areas over which dynamically evaluates the contrast enhancement curve. However, the most interesting feature of DyCoH is its capability to manage, into a single framework, DICOM images produced by US, CT and MR of different vendors, allowing to support many types of clinical tests and to compare results provided by different diagnostic devices. Clinical tests have shown the effectiveness of the software and its capability to concretely support CE diagnoses.

Differentiation of normal and neoplastic bone tissue in dynamic gadolinium-enhanced magnetic resonance imaging: validation of a semiautomated technique

PurposeThis study was undertaken to clinically validate the accuracy of a semiautomated software tool for analysing the enhancement curve in focal malignant bone lesions.Materials and methodsTwenty-three patients affected by cancer with malignant focal bone lesions underwent dynamic gadolinium-enhanced magnetic resonance (MR) imaging using the following protocol: T1-weighted turbo spin-echo sequences (time to repeat [TR] 600 ms, time to echo [TE] 8.6 ms, field of view [FOV] 40×40 cm) before and after intravenous injection of gadolinium-containing contrast agent. Image postprocessing was performed using the software DyCoH. Each region of interest (5×5 pixels), drawn to include the area of the lesion with the highest values of the area under the curve map, was analysed to obtain time-intensity curves and relative perfusion parameters: time to peak (TTP), peak intensity (PI), slope (60-s slope), intensity at 60 s after contrast agent injection (60-s I) and final intensity (FI).ResultsData were obtained by analysing 86 malignant lesions and 86 apparently normal bone regions. PI, 60-s slope, 60-s I and FI were significantly different between neoplastic and apparently normal (p<0.001) samples. Sensitivity, specificity and accuracy were, respectively, 94%, 93% and 94% at a PI threshold of 100 (signal-to-noise ratio), with positive and negative predictive values of 93% and 94%. At a threshold value of 0.85 for 60-s slope, sensitivity and specificity values were both 91%.ConclusionsThe semiautomated technique we report appears to be accurate for identifying neoplastic tissue and for mapping perfusion parameters, with the added value of a consistent measurement of perfusion parameters on colour-coded maps.RiassuntoObiettivoScopo del presente lavoro è stato valutare l’accuratezza di un software di analisi semiautomatica nell’analisi delle curve di potenziamento post-contrastografico delle lesioni ossee focali maligne.Materiali e metodiVentitre pazienti oncologici con lesioni ossee focali maligne sono stati sottoposti ad esame di risonanza magnetica dinamica utilizzando sequenze turbo spin echo T1-pesate (tempo di ripetizione [TR] 600 ms, tempo di eco [TE] 8,6 ms, campo di vista [FOV] 40×40 cm) prima e dopo somministrazione endovenosa di mezzo di contrasto paramagnetico. L’analisi delle immagini è stata poi effettuata utilizzando il software DyCoH. Ciascuna regione di interesse (ROI, 5×5 pixel), posizionata nella zona della lesione che presentava i più alti valori di area sotto la curva (AUC) sulla mappa, è stata analizzata per ottenere le curve intensità/tempo ed i relativi parametri perfusionali: tempo di picco (TTP), intensità di picco (PI), pendenza (60”Slope) ed intensità (60”I) al primo minuto dopo la somministrazione di mezzo di contrasto, intensità finale (FI).RisultatiI risultati sono stati ottenuti dall’analisi di 86 lesioni maligne ed 86 regioni di tessuto osseo apparentemente normale. I parametri PI, 60”Slope, 60”I e FI hanno mostrato valori con differenza statisticamente significativa tra lesioni neoplastiche e tessuto osseo apparentemente normale (p<0,001). La sensibilità, la specificità e l’accuratezza calcolate si sono mostrate rispettivamente del 94%, 93% e 94% ad un valore soglia di PI di 100 (signal to noise ratio, SNR), con valori predittivi positivi e negativi rispettivamente del 93% e 94%. Ad un valore soglia di 0,85 per il parametro 60”Slope, la sensibilità, la specificità, l’accuratezza ed i valori predittivi positivi e negativi erano del 91%.ConclusioniLa tecnica di analisi semiautomatica utilizzata appare accurata nell’identificazione di tessuto neoplastico e nell’elaborazione di mappe parametriche perfusionali, con il valore aggiunto di una valida misura dei parametri perfusionali sulle mappe colorimetriche stesse.

Radiofrequency ablation of renal cell carcinoma in patients with a solitary kidney: a retrospective analysis of our experience

PurposeThis study was done to evaluate the feasibility and safety of radiofrequency ablation (RFA) of renal cell carcinomas (RCCs) in patients with solitary kidney.Materials and methodsSeven patients (two men, five women; age range 52–70 years; mean age 59.7 years) were treated under computed tomography (CT) and ultrasound (US) guidance. Three patients had single lesions, and the remaining four had multiple lesions. Seventeen lesions (4 cortical, 13 exophytic, maximum diameter range 12–40 mm, mean 21.0 mm) not located close to the renal pelvis were treated. CT or magnetic resonance (MR) imaging follow-up studies were obtained for all patients at the end of the procedure and at 1, 3, 6 and 12 months; serum creatinine was also monitored.ResultsTen ablation sessions were performed. In two patients, a perinephric haematoma was detected, and one of these patients had two episodes of self-limiting haematuria. Contrast-enhanced CT and MR imaging at the end of the procedure and at 1 month demonstrated 100% technical success; these results were confirmed at 3, 6 and 12 month. Fisher’s test comparing serum creatinine obtained 1 day before and 1 day after the procedure showed no case of acute renal failure (mean serum creatinine 24 h before the procedure 1.02 mg/dl; mean serum creatinine 24 h after the procedure 0.95 mg/dl; p=0.114; not significant). Serum creatinine at follow-up was always within the normal range.ConclusionsRadiofrequency ablation in the solitary kidney is a safe and effective procedure for treating RCC.RiassuntoObiettivoScopo del nostro lavoro è stato valutare l’efficacia e la sicurezza dell’ablazione a radiofrequenza (RFA) del carcinoma renale (RCC) in pazienti con rene solitario.Materiali e metodiSette pazienti (2 uomini e 5 donne; età compresa tra 52 e 70 anni; età media 59,7 anni) sono stati trattati sotto guida tomografica computerizzata (TC) ed ecografica. Tre pazienti avevano una lesione singola; i restanti quattro presentavano multiple localizzazioni. Complessivamente diciassette lesioni (4 corticali e 13 esofitiche, con diametro massimo compreso tra 12 e 40 mm, in media 21 mm) non adiacenti alla pelvi renale sono state trattate. TC e risonanza magnetica (RM) sono state le metodiche scelte per il follow-up al termine di ogni procedura e a distanza di 1, 3, 6 e 12 mesi; sono stati monitorati anche i valori di creatinina sierica.RisultatiIn totale sono state condotte 10 sedute ablative. In 2 pazienti abbiamo riscontrato la presenza di un ematoma peri-renale ed in uno di questi due pazienti sono stati riportati anche 2 episodi di ematuria, regrediti spontaneamente. Il successo tecnico, raggiunto nel 100% dei casi, è stato dimostrato grazie al controllo mediante TC o RM con somministrazione di agente di contrasto al termine di ogni procedura e a distanza di un mese; i follow-up a 3, 6 e 12 mesi hanno confermato questo dato. Nessun caso di insufficienza renale acuta è stato riscontrato dopo aver applicato il test di Fisher comparando i valori di creatinina sierica misurati il giorno prima e il giorno dopo la procedura, (valore medio di creatinina sierica 24 ore prima della procedura: 1,02 mg/dl; valore medio di creatinina sierica il giorno dopo: 0,95 mg/dl; p=0,114, non significativo). I valori di creatinina sierica nei successivi controlli a distanza sono sempre stati nei limiti della norma.ConclusioniLa RFA si è rivelata una procedura sicura ed efficace nel trattamento dei carcinomi a cellule renali nei pazienti con rene solitario.

The Effect of Intra-Articular Hyaluronic Acid (Sinovial® One) on Knee Osteoarthritis: A Preliminary Study

Intra-articular injections of hyaluronic acid are a valid treatment option for patients with osteoarthritis. Differences in purity, origin, and molecular weight may influence the efficacy and safety of hyaluronic acid products, therefore, we evaluated the safety, efficacy, and duration of improvements following a single intra-articular injection of a low-medium molecular weight hyaluronic acid product of bacterial synthesis, Sinovial® One, on patients with osteoarthritis of the knee. The double-blind study enrolled 21 patients (24 knees) with symptomatic knee osteoarthritis, classified into moderate, severe and very severe osteoarthritis using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain functional Index and the Kellgren and Lawrence scales. At four months there was improvement in measured clinical parameters in 77.6% of the 24 treated knees, particularly in patients with moderate and severe osteoarthritis (improvement in 100% and 66.7%, respectively). No local or systemic adverse events were observed. These preliminary findings suggest that Sinovial® One is safe and effective for patients with knee osteoarthritis, providing long-lasting improvement in clinical parameters.