Five-year survival in 309 patients with colorectal liver metastases treated with radiofrequency ablation

There is little published long-term survival data for patients with colorectal liver metastases treated with radiofrequency ablation (RFA). We present a multivariate analysis of 5-year survival in 309 patients (198 male, aged 64 (24–92)) treated at 617 sessions. Our standard protocol used internally cooled electrodes introduced percutaneously under combined US and CT guidance/monitoring. The number and size of liver metastases, the presence and location of extrahepatic disease, primary resection, clinical, chemotherapy and follow-up data were recorded. Data analysis was performed using SPSS v.10. On multivariate analysis, significant survival factors were the presence of extrahepatic disease (p < 0.001) and liver tumour volume (p = 0.001). For 123 patients with five or less metastases of 5 cm or less maximum diameter and no extrahepatic disease median survival was 46 and 36 months from liver metastasis diagnosis and ablation, respectively; corresponding 3- and 5-year survival rates were 63%, 34% and 49%, 24%. Sixty-nine patients had three or less tumours of below 3.5 cm in diameter and their 5-year survival from ablation was 33%. There were 23/617(3.7%) local complications requiring intervention. Five-year survival of 24–33% post ablation in selected patients is superior to any published chemotherapy data and approaches the results of liver resection.     

Response assessment of colorectal liver metastases with contrast enhanced CT/18F-FDG PET

Purpose

Evaluate the diagnostic performance of contrast enhanced CT/PET (ceCT/PET) in the response assessment of patients with colorectal cancer liver metastases.

Methods

33 ce CT/PET studies of 19 patients with colorectal liver metastases were prospectively evaluated. All of them, 13 (68.4%) were males and 6 (31.6%) females. Mean age and range were 63 [42–78]. All patients were treated with neoadjuvant chemotherapy. In all cases post-therapy diagnostic confirmation of liver lesions was obtained. A ce CT PET/was obtained 1 h after the injection of 370 MBq of 18F-FDG.Metabolic and morphologic studies were evaluated by two blinded nuclear physicians and radiologists respectively to assess the location, size and suspected diagnosis of lesions (benign or malignant). A combined assessment of both techniques was performed.The final diagnosis was established by histopathology or clinical/radiological follow-up greater than 6 months.

Results

A total of 120 liver lesions were identified, 115 were malignant and 5 benign.From the malignant lesions, 105 were identified with the ceCT, 44 with the PET and 109 with ceCT/PET. All of the benign lesions were correctly classified with any of the three imaging techniques.The sensitivity of PET, ceCT and ceCT/PET were of 38%, 91% and 95% respectively and the specificity was 100% in all three of the diagnostic studies.

Conclusion

Administration of intravenous contrast in the PET/CT is mandatory to evaluate treatment response rate of liver metastases due to the limitations of isolated metabolic images in these cases.     

Small colorectal liver metastases: Detection with SPIO-enhanced MRI in comparison with gadobenate dimeglumine-enhanced MRI and CT imaging

The aim of this prospective study was to compare the diagnostic role of superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging (MRI) versus gadobenate dimeglumine (GbD)-enhanced MRI and computed tomography (CT) investigations for detection of small (less than 1 cm) colorectal liver metastases (LMs) of colorectal cancer. Seventy-eight LMs in 16 patients were evaluated with dynamic CT imaging, GbD-enhanced dynamic MR imaging and SPIO-enhanced MR imaging. Two radiologists were reviewed the LMs seperately. Agreement between the readers and three algorithms was analyzed. Differences between the lesion detection ratios of the methods were analyzed by two proportion z test. Sensitivity values of each modality were also calculated. Interobserver agreement values with kappa analysis were found to be the best for three modalities and kappa values were 0.866, 0.843, and 1.0 respectively. For all 78 LMs, SPIO-enhanced MRI detected all lesions (100% sensitivity). This sensitivity value was higher than GbD-enhanced MRI, and there was a significant difference (p < 0.05). GbD-enhanced MRI depicted 71 lesions and this modality could not detected 7 lesions (91% sensitivity). This modality had moderate sensitivity, and this value is greater than CT imaging, so there was a significant difference also (p < 0.05). Dynamic triphasic CT imaging detected 64 (R1) and 65 (R2) LMs. This modality had the lowest sensitivity (R1: 0.82, R2: 0.83 respectively). Only SPIO-enhanced MRI was able to detect all LMs less than 1 cm. LMs were the best detected with SPIO-enhanced MRI. We recommend SPIO-enhanced MRI to be the primary alternative modality especially for diagnosis of small colorectal LMs.     

Performance of integrated FDG-PET/contrast-enhanced CT in the staging and restaging of colorectal cancer: Comparison with PET and enhanced CT

Objective

The purpose of this study was to assess the diagnostic value of PET/CT as a one step examination in patients with colorectal cancer. Therefore we proved whether diagnostic PET/CT adds information over PET or contrast-enhanced CT alone for staging or restaging of patients with colorectal cancer.

Methods

Seventy-three patients (46 males and 27 females; age range: 50-81 years; mean age: 67 years) with known colorectal cancer underwent 18F-FDG-PET/CT for staging or restaging.

Results

Of the 73 patients 26 patients underwent PET/CT for staging and 47 for restaging. 266 metastases could be detected in 60 patients. Contrast-enhanced PET/CT had a lesion-based sensitivity of 100%, contrast-enhanced CT of 91% and PET of 85%. PET/CT identified 2 lesions as false positive. PET/CT could also reach a patient-based sensitivity of 100%, which was superior to contrast-enhanced CT and PET.

Conclusion

Our study clearly demonstrated the added value of contrast-enhanced PET/CT in staging and restaging patients with colorectal cancer over CT and PET alone.     

Depiction and characterization of liver lesions in whole body [F]-FDG PET/MRI

Objectives

To assess the value of PET/MRI with [¹⁸F]-FDG using a whole body protocol for the depiction and characterization of liver lesions in comparison to PET/CT.

Methods

70 patients (31 women, 39 men) with solid tumors underwent [¹⁸F]-FDG PET/CT and followed by an additional PET/MRI using an integrated scanner. Two readers rated the datasets (PET/CT; PET/MRI) regarding conspicuity of hepatic lesions (4-point ordinal scale) and diagnostic confidence (5-point ordinal scale). Median scores for lesion conspicuity and diagnostic confidence were compared using Wilcoxon's rank sum test. Prior examinations, histopathology and clinical follow-up (116 ± 54 days) served as standard of reference.

Results

36 of 70 (51%) patients showed liver lesions. Using PET/CT and PET/MRI all patients with liver metastases could correctly be identified. A total of 97 lesions were found (malignant n = 26; benign n = 71). For lesion conspicuity significantly higher scores were obtained for PET/MRI in comparison to PET/CT (p < 0.001). Significantly better performance for diagnostic confidence was observed in PET/MRI, both for malignant as for benign lesions (p < 0.001).

Conclusions

PET/MRI, even in the setting of a whole body approach, provides higher lesion conspicuity and diagnostic confidence compared to PET/CT and may therefore evolve as an attractive alternative in oncologic imaging.     

大肠癌肝转移的射频消融治疗

目的研究大肠癌肝转移射频消融(RFA)治疗近期局部疗效和不良反应。方法大肠癌肝转移患者32例,病灶总数71个,其中直径小于4.0 cm的病灶41个,4.1~5.0 cm者14个,5.1~6.0 cm者9个,大于6.1 cm者7个。经RFA治疗1个月后行螺旋CT双期增强扫描评价肿瘤治疗效果。结果不同大小瘤灶经消融治疗后达到完全坏死者分别为41个(41/41),13个(13/14),4个(4/9),2个(2/7)。无严重不良反应和并发症。结论RFA安全可靠,不良反应小,是治疗大肠癌肝转移的有效方法之一。     

Role of [18F]FDG-PET/CT after radiofrequency ablation of liver metastases: preliminary results

PURPOSE: Focal metastasis may be treated with radiofrequency ablation (RFA), a low invasive method yet limited by the lack of direct evidence of radicality of treatment. We, hereby, aimed at assessing the role of positron emission tomography-computed tomography (PET/CT) with fluoride radiolabeled deoxy-glucose ([(18)F]FDG) in RFA treatment success evaluation and early diagnosis of local relapse of liver metastasis after RFA procedure. METHODS: RFA was performed in nine patients on 12 liver metastasis, serially imaged through [(18)F]FDG-PET/CT and multidetector CT (MDCT) at 1, 3, 6, and 9 months after treatment. Eight lesions were also scanned with [(18)F]FDG-PET/CT at 1 week after treatment. Imaging analyses were performed on 47 [(18)F]FDG-PET/CT and 51 MDCT. Imaging reading outcomes were compared to each other and to biopsy tissue results when available. RESULTS: In one case, [(18)F]FDG-PET/CT revealed radiotracer uptake at RFA site a week after procedure. Negative concordant outcome was obtained on eight lesions at 1 month after RFA, on eight cases at 3 months, on four at 6 months, and on two cases at 9 months. Extra-liver (peritoneal) disease was detected in one case by both [(18)F]FDG-PET/CT and MDCT. In seven cases, [(18)F]FDG-PET/CT revealed the presence of local recurrence earlier than MDCT. In no cases did MDCT detect local relapse earlier than [(18)F]FDG-PET/CT. CONCLUSION: [(18)F]FDG-PET/CT may detect RFA treatment failure as well as local relapse after RFA earlier than MDCT.     

Value of fusion of PET and MRI for staging of endometrial cancer: Comparison with F-FDG contrast-enhanced PET/CT and dynamic contrast-enhanced pelvic MRI

Purpose

To investigate the diagnostic value of retrospective fusion of pelvic MRI and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET images for assessment of locoregional extension and nodal staging of endometrial cancer.

Materials and methods

Thirty patients with biopsy-proven endometrial cancer underwent preoperative contrast-enhanced PET/CT (PET/ceCT) and pelvic dynamic contrast-enhanced MRI for initial staging. Diagnostic performance of PET/ceCT, contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) for assessing the extent of the primary tumor (T stage) and metastasis to regional LNs (N stage) was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis.

Results

Fused PET/MRI and MRI detected 96.7% of the primary tumors, whereas PET/ceCT detected 93.3%. Accuracy for T status was 80.0% for fused PET/MRI, and MRI proved significantly more accurate than PET/ceCT, which had an accuracy of 60.0% (p = 0.041). Patient-based sensitivity, specificity and accuracy for detecting pelvic nodal metastasis were 100%, 96.3% and 96.7% for both fused PET/MRI and PET/ceCT, and 66.7%, 100% and 96.7% for MRI, respectively. These three parameters were not statistically significant (p = 1).

Conclusion

Fused PET/MRI, which complements the individual advantages of MRI and PET, is a valuable technique for assessment of the primary tumor and nodal staging in patients with endometrial cancer.     

Detection of residual tumor after radiofrequency ablation of liver metastasis with dual-modality PET/CT: initial results

The aim of this study was to determine the accuracy of dual-modality positron emission tomography(PET)/computed tomography (CT) in the detection of residual tumor after radiofrequency ablation (RFA) of liver metastasis of colorectal cancer. Eleven patients with 16 hepatic metastases (mean size 2.9 cm) from colorectal cancer were enrolled in this study, and 19 RFA procedures and 32 PET/CT examinations were performed. The patients had PET/CT before and after RFA using [¹⁸F]-2-fluoro-2-deoxy-D-glucose. CT images alone were read by two radiologists, PET images alone were evaluated by two nuclear physicians. Fused images were read by one physician of each speciality in consensus. The accuracy for detection of residual tumor by the different imaging modalities following RFA was assessed. Eleven patients with a mean age of 63 (range 55–71) years were evaluated. The mean follow-up period was 393 days. The overall procedure-based sensitivity for detection of residual tumor was 65% for PET and PET/CT and 44% for CT alone. The accuracies were 68% and 47%, respectively. Four patients had residual tumor after RFA, six patients total developed local recurrence. PET/CT therefore possibly proved superior to CT alone when assessing the liver for residual tumor after RFA.     

Radio-frequency ablation of colorectal liver metastases in 167 patients

The objective of this paper is to report our results from a prospective study of 167 patients with colorectal liver metastases treated with radio-frequency ablation (RFA). Three hundred fifty-four treatments were performed in 167 patients, 99 males, mean age 57 years (34–87). The mean number of metastases was 4.1 (1–27). The mean maximum diameter was 3.9 cm (1–12). Fifty-one (31%) had stable/treated extra-hepatic disease. Treatments were performed under general anaesthesia using US and CT guidance and single or cluster water-cooled electrodes (Valleylab, Boulder, CO). All patients had been rejected for or had refused surgical resection. Eighty percent received chemotherapy. Survival data were stratified by tumour burden at the time of first RFA. The mean number of RFA treatments was 2.1 (1–7). During a mean follow-up of 17 months (0–89), 72 developed new liver metastases and 71 developed progressive extra-hepatic disease. There were 14/354 (4%) major local complications and 22/354 (6%) minor local complications. For patients with 5 metastases, maximum diameter 5 cm and no extra-hepatic disease, the 5-year survival from the time of diagnosis was 30% and from the time of first thermal ablation was 26%. Given that the 5-year survival for operable patients is a median of 32%, our 5-year survival of 30% is promising.     

Image-guided multipolar radiofrequency ablation of liver tumours: initial clinical results

The local effectiveness and clinical usefulness of multipolar radiofrequency (RF) ablation of liver tumours was evaluated. Sixty-eight image-guided RF sessions were performed using a multipolar device with bipolar electrodes in 53 patients. There were 45 hepatocellular carcinomas (HCC) and 42 metastases with a diameter ≤3 cm (n = 55), 3.1–5 cm (n = 29) and >5 cm (n = 3); 26 nodules were within 5 mm from large vessels. Local effectiveness and complications were evaluated after RF procedures. Mean follow-up was 17 ± 10 months. Recurrence and survival rates were analysed by the Kaplan-Meier method. The primary and secondary technical effectiveness rate was 82% and 95%, respectively. The major and minor complication rate was 2.9%, respectively. The local tumour progression at 1- and 2-years was 5% and 9% for HCC nodules and 17% and 31% for metastases, respectively; four of 26 nodules (15%) close to vessels showed local progression. The survival at 1 year and 2 years was 97% and 90% for HCC and 84% and 68% for metastases, respectively. Multipolar RF technique creates ablation zones of adequate size and tailored shape and is effective to treat most liver tumours, including those close to major hepatic vessels.     

PET/MRI hybrid imaging: devices and initial results

The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI systems have shown promising results by combining high resolution morphology with multifunctional information isochronously.     

PET-CT after radiofrequency ablation of colorectal liver metastases: Suggestions for timing and image interpretation

Introduction. The main area of concern regarding radiofrequency ablation (RFA) of colorectal liver metastases is the risk of developing a local site recurrence (LSR). Reported accuracy of PET-CT in detecting LSR is high compared to morphological imaging alone, but no internationally accepted criteria for image interpretation have been defined. Our aim was to assess criteria for FDG PET-CT image interpretation following RFA, and to define a timetable for follow-up detection of LSR.     

PET/CT versus MRI for diagnosis,staging, and follow‐up of lung cancer

Positron emission tomography / computed tomography (PET/CT), with its metabolic data of ¹⁸F‐fluorodeoxyglucose (FDG) cellular uptake in addition to morphologic CT data, is an established technique for staging of lung cancer and has higher sensitivity and accuracy for lung nodule characterization than conventional approaches. Its strength extends outside the chest, with unknown metastases detected or suspected metastases excluded in a significant number of patients. Lastly, PET/CT is used in the assessment of therapy response. Magnetic resonance imaging (MRI) in the chest has been difficult to establish, but with the advent of new sequences is starting to become an increasingly useful alternative to conventional approaches. Diffusion‐weighted MRI (DWI) is useful for distinguishing benign and malignant pulmonary nodules, has high sensitivity and specificity for nodal staging, and is helpful for evaluating an early response to systemic chemotherapy. Whole‐body MRI/PET promises to contribute additional information with its higher soft‐tissue contrast and much less radiation exposure than PET/CT and has become feasible for fast imaging and can be used for cancer staging in patients with a malignant condition. J. Magn. Reson. Imaging 2015;42:247–260.     

Actual role of radiofrequency ablation of liver metastases

The liver is, second only to lymph nodes, the most common site for metastatic disease irrespective of the primary tumour. More than 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improved survival in patients with colorectal metastases, only approximately 20% of patients are eligible for surgery. Thermal ablation and especially radiofrequency ablation emerge as an important additional therapy modality for the treatment of liver metastases. RF ablation shows a benefit in life expectancy and may lead in a selected patient group to cure. Percutaneous RF ablation appears safer (versus cryotherapy), easier (versus laser), and more effective (versus ethanol instillation and transarterial chemoembolisation) compared with other minimally invasive procedures. RF ablation can be performed by a percutaneous, laparoscopical or laparotomic approach, and may be potentially combined with chemotherapy and surgery. At present ideal candidates have tumours with a maximum diameter less than 3.5 cm. An untreatable primary tumour or a systemic disease represents contraindications for performing local therapies. Permanent technical improvements of thermal ablation devices and a better integration of thermal ablation in the overall patient care may lead to prognosis improvement in patients with liver metastases.     

Prospective evaluation of MRI,C-acetate PET/CT and contrast-enhanced CT for staging of bladder cancer

Purpose

To prospectively evaluate the diagnostic performance of magnetic resonance imaging (MRI), ¹¹C-acetate positron emission tomography/computed tomography (PET/CT) and contrast-enhanced CT for bladder cancer staging, using whole-mount pathologic review of radical cystectomy and pelvic lymph node specimens as the reference standard.

Materials and methods

The institutional review board approved this prospective study, which was compliant with the Health Insurance Portability and Accountability Act. Written informed consent was obtained from 16 patients with histologically confirmed bladder cancer who underwent MRI, ¹¹C-acetate PET/CT and contrast-enhanced CT before radical cystectomy and pelvic lymph node dissection. Before imaging 4/16 patients had received intravesical Bacillus Calmette-Guérin treatment, 6 had received systemic chemotherapy, 3 had received both and 3 had received neither. Measures of diagnostic performance including accuracy, sensitivity and specificity were estimated separately for each imaging modality.

Results

MRI correctly staged 56% of patients (9/16), overstaged 38% (6/16) and understaged 6% (1/16). CT correctly staged 50% of patients (8/16), overstaged 44% (7/16) and understaged 6% (1/16). In 9 patients, ¹¹C-acetate PET/CT showed uptake within the bladder wall; the uptake was true-positive in 7 patients and false-positive in 2 patients. Of the remaining 7 patients, 5 had true-negative and 2 had false-negative PET/CT results for cancer in the bladder wall. For all modalities, staging accuracy was reduced in patients with a history of prior intravesical and/or systemic chemotherapy.

Conclusion

In staging bladder cancer, MRI, ¹¹C-acetate PET/CT and CT displayed similar levels of accuracy. For all modalities, a history of intravesical and/or systemic chemotherapy affected staging accuracy.     

射频治疗肝脏恶性肿瘤的CT评价(附35例分析)

目的 :应用螺旋CT评价射频治疗肝癌的近期疗效。方法 :对 35例肝癌 35个病灶射频治疗术前、后肿瘤大小、密度的变化、肿瘤凝固性坏死的形态、范围及术后CT增强扫描的特征进行观察。其中术前进行肝动脉碘油及明胶海绵碎块栓塞 2 3例。结果 :35例肝癌射频术后 5min均有增大 ,术前、后肿块最大径分别为 5 .75± 2 .84cm和 6 .2 2± 1 .1 2cm ,统计学无显著性差异 (P >0 .0 5)。病灶CT值术后 5min均减低 ,术前、后病灶CT值分别为 45 .3± 6 .33Hu和 32 .8± 7.83Hu,均有显著性差异 (P <0 .0 5)。术后 5min 94.2 8% (33/ 35)的病灶呈不同程度凝固性坏死。随访 1～ 1 1个月 ,平均随访 4个月 ,71 % (2 5/ 35)病灶较原病灶缩小 ,2 9% (1 0 / 35)病灶扩大 ,病灶CT值减低 1 1Hu±。CT增强 1 0例 ,其中 5例坏死区表现为无强化 ,5例残留灶 /复发灶显示为结节状或花环状强化。结论 :螺旋CT可准确评价肝癌射频治疗的效果 ,并提示射频结合肝动脉栓塞治疗有助于提高疗效     

PET/MRI of the breast

The future clinical use of the combination of positron emission tomography (PET) with 2-Fluoro[F-18]-2-Deoxy-d-Glucose (FDG)and MRI is still unclear. If a patient requires a PET and breast DCE-MRI for staging purposes, both scans can be done in the same visit. In the breast, DCE-MRI is better at lesion detection (sensitivity), margin evaluation, and has a higher specificity than CT. The potential for multiparametric qualitative and quantitative imaging is also an advantage of PET/MRI which provides opportunity to improve tumor characterization and may ultimately lead to outcome prediction. This review discusses technical and clinical aspects of this emerging technology in breast cancer patients.     

Value of Surveillance 18F-FDG PET/CT in Colorectal Cancer: Comparison with Conventional Imaging Studies

Purpose

To assess the value of PET/CT for detecting local or distant recurrence in patients who undergo surgery for colorectal cancer (CRC) and to compare the accuracy of PET/CT to that of conventional imaging studies (CIS).

Methods

Tumor surveillance PET/CT scans done between March 2005 and December 2009 of disease-free patients after surgery with or without adjuvant chemotherapy for CRC were retrospectively studied. CIS (serial enhanced CT from lung base to pelvis and plain chest radiograph) were performed within 1 month of PET/CT. We excluded patients with distant metastasis on initial staging, a known recurrent tumor, and a lack of follow-up imaging. The final diagnosis was based on at least 6 months of follow-up with colonoscopy, biopsy, and serial imaging studies in combination with carcinoembryonic antigen levels.

Results

A total of 262 PET/CT scans of 245 patients were included. Local and distant recurrences were detected in 27 cases (10.3%). On case-based analysis, the overall sensitivity, specificity, and accuracy were 100, 97.0, and 97.3% for PET/CT and 85.1, 97.0, and 95.8% for CIS, respectively. On lesion-based analysis, PET/CT detected more lesions compared to CIS in local recurrence and lung metastasis. PET/CT and CIS detected the same number of lesions in abdominal lymph nodes, hepatic metastasis, and peritoneal carcinomatosis. PET/CT detected two more metachronous tumors than did CIS in the lung and thyroid gland.

Conclusion

PET/CT detected more recurrences in patients who underwent surgery for CRC than did CIS and had the additional advantage of evaluating the entire body during a single scan.