Apparent Diffusion Coefficient Can Predict Therapy Response of Hepatocellular Carcinoma to Transcatheter Arterial Chemoembolization.

AIM: The goal of this meta-analysis was to assess the apparent diffusion coefficient (ADC) as a pre- and posttreatment (ADC value changes [ΔADC]) predictive imaging biomarker of response to transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). METHODS: Scopus database, Embase database, and MEDLINE library were scanned for connections between pre- and posttreatment ADC values of HCC and response to TACE. Six studies qualified for inclusion. The following parameters were collected: authors, publication year, study design, number of patients, drugs for TACE, mean ADC value, standard deviation, measure method, b values, and Tesla strength. The Quality Assessment of Diagnostic Studies 2 instrument was employed to check the methodological quality of each study. The meta-analysis was performed by utilizing RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance were used to regard heterogeneity. The mean ADC values and 95% confidence intervals were computed. RESULTS: Six studies (n = 271 patients with 293 HCC nodules) were included. The pretreatment mean ADC in the responder group was 1.20 × 10-3 mm2/s (0.98, 1.42) and 1.14 × 10-3 mm2/s (0.89, 1.39) in the nonresponder group. The analysis of post-TACE ΔADC revealed a threshold of ≥20% to identify treatment responders. No suitable pretreatment ADC threshold to predict therapy response or discriminate between responders and nonresponders before therapy could be discovered. CONCLUSION: ΔADC can facilitate early objective response evaluation through post-therapeutic ADC alterations ≥20%. Pretreatment ADC cannot predict response to TACE.

Apparent Diffusion Coefficient Can Predict Response to Chemotherapy of Liver Metastases in Colorectal Cancer.

RATIONALE AND OBJECTIVES: The aim of this meta-analysis was to evaluate the suitability of apparent diffusion coefficient (ADC) as a predictor of response to systemic chemotherapy in patients with metastatic colorectal carcinoma (CRC). MATERIALS AND METHODS: MEDLINE library, SCOPUS database, and EMBASE database were screened for relationships between pretreatment ADC values of hepatic CRC metastases and response to systemic chemotherapy. Overall, five eligible studies were identified. The following data were extracted: authors, year of publication, study design, number of patients, mean value ADC and standard-deviation, measure method, b-values, and Tesla-strength. The methodological quality of every study was checked according to the Quality Assessment of Diagnostic Studies-2 instrument. The meta-analysis was undertaken by employing RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used to account for heterogeneity. Mean ADC values including 95% confidence intervals were calculated. RESULTS: Five studies (n = 114 patients) were included. The pretreatment mean ADC in the responder group was 1.15 × 10-3 mm2/s (1.03, 1.28) and 1.37 × 10-3 mm2/s (1.3, 1.44) in the nonresponder group. An ADC baseline threshold of 1.2 × 10-3 mm2/s, below which no nonresponder was found, can distinguish both groups. CONCLUSION: The results indicate ADC can serve as a predictor of response to chemotherapy for CRC patients.

Intra-hepatic Abscopal Effect Following Radioembolization of Hepatic Metastases.

PURPOSE: To search for abscopal effects (AE) distant to the site of radiation after sequential Yittrium-90 (Y-90) radioembolization (RE) of liver malignancies. METHODS AND MATERIALS: In this retrospective analysis, all patients treated by RE between 2007 and 2018 (n = 907) were screened for the following setting/conditions: sequential RE of left and right liver lobe in two sessions, liver-specific MRI (MRI1) acquired max. 10 days before or after first RE (RE1), liver-specific MRI (MRI2) acquired with a minimum time interval of 20 days after MRI1, but before second RE (RE2). No systemic tumor therapies between MRI1 and MRI2. No patients with liver cirrhosis. Metastases > 5 mm in untreated liver lobes were compared in MRI1 and MRI2 and rated as follows: same size or larger in MRI2 = no abscopal effect (NAE); > 30% shrinkage without Y-90 contamination in SPECT/CT = abscopal effect (AE). RESULTS: Ninety six of 907 patients met aforementioned criteria. Median time-frame between RE1 and MRI2 was 34 (20-64) days. These 96 cases had 765 metastases which were evaluable (median 5(1-40) metastases per patient). Four patients could be identified with at least one shrinking metastasis of the untreated site: one patient with breast cancer (3 metastases: 0 NAE; 3 AE), one patient with prostate cancer (6 metastases: 3 NAE; 3 metastases > 30% shrinkage but possible Y-90 contamination) and two patients with shrinkage of one metastasis each but less than 30%. CONCLUSION: Our retrospective study documents AE after RE of liver tumors in 1 out of 96 cases, 3 other cases remain unclear.

Efficacy and safety of guidewireless catheterization with a steerable microcatheter in patients scheduled for yttrium-90 radioembolization: a prospective multicenter trial.

INTRODUCTION: A steerable, guidewireless microcatheter is of interest to interventional radiologists because it can improve effectiveness and reduce procedure timing and cost. AIM: To assess the feasibility and safety of yttrium 90 radioembolization with a new steerable microcatheter without the need to use a guidewire. MATERIAL AND METHODS: A steerable microcatheter (Direxion; Boston Scientific, Natick, MA, USA) was prospectively used for yttrium-90 microsphere delivery in 50 patients (57 applications). The following factors were documented: vessel anatomy; shape and position of the guiding catheter; anticipated catheter position; technical success of catheterization; degree of difficulty in maneuvering; time to reach the target position; and complications. RESULTS: The microcatheter target position was in the right hepatic artery (n = 30, 53%), the middle hepatic artery (n = 4, 7%), the left hepatic artery (n = 19, 33%), or in a segmental artery (n = 4, 7%). Vessel catheterization was successful in 53 of 57 hepatic arteries (93%). The mean time to reach the target position was 53.3 ±53.0 s. The mean degree of difficulty in maneuvering the catheter to the target position was 2.3 ±1.3 (easy) on a 6-point scale. The only complication observed was mild vasospasm in 1 patient. CONCLUSIONS: The Direxion steerable microcatheter is characterized by unique steerability, allowing yttrium 90 delivery to be performed safely without use of a guidewire.

Treatment of metastatic gastric adenocarcinoma with image-guided high-dose rate, interstitial brachytherapy as second-line or salvage therapy.

PURPOSE: We aimed to evaluate the safety and effectiveness of image-guided high-dose rate interstitial brachytherapy (iBT) for the treatment of patients with hepatic, lymphatic, and pancreatic metastases originating from gastric cancer, an entity rarely surgically treatable with curative intent. METHODS: Twelve patients with a cumulative number of 36 metastases (29 liver, 2 pancreatic, 5 lymph node) from histologically proven gastric adenocarcinoma received iBT between 2010 and 2016 and were retrospectively analyzed. Every patient underwent palliative chemotherapy prior to iBT. The iBT procedure employs a temporarily, intratumorally placed iridium-192 source in a single fraction with the goal of tumor cell eradication. Effectiveness was assessed clinically and by radiologic imaging every three months. RESULTS: Local tumor control was achieved in 32 of all treated metastases (89%). Four lesions showed a local recurrence after 7 months. Lesion sizes varied from 9 to 102 mm with a median of 20 mm. The median progression-free survival was 6.6 months (range, 1.8-46.8 months). The median overall survival was 11.4 months (range, 5-47 months). One patient suffered a major complication following iBT, hepatic hematoma and abscess (Common Terminology Criteria for Adverse Events grade 3), successfully dealt with by transcutaneous drainage. CONCLUSION: iBT is an overall safe procedure, which facilitates high rates of local tumor control in treatment of metastatic gastric adenocarcinoma. Compared with surgical metastasectomy, similar overall survival rates could be achieved in our patient collective after iBT application.

Treatment of hepatic pancreatic ductal adenocarcinoma metastases with high-dose-rate image-guided interstitial brachytherapy: a single center experience.

PURPOSE: To evaluate the efficacy and safety of image-guided (computed tomography/magnetic resonance imaging - CT/MRI) high-dose-rate (HDR) interstitial brachytherapy (iBT) as a salvage maneuver for the treatment of hepatic metastases originating from hepatic pancreatic ductal adenocarcinoma (PDAC). PDAC metastases present a major and unresolved problem, and any surgical approach or local therapeutic intervention remains extremely controversial. MATERIAL AND METHODS: A cumulative number of 45 hepatic PDAC metastases in 16 patients were treated and retrospectively analyzed. Synchronous metastatic spread was observed in five patients, metachronous in eleven. 14 patients had resection of the pancreatic primary prior to iBT: eight Whipple/PPPD and six distal pancreatectomy procedures. The hepatic metastases were progressing under chemotherapy, thus iBT was applied as a salvage maneuver with the intention of local tumor control and prolonged survival. iBT is applied interstitially, with temporarily introduced 192Ir source in a single fraction HDR irradiation regime to eradicate vital tumor cells. Response to treatment was assessed clinically with CT/MRI every three months. RESULTS: Local tumor control was achieved in 87% of all treated metastases. The median diameter of the irradiated lesions was 2.2 cm (range, 1-11.2 cm), the median irradiation dose was 21 Gy (range, 5-29.1 Gy). Median progression-free survival (PFS) after iBT was 3.4 months (range, 1.5-19.6 months), the median overall survival (OS) after iBT was 8.9 months (range, 3.1-29.3 months). Three major complications (CTCAE grade 3) occurred following iBT: three cases of liver abscess, which were successfully resolved with drainage and antibiotics. CONCLUSIONS: Overall, iBT is a safe procedure, which enables excellent rates of local tumor control and presents a viable anti-neoplastic treatment option as a salvage therapy for metastatic PDAC patients.

Treatment of metastatic, imatinib refractory, gastrointestinal stroma tumor with image-guided high-dose-rate interstitial brachytherapy.

PURPOSE: Evaluation of efficacy and safety of CT- or MRI-guided high-dose-rate interstitial brachytherapy (iBT) in the treatment of advanced, imatinib refractory, metastatic gastrointestinal stroma tumors (GISTs) was the objective of this retrospective study. METHODS AND MATERIALS: A cumulative number of 40 unresectable metastases (30 hepatic, 10 peritoneal) were treated with iBT in 10 selected patients with histologically proven GISTs. Six patients had peritoneal disease, and 5 patients were even progressing under sunitinib (second line)-thus iBT was applied as a salvage maneuver. IBT uses an interstitially introduced 192iridium source in a high-dose-rate irradiation regime to destroy vital cells in a single fraction. Response to treatment was assessed clinically and with acquisition of MRI/CT every 3 months. RESULTS: Local tumor control was reached in 97.5% of all treated metastases during a median time of 25 months-only one local relapse was observed during followup. The median diameter of the irradiated lesions was 2.4 cm (range 0.6-11.2 cm); a median dose of 15 Gy (range 6.7-21.96 Gy) was applied. The median progression-free survival after iBT was 6.8 (range 3.0-20.2) months; the median overall survival was 37.3 months (range 11.4-89.7). Two major complications (Common Terminology for Adverse Events grade 3) occurred following the intervention: local hemorrhage and pneumothorax, successfully dealt with by angiographic embolization and pleural drainage, respectively. CONCLUSIONS: In selected patients with metastatic, imatinib refractory GISTs, iBT safely enables high rates of local tumor control and presents an alternative, anti-neoplastic treatment option even in a salvage situation.