PURPOSE:The ablated tumor ghost can be visually distinguished on MR images after ablation. This retrospective study aimed to assess the performance of tumor ghost on post-ablation contrast-enhanced MRI with excellular contrast agent gadolinium-DTPA in evaluating the ablative margin of hepatocellular carcinoma (HCC) after microwave ablation (MWA). METHOD:315 HCC lesions less than 5 cm in 287 patients completely treated by MWA were enrolled in the study. The tumor ghost was characterized as a lower signal intensity area than the surrounding tissues of the ablation zone on T1WI imaging. The ablation margin (AM) status was classified into AM0 (＞5mm) and AM1 (＜5mm) according to the minimum distance between the tumor ghost and ablated zone. Inter-observer agreement between two radiologists on the AM assessment was analyzed using the Cohen κ coefficient. Multivariate analysis using Cox proportional hazard model was performed to investigate independent risk factors for LTP. RESULTS:175 and 140 tumors were evaluated as AM0 and AM1 through tumor ghost. The inter-observer agreement level between two radiologists for assessment of AM was good (κ coefficient = 0.752, 95 % confidence interval: 0.679-0.825, p < 0.001). The mediate follow-up period was 32.2 months (range 3.0-60.8 months). The incidence of LTP in the AM0 lesions and AM1 lesions was 6.3 % (11/175) and 20.0 % (28/140), respectively. AM status was identified as an independent prognostic factor for LTP (HR 3.057, 95 % CI, 1.445-6.470, p = 0.003). CONCLUSIONS:The assessment of the AM by tumor ghost on post-ablation MRI is an accurate and efficiently method for evaluating the completeness of microwave ablation for hepatocellular carcinoma.

The aim of this study was to evaluate the safety and clinical efficacy of a combined preoperative regimen consisting of volumetric modulated arc therapy-simultaneous integrated boost and capecitabine chemotherapy for distal rectal cancer. A total of 26 patients with locally advanced distal rectal cancer were enrolled from March 2015 to May 2016. The radiation dose fractionation was 58.75 Gy/25 fractions (2.35 Gy/fraction) for rectal tumor and pelvic lymph node metastasis and 50 Gy/25 fractions for pelvic lymph node stations, accompanied with simultaneous capecitabine chemotherapy. Completion of the simultaneous chemotherapy was ensued by 1 week of rest and then another cycle of induction chemotherapy with capecitabine. A radical rectal cancer surgery was performed 6 to 8 weeks after the simultaneous chemoradiotherapy. The primary end points were the complete pathological response rate and the postoperative sphincter preservation rate. All 26 patients completed the neoadjuvant chemoradiotherapy, among which 25 received surgical treatment. The postoperative complete pathological response rate was as high as 32% (8/25), while the sphincter preservation rate was 60% (15/25), the overall tumor/node (T/N) downstaging rate was 92% (23/25), and the R0 resection rate was 100%. During the chemoradiation, the most common adverse events were grade 1 and 2; grade 3 radiodermatitis occurred in 2 cases but no occurrence of acute adverse events occurred that were grade 4 and above. After the surgery, there was one case of ureteral injury and one case of intestinal obstruction, but no perioperative deaths occurred. In conclusion, the chemoradiation regimen of preoperative volumetric modulated arc therapy-simultaneous integrated boost (VMAT-SIB58.75Gy) and a single cycle of induction chemotherapy with capecitabine for patients with distal rectal cancer is safe and feasible with a satisfactory complete pathological response rate, sphincter preservation rate, and R0 resection rate.

Objective To evaluate the feasibility and clinical efficacy of preoperative simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) combined with neoadjuvant chemotherapy of capecitabine in patients with locally-advanced low rectal cancer.Methods Between 2015 and 2016,26 patients admitted to 301 Hospital who were diagnosed with locally-advanced low rectal cancer,which was located within 5 cm from the anal verge,were enrolled in this investigation.Dose fractionation pattern was delivered:58.75 Gy in 25 fractions (2.35 Gy/fraction) for rectal cancer and lymph node metastasis and 50 Gy in 25 fractions for the pelvic lymphatic drainage area and simultaneously combined with capecitabine chemotherapy (825 mg/m2,bid d 1-5 weekly).One cycle of capecitabine (1 250 mg/m2,twice daily,d 1-14)was given at one week after the completion of chemoradiotherapy (CRT).Total mesorectal excision (TME)was performed at 6 to 8 weeks after the completion of CRT.The primary endpoints included pathological complete response rate (ypCR) and sphincter-preserving rate.The secondary endpoints included acute toxicity,tumor downstaging rate and postoperative complications.Results Twenty-six patients successfully completed neoadjuvant CRT,25 of them underwent surgical resection and one patient failed to receive surgery due to pxrianal edema.Postoperative ypCR rate was 32％ (8/25),the sphincter-preserving rate was 60％ (15/25),the tumor downstaging rate was 92％ (23/25) and the R0 resection rate was 100％.During the period of CRT,grade 1 and 2 adverse events occurred in 24 patients,grade 3 radiation dermatitis was noted in 2 cases.No ≥ grade 4 acute adverse event was observed.Postoperative complications included ureteral injury in one case and intestinal obstruction in one patient.Conclusions Preoperative SIB-IMRT combined with neoadjuvant chemotherapy of capecitabine is a feasible and safe treatment for patients with locallyadvanced low rectal cancer,which yields expected ypCR rate,R0 resection rate and sphincter-preserving rate.Nevertheless,the long-term clinical benefits remain to be elucidated.Clinical Trial Registry Chinese Clinical Trial Registry,registration number:ChiCTR-ONC-12002387.

Objective To investigate the feasibility, safety, and short?term efficacy of preoperative capecitabine and simultaneous integrated boost intensity?modulated radiotherapy ( SIB?IMRT ) followed by one cycle of neoadjuvant capecitabine in patients with locally advanced rectal cancer ( LARC ) . Methods From March 2015 to April 2016, a total of 37 patients with LARC were enrolled in this study. They received capecitabine (825 mg/m2 orally twice daily for 5 weeks, days 1?5 weekly) and SIB?IMRT (5875 Gy in 25 fractions for rectal lesion and positive lymph nodes and 5000 Gy in 25 fractions for pelvic lymphatic drainage area) . After the concurrent chemoradiotherapy, they were allowed to rest for one week. And then they received one cycle of induction chemotherapy with capecitabine (1250 mg/m2 orally twice daily for 14 days) . And total mesorectal excision ( TME ) was scheduled at 6?8 weeks after the concurrent chemoradiotherapy. The primary endpoint was pathologic complete response ( pCR) rate, and the secondary endpoints included tumor and nodal ( TN) downstaging rate, the rate of sphincter?preserving surgery, and adverse events. Results All the 37 patients successfully received the preoperative concurrent chemoradiotherapy. Only 32 patients underwent the surgical resection, 4 patients refused surgery due to symptom relief, and 1 patient delayed surgery due to perianal edema after radiotherapy. The pCR rate was 34%(11/32);the TN downstaging rate was 91%(29/32);the R0 resection rate was 100%;24 patients ( 75%) underwent the sphincter?preserving surgery. During the period of chemoradiotherapy, most of the patients experienced grade 1/2 acute adverse events and grade 3/4 adverse events occurred in 3 patients. The postoperative complications included ureteral injury (1 patient) and intestinal obstruction (1 patient), and no death occurred in the perioperative period. Conclusions For patients with LARC, preoperative SIB?IMRT combined with one cycle of capecitabine followed by TME is safe and feasible, and has good short?term efficacy and mild acute adverse events.

Objective To investigate the dosimetric feasibility of volumetric modulated arc therapy (VMAT)with a simultaneous integrated boost(SIB-VMAT58.75 Gy)for preoperative chemoradiotherapy in patients with locally advanced rectal cancer(LARC),and to provide a basis for clinical practice.Methods Nine patients with stage Ⅱ-Ⅲ rectal cancer who underwent preoperative concurrent chemoradiotherapy were involved in the study,and two plans were performed for each patient:SIB-VMAT58.75 Gy and VMAT50.00 Gy. For the SIB-VMAT58.75 Gy plan,the prescribed dose was 58.75 Gy(2.35 Gy/fraction)for the local rectal tumor and positive lymph nodes(GTV 58.75 Gy),and 50 Gy(2 Gy/fraction)for the regions at high risk of harboring microscopic disease(pelvic lymphatic drainage area)(PTV 50Gy).For the VMAT50.00 Gy plan,the prescribed dose was 50 Gy(2 Gy/fraction)for the regions at high risk of harboring microscopic disease(pelvic lymphatic drainage area)without a boost. The conformity index(CI),homogeneity index (HI),and dose for target areas and organs at risk(OAR)were assessed according to the dose-volume histogram. The paired t-test or nonparametric rank test was used to compare the differences between the two plans. Results Both plans met the prescription goal for PTV dose coverage. There was no significant difference in CI for the PTV between the two plans(1.0±0.0 vs. 1.0±0.0,P>0.05).The SIB-VMAT58.75 Gy plan had a worse HI than the VMAT50.00 Gy plan(0.2± 0.2 vs. 0.1± 0.0,P<0.05).There was no significant difference in V10-V50of the small intestine,bladder,femoral heads,and pelvis between the two plans(P>0.05),but D 2 cm3of the small intestine was significantly higher in the SIB-VMAT58.75 Gy plan than in the VMAT50.00 Gy plan(P=0.038). Conclusions The SIB-VMAT58.75 Gy plan for LARC achieves required target volume dose coverage and OAR dose constraints,which is safe and feasible in terms of dosimetry,and its clinical efficacy and adverse effects need further evaluation.