Dosimetric benefits of dynamic wave arc over co-planar volumetric modulated radiotherapy for locally advanced pancreatic cancer

2020 ◽  
Author(s):  
Alshaymaa Abdelghaffar ◽  
Noriko Kishi ◽  
Ryo Ashida ◽  
Yukinori Matsuo ◽  
Hideaki Hirashima ◽  
...  

Abstract Background: Dose reduction to the duodenum is important to decrease gastrointestinal toxicities in patients with locally advanced pancreatic cancer (LAPC) treated with definitive radiotherapy. We aimed to investigate whether dynamic wave arc (DWA), a volumetric-modulated beam delivery technique with simultaneous gantry/ring rotations passing the waved trajectories, is superior to coplanar VMAT (co-VMAT) with respect to dose distributions in LAPC. Methods: DWA and co-VMAT plans were created for 13 patients with LAPC in the pancreatic head or body. The prescribed dose was 45.6 or 48 Gy in 15 fractions. The dose volume indices (DVIs) for the gross tumor volume, planning target volume (PTV), stomach, duodenum, small bowel, large bowel, kidney, liver, and spinal cord were compared between the corresponding plans. The values of the gamma passing rate, monitor unit (MU), and beam-on time were also compared. Results: DWA significantly reduced the volumes of the duodenum receiving 39, 42, and 45 Gy by 1.1, 0.8, and 0.2 cm3, respectively. However, the mean liver dose and maximal dose of the spinal cord were increased in DWA by 1.0 and 1.1 Gy, respectively. Meanwhile, there was no significant difference in the target volumes except for dose irradiated to 2% of PTV (PTV D2%) (110.4% in DWA vs. 109.6% in co-VMAT). There were also no significant differences in the other DVIs. Further, the gamma passing rate was similar in both plans. The MU and beam-on time increased in DWA by 31 MUs and 15 seconds, respectively. Conclusion: Compared with co-VMAT, DWA generated significantly lower duodenal doses with acceptable trade-offs in LAPC.

2020 ◽  
Author(s):  
Alshaymaa Abdelghaffar ◽  
Noriko Kishi ◽  
Ryo Ashida ◽  
Yukinori Matsuo ◽  
Hideaki Hirashima ◽  
...  

Abstract Background: Dose reduction to the duodenum is important to decrease gastrointestinal toxicities in patients with locally advanced pancreatic cancer (LAPC) treated with definitive chemoradiotherapy. We aimed to compare dynamic wave arc (DWA), a volumetric-modulated beam delivery technique with simultaneous gantry/ring rotations passing the waved trajectories, with coplanar VMAT (co-VMAT) with respect to dose distributions in LAPC. Methods: DWA and co-VMAT plans were created for 13 patients with LAPC in the pancreatic head or body. The prescribed dose was 45.6 or 48 Gy in 15 fractions. The dose volume indices (DVIs) for the gross tumor volume, planning target volume (PTV), stomach, duodenum, small bowel, large bowel, kidney, liver, and spinal cord were compared between the corresponding plans. The values of the gamma passing rate, monitor unit (MU), and beam-on time were also compared. Results: The volumes of the duodenum receiving 39, 42, and 45 Gy were significantly reduced to 2.8, 0.8 and 0.15 cm3 in DWA from 3.9, 1.6 and 0.34 cm3 in co-VMAT, respectively. The mean dose of the liver and D2cm3 of the planning volume for the spinal cord were significantly increased to 6.9 and 31.7 Gy in DWA from 5.9 and 30.2 Gy in co-VMAT, respectively. Meanwhile, there was no significant difference in the target volumes except for dose irradiated to 2% of PTV (110.4% in DWA vs. 109.6% in co-VMAT). There were also no significant differences in the other DVIs. Further, the gamma passing rate was 96.5% for DWA and 96.7% for co-VMAT (p = 0.65). The MU was significantly higher in DWA than in co-VMAT (620 vs. 589, p = 0.001), and there was a significant increase in the beam-on time (104 sec vs. 89 sec, p = 0.04).Conclusion: DWA was superior to co-VMAT regarding dose distributions in the duodenum in LAPC, albeit with slight increasing doses to the liver and the spinal cord and increasing MU and the beam delivery time. Further evaluation is needed to know how the dose differences would affect the clinical outcomes in chemoradiotherapy for LAPC.


2021 ◽  
Vol 11 ◽  
Author(s):  
Gabriella Rossi ◽  
Nicola Simoni ◽  
Salvatore Paiella ◽  
Roberto Rossi ◽  
Martina Venezia ◽  
...  

Background and ObjectiveTo assess the efficacy of a Risk-Adapted Ablative Radiotherapy (RAdAR) approach, after intensive induction chemotherapy, in patients with locally advanced pancreatic cancer (LAPC).Material and MethodsPatients with LAPC who received RAdAR following induction chemotherapy from January 2017 to December 2019 were included in this observational study. The RAdAR approach consisted of an anatomy- and simultaneous integrated boost (SIB)-based dose prescription strategy. RAdAR was delivered with stereotactic ablative radiation therapy (SAbR), administering 30 Gy in 5 fractions to the tumor volume (PTVt) and 50 Gy SIB (BED10 100 Gy) to the vascular involvement, or with (hypo-)fractionated ablative radiotherapy (HART) prescribing 50.4 Gy in 28 fractions to the PTVt, with a vascular SIB of 78.4 Gy (BED10 100 Gy). Primary end points were freedom from local progression (FFLP), overall survival (OS), and progression-free survival (PFS).ResultsSixty-four LAPC patients were included. Induction chemotherapy consisted of gemcitabine/nab-paclitaxel in 60.9% and FOLFIRINOX in 39.1% of cases. SAbR was used in 52 (81.2%) patients, and HART in 12 (18.8%). After RAdAR, surgery was performed in 17 (26.6%) patients. Median follow-up was 16.1 months. Overall local control (LC) rate was 78.1%, with no difference between resected and non-resected patients (2-year FFLP 75.3% vs 56.4%; p = 0.112). Median OS and PFS were 29.7 months and 8.7 months, respectively, for the entire cohort. Resected patients had a better median OS (not reached versus 26.1 months; p = 0.0001) and PFS (19 versus 5.6 months; p < 0.0001) compared to non-resected patients. In non-resected patients, no significant difference was found between SAbR and HART for median FFLP (28.1 versus 18.5 months; p = 0.614), OS (27.4 versus 25.3 months; p = 0.624), and PFS (5.7 versus 4.3 months; p = 0.486). One patient (1.6%) experienced acute grade 4 gastro-intestinal bleeding. No other acute or late grade ≥ 3 toxicities were observed.ConclusionsThe RAdAR approach, following intensive induction chemotherapy, is an effective radiation treatment strategy for selected LAPC patients, representing a promising therapeutic option in a multimodality treatment regimen.


2016 ◽  
Vol 101 (1-2) ◽  
pp. 58-63 ◽  
Author(s):  
Qinghui Fu ◽  
Ying Chen ◽  
Xiaohan Liu

This study aimed to investigate the clinical significance of palliative operation for carcinoma of pancreas between bypass surgery and interventional therapy. Most patients with locally advanced pancreatic cancer cannot undergo resection and show obstructive jaundice at presentation. Methods of palliation in these patients comprise biliary stent or surgical bypass. We retrospectively analyzed the clinical data of 53 patients who underwent palliative treatment with incurable locally advanced pancreatic ductal adenocarcinoma. This retrospective study compared morbidity, mortality, hospital stay, readmission rate, and survival in these patients. A total of 31 patients underwent biliary bypass surgery, and 22 had interventional therapy. There was no significant difference in the patients' basic condition before operation and in the 30-day mortality between surgical palliation and intervention. However, there were some differences in the early complications, survival time, successful biliary drainage, and recurrent jaundice. Through analysis of these clinical data and the published studies, we conclude that surgical bypass is a better effective palliative method for patients than biliary and duodenum stent with locally advanced pancreatic cancer. Patients need to be carefully selected in consideration of operative risk and perceived overall survival.


2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 209-209 ◽  
Author(s):  
C. H. Crane ◽  
J. S. Yordy ◽  
G. R. Varadhachary ◽  
W. Haque ◽  
R. A. Wolff ◽  
...  

209 Background: An autopsy study has identified DPC-4 as a potential biomarker of the pattern of disease spread in pancreatic cancer patients (Iacobuzio-Donahue et al, JCO, 2009). We sought to determine whether DPC-4 expression determined by immunohistochemistry (IHC) staining of primary tumor cytology specimens correlates with the clinical pattern of progression in patients with locally advanced pancreatic cancer (LAPC). Methods: LAPC patients with ECOG 0-1 PS were treated with gemcitabine (1000 mg/m2), oxaliplatin (100 mg/m2), and cetuximab for (500mg/m2) q2wks for 4 doses followed by XRT (50.4 Gy to the gross tumor only) with capecitabine (825 mg/m2 twice daily, days of radiation) and cetuximab on a multiinstitutional trial. Forty-one of 58 patients treated at our institution had cytology specimens suitable for IHC staining. The patterns of progression were determined based on radiographic studies and clinical symptoms. Findings were blinded from the IHC results. Patients were categorized as 1) local disease dominant, 2) distant disease dominant, 3) indeterminate pattern, and 4) no progression. The IHC scoring of DPC-4 was determined by an experienced cytopathologist who was blinded from the clinical data. Results: Median, 1yr and 3yr actuarial OS are 18.2 months, 67.2% and 18.5%. Dominant progression pattern was local (n=15), distant (n=14), indeterminate (n=8), and no progression (n=4). Intact DPC expression correlated with local dominant progression (11/15) and DPC-4 loss correlated with distant dominant progression (10/14), p=0.016. The median DM free survival rate was 18.0 for intact DPC-4 versus 12.5 mo for DPC-4 loss patients (p=NS). There was no significant difference in overall survival based on DPC-4 status. Conclusions: Determination of DPC-4 expression from cytology specimens is feasible. DPC-4 expression correlated with the pattern of progression and is consistent with previous autopsy data. DPC-4 expression does not appear to be predictive or prognostic. Prospective validation of DPC-4 as a biomarker of disease progression is warranted and may lead to personalized treatment strategies for patients with LAPC. [Table: see text]


Author(s):  
Amit Dang ◽  
Surendar Chidirala ◽  
Prashanth Veeranki ◽  
BN Vallish

Background: We performed a critical overview of published systematic reviews (SRs) of chemotherapy for advanced and locally advanced pancreatic cancer, and evaluated their quality using AMSTAR2 and ROBIS tools. Materials and Methods: PubMed and Cochrane Central Library were searched for SRs on 13th June 2020. SRs with metaanalysis which included only randomized controlled trials and that had assessed chemotherapy as one of the treatment arms were included. The outcome measures, which were looked into, were progression-free survival (PFS), overall survival (OS), and adverse events (AEs) of grade 3 or above. Two reviewers independently assessed all the SRs with both ROBIS and AMSTAR2. Results: Out of the 1,879 identified records, 26 SRs were included for the overview. Most SRs had concluded that gemcitabine-based combination regimes, prolonged OS and PFS, but increased the incidence of grade 3-4 toxicities, when compared to gemcitabine monotherapy, but survival benefits were not consistent when gemcitabine was combined with molecular targeted agents. As per ROBIS, 24/26 SRs had high risk of bias, with only 1/26 SR having low risk of bias. As per AMSTAR2, 25/26 SRs had critically low, and 1/26 SR had low, confidence in the results. The study which scored ‘low’ risk of bias in ROBIS scored ‘low confidence in results’ in AMSTAR2. The inter-rater reliability for scoring the overall confidence in the SRs with AMSTAR2 and the overall domain in ROBIS was substantial; ROBIS: kappa=0.785, SEM=0.207, p<0.001; AMSTAR2: kappa=0.649, SEM=0.323, p<0.001. Conclusion: Gemcitabine-based combination regimens can prolong OS and PFS but also worsen AEs when compared to gemcitabine monotherapy. The included SRs have an overall low methodological quality and high risk of bias as per AMSTAR2 and ROBIS respectively.


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