skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma

Abstract

Purpose: To report the outcomes and toxicities in patients treated with intensity-modulated radiotherapy (IMRT) for pancreatic adenocarcinoma. Methods and Materials: Forty-seven patients with pancreatic adenocarcinoma were treated with IMRT between 2003 and 2008. Of these 47 patients, 29 were treated adjuvantly and 18 definitively. All received concurrent 5-fluorouracil chemotherapy. The treatment plans were optimized such that 95% of the planning target volume received the prescription dose. The median delivered dose for the adjuvant and definitive patients was 50.4 and 54.0 Gy, respectively. Results: The median age at diagnosis was 63.9 years. For adjuvant patients, the 1- and 2-year overall survival rate was 79% and 40%, respectively. The 1- and 2-year recurrence-free survival rate was 58% and 17%, respectively. The local-regional control rate at 1 and 2 years was 92% and 80%, respectively. For definitive patients, the 1-year overall survival, recurrence-free survival, and local-regional control rate was 24%, 16%, and 64%, respectively. Four patients developed Grade 3 or greater acute toxicity (9%) and four developed Grade 3 late toxicity (9%). Conclusions: Survival for patients with pancreatic cancer remains poor. A small percentage of adjuvant patients have durable disease control, and with improved therapies, this proportion will increase. Systemic therapy offers themore » greatest opportunity. The present results have demonstrated that IMRT is well tolerated. Compared with those who received three-dimensional conformal radiotherapy in previously reported prospective clinical trials, patients with pancreatic adenocarcinoma treated with IMRT in our series had improved acute toxicity.« less

Authors:
; ; ;  [1]; ; ;  [2]; ; ;  [3];  [1];  [1]
  1. Department of Radiation Oncology, Stanford University, Stanford, CA (United States)
  2. Department of Medical Oncology, Stanford University, Stanford, CA (United States)
  3. Department of Surgical Oncology, Stanford University, Stanford, CA (United States)
Publication Date:
OSTI Identifier:
22056158
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 82; Journal Issue: 4; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; CARCINOMAS; CHEMOTHERAPY; CLINICAL TRIALS; DIAGNOSIS; PANCREAS; PATIENTS; PLANNING; RADIATION DOSES; RADIOTHERAPY; TOXICITY; URACILS

Citation Formats

Abelson, Jonathan A., Murphy, James D., Minn, Ann Yuriko, Chung, Melody, Fisher, George A., Ford, James M., Kunz, Pamela, Norton, Jeffrey A., Visser, Brendan C., Poultsides, George A., Koong, Albert C., and Chang, Daniel T., E-mail: dtchang@stanford.edu. Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma. United States: N. p., 2012. Web. doi:10.1016/J.IJROBP.2011.09.035.
Abelson, Jonathan A., Murphy, James D., Minn, Ann Yuriko, Chung, Melody, Fisher, George A., Ford, James M., Kunz, Pamela, Norton, Jeffrey A., Visser, Brendan C., Poultsides, George A., Koong, Albert C., & Chang, Daniel T., E-mail: dtchang@stanford.edu. Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma. United States. doi:10.1016/J.IJROBP.2011.09.035.
Abelson, Jonathan A., Murphy, James D., Minn, Ann Yuriko, Chung, Melody, Fisher, George A., Ford, James M., Kunz, Pamela, Norton, Jeffrey A., Visser, Brendan C., Poultsides, George A., Koong, Albert C., and Chang, Daniel T., E-mail: dtchang@stanford.edu. 2012. "Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma". United States. doi:10.1016/J.IJROBP.2011.09.035.
@article{osti_22056158,
title = {Intensity-Modulated Radiotherapy for Pancreatic Adenocarcinoma},
author = {Abelson, Jonathan A. and Murphy, James D. and Minn, Ann Yuriko and Chung, Melody and Fisher, George A. and Ford, James M. and Kunz, Pamela and Norton, Jeffrey A. and Visser, Brendan C. and Poultsides, George A. and Koong, Albert C. and Chang, Daniel T., E-mail: dtchang@stanford.edu},
abstractNote = {Purpose: To report the outcomes and toxicities in patients treated with intensity-modulated radiotherapy (IMRT) for pancreatic adenocarcinoma. Methods and Materials: Forty-seven patients with pancreatic adenocarcinoma were treated with IMRT between 2003 and 2008. Of these 47 patients, 29 were treated adjuvantly and 18 definitively. All received concurrent 5-fluorouracil chemotherapy. The treatment plans were optimized such that 95% of the planning target volume received the prescription dose. The median delivered dose for the adjuvant and definitive patients was 50.4 and 54.0 Gy, respectively. Results: The median age at diagnosis was 63.9 years. For adjuvant patients, the 1- and 2-year overall survival rate was 79% and 40%, respectively. The 1- and 2-year recurrence-free survival rate was 58% and 17%, respectively. The local-regional control rate at 1 and 2 years was 92% and 80%, respectively. For definitive patients, the 1-year overall survival, recurrence-free survival, and local-regional control rate was 24%, 16%, and 64%, respectively. Four patients developed Grade 3 or greater acute toxicity (9%) and four developed Grade 3 late toxicity (9%). Conclusions: Survival for patients with pancreatic cancer remains poor. A small percentage of adjuvant patients have durable disease control, and with improved therapies, this proportion will increase. Systemic therapy offers the greatest opportunity. The present results have demonstrated that IMRT is well tolerated. Compared with those who received three-dimensional conformal radiotherapy in previously reported prospective clinical trials, patients with pancreatic adenocarcinoma treated with IMRT in our series had improved acute toxicity.},
doi = {10.1016/J.IJROBP.2011.09.035},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 4,
volume = 82,
place = {United States},
year = 2012,
month = 3
}
  • We assessed dosimetric differences in pancreatic cancer radiotherapy via helical intensity-modulated radiotherapy (HIMRT), linac-based IMRT, and 3D-conformal radiation therapy (3D-CRT) with regard to successful plan acceptance and dose to critical organs. Dosimetric analysis was performed in 16 pancreatic cases that were planned to 54 Gy; both post-pancreaticoduodenectomy (n = 8) and unresected (n = 8) cases were compared. Without volume modification, plans met constraints 75% of the time with HIMRT and IMRT and 13% with 3D-CRT. There was no statistically significantly improvement with HIMRT over conventional IMRT in reducing liver V35, stomach V45, or bowel V45. HIMRT offers improved planningmore » target volume (PTV) dose homogeneity compared with IMRT, averaging a lower maximum dose and higher volume receiving the prescription dose (D100). HIMRT showed an increased mean dose over IMRT to bowel and liver. Both HIMRT and IMRT offer a statistically significant improvement over 3D-CRT in lowering dose to liver, stomach, and bowel. The results were similar for both unresected and resected patients. In pancreatic cancer, HIMRT offers improved dose homogeneity over conventional IMRT and several significant benefits to 3D-CRT. Factors to consider before incorporating IMRT into pancreatic cancer therapy are respiratory motion, dose inhomogeneity, and mean dose.« less
  • Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction externalmore » beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.« less
  • Intensity modulated radiotherapy (IMRT) provides an improvement in the conformality of radiotherapy dose distributions. Its application to photon radiotherapy for prostate adenocarcinoma is well established. A quality assurance tool for verifying photon IMRT treatment and the potential application of intensity modulation to neutron radiotherapy (IMNRT) to prostate cancer are investigated here. This study evaluates the use of an amorphous silicon flat panel imager for dose verification of photon IMRT fields. Various correction factors were developed to allow accurate estimation of the absorbed dose using this portal imager. The ratio of the dose measured with the portal imager to that measuredmore » using an ionization chamber was found to be 0.991{+-}0.026 for 23 measured IMRT fields. The study also yielded an accurate estimate of the relative beamlet intensity (fluence) at the plane of the detector. The raw difference between the relative beamlet intensity predicted by the EPID and that of the planning system for 23 IMRT fields was found to be -0.65{+-}2.69. These results demonstrate the capabilities of this imager as a robust IMRT quality assurance tool. An in-house optimization algorithm was used to optimize forward planned segments for the treatment of prostate cancer using IMNRT. The applicability of two different algorithms was investigated for IMNRT dose calculation, namely, the differential scatter air ratio (DSAR) and the finite size pencil beam (FSPB) algorithms. Measured profiles and absolute point doses were compared to results calculated by the treatment planning system. Dual ion-chamber measurements were performed to determine the individual neutron and gamma doses and to estimate the whole body dose equivalent. IMNRT plans retrospectively calculated for five prostate cancer patients provided dose distributions superior to conventional fast neutron therapy. When normalized to provide equivalent target coverage, the volume of the rectum and bladder receiving 80% of the prescription dose in the IMNRT plans was reduced by an average of 16% and 13%, respectively. Measured and calculated profiles for IMNRT fields matched to within {+-}3% with the exception of the penumbral region. Absolute point dose measurements also agreed with calculated doses to within {+-}3% at various points within the modulated dose distribution. Whole body dose estimates for IMNRT plans generated in this study were only an average of 16% higher than conventional fast neutron therapy and no significant variations in RBE are expected based on current measurements. Based on the results presented here, clinical implementation of IMNRT is currently achievable.« less
  • Adenocarcinoma of the prostate (CaP) is treated by surgery or irradiation, or both, with the type of treatment determined largely by local resources and referral patterns. Although the techniques employed by surgeons and radiation oncologists have improved and the morbidities associated with each have declined, for neither are they negligible. Epidemiologic data suggest that between 81% and 85% of men with CaP die of other causes, and a recent survey of untreated men arrived at a similar figure of 83%. Clinical reports, based upon postoperative tumor volume and grade, show that at least 5% of prostatectomies are unnecessary but themore » extent to which the other 95% benefit from this procedure is unclear. Some sense of these benefits is provided by a randomized, prospective clinical trial that compared prostatectomy with watchful waiting, and found only a 6% gain in overall survival after 8 years. These data call into question the promotion of highly complex and expensive radiation therapy equipment for the treatment of CaP when the prospects for increased life expectancies are at best small and unlikely to be distinguishable from results achieved by surgery, conventional external beam, or radioactive-seed implants.« less
  • Purpose: This study investigates the enhanced conformality of neutron dose distributions obtainable through the application of intensity modulated neutron radiotherapy (IMNRT) to the treatment of prostate adenocarcinoma. Methods and Materials: An in-house algorithm was used to optimize individual segments for IMNRT generated using an organ-at-risk (OAR) avoidance approach. A number of beam orientation schemes were investigated in an attempt to approach an optimum solution. The IMNRT plans were created retrospectively for 5 patients previously treated for prostate adenocarcinoma using fast neutron therapy (FNT), and a comparison of these plans is presented. Dose distributions and dose-volume histograms (DVHs) were analyzed andmore » plans were evaluated based on percentage volumes of rectum and bladder receiving 95%, 80%, and 50% (V{sub 95}, V{sub 80}, V{sub 50}) of the prescription dose, and on V{sub 60} for both the femoral heads and GM{sub muscle} group. Results: Plans were normalized such that the IMNRT DVHs for prostate and seminal vesicles were nearly identical to those for conventional FNT plans. Use of IMNRT provided reductions in rectum V{sub 95} and V{sub 80} of 10% (2-27%) and 13% (5-28%), respectively, and reductions in bladder V{sub 95} and V{sub 80} of 12% (3-26%) and 4% (7-10%), respectively. The average decrease in V{sub 60} for the femoral heads was 4.5% (1-18%), with no significant change in V{sub 60} for the GM{sub muscle} group. Conclusions: This study provides the first analysis of the application of intensity modulation to neutron radiotherapy. The IMNRT technique provides a substantial reduction in normal tissue dose in the treatment of prostate cancer. This reduction should result in a significant clinical advantage for this and other treatment sites.« less