Christopher L. Hallemeier

Dr. Christopher L. Hallemeier

Department of Radiation Oncology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2017 in Radiotherapy and Oncology
Verified
Journal Article
Closed access
SLSteven Lin
Steven Lin
KMKenneth W. Merrell
Kenneth W. Merrell
JSJincheng Shen
Jincheng Shen
VVVivek Verma
Vivek Verma
ACArlene M. Correa
Arlene M. Correa
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier

1 January 2018 in Advances in Radiation Oncology
Verified
Journal Article
Open access
WBWilliam Breen
William Breen
IBIrina Bancos
Irina Bancos
WYWilliam F. Young
William F. Young
KBKeith C. Bible
Keith C. Bible
NLNadia N. Laack
Nadia N. Laack
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier
To evaluate the role of external beam radiation therapy (EBRT) for treatment of malignant paraganglioma (PGL) and pheochromocytoma (PCC). A retrospective review was performed of all patients with malignant PGL/PCC treated with EBRT at our institution between 1973 and 2015. Local control (LC) per treated lesion and overall survival were estimated using the Kaplan-Meier method. Toxicities were scored using the Common Toxicity Criteria for Adverse Events (AE), version 4. The cohort included 41 patients with 107 sites treated. Median (range) age at EBRT was 33 (11-80) years. Treatment intention was curative in 20 patients (30 lesions) and palliative in 21 patients (77 lesions). The primary tumor was PGL (63%) and PCC (37%). Previous local therapies were surgical resection (90%) and percutaneous ablation (19%). Indications for EBRT were local control (66%), pain (22%), or spinal cord compression (12%). Treatment site included bone (69%), soft tissue (30%), and liver (1%). Median (range) EBRT dose was 40 (6.5-70) Gy. Median biologic effective dose using α/β = 10 (BED10) was 53 (9-132). Median follow-up was 3.8 years (0.04-41.5), and mean follow-up was 9.7 years. Overall survival at 5 years was 65%: 79% for curative- and 50% for palliative-intention patients (P = .028). LC at 5 years was 81% for all lesions; 91% for lesions receiving BED10 ≥53, and 62% for lesions receiving BED10 <53 (P = .001). All 11 lesions treated with stereotactic body RT or radiosurgery had LC at a median of 3.0 (0.2-5.4) years. For the symptomatic lesions, symptoms improved in 94%. There were no acute grade ≥3 treatment-related AEs, including no hypertensive crises. Two patients developed a late grade ≥3 AE. EBRT is a useful treatment modality for malignant PGL and PCC. Higher RT dose was associated with improved LC.

11 May 2015 in Endoscopy
Verified
Journal Article
Closed access
PDF file
SMSaurabh Mukewar
Saurabh Mukewar
AGArjun Gupta
Arjun Gupta
TBTodd H Baron
Todd H Baron
GGGregory Gores
Gregory Gores
KFKeith Furutani
Keith Furutani
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier
Background and aim: Selected patients with unresectable perihilar cholangiocarcinoma can undergo neoadjuvant chemoradiotherapy followed by liver transplantation, which has been shown to improve survival. The aim of this study was to determine the feasibility and safety of endoscopic transpapillary insertion of nasobiliary tubes (NBTs) and brachytherapy catheters for high dose-rate (HDR) brachytherapy as part of this neoadjuvant chemoradiotherapy. Patients and methods: Medical records of patients undergoing biliary brachytherapy for hilar cholangiocarcinoma at the Mayo Clinic, Rochester were reviewed. Patients were treated with curative intent using external beam radiotherapy (4500 cGy), chemotherapy (5-FU or capecitabine), and HDR brachytherapy (930 – 1600 cGy in one to four fractions delivered over 1 – 2 days) prior to planned liver transplantation. Results: Between 2009 and 2013, 40 patients underwent biliary HDR brachytherapy via endoscopically placed NBTs (8.5 – 10 Fr). Patients had a median age of 55 years (range 28 – 68); 25 patients (62.5 %) had primary sclerosing cholangitis. Prior to therapy, 29 patients (72.5 %) had plastic stents, two (5 %) had metal stents, and nine (22.5 %) had no stents. Bilateral NBTs were placed in five patients (12.5 %). NBT/brachytherapy catheter displacement was seen in eight patients (20 %) – five intraprocedure and three post-procedure. A radiotherapy error and NBT kinking each occurred once. Post-procedure adverse events included: cholangitis (n = 5; 12.5 %), severe abdominal pain (n = 3; 7.5 %), duodenopathy (n = 3; 7.5 %), gastropathy (n = 3; 7.5 %), and both duodenopathy and gastropathy (n = 2; 5 %). Conclusion: HDR biliary brachytherapy administered via endoscopically placed NBTs and brachytherapy catheters is technically feasible and appears reasonably safe in selected patients with unresectable perihilar cholangiocarcinoma.

1 May 2020 in Radiotherapy and Oncology
Verified
Journal Article
Closed access
KJKrishan R. Jethwa
Krishan R. Jethwa
SJSamuel Jang
Samuel Jang
TMTrey C. Mullikin
Trey C. Mullikin
WHWilliam S. Harmsen
William S. Harmsen
MPMolly M. Petersen
Molly M. Petersen
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier

1 July 2021 in Advances in Radiation Oncology
Verified
Journal Article
Open access
RBRonik S. Bhangoo
Ronik S. Bhangoo
TMTrey C. Mullikin
Trey C. Mullikin
JAJonathan B. Ashman
Jonathan B. Ashman
TCTiffany W. Cheng
Tiffany W. Cheng
MGMichael A. Golafshar
Michael A. Golafshar
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier
Our purpose was to assess the safety and efficacy of intensity modulated proton therapy (IMPT) for the treatment of hepatocellular carcinoma (HCC). A retrospective review was conducted on all patients who were treated with IMPT for HCC with curative intent from June 2015 to December 2018. All patients had fiducials placed before treatment. Inverse treatment planning used robust optimization with 2 to 3 beams. The majority of patients were treated in 15 fractions (n = 30, 81%, 52.5-67.5 Gy, relative biological effectiveness), whereas the remainder were treated in 5 fractions (n = 7, 19%, 37.5-50 Gy, relative biological effectiveness). Daily image guidance consisted of orthogonal kilovoltage x-rays and use of a 6° of freedom robotic couch. Outcomes (local control, progression free survival, and overall survival) were determined using Kaplan-Meier methods. Thirty-seven patients were included. The median follow-up for living patients was 21 months (Q1-Q3, 17-30 months). Pretreatment Child-Pugh score was A5-6 in 70% of patients and B7-9 in 30% of patients. Nineteen patients had prior liver directed therapy for HCC before IMPT. Eight patients (22%) required a replan during treatment, most commonly due to inadequate clinical target volume coverage. One patient (3%) experienced a grade 3 acute toxicity (pain) with no recorded grade 4 or 5 toxicities. An increase in Child-Pugh score by ≥ 2 within 3 months of treatment was observed in 6 patients (16%). At 1 year, local control was 94%, intrahepatic control was 54%, progression free survival was 35%, and overall survival was 78%. IMPT is safe and feasible for treatment of HCC.

1 July 2018 in Advances in Radiation Oncology
Verified
Journal Article
Open access
KJKrishan R. Jethwa
Krishan R. Jethwa
ETErik J. Tryggestad
Erik J. Tryggestad
TWThomas J. Whitaker
Thomas J. Whitaker
BGBroc T. Giffey
Broc T. Giffey
BKBret D. Kazemba
Bret D. Kazemba
Christopher L. HallemeierChristopher L. Hallemeier
Christopher L. Hallemeier
Pencil-beam scanning intensity modulated proton therapy (IMPT) may allow for an improvement in the therapeutic ratio compared with conventional techniques of radiation therapy delivery for pancreatic cancer. The purpose of this study was to describe the clinical implementation of IMPT for intact and clinically localized pancreatic cancer, perform a matched dosimetric comparison with volumetric modulated arc therapy (VMAT), and report acute adverse event (AE) rates and patient-reported outcomes (PROs) of health-related quality of life. Between July 2016 and March 2017, 13 patients with localized pancreatic cancer underwent concurrent capecitabine or 5-fluorouracil-based chemoradiation therapy (CRT) utilizing IMPT to a dose of 50 Gy (radiobiological effectiveness: 1.1). A VMAT plan was generated for each patient to use for dosimetric comparison. Patients were assessed prospectively for AEs and completed PRO questionnaires utilizing the Functional Assessment of Cancer Therapy-Hepatobiliary at baseline and upon completion of CRT. There was no difference in mean target coverage between IMPT and VMAT (P > .05). IMPT offered significant reductions in dose to organs at risk, including the small bowel, duodenum, stomach, large bowel, liver, and kidneys (P < .05). All patients completed treatment without radiation therapy breaks. The median weight loss during treatment was 1.6 kg (range, 0.1-5.7 kg). No patients experienced grade ≥3 treatment-related AEs. The median Functional Assessment of Cancer Therapy-Hepatobiliary scores prior to versus at the end of CRT were 142 (range, 113-163) versus 136 (range, 107-173; P = .18). Pencil-beam scanning IMPT was feasible and offered significant reductions in radiation exposure to multiple gastrointestinal organs at risk. IMPT was associated with no grade ≥3 gastrointestinal AEs and no change in baseline PROs, but the conclusions are limited due to the patient sample size. Further clinical studies are warranted to evaluate whether these dosimetric advantages translate into clinically meaningful benefits.