Jean-Claude M Rwigema1, Allen M Chen1, Pin-Chieh Wang1, Jay M Lee2, Edward Garon3, Percy Lee4. 1. Department of Radiation Oncology, Ronald Reagan UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA. 2. Division of Thoracic Surgery, Ronald Reagan UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA. 3. Department of Medical Oncology, Ronald Reagan UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA. 4. Department of Radiation Oncology, Ronald Reagan UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, CA. Electronic address: percylee@mednet.ucla.edu.
Abstract
BACKGROUND: Patients with stage I non-small-cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT) do not undergo a staging mediastinoscopy, yet reported mediastinal recurrence rates appear lower than in patients undergoing surgical resection. We determined incidental SBRT doses to assess whether this could account for the low rates of recurrence. PATIENTS AND METHODS: Between March 2009 and September 2012, we reviewed cases of patients with inoperable lung tumors (n = 136) treated with SBRT at our institution. The SBRT regimen was 54 Gy in 3 fractions with positron emission tomography/computed tomography (PET/CT) staging. Incidental doses to the mediastinal lymph node stations (MLNSs), primary tumor control, locoregional (LR), distant control (DC), and overall survival (OS) rates were determined. RESULTS: Forty-six patients with stage I NSCLC met the inclusion criteria. The calculated median incidental SBRT dose to all MLNSs was < 5 Gy for the majority of patients (75%). At a median follow-up of 16.8 months (0.6-38.9 months), the 1- and 2-year primary tumor control, LR, OS, and DC rates were 100% and 95.5%, 97.4% and 81.7%, 88.1% and 81%, and 96.9% and 86.9%, respectively. Only 2 patients (4.9%) had mediastinal recurrence, with incidental SBRT doses to MLNSs that were similar to the rest of patients (P > .05). CONCLUSION: Low mediastinal recurrence rates in stage I NSCLC treated with SBRT validates the omission of staging mediastinoscopy. The low incidental dose to MLNSs does not seem to explain the low mediastinal recurrence in the majority of patients. Our findings also confirm that prophylactic radiation to the mediastinum is not necessary and support the hypothesis that local ablation of the primary lesion could indirectly affect subclinical nodal disease through unknown mechanisms.
BACKGROUND:Patients with stage I non-small-cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT) do not undergo a staging mediastinoscopy, yet reported mediastinal recurrence rates appear lower than in patients undergoing surgical resection. We determined incidental SBRT doses to assess whether this could account for the low rates of recurrence. PATIENTS AND METHODS: Between March 2009 and September 2012, we reviewed cases of patients with inoperable lung tumors (n = 136) treated with SBRT at our institution. The SBRT regimen was 54 Gy in 3 fractions with positron emission tomography/computed tomography (PET/CT) staging. Incidental doses to the mediastinal lymph node stations (MLNSs), primary tumor control, locoregional (LR), distant control (DC), and overall survival (OS) rates were determined. RESULTS: Forty-six patients with stage I NSCLC met the inclusion criteria. The calculated median incidental SBRT dose to all MLNSs was < 5 Gy for the majority of patients (75%). At a median follow-up of 16.8 months (0.6-38.9 months), the 1- and 2-year primary tumor control, LR, OS, and DC rates were 100% and 95.5%, 97.4% and 81.7%, 88.1% and 81%, and 96.9% and 86.9%, respectively. Only 2 patients (4.9%) had mediastinal recurrence, with incidental SBRT doses to MLNSs that were similar to the rest of patients (P > .05). CONCLUSION: Low mediastinal recurrence rates in stage I NSCLC treated with SBRT validates the omission of staging mediastinoscopy. The low incidental dose to MLNSs does not seem to explain the low mediastinal recurrence in the majority of patients. Our findings also confirm that prophylactic radiation to the mediastinum is not necessary and support the hypothesis that local ablation of the primary lesion could indirectly affect subclinical nodal disease through unknown mechanisms.
Authors: Ariel E Marciscano; Ali Ghasemzadeh; Thomas R Nirschl; Debebe Theodros; Christina M Kochel; Brian J Francica; Yuki Muroyama; Robert A Anders; Andrew B Sharabi; Esteban Velarde; Wendy Mao; Kunal R Chaudhary; Matthew G Chaimowitz; John Wong; Mark J Selby; Kent B Thudium; Alan J Korman; David Ulmert; Daniel L J Thorek; Theodore L DeWeese; Charles G Drake Journal: Clin Cancer Res Date: 2018-06-13 Impact factor: 12.531
Authors: Percy Lee; Billy W Loo; Tithi Biswas; George X Ding; Issam M El Naqa; Andrew Jackson; Feng-Ming Kong; Tamara LaCouture; Moyed Miften; Timothy Solberg; Wolfgang A Tome; An Tai; Ellen Yorke; X Allen Li Journal: Int J Radiat Oncol Biol Phys Date: 2019-04-05 Impact factor: 8.013
Authors: Pranshu Mohindra; Amit Sawant; Robert J Griffin; Narottam Lamichhane; Erina Vlashi; Meng Xu-Welliver; Michael Dominello; Michael C Joiner; Jay Burmeister Journal: J Appl Clin Med Phys Date: 2019-02-22 Impact factor: 2.102