Ritsuko U. Komaki, MD, FACR, FASTRO, Oral History Interview, January 23, 2019

Major Topics Covered: Impact of gender and culture on career, impact of marriage on careerhttps://openworks.mdanderson.org/mchv_interviewsessions/1251/thumbnail.jp

Ritsuko U. Komaki, MD, FACR, FASTRO, Oral History Interview, November 28, 2018

Major Topics Covered: Educational path: Japan, early experiences with US monitoring of bomb aftereffects Research: radiation dosage and fractionation and preservation of normal tissue, impact on breast and lung cancer, integration into multi-modal treatment;https://openworks.mdanderson.org/mchv_interviewsessions/1249/thumbnail.jp

Ritsuko U. Komaki, MD, FACR, FASTRO, Oral History Interview, February 21, 2019

Major Topics Covered: Views of MD Anderson culture, institutional change; experiences of administrative shifts within the Division of Radiation Oncology; critique of division culturehttps://openworks.mdanderson.org/mchv_interviewsessions/1252/thumbnail.jp

Ritsuko U. Komaki, MD, FACR, FASTRO, Oral History Interview, December 19, 2018

Major Topics Covered: Radiation oncology at MD Anderson: work with Gilbert Fletcher; evolution of radiation oncology; establishing the Proton Therapy Centerhttps://openworks.mdanderson.org/mchv_interviewsessions/1250/thumbnail.jp

Ritsuko U. Komaki, MD, FACR, FASTRO, Oral History Interview, November 6, 2018

Major Topics Covered: Personal background: experiences in Hiroshima, Japan, in aftermath of the atomic bomb Japanese versus American attitudes about radiation: impact on evolution of radiation therapy, radiation oncologyhttps://openworks.mdanderson.org/mchv_interviewsessions/1248/thumbnail.jp

Exclusion of elective nodal irradiation is associated with minimal elective nodal failure in non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Controversy still exists regarding the long-term outcome of patients whose uninvolved lymph node stations are not prophylactically irradiated for non-small cell lung cancer (NSCLC) treated with definitive radiotherapy. To determine the frequency of elective nodal failure (ENF) and in-field failure (IFF), we examined a large cohort of patients with NSCLC staged with positron emission tomography (PET)/computed tomography (CT) and treated with 3-dimensional conformal radiotherapy (3D-CRT) that excluded uninvolved lymph node stations.</p> <p>Methods</p> <p>We retrospectively reviewed the records of 115 patients with non-small cell lung cancer treated at our institution with definitive radiation therapy with or without concurrent chemotherapy (CHT). All patients were treated with 3D-CRT, including nodal regions determined by CT or PET to be disease involved. Concurrent platinum-based CHT was administered for locally advanced disease. Patients were analyzed in follow-up for survival, local regional recurrence, and distant metastases (DM).</p> <p>Results</p> <p>The median follow-up time was 18 months (3 to 44 months) among all patients and 27 months (6 to 44 months) among survivors. The median overall survival, 2-year actuarial overall survival and disease-free survival were 19 months, 38%, and 28%, respectively. The majority of patients died from DM, the overall rate of which was 36%. Of the 31 patients with local regional failure, 26 (22.6%) had IFF, 5 (4.3%) had ENF and 2 (1.7%) had isolated ENF. For 88 patients with stage IIIA/B, the frequencies of IFF, any ENF, isolated ENF, and DM were 23 (26%), 3 (9%), 1 (1.1%) and 36 (40.9%), respectively. The comparable rates for the 22 patients with early stage node-negative disease (stage IA/IB) were 3 (13.6%), 1(4.5%), 0 (0%), and 5 (22.7%), respectively.</p> <p>Conclusion</p> <p>We observed only a 4.3% recurrence of any ENF and a 1.7% recurrence of isolated ENF in patients with NSCLC treated with definitive 3D-CRT without prophylactic irradiation of uninvolved lymph node stations. Thus, distant metastasis and IFF remain the primary causes of treatment failure and cancer death in such patients, suggesting little value of ENI in this cohort.</p

Dosimetric Selection for Helical Tomotherapy Based Stereotactic Ablative Radiotherapy for Early-Stage Non-Small Cell Lung Cancer or Lung Metastases

Background No selection criteria for helical tomotherapy (HT) based stereotactic ablative radiotherapy (SABR) to treat early stage non-small cell lung cancer (NSCLC) or solitary lung metastases has been established. In this study, we investigate the dosimetric selection criteria for HT based SABR delivering 70 Gy in 10 fractions to avoid severe toxicity in the treatment of centrally located lesions when adequate target dose coverage is desired. Materials and Methods 78 HT-SABR plans for solitary lung lesions were created to prescribe 70 Gy in 10 fractions to the planning target volume (PTV). The PTV was set to have ≥95% PTV receiving 70 Gy in each case. The cases for which dose constraints for ≥1 OAR could not be met without compromising the target dose coverage were compared with cases for which all target and OAR dose constraints were met. Results There were 23 central lesions for which OAR dose constraints could not be met without compromising PTV dose coverage. Comparing to cases for which optimal HT-based SABR plans were generated, they were associated with larger tumor size (5.72±1.96 cm vs. 3.74±1.49 cm, p\u3c0.0001), higher lung dose, increased number of immediately adjacent OARs ( 3.45±1.34 vs. 1.66±0.81, p\u3c0.0001), and shorter distance to the closest OARs (GTV: 0.26±0.22 cm vs. 0.88±0.54 cm, p\u3c0.0001; PTV 0.19±0.18 cm vs. 0.48±0.36 cm, p = 0.0001). Conclusion Delivery of 70 Gy in 10 fractions with HT to meet all the given OAR and PTV dose constraints are most likely when the following parameters are met: lung lesions ≤3.78 cm (11.98 cc), ≤2 immediately adjacent OARs which are ≥0.45 cm from the gross lesion and ≥0.21 cm from the PTV

Patterns of Cardiac Perfusion Abnormalities After Chemoradiotherapy in Patients with Lung Cancer

Objective:We evaluated the prevalence of myocardial perfusion defects using myocardial perfusion imaging (MPI) after chemoradiation or radiation therapy (CRT/RT) in lung cancer patients and described their patterns in relation to tumor location.Methods:MPI in 44 patients who received RT for lung cancer and 44 control patients were compared. The two groups were comparable in risk factors for coronary artery disease. Data regarding tumor stage and location, interval between CRT/RT and MPI, and mean radiation dose to the heart was collected. The level of radiation delivered to the affected segments of the left ventricle versus the normal segments was compared using the isodose lines on the simulation computed tomography.Results:Considering all tumor locations, 8 patients (18%) demonstrated MPI defects after CRT/RT versus 9 (20%) in the controls. However, 7 of 18 patients (39%) with centrally located tumors in the CRT/RT group versus only 1 of 15 patients (7%) in the control group demonstrated MPI defect (p= 0.04). The defects in the CRT/RT group were in the anterior and septal segments while the defects were in different segments in the controls. The median interval between end of RT and MPI was 12.3 months. The affected segments in the CRT/RT group received a mean radiation dose of 39.6 versus 11.4 Gy (p = 0.003) to the normal segments.Conclusions:CRT/RT to centrally located lung tumors tends to cause anterior/septal MPI defects. Abnormal MPI segments in the CRT/RT group have received significantly higher radiation than normal segments

Critical Structure Sparing in Stereotactic Ablative Radiotherapy for Central Lung Lesions: Helical Tomotherapy vs. Volumetric Modulated Arc Therapy

Background Helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) are both advanced techniques of delivering intensity-modulated radiotherapy (IMRT). Here, we conduct a study to compare HT and partial-arc VMAT in their ability to spare organs at risk (OARs) when stereotactic ablative radiotherapy (SABR) is delivered to treat centrally located early stage non-small-cell lung cancer or lung metastases. Methods 12 patients with centrally located lung lesions were randomly chosen. HT, 2 & 8 arc (Smart Arc, Pinnacle v9.0) plans were generated to deliver 70 Gy in 10 fractions to the planning target volume (PTV). Target and OAR dose parameters were compared. Each technique’s ability to meet dose constraints was further investigated. Results HT and VMAT plans generated essentially equivalent PTV coverage and dose conformality indices, while a trend for improved dose homogeneity by increasing from 2 to 8 arcs was observed with VMAT. Increasing the number of arcs with VMAT also led to some improvement in OAR sparing. After normalizing to OAR dose constraints, HT was found to be superior to 2 or 8-arc VMAT for optimal OAR sparing (meeting all the dose constraints) (p = 0.0004). All dose constraints were met in HT plans. Increasing from 2 to 8 arcs could not help achieve optimal OAR sparing for 4 patients. 2/4 of them had 3 immediately adjacent structures. Conclusion HT appears to be superior to VMAT in OAR sparing mainly in cases which require conformal dose avoidance of multiple immediately adjacent OARs. For such cases, increasing the number of arcs in VMAT cannot significantly improve OAR sparing