Incidence and Risk Factors of Symptomatic Radiation Pneumonitis in Non-Small-Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy and Consolidation Durvalumab.

INTRODUCTION: Data on the risk factors for symptomatic radiation pneumonitis (RP) in non-small-cell lung cancer (NSCLC) patients treated with concurrent chemoradiotherapy (CCRT) and consolidation durvalumab are limited; we aimed to investigate these risk factors. MATERIALS AND METHODS: This multicenter retrospective study, conducted at 15 institutions in Japan, included patients who were ≥20 years of age; who started definitive CCRT for NSCLC between July 1, 2018, and July 31, 2019; and who then received durvalumab. The primary endpoint was grade 2 or worse (grade 2+) RP. RESULTS: In the 146 patients analyzed, the median follow-up period was 16 months. A majority of the patients had stage III disease (86%), received radiation doses of 60 to 66 Gy equivalent in 2-Gy fractions (93%) and carboplatin and paclitaxel/nab-paclitaxel (77%), and underwent elective nodal irradiation (71%) and 3-dimensional conformal radiotherapy (75%). RP grade 2 was observed in 44 patients (30%); grade 3, in four patients (3%); grade 4, in one patient (1%); and grade 5, in one patient (1%). In the multivariable analysis, lung V20 was a significant risk factor, whereas age, sex, smoking history, irradiation technique, and chemotherapy regimen were not. The 12-month grade 2+ RP incidence was 34.4% (95% confidence interval [CI], 26.7%-42.1%); the values were 50.0% (95% CI, 34.7%-63.5%) and 27.1% (95% CI, 18.8%-36.2%) in those with lung V20 ≥ 26% and < 26%, respectively (P = .007). CONCLUSION: The incidence of grade 2+ RP was relatively high in this multicenter real-world study, and its risk increased remarkably at elevated lung V20. Our findings can aid in RP risk prediction and the safe radiotherapy treatment planning.

[Propofol Infusion Syndrome Treated Successfully by Early Diagnosis].

Propofol infusion syndrome (PRIS) is one of the severe complications which occur during continuous venous infusion of propofol, and has a high mortality rate. It is featured by high fever, oliguria, myogloblin urine, acute renal failure, hepatomegaly, fatty liver, and so on. We have experienced a case of PRIS who was saved by prompt changing of sedatives from propofol to midazolam and dexmedetomidine. The patient was an 82-year-old man, who underwent off-pump coronary bypass grafting due to effort angina pectoris. After the operation, he suffered from continuous high fever over 38 ℃, acute renal impairment, and high level of creatine kinase (CK) without CK-MB increment, suggesting PRIS. We promptly changed sedatives from propofol to midazolam and dexmedetomidine, then the patient recuperated from these abnormalities. It is strongly suggested that meticulous observation is necessary during propofol infusion.

Application and limitation of radiomics approach to prognostic prediction for lung stereotactic body radiotherapy using breath-hold CT images with random survival forest: A multi-institutional study.

PURPOSE: To predict local recurrence (LR) and distant metastasis (DM) in early stage non-small cell lung cancer (NSCLC) patients after stereotactic body radiotherapy (SBRT) in multiple institutions using breath-hold computed tomography (CT)-based radiomic features with random survival forest. METHODS: A total of 573 primary early stage NSCLC patients who underwent SBRT between January 2006 and March 2016 and met the eligibility criteria were included in this study. Patients were divided into two datasets: training (464 patients in 10 institutions) and test (109 patients in one institution) datasets. A total of 944 radiomic features were extracted from manually segmented gross tumor volumes (GTVs). Feature selection was performed by analyzing inter-segmentation reproducibility, GTV correlation, and inter-feature redundancy. Nine clinical factors, including histology and GTV size, were also used. Three prognostic models (clinical, radiomic, and combined) for LR and DM were constructed using random survival forest (RSF) to deal with total death as a competing risk in the training dataset. Robust models with optimal hyper-parameters were determined using fivefold cross-validation. The patients were dichotomized into two groups based on the median value of the patient-specific risk scores (high- and low-risk score groups). Gray's test was used to evaluate the statistical significance between the two risk score groups. The prognostic power was evaluated by the concordance index with the 95% confidence intervals (CI) via bootstrapping (2000 iterations). RESULTS: The concordance indices at 3 yr of clinical, radiomic, and combined models for LR were 0.57 [CI: 0.39-0.75], 0.55 [CI: 0.38-0.73], and 0.61 [CI: 0.43-0.78], respectively, whereas those for DM were 0.59 [CI: 0.54-0.79], 0.67 [CI: 0.54-0.79], and 0.68 [CI: 0.55-0.81], respectively, in the test dataset. The combined DM model significantly discriminated its cumulative incidence between high- and low-risk score groups (P < 0.05). The variable importance of RSF in the combined model for DM indicated that two radiomic features were more important than other clinical factors. The feature maps generated on the basis of the most important radiomic feature had visual difference between high- and low-risk score groups. CONCLUSIONS: The radiomics approach with RSF for competing risks using breath-hold CT-based radiomic features might predict DM in early stage NSCLC patients who underwent SBRT although that may not have potential to predict LR.

A case of giant right coronary artery aneurysm due to IgG4-related disease.

A man diagnosed with immunoglobulin G4 (IgG4)-related disease at the age of 65 years underwent abdominal aortic replacement due to an abdominal aortic aneurysm. In the same hospitalization period, a small coronary artery aneurysm was noticed. He was treated with corticosteroids and his serum IgG levels returned to normal. After experiencing sudden chest pain at age 74 years, coronary angiography showed that the size of the aneurysm had increased dramatically. He underwent coronary artery bypass graft and coronary artery resection without using cardiopulmonary bypass. Thus, we conclude that observation of aneurysms in patients with IgG4-related disease is important, even under corticosteroid therapy.

[Risk Factors for Early Progression of Carotid Stenosis after Cervical Radiation Therapy].

OBJECTIVE: Carotid stenosis may occur as a late complication following cervical radiation therapy(RT);however, it may also progress in the early post-RT period. This study aimed to characterize the clinical features associated with the early progression of post-RT carotid stenosis. METHODS: We retrospectively reviewed clinical records of 30 patients who had undergone unilateral or bilateral cervical RT between January 2010 and November 2014. We analyzed the pre- and post-RT stenosis of their carotid arteries using contrast-enhanced computed tomography images. The arteries were classified as progressive or non-progressive according to the presence or absence of stenosis progression within five years after RT. Using univariate and multivariate analyses, we evaluated the following potential clinical risk factors:age;gender;history of hypertension, hyperlipidemia, diabetes mellitus, coronary artery disease, or smoking habit;antiplatelet or statin use;radiation dose;and prior presence of carotid stenosis before RT. RESULTS: In total, we reviewed 57 irradiated carotid arteries and identified 9 with early post-RT progression. Carotid stenosis before RT was observed in 88.9% of arteries in the progressive group but only 2% of arteries in the non-progressive group and it predicted progression(univariate and multiple logistic regression analyses, p<0.0001). No other clinical characteristics had a significant association with the progression of carotid stenosis. CONCLUSION: Prior presence of carotid stenosis may be a risk factor for its early progression after RT. Pre-RT screening of cervical arteries may be useful, and strict management of carotid stenosis is critical in patients with cervical radiation therapy.

[Therapeutic Effects of Low-Dose Bevacizumab for the Treatment of Recurrent Brain Metastases].

OBJECTIVE: Molecularly targeted therapy has been adopted to treat a number of cancers. Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor, is a representative agent used in molecularly targeted therapeutic regimens. However, the therapeutic effect of bevacizumab for the treatment of brain metastases remains unknown. We report the clinical effects of low dose bevacizumab(≤2.5mg/kg/week)to treat recurrent brain metastases. METHODS: We retrospectively analyzed patients with brain metastases who had been treated with bevacizumab between 2012 and 2016 at our institution. We identified clinical characteristics, including age, gender, primary tumor site, dose of bevacizumab, therapeutic and adverse effects, and magnetic resonance imaging results. The lesions were assessed with the RECIST criteria based on gadolinium-enhanced T1-weighted, T2-weighted, and FLAIR images. Statistical analysis was performed using t-test and Fisher's exact test. RESULTS: The cohort comprised 26 patients(8 men, 18 women)with a median age of 61 years(range 39-82 years). There were no significant clinical differences between the low dose and non-low dose groups. Patients in the low dose group did not report any adverse effects from bevacizumab. Three patients with brain metastases from colon cancer are illustrated to report the clinical course of low dose bevacizumab. CONCLUSION: Low dose bevacizumab may be a safe and effective therapeutic option to treat recurrent brain metastases from bevacizumab-sensitive cancers.

The Use of External-beam Radiotherapy for Muscle-invasive Bladder Cancer in Elderly or Medically-fragile Patients.

AIM: To evaluate the clinical results of external-beam radiotherapy (EBRT) for muscle-invasive bladder cancer (MIBC) in elderly or medically-fragile patients. PATIENTS AND METHODS: Twenty-five consecutive patients with MIBC (cT2-4N0-1M0) receiving EBRT were retrospectively analyzed. Their median age was 82 years. Radiotherapy median dose was 60 Gy administered in 30 fractions. RESULTS: Median follow-up period was 14.7 months. Median overall survival (OS) and progression-free survival (PFS) were 14.7 months and 7.8 months, respectively. The OS, cause-specific survival (CSS), and PFS rates at 1-year were 56.0%, 68.5%, and 40.0%, respectively. The local progression-free rates (LPFR) at 6 months and 1 year were 89.3% and 59.5%, respectively. Performance status 3 was a significantly unfavorable factor for OS, CSS, and progression-free survival; clinical N stage was a significantly unfavorable factor for progression-free survival; and lower irradiation dose (≤50.4 Gy) was a significantly unfavorable factor for LPFR. CONCLUSION: EBRT for elderly or medically-fragile patients is feasible, and achieves acceptable local progression-free status.

Aortic valve replacement after coronary artery bypass grafting with the in situ right gastroepiploic artery to the occluded right coronary artery using a temporary vein graft for cardioplegia.

BACKGROUND: The operation of aortic valve replacement (AVR) after CABG is a technically challenging procedure in respect to dissection of living grafts from its surrounding tissue, myocardial protection, and so on, especially that procedure to patients with living in situ functional arterial grafts to occluded native coronary arteries has a special problem in regard to myocardial protection because myocardial blood supply originates from various arteries including the left internal thoracic artery (LITA), the right internal thoracic artery (RITA), and the right gastroepiploic artery (GEA); hence, adequate myocardial protection should be fastidiously considered. CASE PRESENTATION: A 68-year-old woman, who underwent CABG comprised of the in situ LITA to the LAD, the in situ GEA to the RCA, and the saphenous vein graft (SVG) to the obtuse marginal branch of the left circumflex artery (LCX) to the triple vessel coronary disease 9 years before, was referred to our hospital due to the aortic valve stenosis. CONCLUSION: We successfully underwent an aortic valve operation to a patient with a functioning LITA to the occluded left anterior descending artery and a GEA to the right coronary artery (RCA) by using a temporary vein graft to the RCA for the infusion of cardioplegic solution in addition to the conventional antegrade and retrograde cardioplegic infusions with ice slush topical cooling.

Immunoglobulin G4-related multiple cardiovascular lesions successfully treated with a combination of open surgery and corticosteroid therapy.

Immunoglobulin G4-related disease, a newly emerging systemic autoimmune disorder, can potentially involve the cardiovascular system. The standard treatment for immunoglobulin G4-related cardiovascular disease has not been established. We encountered a very rare case of an immunoglobulin G4-related inflammatory abdominal aortic aneurysm coexisting with a coronary artery aneurysm and periarteritis. The patient underwent surgical resection for the abdominal aortic aneurysm, followed by successful corticosteroid therapy for the coronary artery lesions. This is the first report of steroid-sensitive immunoglobulin G4-related coronary artery disease. A carefully planned treatment strategy for the multiple cardiovascular lesions was invaluable in the present case.

Asymmetric synthesis of the carbon-14-labeled selective glucocorticoid receptor modulator using cinchona alkaloid catalyzed addition of 6-bromoindole to ethyl trifluoropyruvate.

We describe in this study the asymmetric synthesis of radioisotope (RI)-labeled selective glucocorticoid receptor modulator. This synthesis is based on optimization of the cinchona alkaloid catalyzed addition of 6-bromoindole to ethyl trifluoropyruvate and Negishi coupling of zinc cyanide to the 6-bromoindole moiety. [¹4C] Labeled (-)-{4-[(1-{2-[6-cyano-1-(cyclohexylmethyl)-1H-indol-3-yl]-3,3,3-trifluoro-2-hydroxypropyl}piperidin-4-yl)oxy]-3-methoxyphenyl}acetic acid (-)-1 was synthesized successfully with high enantioselectivity (>99% ee) and sufficient radiochemical purity.

One-stage operation for esophageal perforation of a thoracic aortic aneurysm.

The patient was a 65-year-old man. Preoperative computed tomography showed a ruptured thoracic aortic aneurysm that formed a submucosal hematoma in the thoracic esophagus with perforation near the esophageal-cardiac junction. A one-stage operation was performed. The aortic arch and proximal descending aorta were replaced with rifampicin-soaked synthetic grafts, followed by subtotal esophagectomy with primary reconstruction using a gastric tube. His early postoperative course was uneventful, and he started oral intake on postoperative day (POD) 15; however, dysphagia occurred on POD 20, and an esophageal fistula and mediastinitis developed more than 1 month after the operation. The patient recovered from mediastinitis after 4 months of mediastinal drainage and administration of antibiotics. Thus, a one-stage operation for esophageal perforation of a ruptured thoracic aortic aneurysm with primary esophageal reconstruction is possible in selected patients. Care must be taken to avoid postoperative compression of the reconstructed esophagus by a mediastinal hematoma.

Long-term outcomes of three-dimensional conformal radiation therapy combined with neoadjuvant hormonal therapy in Japanese patients with locally advanced prostate cancer.

BACKGROUND: The outcomes of three-dimensional conformal radiation therapy (3D-CRT) combined with neoadjuvant hormonal therapy (NAHT) in Japanese patients with locally advanced prostate cancer who initiated salvage hormonal therapy (SHT) at a relatively early phase were evaluated. METHODS: Between April 1998 and April 2003, 70 Japanese patients with T3N0M0 prostate cancer who received radical 3D-CRT treatment were evaluated. The median age, initial prostate-specific antigen (PSA) level, and duration of NAHT were 73 years old, 26.3 ng/ml, and 4 months, respectively. Seventy grays were given in 35 fractions that were confined to the prostate and seminal vesicles. Adjuvant hormonal therapy was not administered after 3D-CRT in any of the cases. RESULTS: The median follow-up period was 64.9 months. The median PSA value at the time of initiation of SHT was 5.0 ng/ml (range 0.1-21.6 ng/ml). Overall, disease-specific, PSA failure-free (based on the Phoenix definition) and SHT-free survival rates at 5 years were 90.3% (95% CI 86.5-94.0), 96.5% (94.0-98.9), 60.5% (48.2-72.7), and 63.5% (57.2-69.8), respectively. Therefore, two-thirds of the patients were still hormone-free at 5 years. CONCLUSIONS: PSA control rates in our series of Japanese patients with stage T3N0M0 prostate cancer treated with the standard dose of 3D-CRT combined with NAHT seemed higher than expected. This approach involving 3D-CRT combined with NAHT with the initiation of SHT at PSA values of around 5 ng/ml may be one option for Japanese patients with locally advanced prostate cancer, although further prospective study is required to confirm the validity.

Longitudinal growth of the autologous vessels above and below the Gore-Tex graft after the extracardiac conduit Fontan procedure.

OBJECTIVE: Reflecting excellent mid-term outcomes, extracardiac conduit Fontan procedure (ECFP) using Gore-Tex tube graft has been performed with increasing frequency in patients with functional single ventricle. Nevertheless, due to the lack of growth potential of the artificial conduit, the status of the venous pathway along with somatic growth is a continuing concern. In this study, we evaluated the longitudinal growth of the autologous vessels above and below the Gore-Tex graft used in the ECFP. METHODS: This study included 34 patients who had completed cardiac catheterisations at 1 month and 5.1 years after the ECFP. The average age, weight and height at the ECFP were 3.8+/-2.5 years (1.8-12.7 years), 12.7+/-4.6 kg (7.4-33.0 kg) and 92.9+/-16.1cm (72.5-153.5 cm), respectively. We measured the vertical lengths of three different parts angiographically: the length between the confluence point of the innominate vein and the anastomotic site of the conduit to the pulmonary artery (SVC-C), the conduit vertical length (C) and the length between the confluence point of the hepatic vein and the conduit's anastomotic site to the inferior vena cava (IVC-C). RESULTS: We have not observed stenosis or thrombus formation in the conduit or distortion of the conduit or pulmonary artery in any of the cases. No intervention or re-operation related to the extracardiac conduit was required, and laminar flow through the conduit was maintained with efficient Fontan haemodynamics. At 5.1 years after the ECFP, the average weight and height gain were 10.3+/-4.4 kg and 28.5+/-1.9 cm, respectively. The length of SVC-C, C and IVC-C were significantly increased as 124+/-15%, 106+/-7% and 132+/-24%, respectively, compared to the lengths at 1 month after the ECFP. The degree of increase in SVC-C and IVC-C was significantly larger than that in C. CONCLUSIONS: Along with the patient's somatic growth, longitudinal growth of the autologous vessels above and below the Gore-Tex graft was demonstrated to compensate for the lack of growth potential of the artificial graft.

Catastrophic hemorrhage due to aortic injury during resternotomy: what to do?

Aortic injury occurred during resternotomy in a 22-year-old woman who had undergone a Rastelli-type operation. Although extracorporeal circulation using the right femoral artery and vein was commenced immediately, hemostasis through the midline incision was impossible, and her circulation was hardly maintained. Thus, the parasternal approach was attempted, dividing the right first through fourth ribs and the head of the right clavicle. This approach enabled the assistant to give effective compression to the aortic injury site. Dissection of the adhesions around the ascending aorta was safely carried out, and the aortic laceration was closed without the help of circulatory arrest.

Mid-term follow-up of the status of Gore-Tex graft after extracardiac conduit Fontan procedure.

OBJECTIVE: Extracardiac conduit Fontan procedure (ECFP) using Gore-Tex graft has been performed with increasing frequency for the patients with functional single ventricle. However, lack of growth potential and longevity of the conduit are consistent concerns and main points of criticism of the ECFP. In this study, we investigated the mid-term status of the Gore-Tex graft used in the ECFP by comparing the internal diameter of the graft with the inferior vena cava (IVC) diameter at 1 month and 5.2 years after the ECFP. METHODS: Of 79 patients who underwent ECFP using Gore-Tex graft between November 1997 and December 2007, 33 patients who had completed cardiac catheterization at 1 month (21-73 days) and 5.2 years (3.3-9.6 years) after the ECFP were included in this study. We measured the internal diameter of the Gore-Tex graft and IVC at both catheterizations retrospectively. RESULTS: The size of the Gore-Tex graft used in the ECFP was 16 mm in 17 patients, 18 mm in 9 patients, and 20mm in 7 patients. Laminar flow through the conduits was maintained without any stenosis or kinking of the graft in these 33 patients. No intervention or reoperation related to the extracardiac conduit has been required. There were no significant differences in mean cross-sectional area (CSA) of the conduits at 1 month versus 5.2 years after the ECFP for each conduit size, and no significant changes in the conduit-to-IVC CSA ratio (0.98+/-0.40 vs 0.82+/-0.21 for 16 mm, 1.09+/-0.30 vs 0.92+/-0.33 for 18 mm, and 1.16+/-0.55 vs 0.94+/-0.44 for 20mm conduit). CONCLUSIONS: The conduit CSA and conduit-to-IVC CSA ratio remained unchanged in small caliber grafts down to 16 mm at 5.2 years after the ECFP. However, further investigation is necessary to evaluate the fate of the Gore-Tex graft and late hemodynamics in the patients with small conduits after they achieve full somatic growth.

Clinical results of commissure plication annuloplasty for mitral regurgitation in children.

PURPOSE: We evaluated the clinical results of commissure plication annuloplasty for mitral regurgitation (MR) in children. METHODS: Twenty-eight patients underwent a valve repair with commissure plication annuloplasty for MR from 1988 to 2005. The mean age was 2.7 +/- 3.3 years. Several appropriate techniques were combined (cleft closure in 5 patients, chordal shortening in 2 patients, artificial chordal replacement in 4 patients, leaflet fixation in 2 patients, and so on). The mean follow-up period was 6.2 years. RESULTS: There was one operative death (3.6%) and no late deaths. Two patients underwent a second repair 19 and 23 months after their initial repairs. The actuarial freedom from the reoperation rate was 90.4% +/- 0.6% at 10 years. The freedom from moderate MR or more was shown to decrease over time, 87.8% +/- 0.7% at 5 years and 78.0% +/- 11.0% at 10 years. Furthermore, the 10-year freedom from mild MR or more was 56.5% +/- 11.9%. A progression of MR was seen. Most of the residual or recurrent MR cases weighed less than 10 kg at operation. CONCLUSIONS: The combination of commissure plication annuloplasty and several appropriate techniques provided adequate results for MR in children. Since a progression of MR was observed, a careful follow-up is therefore needed in such cases.

Stereotactic body radiotherapy for oligometastatic lung tumors.

PURPOSE: Since 1998, we have treated primary and oligometastatic lung tumors with stereotactic body radiotherapy (SBRT). The term "oligometastasis" is used to indicate a small number of metastases limited to an organ. We evaluated our clinical experience of SBRT for oligometastatic lung tumors. METHODS AND MATERIALS: A total of 34 patients with oligometastatic lung tumors were included in this study. The primary involved organs were the lung (n = 15), colorectum (n = 9), head and neck (n = 5), kidney (n = 3), breast (n = 1), and bone (n = 1). Five to seven, noncoplanar, static 6-MV photon beams were used to deliver 48 Gy (n = 18) or 60 Gy (n = 16) at the isocenter, with 12 Gy/fraction within 4-18 days (median, 12 days). RESULTS: The overall survival rate, local relapse-free rate, and progression-free rate at 2 years was 84.3%, 90.0%, and 34.8%, respectively. No local progression was observed in tumors irradiated with 60 Gy. SBRT-related pulmonary toxicities were observed in 4 (12%) Grade 2 cases and 1 (3%) Grade 3 case. Patients with a longer disease-free interval had a greater overall survival rate. CONCLUSION: The clinical result of SBRT for oligometastatic lung tumors in our institute was comparable to that after surgical metastasectomy; thus, SBRT could be an effective treatment of pulmonary oligometastases.

Surgical results of anomalous origin of the right pulmonary artery from the ascending aorta including reoperation for infrequent complications.

BACKGROUND: We evaluated the results of surgery for an anomalous origin of the right pulmonary artery from the ascending aorta. METHODS: From August 1986 to December 2005, 8 children (6 neonates) aged 7 to 180 days (mean, 35 +/- 59 days) with anomalous origin of the right pulmonary artery from the ascending aorta underwent surgical repair at our institute. All except one child, who had the distal form, had the proximal form. Cardiac catheterization showed that the left pulmonary artery to systemic pressure ratio was 1.0 or more. Surgery was performed by direct anastomosis in 7 patients and by graft interposition in 1. RESULTS: There were no operative or late deaths. All patients postoperatively underwent cardiac catheterization that showed decreased left pulmonary artery to systemic pressure ratio ranging from 0.2 to 0.6. Follow-up periods ranged from 2 months to 13 years. We undertook reoperations for two infrequent postoperative causes. One patient exhibited significant supravalvar aortic stenosis and required patch enlargement of the ascending aorta 3 years after operation. The other patient (with the distal form) needed a reoperation after 1 month because of progressive stenosis at the anatomic site. Graft interposition was performed, and histopathologic examination showed that the tissue from the stenotic region looked like that of a ductus. CONCLUSIONS: We undertook surgical repair for anomalous origin of the right pulmonary artery from the ascending aorta. Pulmonary hypertension was improved in all patients. Careful follow-up was necessary to detect supravalvar aortic and anastomotic stenosis early and late after operation.

Evaluation of mass-like consolidation after stereotactic body radiation therapy for lung tumors.

BACKGROUND: The purpose of this study was to evaluate the characteristics of mass-like consolidation of the lung on computed tomography (CT) after stereotactic body radiation therapy (SBRT) retrospectively. METHODS: Forty lung tumors in 37 patients who underwent SBRT were evaluated. Mass-like consolidation was defined as a dense consolidation that newly appeared over or around the original tumor, which included radiation-induced lung injury (RILI) and local recurrence. Time of appearance, initial CT findings (ectatic bronchi and conformity to dose distribution) and serial changes in the size of the mass-like consolidation were evaluated. RESULTS: Mass-like consolidation appeared in 27 (68%) of 40 tumors at a median of 5 months after SBRT. Follow-up examination revealed that 24 (89%) of the 27 mass-like consolidations were RILI and 3 (11%) were local recurrence. There were no significant differences in the initial CT findings between RILI and local recurrence. The size of the mass-like consolidation varied in the 12 months after SBRT. After 12 months or more, however, the size did not increase in any of the RILI cases, but it did increase in all recurrence cases. CONCLUSION: Mass-like consolidations were observed in 68% of cases at a median of 5 months after SBRT. Although most of the mass-like consolidations were RILI, local recurrence was observed in a few cases. Early detection of local recurrence after SBRT was difficult.

Interinstitutional variations in planning for stereotactic body radiation therapy for lung cancer.

PURPOSE: The aim of this study was to assess interinstitutional variations in planning for stereotactic body radiation therapy (SBRT) for lung cancer before the start of the Japan Clinical Oncology Group (JCOG) 0403 trial. METHODS AND MATERIALS: Eleven institutions created virtual plans for four cases of solitary lung cancer. The created plans should satisfy the target definitions and the dose constraints for the JCOG 0403 protocol. RESULTS: FOCUS/XiO (CMS) was used in six institutions, Eclipse (Varian) in 3, Cadplan (Varian) in one, and Pinnacle3 (Philips/ADAC) in one. Dose calculation algorithms of Clarkson with effective path length correction and superposition were used in FOCUS/XiO; pencil beam convolution with Batho power law correction was used in Eclipse and Cadplan; and collapsed cone convolution superposition was used in Pinnacle3. For the target volumes, the overall coefficient of variation was 16.6%, and the interinstitutional variations were not significant. For maximal dose, minimal dose, D95, and the homogeneity index of the planning target volume, the interinstitutional variations were significant. The dose calculation algorithm was a significant factor in these variations. No violation of the dose constraints for the protocol was observed. CONCLUSION: There can be notable interinstitutional variations in planning for SBRT, including both interobserver variations in the estimate of target volumes as well as dose calculation effects related to the use of different dose calculation algorithms.