The influence of image reconstruction methods on the diagnosis of pulmonary emphysema with convolutional neural network.

This study investigated the influence of iterative reconstruction (IR) methods on computed tomography (CT) images when training convolutional neural network (CNN) models to diagnose pulmonary emphysema. To evaluate the influence of the IR algorithm on CNN, the present study comprised two steps: the comparison of noise reduction by IR algorithms using phantom examinations and the change in performance of CNN with IR algorithms using patient data. We retrospectively analyzed 97 patients. Raw CT data were reconstructed using the filtered back-projection (FBP) and adaptive statistical iterative reconstruction V (ASIR-V) algorithms with blending levels of 30%, 50%, and 70%. The models were trained using reconstructed CT images and were named the FBP, ASIR-V30, ASIR-V50, and ASIR-V70 models. The mean and the standard deviation of the CT values were 11.3 ± 21.2 at FBP, 11.0 ± 17.3 at ASIR-V30, 11.0 ± 14.4 at ASIR-V50, and 11.0 ± 11.8 at ASIR-V70. For all the evaluation metrics, the best values were obtained with the FBP model applied to the ASIR-V70 test images. The worst values were obtained with the ASIR-V70 model applied to the FBP test images. The model trained with FBP images exhibited significantly better performance than the models trained using IR images. The reduction in image noise with the IR algorithm on the test images contributed to improving the accuracy of the classification of emphysema subtypes using CNN.

Palliative brachytherapy and external beam radiotherapy for dysphagia from esophageal cancer: a nationwide survey in Japan.

BACKGROUND: International guidelines recommend brachytherapy for patients with dysphagia from esophageal cancer, whereas brachytherapy is infrequently used to palliate dysphagia in some countries. To clarify the availability of palliative treatment for dysphagia from esophageal cancer and explain why brachytherapy is not routinely performed are unknown, this study investigated the use of brachytherapy and external beam radiotherapy for dysphagia from esophageal cancer. METHODS: Japanese Radiation Oncology Study Group members completed a survey and selected the treatment that they would recommend for hypothetical cases of dysphagia from esophageal cancer. RESULTS: Of the 136 invited facilities, 61 completed the survey (44.9%). Four (6.6%) facilities performed brachytherapy of the esophagus, whereas brachytherapy represented the first-line treatment at three (4.9%) facilities. Conversely, external beam radiotherapy alone and chemoradiotherapy were first-line treatments at 61 and 58 (95.1%) facilities, respectively. In facilities that performed brachytherapy, the main reason why brachytherapy of the esophagus was not performed was high invasiveness (30.2%). Definitive-dose chemoradiotherapy with (≥50 Gy) tended to be used in patients with expected long-term survival. CONCLUSIONS: Few facilities routinely considered brachytherapy for the treatment of dysphagia from esophageal cancer in Japan. Conversely, most facilities routinely considered external beam radiotherapy. In the future, it will be necessary to optimize external beam radiotherapy.

Practice patterns for postoperative radiation therapy in patients with metastases to the long bones: a survey of the Japanese Radiation Oncology Study Group.

Evidence regarding postoperative radiation therapy (PORT) for metastases to the long bones is lacking. Characterizing the current practice patterns and identifying factors that influence dose-fractionation schedules are essential for future clinical trials. An internet-based survey of the palliative RT subgroup of the Japanese Radiation Oncology Study Group was performed in 2017 to collect data regarding PORT prescription practices and dose-fractionation schedules. Responders were also asked to recommend dose-fractionation schedules for four hypothetical cases that involved a patient with impending pathological fractures and one of four clinical features (poor prognosis, solitary metastasis, radio-resistant primary tumor or expected long-term survival). Responders were asked to indicate their preferred irradiation fields and the reasons for the dose fractionation schedule they chose. Responses were obtained from 89 radiation oncologists (67 institutions and 151 RT plans) who used 22 dose-fractionation schedules, with the most commonly used and recommended schedule being 30 Gy in 10 fractions. Local control was the most common reason for preferring longer-course RT. High-dose fractionated schedules were preferred for oligometastasis, and low-dose regimens were preferred for patients with a poor prognosis; however, single-fraction RT was not preferred. Most respondents recommended targeting the entire orthopedic prosthesis. These results indicated that PORT using 30 Gy in 10 fractions to the entire orthopedic prosthesis is preferred in current Japanese practice and that single-fraction RT was not preferred. Oligometastasis and poor prognosis influenced the selection of high- or low-dose regimens.

Evaluation of a Monte Carlo-based algorithm for the influence of totally implantable venous access ports in external radiation therapy.

PURPOSE: This study aimed to assess whether a Monte Carlo (MC)-based algorithm reflects the influence of totally implantable venous access ports (TIVAPs) in external radiation therapy. MATERIALS AND METHODS: The present study comprised two steps: experimental measurements of depth doses and surface doses with and without TIVAPs and calculation with an MC-based algorithm. RESULTS: The TIVAP-associated maximum dose reduction compared with the dose at the same depths without TIVAPs was 7.8% at 4 MV, 6.9% at 6 MV, and 5.7% at 10 MV in measurement, and 7.4% at 4 MV, 6.6% at 6 MV, and 5.5% at 10 MV in calculation. Relative surface doses were higher with TIVAPs made of titanium, due to a higher fluence of backscattered electrons from the TIVAPs, than with plastic TIVAPs. There were no significant differences in the relative differences between the measured and calculated doses of the titanium TIVAP group and the plastic TIVAP group at 4 MV (p = 0.99), 6 MV (p = 0.67), and 10 MV (p = 0.54). CONCLUSION: TIVAPs caused target dose reductions and dose increase near the TIVAP, especially when made of titanium. The influences are reflected in the MC-based algorithm.

Japanese structure survey of radiation oncology in 2012.

This paper describes the ongoing structure of radiation oncology in Japan in terms of equipment, personnel, patient load and geographic distribution to identify and overcome any existing limitations. From March 2013 to August 2016, the Japanese Society for Radiation Oncology conducted a questionnaire based on the Japanese national structure survey of radiation oncology in 2012. Data were analyzed based on the institutional stratification by the annual number of new patients treated with radiotherapy per institution. The estimated annual numbers of new and total (new plus repeat) patients treated with radiation were 213 000 and 251 000, respectively. Additionally, the estimated cancer incidence was 865 238 cases with ~24.6% of all newly diagnosed patients being treated with radiation. The types and numbers of treatment devices actually used included linear accelerator (LINAC; n = 864), telecobalt (n = 0), Gamma Knife (n = 44), 60Co remote afterloading system (RALS; n = 23) and 192Ir RALS (n = 130). The LINAC system used dual-energy functions in 651 units, 3D conformal radiotherapy functions in 759 and intensity-modulated radiotherapy (IMRT) functions in 466. There were 792 Japan Radiological Society/Japanese Society for Radiation Oncology-certified radiation oncologists, 1061.6 full-time equivalent (FTE) radiation oncologists, 2124.2 FTE radiotherapy technologists, 181.3 FTE medical physicists, 170.9 FTE radiotherapy quality managers and 841.5 FTE nurses. The frequency of IMRT use significantly increased during this time. In conclusion, the Japanese structure of radiation oncology has clearly improved in terms of equipment and utility although there was a shortage of personnel in 2012.

Japanese Structure Survey of Radiation Oncology in 2011.

We evaluated the evolving structure of radiation oncology in Japan in terms of equipment, personnel, patient load and geographic distribution to identify and overcome any existing limitations. From March 2012 to August 2015, the Japanese Society for Radiation Oncology conducted a questionnaire based on the Japanese national structure survey of radiation oncology in 2011. Data were analyzed based on the institutional stratification by the annual number of new patients treated with radiotherapy per institution. The estimated annual numbers of new and total (new plus repeat) patients treated with radiation were 211 000 and 250 000, respectively. Additionally, the estimated cancer incidence was 851 537 cases with approximately 24.8% of all newly diagnosed patients being treated with radiation. The types and numbers of treatment devices actually used included linear accelerator (LINAC; n = 836), telecobalt (n = 3), Gamma Knife (n = 46), 60Co remote afterloading system (RALS; n = 24), and 192Ir RALS (n = 125). The LINAC system used dual-energy functions in 619 units, 3D conformal radiotherapy functions in 719 and intensity-modulated radiotherapy (IMRT) functions in 412. There were 756 JRS or JASTRO-certified radiation oncologists, 1018.5 full-time equivalent (FTE) radiation oncologists, 2026.7 FTE radiotherapy technologists, 149.1 FTE medical physicists, 141.5 FTE radiotherapy quality managers and 716.3 FTE nurses. The frequency of IMRT use significantly increased during this time. To conclude, although there was a shortage of personnel in 2011, the Japanese structure of radiation oncology has clearly improved in terms of equipment and utility.

Japanese structure survey of radiation oncology in 2010.

We evaluated the evolving structure of radiation oncology in Japan in terms of equipment, personnel, patient load, and geographic distribution to identify and overcome any existing limitations. From March 2011 to June 2013, the Japanese Society for Radiation Oncology conducted a questionnaire based on the Japanese national structure survey of radiation oncology in 2010. Data were analyzed based on the institutional stratification by the annual number of new patients treated with radiotherapy per institution. The estimated annual numbers of new and total (new plus repeat) patients treated with radiation were 211 000 and 251 000, respectively. Additionally, the estimated cancer incidence was 805 236 cases, with ~26.2% of all newly diagnosed patients being treated with radiation. The types and numbers of treatment devices actually used included linear accelerator (LINAC; n = 829), telecobalt (n = 9), Gamma Knife (n = 46), 60Co remote afterloading system (RALS; n = 28), and 192Ir RALS (n = 131). The LINAC system used dual-energy functions in 586 units, three-dimensional conformal radiotherapy functions in 663, and intensity-modulated radiotherapy (IMRT) functions in 337. There were 564 JASTRO-certified radiation oncologists, 959.2 full-time equivalent (FTE) radiation oncologists, 1841.3 FTE radiotherapy technologists, 131.3 FTE medical physicists, 121.5 FTE radiotherapy quality managers, and 649.6 FTE nurses. The frequency of IMRT use significantly increased during this year. To conclude, although there was a shortage of personnel in 2010, the Japanese structure of radiation oncology has clearly improved in terms of equipment and utility.

Present clinical practices of stereotactic irradiation for metastatic brain tumors in Japan: results of questionnaire survey of the Japanese Radiation Oncology Study Group (JROSG) working subgroup for neurological tumors.

BACKGROUND: To determine the current practice of stereotactic irradiation (STI) for brain metastases in Japan by a questionnaire survey. METHODS: A questionnaire was distributed to 313 institutions performing STI with one of the following machines: Gamma Knife (GK), CyberKnife (CK), Novalis (Nov), or other linear accelerator (LINAC)-based systems (OLS). The participation was voluntary. RESULTS: There were 163 responding institutions. The total number of STI treatments between April 2013 and March 2014 was 10,684. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) were performed in 8624 (80.7%) and 2060 (19.3%) cases, respectively. Whole-brain radiation therapy (WBRT) was performed for a total of 3515 cases. For a case model of a 1.5-cm solitary brain metastasis in a non-eloquent area, the most common GTV-PTV margin was 2 mm (22 of 114 institutions), and an institutional standard fraction was 1 (75 of 114 institutions). The doses for the model case also varied from 13.0 to 26.0 Gy (Median 20 Gy) when converted to SRS (α/ß = 10). A prescription point was at the PTV margin the most. The median dose constraints which were converted to SRS (α/ß = 3) to organs at risk were 12.2, 12.7, and 13.7 Gy for optic nerves, cavernous sinus, and brainstem, respectively. CONCLUSIONS: STI for brain metastases in current practice varied significantly among institutions. These different strategies relied mostly on the type of treatment machine used. It is thus necessary to establish a common guideline to express dose prescriptions and plan qualities for different STI machines.

Effects of Surgery With Salvage Stereotactic Radiosurgery Versus Surgery With Whole-Brain Radiation Therapy in Patients With One to Four Brain Metastases (JCOG0504): A Phase III, Noninferiority, Randomized Controlled Trial.

Purpose Whereas whole-brain radiotherapy (WBRT) has been the standard treatment of brain metastases (BMs), stereotactic radiosurgery (SRS) is increasingly preferred to avoid cognitive dysfunction; however, it has not been clearly determined whether treatment with SRS is as effective as that with WBRT or WBRT plus SRS. We thus assessed the noninferiority of salvage SRS to WBRT in patients with BMs. Patients and Methods Patients age 20 to 79 years old with performance status scores of 0 to 2-and 3 if caused only by neurologic deficits-and with four or fewer surgically resected BMs with only one lesion > 3 cm in diameter were eligible. Patients were randomly assigned to WBRT or salvage SRS arms within 21 days of surgery. The primary end point was overall survival. A one-sided α of .05 was used. Results Between January 2006 and May 2014, 137 and 134 patients were enrolled in the WBRT and salvage SRS arms, respectively. Median overall survival was 15.6 months in both arms (hazard ratio, 1.05; 90% CI, 0.83 to 1.33; one-sided P for noninferiority = .027). Median intracranial progression-free survival of patients in the WBRT arm (10.4 months) was longer than that of patients in the salvage SRS arm (4.0 months). The proportions of patients whose Mini-Mental Status Examination and performance status scores that did not worsen at 12 months were similar in both arms; however, 16.4% of patients in the WBRT arm experienced grade 2 to 4 cognitive dysfunction after 91 days postenrollment, whereas only 7.7% of those in the SRS arm did ( P = .048). Conclusion Salvage SRS is noninferior to WBRT and can be established as a standard therapy for patients with four or fewer BMs.

Pulmonary Apical Opacities on Thin-Section Computed Tomography: Relationship to Primary Spontaneous Pneumothorax in Young Male Patients and Corresponding Histopathologic Findings.

OBJECTIVE: The purpose of this study was to test the hypothesis that apical opacities on computed tomography (CT) are related to occurrence of primary spontaneous pneumothorax (PSP) in young male patients. METHODS: We compared the frequency of apical opacities on thin-section CT between 70 male patients with PSP (PSP group) and 74 male patients without a history of PSP (non-PSP group). We also evaluated histopathologic findings of 39 specimens from 37 surgical cases in the PSP group. RESULTS: Apical opacities were significantly more frequent in the PSP group than in the non-PSP group (right side, P = 0.01; left side, P = 0.005). Histopathologically, subpleural band-like alveolar collapse was seen in 35 specimens (89.7%), which was always accompanied by fibroelastosis and fibroblastic foci. CONCLUSIONS: Apical opacities on CT were significantly associated with PSP in young male patients. These apical opacities histopathologically correspond to fibrotic pleural thickening with subpleural alveolar collapse.

Solitary synovial chondromatosis arising in the gluteus maximus bursa: computed tomography and magnetic resonance imaging findings.

Chondral tumors in soft tissue are referred to as soft-tissue chondromas or extraskeletal chondromas, or as synovial chondromatosis if they arise in synovial tissue. We report the case of a 29-year-old man with synovial chondromatosis, also called synovial osteochondromatosis, which appeared in a solitary and extra-articular form. On magnetic resonance imaging (MRI) and computed tomography, the central portion of the tumor showed similar characteristics to bone marrow, despite the absence of any connection to adjacent bone. T2-weighted imaging displayed marked peripheral hyperintensity consistent with a cartilaginous area. These findings suggested the presence of enchondral ossification and were similar to those of skeletal osteochondroma, with the exception of the absence of attachment to bone. MRI is useful for distinguishing solitary synovial chondromatosis from other lesions, such as myositis ossificans, extraskeletal chondrosarcoma, and parosteal osteosarcoma.

Stereotactic Radiosurgery With or Without Whole-Brain Radiotherapy for Brain Metastases: Secondary Analysis of the JROSG 99-1 Randomized Clinical Trial.

IMPORTANCE: It remains uncertain whether treatment with stereotactic radiosurgery (SRS) alone can be safely applied to all patient populations with 1 to 4 brain metastases (BMs) exhibiting heterogeneous prognoses. OBJECTIVE: To investigate the feasibility of SRS alone for patients with different prognoses determined by the diagnosis-specific Graded Prognostic Assessment (DS-GPA). DESIGN, SETTING, AND PARTICIPANTS: A secondary analysis (performed in September 2014) of the Japanese Radiation Oncology Study Group (JROSG) 99-1, a phase 3 randomized trial, comparing SRS alone and whole-brain radiotherapy (WBRT) + SRS conducted in 1999 to 2003. Among a total of 132 patients, 88 with non-small-cell lung cancer (NSCLC) and 1 to 4 BMs were included and poststratified by DS-GPA scores to avoid potential bias from BMs from different primary cancer types. The median follow-up time was 8.05 months. INTERVENTIONS: The WBRT schedule was 30 Gy in 10 fractions over 2 to 2.5 weeks. The mean SRS dose was 21.9 Gy in SRS alone and 16.6 Gy in WBRT + SRS. MAIN OUTCOMES AND MEASURES: The primary end point was overall survival (OS), and the secondary end points included brain tumor recurrence (BTR), salvage treatment, and radiation toxic effects. RESULTS: Forty-seven patients had a favorable prognosis, with DS-GPA scores of 2.5 to 4.0 (26 SRS-alone and 21 WBRT + SRS [DS-GPA 2.5-4.0 group]), and 41 had an unfavorable prognosis, with DS-GPA scores of 0.5 to 2.0 (19 SRS-alone and 22 WBRT + SRS [DS-GPA 0.5-2.0 group]). Significantly better OS was observed in the DS-GPA 2.5-4.0 group in WBRT + SRS vs the SRS alone, with a median survival time of 16.7 (95% CI, 7.5-72.9) months vs 10.6 (95% CI, 7.7-15.5) months (P = .04) (hazard ratio [HR], 1.92; 95% CI, 1.01-3.78). However, no such difference was observed in the DS-GPA 0.5-2.0 group (HR, 1.05; 95% CI, 0.55-1.99) (P = .86). This benefit could be explained by the differing BTR rates, in that the prevention against BTR by WBRT had a more significant impact in the DS-GPA 2.5-4.0 group (HR, 8.31; 95% CI, 3.05-29.13) (P < .001) vs the DS-GPA 0.5-2.0 group (HR, 3.57; 95% CI, 1.02-16.49) (P = .04). CONCLUSIONS AND RELEVANCE: Despite the current trend of using SRS alone, the important role of WBRT for patients with BMs from NSCLC with a favorable prognosis should be considered. Our findings should be validated through appropriately designed prospective studies. TRIAL REGISTRATION: umin.ac.jp/ctr Identifier: C000000412.

Phase 3 trials of stereotactic radiosurgery with or without whole-brain radiation therapy for 1 to 4 brain metastases: individual patient data meta-analysis.

PURPOSE: To perform an individual patient data (IPD) meta-analysis of randomized controlled trials evaluating stereotactic radiosurgery (SRS) with or without whole-brain radiation therapy (WBRT) for patients presenting with 1 to 4 brain metastases. METHOD AND MATERIALS: Three trials were identified through a literature search, and IPD were obtained. Outcomes of interest were survival, local failure, and distant brain failure. The treatment effect was estimated after adjustments for age, recursive partitioning analysis (RPA) score, number of brain metastases, and treatment arm. RESULTS: A total of 364 of the pooled 389 patients met eligibility criteria, of whom 51% were treated with SRS alone and 49% were treated with SRS plus WBRT. For survival, age was a significant effect modifier (P=.04) favoring SRS alone in patients ≤50 years of age, and no significant differences were observed in older patients. Hazard ratios (HRs) for patients 35, 40, 45, and 50 years of age were 0.46 (95% confidence interval [CI] = 0.24-0.90), 0.52 (95% CI = 0.29-0.92), 0.58 (95% CI = 0.35-0.95), and 0.64 (95% CI = 0.42-0.99), respectively. Patients with a single metastasis had significantly better survival than those who had 2 to 4 metastases. For distant brain failure, age was a significant effect modifier (P=.043), with similar rates in the 2 arms for patients ≤50 of age; otherwise, the risk was reduced with WBRT for patients >50 years of age. Patients with a single metastasis also had a significantly lower risk of distant brain failure than patients who had 2 to 4 metastases. Local control significantly favored additional WBRT in all age groups. CONCLUSIONS: For patients ≤50 years of age, SRS alone favored survival, in addition, the initial omission of WBRT did not impact distant brain relapse rates. SRS alone may be the preferred treatment for this age group.

Imaging of community-acquired pneumonia: Roles of imaging examinations, imaging diagnosis of specific pathogens and discrimination from noninfectious diseases.

This article reviews roles of imaging examinations in the management of community-acquired pneumonia (CAP), imaging diagnosis of specific CAP and discrimination between CAP and noninfectious diseases. Chest radiography is usually enough to confirm the diagnosis of CAP, whereas computed tomography is required to suggest specific pathogens and to discriminate from noninfectious diseases. Mycoplasma pneumoniae pneumonia, tuberculosis, Pneumocystis jirovecii pneumonia and some cases of viral pneumonia sometimes show specific imaging findings. Peribronchial nodules, especially tree-in-bud appearance, are fairly specific for infection. Evidences of organization, such as concavity of the opacities, traction bronchiectasis, visualization of air bronchograms over the entire length of the bronchi, or mild parenchymal distortion are suggestive of organizing pneumonia. We will introduce tips to effectively make use of imaging examinations in the management of CAP.

The long-term outcomes of radiosurgery for intracranial hemangioblastomas.

BACKGROUND: Optimal timing in the treatment of intracranial hemangioblastoma (HB) remains controversial, particularly for patients of von Hippel-Lindau disease (VHL) with multiple small lesions. We evaluated efficacy of stereotactic radiosurgery (SRS) for intracranial HB based on the longer follow-up data with a larger number of patients and lesions. METHODS: Twenty-one patients (11 men, 10 women) initially underwent SRS for 57 intracranial HBs. Seven patients had sporadic lesions and 14 had VHL-related lesions. During the follow-up, 40 lesions were additionally treated in VHL patients in 10 SRS treatments. Thus, a total of 97 lesions were included in this study. Median tumor volume was 0.13 cm(3) (range, 0.004-9.5 cm(3)), and median margin dose was 18 Gy (range, 14-20 Gy). RESULTS: Median duration of follow-up was 96 months (range, 3-235 mo) after initial SRS treatment. Ten tumors in 7 patients showed progression after SRS. Actuarial tumor control rates after SRS at 5 and 10 years were 94% and 80%, respectively. Factors associated with longer control were solid lesion (P = .03), smaller volume (P = .01), and lesions associated with VHL (P = .0005) in univariate analysis. Five- and 10-year tumor control rates were 67% and 44% for sporadic patients and 97% and 83% for VHL patients. CONCLUSION: SRS could be offered as an effective treatment for small, solid, and VHL-associated HBs. If the tumors show apparent enlargement in size or can possibly become symptomatic along with a slight increase in size, SRS should be recommended before they present with the clinical symptoms.

Variability in the point to which single direct field irradiation is prescribed for spinal bone metastases: a survey of practice patterns in Japan.

Direct single fields are commonly used in radiotherapy for spinal bone metastases, and it is crucial to define the point for which the dose is prescribed. According to the guidelines from the International Bone Metastases Consensus Working Party (IBMCWP) updated in 2010, different opinions exist on whether this therapy should be prescribed to the mid-vertebral or anterior vertebral body. To our knowledge, no previous studies have surveyed practice patterns regarding this discrepancy. Therefore, we performed an Internet-based survey of members of the Japanese Radiation Oncology Study Group (JROSG) to investigate the current practice patterns in Japan. The respondents mentioned the point to which they prescribed radiotherapy for a single direct field. A total of 52 radiation oncologists from 50 institutions (36% of JROSG institutions) responded. Respondent prescription for radiotherapy varied widely. Only 21% and 6% of respondents prescribed irradiation to the mid-vertebral body and anterior vertebral body, respectively. A larger proportion of respondents (27%) prescribed irradiation to the spinal cord (center of the spinal canal). Still another group of respondents (27%) stated that they never use a single direct field. In conclusion, the point to which irradiation dosages are prescribed varies widely for a single direct field in cases of spinal bone metastases. This variation may lead some radiation oncologists to misunderstand the tolerance dosage of the spinal cord, especially in cases of re-irradiation. Thus, careful consideration is required before any prescriptions are made.

Pulmonary focal fibrosis associated with microscopic arterio-venous fistula manifesting as focal ground-glass opacity on thin-section CT.

BACKGROUND: Focal ground-glass opacity (GGO) on thin-section computed tomography (CT) may be seen in atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ that has recently been renamed from bronchioloalveolar carcinoma (BAC) and various benign conditions. CASE PRESENTATION: We report a case of pulmonary focal fibrosis associated with microscopic arterio-venous fistula (AVF), which showed a focal area of GGO on thin-section CT. The patient was a 58-year-old woman with a GGO on thin-section CT which had increased in size over the period of 2 years. Slightly dilated vessels and thickened interlobular septa were also noted around the GGO. It was diagnosed preoperatively as adenocarcinoma in situ and a partial lung resection by video-assisted thoracic surgery (VATS) was performed. Pathological examination yielded a diagnosis of focal fibrosis associated with microscopic AVF. CONCLUSION: We speculate that the focal fibrosis was produced by a prolonged congestion due to the AVF and that the dilated vessels and thickening of interlobular septa on thin-section CT related to the AVF. Microscopic AVF may be one of the etiologies of focal fibrosis showing focal GGO on thins-section CT. Dilated vessels and thickened interlobular septa around the GGO might offer a clue to the diagnosis of this disease entity. In addition, it should be noted that focal fibrosis may increase in size.

Japanese structure survey of radiation oncology in 2009 with special reference to designated cancer care hospitals.

BACKGROUND: The structure of radiation oncology in designated cancer care hospitals in Japan was surveyed in terms of equipment, personnel, patient load, and geographic distribution, and compared with the structure in other radiotherapy facilities and the previous survey. METHODS: The Japanese Society for Therapeutic Radiology and Oncology surveyed the national structure of radiation oncology in 2009. The structures of 365 designated cancer care hospitals and 335 other radiotherapy facilities were compared. RESULTS: Designated cancer care hospitals accounted for 50.0% of all the radiotherapy facilities in Japan. The patterns of equipment and personnel in designated cancer care hospitals and the other radiotherapy facilities were, respectively, as follows: linear accelerators per facility: 1.4 and 1.0; dual-energy function: 78.6 and 61.3%; three-dimensional conformal radiotherapy function: 88.5 and 70.0%; intensity-modulated radiotherapy function: 51.6 and 25.3%; annual number of patients per linear accelerator: 301.3 and 185.2; Ir-192 remote-controlled after-loading systems: 31.8 and 4.2%; and average number of full-time equivalent radiation oncologists per facility: 1.8 and 0.8. Compared with the previous survey, the ownership ratio of equipment and personnel improved in both designated cancer care hospitals and the other radiotherapy facilities. Annual patient loads per full-time equivalent radiation oncologist in the designated cancer care hospitals and the other radiotherapy facilities were 225.5 and 247.6, respectively. These values exceeded the standard guidelines level of 200. CONCLUSIONS: The structure of radiation oncology in designated Japanese cancer care hospitals was more mature than that in the other radiotherapy facilities. There is still a shortage of personnel. The serious understaffing problem in radiation oncology should be corrected in the future.

Well differentiated fetal adenocarcinoma of the lung in a 38-year-old woman: dynamic computed tomography findings.

We report a case of well-differentiated fetal adenocarcinoma (WDFA) of the lung, with emphasis on dynamic CT (computed tomography) findings. The patient was a 38-year-old woman who was found to have a mass in the left upper lung field in chest radiograph screening. Chest radiograph showed a 5.5 cm well-defined mass in the left upper lung field. CT revealed a well-circumscribed mass measuring 5.5 × 5.5 × 5.0 cm with a lobulated margin in the left upper lobe. Intratumoral enhancing vasculature was noted in the early phase of dynamic CT. In the delayed phase, persistent and plateau enhancement was seen. The tumor also had consistently unenhanced areas, suggesting the presence of necrosis. Left upper lobectomy with mediastinal lymph node dissection was performed. The pathology specimen contained tubular glands consisting of non-ciliated columnar cells with areas of solid nests of epithelial cells with weakly eosinophilic cytoplasm (morule) mimicking fetal lung tissue. The tumor was moderately vascularized with areas of comedo necrosis; the stroma was relatively scanty. Final pathological diagnosis was WDFA with left hilar lymph node metastasis (stage T2bN1M0). This is the first report of dynamic CT findings of WDFA, a rare lung tumor. Although these findings are non-specific, they well reflected the pathological characteristics of this tumor.