Pulmonary pleomorphic carcinoma arising in mixed squamous and glandular papilloma: A case report.

Solitary pulmonary papillomas (SPPs) are rare lung neoplasms. Histologically, SPP is classified into three subtypes, and mixed squamous and glandular papilloma (MP) is the rarest subtype. Although SPPs are considered benign tumors, there have been several reports on the synchronous malignant transformation in SPPs. An 82-year-old asymptomatic man was referred to our hospital for further examination of a 2.2 cm-sized left lung tumor. Pathology of bronchoscopic specimens showed the possibility of pulmonary papilloma but did not reveal any malignancy. The patient complained of bloody sputum during the eighth month after the initial visit. The size of the lesion had increased to 4.3 cm. These data suggested the existence of malignancy, and the patient underwent an operation. Histologically, the tumor was composed of fibrovascular cores and papillomatous fronds lined by pseudostratified columnar cells and mucin-filled goblet cells. Keratinizing squamous epithelium was also observed. Overall, the diagnosis of MP was obtained by fundamental histology. In addition, a solid part beneath mild atypical squamous epithelia, which was composed of malignant-appearing squamous cells and spindle-shaped atypical cells, was observed. The spindle portion was positive for cytokeratin AE1/AE3 and vimentin, and focally positive for alpha-smooth muscle actin (αSMA). The final diagnosis was pulmonary pleomorphic carcinoma (PPC) arising in the MP. Only two cases have been reported for atypical spindle tumor cells that are found in MP or bronchiolar adenoma/ciliated muconodular papillary tumor (BA/CMPT), which has histologically similar features to MP. This is the second case report of PPC arising in MP.

A Th1-like CD4+ T-cell Cluster That Predicts Disease-free Survival in Early-stage Lung Cancer.

Perioperative immune checkpoint inhibitors have been shown to improve prognosis in early-stage lung cancer. However, no biomarkers are known to indicate the requirement for treatment. This study aimed to identify T-cell clusters responsible for antitumor immunity in patients with early-stage lung cancer. Preoperative blood samples from 50 consecutive patients with lung cancer who were diagnosed as operable and underwent complete resection were analyzed by mass cytometry. Patients were divided into two groups: no recurrence at a minimum observation period of 851 days (median observation period: 1,031.5 days) and recurrence by the last observation date. Mass cytometry and single-cell RNA sequencing analysis of lymph nodes (LN) and tumor-infiltrating T cells were also performed. CCR4-CCR6+ Th7R showed discriminative ability between recurrence and non-recurrence patients with lung cancer. Patients with more than 3.04% Th7R showed significantly favorable disease-free survival. Th7R was a major component of CD4+ T cells in tumor microenvironments and LNs adjacent to lung cancer tissues and was the only cluster that decreased in peripheral blood after the removal of cancer tissues, suggesting that Th7R was primed and proliferated in tumor-draining LNs in the presence of cancer tissues. Th7R had the kinetics that antitumor T cells should have, as indicated by the cancer immunity cycle; thus, peripheral blood Th7R could represent the potency of tumor immunity by reflecting priming and proliferation in tumor-draining LNs and Th7R in the tumor microenvironment. Prediction using peripheral Th7R before surgery could allow the selection of patients who require perioperative drug therapy and optimize therapeutic interventions with clinical implications. Significance: Peripheral Th7R, a Th1-like CD4+ T-cell cluster reflecting priming status in draining LNs and immune status in the tumor microenvironment, predicts disease-free survival after complete resection and has significant clinical relevance in selecting appropriate therapeutic interventions in patients with early-stage lung cancer.

Prognostic significance of lymph node dissection for lung cancer surgery: a narrative review.

Background and Objective: Theoretically, systematic lymph node dissection (SLND) in lung cancer surgery is a technique that leaves less cancer cells behind and is speculated to improve the prognosis, but its prognostic significance still remains controversial. In addition, the social environment surrounding lymph node dissection has changed with the advent of limited surgery for peripheral small-sized lung cancer and emergence of immune check inhibitor (ICI). Therefore, we reconsidered the role of lymph node dissection. Methods: By referring to past reports, we reviewed the process leading up to the establishment of SLND in lung cancer surgery. We compared five randomized prospective comparative studies on SLND and lymph node sampling (LNS) in lung cancer surgery. Key Content and Findings: Of the five randomized prospective comparative studies, two reported an improvement in overall survival (OS) with SLND, but the remaining three reported no significant difference in OS between SLND and LNS. One out of the five reports revealed a significant increase in complications with SLND. For peripheral non-small cell lung cancer (NSCLC) cases with tumor diameter ≤2 cm and consolidation-to-tumor ratio >0.5 segmentectomy was found to significantly improve the hazard ratio of OS, when compared to a lobectomy. However, the proportion of SLND and lobe-specific lymph node dissection (L-SLND) in each group seems to be unclear. In segmentectomy, the dissection of intersegmental lymph nodes tends to be lenient, and therefore it seems necessary to examine the significance of lymph node dissection in segmentectomy. ICIs are already showing excellent effects, and it may be necessary to examine how they will be affected by removal of regional lymph nodes where cancer-specific cytotoxic T lymphocytes (CTLs) are concentrated. SLND is essential for accurate staging, but ideally-in a host with no cancer cells in the lymph node or a host with cancer cells having a high sensitivity to ICI-it might be better to leave the regional lymph node. Conclusions: SLND may not be the right choice in all cases. A time may come when the extent of lymph node dissection is determined individually for each case. Future verification results are awaited.

Paravertebral extramedullary hematopoiesis in a case of myelodysplastic syndrome with ring sideroblasts and an SF3B1 mutation.

We present the case of a 56-year-old male patient with paravertebral extramedullary hematopoiesis (EMH) secondary to myelodysplastic syndrome with ring sideroblasts and multilineage dysplasia. In a routine health checkup over 5 years prior, he presented with asymptomatic mild anemia and a posterior mediastinal mass. Pathological and cytomorphological findings of the resected paravertebral mass were similar to those of his bone marrow specimen, and included cellularity with erythroid hyperplasia, multilineage dysplastic changes, and the presence of ring sideroblasts. A concordant SF3B1 mutation was detected in both bone marrow and paravertebral mass samples, suggesting that the EMH cells were derived from the bone marrow.

Tumor immunity is related to 18 F-FDG uptake in thymic epithelial tumor.

BACKGROUND: 2-deoxy-2-[fluorine-18] fluoro-d-glucose (18 F-FDG) positron emission tomography (18 F-FDG-PET) is a convenient modality to assess the metabolic activity within tumor cells. However, there is no consensus regarding the relationship between 18 F-FDG uptake and the immune environment in thymic epithelial tumors (TETs). We conducted a clinicopathological study to elucidate the relationship between 18 F-FDG uptake and programmed death ligands 1 and 2 (PD-L1/PD-L2) expression in patients with TETs. METHODS: A total of 108 patients with histologically confirmed TETs classified as thymomas or thymic carcinomas who underwent surgical resection or biopsy or needle biopsy and 18 F-FDG PET before any treatment between August 2007 and March 2020 were enrolled in this study. Tumor specimens underwent immunohistochemical staining for PD-L1, PD-L2, GLUT1, HIF-1α, VEGFR2, VEGF-C, and ß2 adrenergic receptor. RESULTS: High uptakes of SUVmax , SUVmean , MTV, and TLG were identified in 28 (25.9%), 61 (56.5%), 55 (50.9%), and 55 (50.9%) of 108 patients, respectively. High uptake of SUVmax significantly correlated with PS (performance status) of 1-2, thymic carcinoma, and advanced stage, and SUVmax on 18 F-FDG uptake displayed a close association with PD-L1 and PD-L2 expressions, but not with MTV and TLG. Our analysis revealed that SUVmax was identified as being significant relationship for positive PD-L1/PD-L2 expression. GLUT1, HIF-1α, and VEGFR2 were significantly associated with the expression of PD-L1/PD-L2 from the biological viewpoint. CONCLUSION: 18 F-FDG accumulation was closely associated with the expression of PD-L1/PD-L2, which, in turn, was correlated with glucose metabolism and hypoxia. PD-L1/PD-L2 could affect the glucose metabolism and hypoxia in thymic tumor cells.

Chylothorax associated with lymphatic reflux in a thoracic duct tributary after lung cancer surgery.

Chyle leaks are attributed to damage to the thoracic duct itself or its tributaries during surgery. Chylothorax after lung cancer surgery can occur due to damaged thoracic duct tributaries; however, little is known of the mechanism involved. A 71-year-old female underwent a left upper lobectomy with hilar and mediastinal lymphadenectomy for a 1.8-cm primary squamous cell carcinoma, and developed a chylothorax a day later. Catheter lymphangiography revealed high-flow chyle leaks from a damaged thoracic duct tributary, known as a bronchomediastinal lymph trunk, due to a lymphatic reflex from the thoracic duct. Subsequently, catheter embolization of the tributary repaired the chylothorax. The potential for persistent chylothorax after lung cancer surgery and successful lymphatic intervention should be noted.

Reversible dementia due to vitamin B12 deficiency in a lung cancer patient: Relevance of preoperative evaluation.

OBJECTIVE: Cognitive dysfunction has a negative effect on cancer treatment; however, in a cancer setting, specific treatments can restore cognitive function. Such conditions are known as reversible dementia, with one of these being vitamin B12 (VB12) deficiency. However, there have been no reports of VB12 deficiency identified by preoperative evaluation in cancer patients. METHOD: We studied a patient who was referred to the Department of Psycho-oncology on suspicion of cognitive decline prior to lung cancer surgery. Preoperative evaluation revealed VB12 deficiency. RESULTS: The patient was an 82-year-old woman diagnosed with lung cancer. She also presented with cognitive decline and, therefore, was referred to the Department of Psycho-oncology for preoperative evaluation. The patient scored 19 points on a Mini-Mental State Examination (MMSE), which is indicative of cognitive decline. As the onset of symptoms occurred several months previously and they were subacute, the possibility of reversible dementia was considered. Extensive examination revealed VB12 deficiency, and VB12 replacement therapy normalized the MMSE score to 25 points before surgery. SIGNIFICANCE OF THE RESULTS: When cognitive decline is observed in cancer patients, it is necessary to actively evaluate the serum levels of some B vitamins, including VB12.

Pulmonary high-grade fetal adenocarcinoma associated with cystic airspace: A case report.

Lung cancers associated with cystic airspaces have a life-threatening risk of a missed or delayed diagnosis. Here, we report a case of pulmonary high-grade fetal adenocarcinoma, a rare lung carcinoma associated with cystic airspaces, as confirmed by computed tomography (CT) scan. A 73-year-old asymptomatic male with a 52-pack a year smoking habit was referred to our hospital. Lung CT showed a thin-walled cystic space with exophytic and endophytic solid nodules along the cyst wall. After surgery, histological analysis of a resected lung specimen revealed a pure high-grade fetal adenocarcinoma probably associated with emphysematous bullae in pulmonary emphysema, suggesting smoking contributed to this pure form, as well as the emphysema. In conclusion, when treating elderly men with a smoking history, physicians need to carefully examine the walls of cystic airspaces on CT for fetal adenocarcinoma. KEY POINTS: Significant findings of the study •Pulmonary high-grade fetal adenocarcinoma may be associated with emphysematous bullae manifesting as cystic air spaces as shown by computed tomography. What this study adds •When scanning by computed tomography, physicians should carefully examine the pulmonary cystic airspace walls in elderly men with a smoking history.

Primary pulmonary synovial sarcoma with calcification: A case report.

The lung is the organ most commonly affected by primary synovial sarcoma. Intratumoral calcification is less common in this organ versus soft tissue. Meanwhile, the presence of calcification in a lung nodule reduces the risk of lung cancer. Here, we report a case of pulmonary synovial sarcoma which manifested as a nodule with calcification, depicted on computed tomography (CT). A 52-year-old asymptomatic male was referred to Saitama Medical University International Medical Center and CT revealed a well-defined nodule (1.8 cm), with punctate and eccentric calcification in the right lower lobe. Enhanced CT and 18F-fluorodeoxyglucose positron-emission tomography suggested a malignant tumor, and surgery was performed. Histology provided a preliminary diagnosis of monophasic spindle-cell synovial sarcoma with hyalinized collagen bands and calcifications. Genetically, the presence of the SYT-SSX2 fusion gene was consistent with the features of this disease. We conclude that primary pulmonary synovial sarcoma should be listed as a differential diagnosis for solitary pulmonary nodules with calcification.

Pulmonary intravascular large B-cell lymphoma accompanying synchronous primary pulmonary adenocarcinoma and benign interstitial lesions.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma, and initial or predominant presentation in the lungs is uncommon. The synchronous occurrence of IVLBCL and malignant tumors is less frequent, and no such reports have described pulmonary presentations. We report a rare case of pulmonary IVLBCL accompanying lung cancer and interstitial lesions. A 73-year-old man with a history of pneumonia underwent a follow-up examination. Computed tomography revealed diffuse, bilateral ground-glass opacities (GGO) with a partial solid mass. Histologically, the mass consisted of adenocarcinoma. However, two other types of interstitial lesions were scattered throughout the resected lung: 1) peribronchovascular thickening with the aggregation of macrophages and anthracosis, and 2) alveolar septal thickening in the centrilobular area with atypical CD20-positive large cells in the capillaries. These two types of lesions were not mixed. Computed tomography and positron emission tomography demonstrated no other organ involvement. The patient was considered to have the synchronous occurrence of pulmonary IVLBCL and lung cancer (adenocarcinoma). After R-CHOP therapy, GGO on CT disappeared. Lung cancer often accompanies benign background lesions, and the combination of these lesions with lung cancer may make it difficult to detect the presence of pulmonary IVLBCL. However, the histological distribution pattern of IVLBCL may be a clue to the correct diagnosis.

[Surgical Outcome of Sublobar Resection in High-risk Patients with Non-small Cell Lung Cancer].

OBJECTIVES: Pulmonary lobectomy is the standard surgical procedure for resectable non-small cell lung cancer (NSCLC), while sublobar resection is an important surgical alternative for high-risk patients with comorbidities. We evaluated the treatment outcome and prognostic factors of sublobar resection in high-risk patients with NSCLC. METHODS: Eighty three high-risk patients who underwent compromised sublobar resection for clinical-N0 NSCLC with a solid appearance were retrospectively reviewed. A total of 47 wedge resections and 36 segmentectomies performed. RESULTS: Poor pulmonary function and synchronous or metachronous multiple lung cancer were found in 56.7% and 20.5% of patients respectively, all requiring sublobar resection. There were 21 instances of tumor recurrence and 24 deaths during a mean follow-up of 1,500 days. There was no local recurrence in the segmentectomy group. The 3-year recurrence free survival (RFS) and overall survival (OS) were 72.6% and 73.8% respectively. A multivariate analysis indicated that resection type and lymphatic invasion were independent prognostic factors for RFS. In the wedge resection group, a ratio of surgical margin to clinical tumor size greater than 1 (MT ratio≥1) was an independent prognostic factor for RFS( 87.1%,p=0.001). CONCLUSION: Segmentectomy leads to a favorable prognosis. MT ratio was independently associated with a longer RFS in the wedge resection group.

Optimal sublobar resection for c-stage I non-small cell lung cancer: significance of margin distance to tumor size ratio and margin cytology (Supplementary analysis of KLSG-0801): complete republication.

BACKGROUND: Sublobar resection for lung cancer is associated with a higher risk of recurrence than that of lobectomy; we evaluated the factors considered to be predictors of recurrence. METHODS: By analyzing multicenter prospective studies of sublobar resection for patients with c-stage I non-small lung cancer who were unable to undergo lobectomy (KLSG-0801), we investigated the relationship between (1) tumor location (TL) and margin distance from the stump (MD), (2) the MD/tumor size (TS) ratio and prognosis, (3) and the margin cytology (MC) and prognosis. RESULTS: The correlation between TS and MD was statistically significant in cases of easily resectable regions defined by Lewis' classification (n = 18). However, there was no correlation in difficult-to-resect regions (n = 14). Among cases of recurrence, the MD/TS ratio was less than 1. The 3-year survival rate was 100% for patients with MD/TS > 1 (n = 12), 59.7% for patients with MD/TS ≤ 1 (n = 20) (p = 0.06), 88.1% in cases of negative MC (n = 18), and 20% in cases of positive MC (n = 5) (p = 0.001). CONCLUSION: Cases with positive MC had a significantly worse prognosis than those with negative MC. It may be difficult to secure an MD greater than the TS in a difficult-to-resect region according to Lewis' classification.

Distinctive clinicopathological features of adenocarcinoma in situ and minimally invasive adenocarcinoma of the lung: A retrospective study.

OBJECTIVES: The aim of this study was to investigate distinguishing clinicopathological features, in addition to histological invasiveness, in adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) of the lung. MATERIALS AND METHODS: Patients with lung adenocarcinoma who underwent surgery at our hospital between 2007 and 2014 were reviewed, focusing on computed tomography (CT) images, operative procedures and clinical outcomes, histopathology, Ki-67 immunostaining, and EGFR-mutation status. EGFR mutations were examined using a peptide nucleic acid-locked nucleic acid PCR clamp method. Group comparisons were investigated by Mann-Whitney U or Fisher's exact tests. RESULTS: Of 629 patients with lung adenocarcinoma who underwent surgery, 91 (14%) of 103 AIS (n = 34) or MIA (n = 69) tumors were reviewed. The ratio of male to female patients with MIA compared to AIS was significantly higher (p < 0.02). Of 103 tumors, 99 (96%) were non-mucinous. By CT, 74% of AIS appeared as pure ground-glass nodules and 75% of MIAs as part-solid ground-glass nodules. Pathological tumor diameters and Ki-67 labeling index (LI) values were significantly greater for MIAs compared to AIS (p < 0.001 for both). A Ki-67 LI of ≥2.8% indicated the presence of an MIA rather than an AIS. EGFR mutations were more frequently detected in MIAs (33/69, 48%) than AIS (9/34, 26%; p = 0.055). The ratio of exon 19 deletions to exon 21 missense mutations in MIAs tended to be higher than those in AIS (p = 0.06). Patients did not experience a local recurrence or metastasis after AIS and MIAs were removed by wedge resection, segmentectomy or lobectomy. Five-year recurrence-free survival rates were 100%. CONCLUSION: Despite similar surgical outcomes for AIS and MIAs, we found differences in terms of gender, tumor diameters, CT findings, Ki-67 LI and a subset of EGFR mutations, highlighting the validity of classifying the two subtypes.

Postoperative empyema following lung cancer surgery.

Postoperative empyema following lung cancer surgery is a serious complication. Occurrence rate of postoperative empyema following lung cancer surgery, patient background, surgical procedures, date of empyema onset, treatment, and prognosis of 4772 patients who underwent lung cancer surgery between 2008 and 2012 were investigated. Postoperative empyema following lung cancer surgery was found in 43 patients (0.9%). The occurrence rate of postoperative empyema was significantly higher in patients with the following factors: male gender, extended surgery such as pneumonectomy, bi-lobectomy and thoracotomy, squamous cell carcinoma, and an advanced pathologic stage of II and above. Chest drainage, video-assisted thoracic surgery debridement, fenestration, and thoracoplasy were performed, where 29 patients were cured (67.5%) and 5 patients (11.6%) died from thoracic empyema-related complications. Nine patients were not cured and died due to cancer or other diseases during treatment. When comparing cured and non-cured patients, it is indicated that squamous cell carcinoma, administration of steroids, history of interstitial pneumonia, presence of bronchial stump fistula, exacerbation of interstitial pneumonia and presence of non-fermenting Gram-negative bacilli led to a significantly low prognosis. The five-year overall survival rate was 34.9%.

Pharmacokinetic evaluation of intrapleural perfusion with hyperthermic chemotherapy using cisplatin in patients with malignant pleural effusion.

OBJECTIVES: Malignant pleural effusion (MPE) has a poor prognosis. Most patients are treated with tube thoracostomy and sclerotherapy, although its success rate is around 64%. We have investigated intrapleural perfusion with hyperthermic chemotherapy (IPHC) using cisplatin in a study with a pharmacokinetic evaluation. METHODS: Patients with MPE, performance status of 0-1, possibility of good lung expansion and Cr<1.2mg/dL were treated with IPHC. The circuit was filled with 2000mL of normal saline containing cisplatin at a dose of 80mg/m2. Under video-assisted thoracoscopic surgery, the thoracic cavity was filled and perfused at a speed of approximately 1L/min at a temperature of 43°C for 1h. Perfusion solution and plasma samples were periodically collected, and concentrations of protein-unbound (free) platinum, which was the active derivative of cisplatin, and total platinum were determined by flameless atomic absorption spectrometry. RESULTS: Twenty patients with MPE (8 lung cancers, 7 mesotheliomas, and 5 others) were enrolled in this study. Rate of free platinum concentration relative to total platinum concentration in perfusion solution after 1hr IPHC at 43°C was 61.1±12.9%. Area under curve (AUC) of free platinum in the pleural space was calculated to be 26.3µg/mLxh, resulting in complete control of pleural effusion for 3 months after IHPC in all cases (95% confidence interval: 83-100%). While, absorption rate of total platinum from the pleural space was 33.8±17.0% (27.4±13.6mg/m2), and the maximum concentration of total platinum in serum was low, 0.66±0.31µg/mL, resulting in controllable side effects; grade 1 renal toxicity: 6 patients, grade 1 emesis: 7 patients. CONCLUSIONS: IPHC with cisplatin showed favorable pharmacokinetic profiles for an optional treatment to control malignant pleural effusion.

[Tumors of the diaphragm, diagnosis and surgical treatment].

Primary tumors of the diaphragm are very rare, and we often have difficulties in preoperative diagnosis and accurate evaluation of invasion. We experienced 3 surgical cases of tumor of diaphragm:primary mucinous adenocarcinoma, metastatic gastrointestinal stromal tumor, and mesothelioma. Besides computed tomography (CT) and conventional magnetic resonance imaging(MRI), respiratory dynamic cine magnetic resonance imaging (cine MRI) was performed. Cine MRI was acquired using steady state free precession (SSFP) sequence, and about 80 consecutive images of the same slice were taken while a patient breathed deeply. In all cases, cine MRI showed lack of tumor movement along the diaphragm during respiration. During surgery, we found that tumor was originated from diaphragm and there was no adhesion to other organs. Securing a sufficient margin, we resected tumor including the diaphragm. Since the defect of diaphragm was from 4 to 5cm in short diameter, we could close the diaphragm by direct suture. Cine MRI could provide useful information concerning discrimination between diaphragmatic and para-diaphragmatic tumor.

Lung cancer patients frequently visit the emergency room for cancer-related and -unrelated issues.

Lung cancer patients visit the emergency room (ER) for cancer-related and -unrelated reasons more often compared to patients with other types of cancer. This results in increased admissions and deaths in the ER. In this study, we retrospectively reviewed the characteristics of lung cancer patients visiting the ER in order to optimize the utilization of emergency medical services and improve the patients' quality of life. Lung cancer patients visiting the ER of a single institution over a 2-year period (2010-2011) were analyzed. The patients' chief complaints and diagnoses at presentation in the ER were classified as cancer-related and -unrelated. Hospital admission, discharge from the ER, hospital mortality and survival of advanced lung cancer patients hospitalized through admission to the ER was surveyed. A total of 113 patients visited the ER 143 times. Seventy visits (49.0%) were cancer-related and 73 (51.0%) were cancer-unrelated. Respiratory symptoms, pain, gastrointestinal and neurological events and fever were the most common cancer-related issues recorded. With the progression of cancer stage, the number of ER visits, admissions, ambulance use and hospital mortalities increased. In visits due to cancer-unrelated issues, including infection, cardiovascular and gastrointestinal diseases, fever was the most common complaint. Emergency admissions of advanced-stage patients for cancer-related issues revealed a significantly shorter median survival time compared to that for patients admitted for cancer-unrelated issues (61 vs. 406 days, respectively; P<0.05). It was observed that outpatients with lung cancer visited the ER for cancer-related and -unrelated reasons with a similar frequency. Therefore, accurate differential diagnosis in the ER is crucial for patients with lung cancer.

Primary mucinous adenocarcinoma of the posterior mediastinum.

We report a rare case of primary mucinous adenocarcinoma of the posterior mediastinum. A 36-year-old man was referred to our hospital with right flank pain. Computed tomography showed a cystic mass in the posterior mediastinum, and the tumor displaced the diaphragm downward and the inferior vena cava forward. The patient underwent extirpation of the tumor. The cut surface of the resected tumor showed a unilocular cyst filled with abundant gray gelatinous fluid. Microscopically, the tumor had a fibrous capsule lined with cuboidal and columnar malignant epithelial cells with intracellular mucin accumulation and was diagnosed as a mucinous adenocarcinoma.

Hemithoracic intensity-modulated radiotherapy using helical tomotherapy for patients after extrapleural pneumonectomy for malignant pleural mesothelioma.

Postoperative hemithoracic irradiation is regarded as an important part of the curative treatment for resectable malignant pleural mesothelioma (MPM). Because the clinical target volume in postoperative MPM is irregular and surrounded by dose-limiting critical structures, intensity-modulated radiation therapy (IMRT) is thought to be suitable. However, postoperative hemithoracic IMRT remains experimental due to a high incidence of fatal pneumonitis. Therefore, a Phase I dose escalation study for hemithoracic IMRT using helical tomotherapy was planned, and the results of the first three patients are herein reported because this technique may provide benefits to such patients. For 3 patients with postoperative MPM, who were treated by extrapleural pneumonectomy (EPP), a radiation dose of 45.0 Gy in 25 fractions was given to cover 95% of the PTV. The lung V5s of the three patients were 14.3%, 10.0%, and 31.3%, respectively. The V5s of the present plans was smaller than that of the recent IMRT planning studies. The lung V20s of these patients were 2.4%, 2.2%, and 4.3%, respectively. Their MLDs were 4.3 Gy, 3.4 Gy, and 5.8 Gy, respectively. The follow-up periods of the patients were 26, 14 and 9 months from initiation of IMRT, respectively. All patients were alive, although local and contralateral recurrences had developed in 1 patient. Only 1 patient had Grade 2 acute esophagitis and nausea. There was no treatment-related pneumonitis. Hemithoracic IMRT using helical tomotherapy may play a crucial role in adjuvant treatment for MPM after EPP.