Dosimetric rationale and preliminary experience in proton plus carbon-ion radiotherapy for esophageal carcinoma: a retrospective analysis.

BACKGROUND: Concurrent chemoradiotherapy has been standard of care for unresectable esophageal carcinoma. There were no reports on proton radiotherapy (PRT) plus carbon-ion radiotherapy (CIRT) with pencil beam scanning (PBS) for esophageal carcinoma. This study evaluated the tolerability and efficiency of proton and sequential carbon-ion boost radiotherapy for esophageal carcinoma. METHODS: From April 2017 to July 2020, 20 patients with primary esophageal carcinoma at stages II-IV were treated with PRT plus sequential CIRT with PBS. A median relative biological effectiveness-weighted PRT dose of 50 Gy in 25 fractions, and a sequential CIRT dose of 21 Gy in 7 fractions were delivered. Respiratory motion management was used if the tumor moved > 5 mm during the breathing cycle. A dosimetric comparison of photon intensity-modulated radiotherapy (IMRT), PRT, and CIRT was performed. The median times and rates of survivals were estimated using the Kaplan-Meier method. Comparison of the dose-volume parameters of the organs at risk employed the Wilcoxon matched-pairs test. RESULTS: Twenty patients (15 men and 5 women, median age 70 years) were included in the analysis. With a median follow-up period of 25.0 months, the 2-year overall survival and progression-free survival rates were 69.2% and 57.4%, respectively. The patients tolerated radiotherapy and chemotherapy well. Grades 1, 2, 3, and 4 acute hematological toxicities were detected in 25%, 30%, 10%, and 30% of patients, respectively. Grades 3-5 acute non-hematological toxicities were not observed. Late toxicity events included grades 1, 2, and 3 in 50%, 20%, and 10% (pulmonary and esophageal toxicity in each) of patients. Grades 4-5 late toxicities were not noted. PRT or CIRT produced lower doses to organs at risk than did photon IMRT, especially the maximum dose delivered to the spinal cord and the mean doses delivered to the lungs and heart. CONCLUSIONS: PRT plus CIRT with PBS appears to be a safe and effective treatment for esophageal carcinoma. PRT and CIRT delivered lower doses to organs at risk than did photon IMRT. Further investigation is warranted.

New prognostic system specific for epidermal growth factor receptor-mutated lung cancer brain metastasis.

Introduction: Brain metastases (BM) from lung cancer are heterogeneous, and accurate prognosis is required for effective treatment strategies. This study aimed to identify prognostic factors and develop a prognostic system exclusively for epidermal growth factor receptor (EGFR)-mutated lung cancer BM. Methods: In total, 173 patients with EGFR-mutated lung cancer from two hospitals who developed BM and received tyrosine kinase inhibitor (TKI) and brain radiation therapy (RT) were included. Univariate and multivariate analyses were performed to identify significant EGFR-mutated BM prognostic factors to construct a new EGFR recursive partitioning analysis (RPA) prognostic index. The predictive discrimination of five prognostic scoring systems including RPA, diagnosis-specific prognostic factors indexes (DS-GPA), basic score for brain metastases (BS-BM), lung cancer using molecular markers (lung-mol GPA) and EGFR-RPA were analyzed using log-rank test, concordance index (C-index), and receiver operating characteristic curve (ROC). The potential predictive factors in the multivariable analysis to construct a prognostic index included Karnofsky performance status, BM at initial lung cancer diagnosis, BM progression after TKI, EGFR mutation type, uncontrolled primary tumors, and number of BM. Results and discussion: In the log-rank test, indices of RPA, DS-GPA, lung-mol GPA, BS-BM, and EGFR-RPA were all significant predictors of overall survival (OS) (p ≤ 0.05). The C-indices of each prognostic score were 0.603, 0.569, 0.613, 0.595, and 0.671, respectively; The area under the curve (AUC) values predicting 1-year OS were 0.565 (p=0.215), 0.572 (p=0.174), 0.641 (p=0.007), 0.585 (p=0.106), and 0.781 (p=0.000), respectively. Furthermore, EGFR-RPA performed better in terms of calibration than other prognostic indices.BM progression after TKI and EGFR mutation type were specific prognostic factors for EGFR-mutated lung cancer BM. EGFR-RPA was more precise than other models, and useful for personal treatment.

Preliminary Safety and Efficacy of Proton Plus Carbon-Ion Radiotherapy With Concurrent Chemotherapy in Limited-Stage Small Cell Lung Cancer.

OBJECTIVES: This study aimed to investigate the tolerance and effect of proton plus carbon-ion radiotherapy with concurrent chemotherapy in limited-stage small cell lung cancer using the pencil beam scanning technique. MATERIALS AND METHODS: From March 2017 to April 2020, 25 patients with limited-stage small cell lung cancer treated with combined proton and carbon-ion radiotherapy were analyzed. The primary lesions and involved lymph nodes were irradiated using 2-4 portals. Proton and sequential carbon-ion beams were delivered with a median dose of 67.1 (range, 63-74.8) GyE as fraction doses of 2.0-2.2 GyE with proton beams in 20-23 fractions and 3.0-3.8 GyE with carbon ions in 5-8 fractions. Chemotherapy was delivered concurrently with radiotherapy in all patients. RESULTS: At the last follow-up, the 2-year overall and locoregional progression-free survival rates were 81.7% and 66.7%, respectively. Radiochemotherapy was well tolerated, with grade 1, 2, and 3 acute toxicities occurring in 12.0%, 68.0%, and 20.0% of patients, respectively. All grade 3 acute toxicities were hematologically related changes. One patient experienced grade 3 acute non-hematological toxicity in the esophagus, and one other patient had grade 3 bronchial obstruction accompanied by obstructive atelectasis as a late side effect. CONCLUSION: Proton plus carbon-ion radiotherapy using pencil beam scanning yielded promising survival rates and tolerability in patients with limited-stage small cell lung cancer. A prospective clinical study is warranted to validate the therapeutic efficacy of particle radiotherapy in combination with chemotherapy in limited-stage small cell lung cancer.

Definitive carbon ion radiotherapy for tracheobronchial adenoid cystic carcinoma: a preliminary report.

BACKGROUND: Tracheobronchial adenoid cystic carcinoma (TACC) is a rare tumour. About one-third of patients miss their chance of surgery or complete resection as it is mostly detected in the advanced stage; hence, photon radiotherapy (RT) is used. However, the outcomes of photon RT remain unsatisfactory. Carbon ion radiotherapy (CIRT) is thought to improve the therapeutic gain ratio; however, the outcomes of CIRT in TACC are unclear. Therefore, we aimed to assess the effects and toxicities of CIRT in patients with TACC. METHODS: The inclusion criteria were as follows: 1) age 18-80 years; 2) Eastern Cooperative Oncology Group Performance Status 0-2; 3) histologically confirmed TACC; 4) stage III-IV disease; 5) visible primary tumour; and 6) no previous RT history. The planned prescription doses of CIRT were 66-72.6 GyE/22-23 fractions. The rates of overall survival (OS), local control (LC), and progression-free survival (PFS) were calculated using the Kaplan-Meier method. Treatment-induced toxicities and tumour response were scored according to the Common Terminology Criteria for Adverse Events and Response Evaluation Criteria in Solid Tumors, respectively. RESULTS: Eighteen patients with a median age of 48 (range 30-73) years were enrolled. The median follow-up time was 20.7 (range 5.8-44.1) months. The overall response rate was 88.2%. Five patients developed lung metastasis after 12.2-41.0 months and one of them experienced local recurrence at 31.9 months after CIRT. The rates of 2-year OS, LC, and PFS were 100, 100, and 61.4%, respectively. Except for one patient who experienced grade 4 tracheal stenosis, which was relieved after stent implantation, no other ≥3 grade toxicities were observed. CONCLUSIONS: CIRT might be safe and effective in the management of TACC based on a short observation period. Further studies with more cases and longer observation are warranted.

Sequential boost of intensity-modulated radiotherapy with chemotherapy for inoperable esophageal squamous cell carcinoma: A prospective phase II study.

PURPOSE: This prospective phase II study aimed to determine the efficacy and tolerability of sequential boost of intensity-modulated radiation therapy (IMRT) with chemotherapy for patients with inoperable esophageal squamous cell carcinoma (ESCC). METHODS: Patients with histologically or cytologically proven inoperable ESCC were enrolled in this study (ChiCTR-OIC-17010485). A larger target volume for subclinical lesion was irradiated with 50 Gy, and then, a smaller target volume only including gross tumor was boosted to 66 Gy. The fraction dose was 2 Gy, and no elective node was irradiated. Concurrent and consolidation chemotherapy of fluorouracil (600 mg/m2 , days 1-3) plus cisplatin (25 mg/m2 , days 1-3) was administered every 4 weeks, for 4 cycles in total. The primary endpoint was 2-year progression-free survival (PFS). RESULTS: Eighty-eight patients were enrolled in this study. The median age was 65 years (range: 45-75 years), and 69 patients (78.4%) were men. With the median follow-up of 26 (range: 3-95) months, the 2- and 5-year PFS were 39.3% and 36.9%, respectively, and overall survival (OS) were 57.1% and 39.2%, respectively. Tumor stage and concurrent chemotherapy were independent OS predictors. Major acute adverse events were myelosuppression and esophagitis, most of which were grades 1-2. Nine percent and 2.3% of patients had grade 3 acute esophagitis and late esophageal strictures, respectively. CONCLUSIONS: Sequential boost to 66 Gy by IMRT with chemotherapy was safe and effective for inoperable ESCC. A randomized phase III study to compare with standard dose of 50 Gy is warranted.

Intensity Modulated Radiation Therapy Plus Etoposide/Cisplatin for Patients With Limited Advanced Unresectable Thymic Epithelial Tumors: A Prospective Phase 2 Study.

PURPOSE: This prospective phase 2 study evaluated the efficacy and safety of intensity modulated radiation therapy plus etoposide/cisplatin (EP) for patients with unresectable thymic epithelial tumors (TETs). METHODS AND MATERIALS: Patients with limited advanced unresectable TETs whose lesions could be encompassed within radiation fields were enrolled in this study. Two cycles of EP (75 mg/m2 etoposide and 25 mg/m2 cisplatin on days 1-3 and days 29-31) were administered concurrently with radiation therapy, followed by 2 cycles after radiation therapy. The primary endpoint was the objective response rate. The secondary endpoints were the progression-free survival rate, overall survival rate, and incidence of adverse events. RESULTS: Fifty-six patients were enrolled between June 2011 and May 2018. Twenty-two and 34 patients had thymomas and thymic carcinomas, respectively. The median age was 52 (range, 21-76) years, and 30 patients (53.6%) were men. Eight patients (14.3%) had stage III tumors, 6 (10.7%) had stage IVA tumors, and 42 (75.0%) had stage IVB tumors. The objective response rate was 85.7% (95% confidence interval, 76.3%-95.2%). With a median follow-up of 46 (range, 7-101) months, the 1-, 2-, and 5-year progression-free survival rates were 66.1%, 48.0%, and 29.5%, and the 1-, 2-, and 5-year overall survival rates were 91.0%, 76.2%, and 56.2%, respectively. The most common grade 3 to 4 adverse event was leukopenia (42.9%). Pulmonary fibrosis was also observed (5.3%). CONCLUSIONS: Because intensity modulated radiation therapy with EP is effective and safe for limited advanced unresectable TETs, it could be a suitable treatment option for such patients.

Three-dimensional conformal radiation therapy alone for esophageal squamous cell carcinoma: 10-year survival outcomes.

BACKGROUND: Concurrent chemoradiation is the standard treatment for locally advanced esophageal squamous cell carcinoma (SCC). We conducted a phase II study to explore the effect of three-dimensional conformal radiotherapy (3-DCRT) alone for patients with locally advanced esophageal SCC. This study aimed to analyze the long-term survival outcomes. METHODS: Between November 2004 and April 2007, 30 patients with thoracic esophageal SCC underwent late-course sequential boost 3-DCRT at Fudan University Shanghai Cancer Center. The planning target volume (PTV1) comprised a 1.2-1.5 cm lateral margin around the gross tumor volume and a 3.0 cm margin, superior and inferior to the gross tumor volume. PTV2 encompassed the gross tumor volume with a margin of 0.5-0.7 cm. The PTV1 dose delivered was 50 Gy, and the PTV2 dose was a boost dose of 16 Gy, resulting in a total dose of 66 Gy. No chemotherapy was administered. RESULTS: The median follow-up time was 30 months for all patients, and 132 months for patients who were alive. The median overall survival was 27 months (95% confidence interval [CI] 18.9-35.0). The 2-, 5-, and 10-year overall survival rates were 56.6%, 33.3%, and 26.6%, respectively. The median progression-free survival was 14 months (95% CI 7.7-20.2 months), and the 2-, 5-, and 10-year progression-free survival rates were 33.3%, 30.0%, and 26.6%, respectively. No severe late toxicity was observed in long-term survivors. CONCLUSION: Late-course sequential boost 3-DCRT is safe and feasible with promising long-term outcomes for esophageal SCC.

Simultaneously avoiding the hippocampus and hypothalamic-pituitary axis during whole brain radiotherapy: A planning study.

Whole brain radiotherapy (WBRT) is the preferred treatment for multiple brain metastases, and patients with limited-stage small cell lung cancer undergo prophylactic cranial irradiation after complete remission. However, neurotoxicity remains a complication. In addition to protecting the hippocampus from irradiation to preserve cognitive function, it is also critical to avoid irradiating the hypothalamic-pituitary axis to preserve endocrine and immune function. This study aimed to evaluate the feasibility of delivering WBRT while protecting the hippocampus and hypothalamic-pituitary axis. Thirteen patients with limited-stage small cell lung cancer were enrolled in this study. The hippocampus, hypothalamus, and pituitary gland were contoured based on T1-weighted magnetic resonance imaging. The prescribed dose to the whole brain planning target volume was 25 Gy in 10 fractions. Two treatment plans using equispaced coplanar intensity-modulated radiotherapy (IMRT) were generated: WBRT with hippocampus avoidance (H-A) and WBRT with hippocampus, hypothalamus, and pituitary gland avoidance (H-HP-A). Both "H-A" and "H-HP-A" plans successfully protected the hippocampus, which received mean doses of 9.1 and 9.6 Gy, respectively (p = 0.0002), whereas the "H-HP-A" plan decreased the doses to both the hypothalamus (mean dose 11.06 Gy) and the pituitary gland (mean dose 10.66 Gy). Both "H-A" and "H-HP-A" plans showed similar target coverage of 95.1%. The homogeneity index of the "H-A" plan was slightly better than that of the "H-HP-A" plan (0.20 vs 0.23, p= 0.0012). In conclusion, the use of equispaced coplanar IMRT was found to simultaneously protect the hippocampus and hypothalamic-pituitary axis while delivering WBRT with acceptable target coverage and homogeneity.

Electroacupuncture Improves Cognitive Function and Hippocampal Neurogenesis after Brain Irradiation.

Cognitive impairments after brain irradiation seriously affect quality of life for patients, and there is currently no effective treatment. In this study using an irradiated rat model, the role of electroacupuncture was investigated for treatment of radiation-induced brain injury. Animals received 10 Gy exposure to the entire brain, and electroacupuncture was administered 3 days before irradiation as well as up to 2 weeks postirradiation. Behavioral tests were performed one month postirradiation, and rats were then sacrificed for histology or molecular studies. Electroacupuncture markedly improved animal performance in the novel place recognition test. In the emotion test, electroacupuncture reduced defecation during the open-field test, and latency to consumption of food in the novelty suppressed feeding test. Brain irradiation inhibited the generation of immature neurons, but did not cause neural stem cell loss. Electroacupuncture partially restored hippocampal neurogenesis. Electroacupuncture decreased the amount of activated microglia and increased resting microglia in the hippocampus after irradiation. In addition, electroacupuncture promoted mRNA and protein expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. In conclusion, electroacupuncture could improve cognitive function and hippocampal neurogenesis after irradiation, and the protective effect of electroacupuncture was associated with the modulation of microglia and upregulation of BDNF in the hippocampus.

Stage IVb thymic carcinoma: patients with lymph node metastases have better prognoses than those with hematogenous metastases.

BACKGROUND: This study aimed to analyze the pattern of lymphogenous and hematogenous metastases in patients with stage IVb thymic carcinomas and identify prognostic factors for their survivals. METHODS: Between September 1978 and October 2014, 68 patients with pathologically confirmed stage IVb thymic carcinomas were treated at Fudan University Shanghai Cancer Center. Forty-three patients had lymph node involvement without distant metastases, and the remaining 25 patients had hematogenous metastases. Clinical-pathological characteristics, including age, sex, histologic subtype, tumor size, metastasis, treatment modalities, such as surgical resection, radiotherapy, and chemotherapy, and clinical outcomes, such as overall survival (OS) and progression free survival (PFS), were analyzed. RESULTS: The median follow-up time was 22 months (range, 1-126 months). The median OS of all patients with stage IVb thymic carcinomas was 30 months, and the 5-year overall survival rate was 25.1%. The median PFS was 11 months, and the 5-year PFS was 17.9%. Stage IVb patients with lymph node involvement had a better survival than those with distant metastasis (40 vs. 20 months, p = 0.002). Patients with myasthenia gravis had a worse prognosis (p = 0.033). Multivariate analysis identified metastatic status as an independent prognostic factor for OS in patients with stage IVb thymic carcinomas. CONCLUSIONS: Patients with lymph node involvement had a better survival than those with distant metastases. Much work remains to investigate the prognosis of patients with stage IVb thymic carcinomas and to explore different treatment strategies for patients with lymph node involvement and distant metastases.

Hypo- or conventionally fractionated radiotherapy combined with chemotherapy in patients with limited stage small cell lung cancer.

BACKGROUND: Previous data from our institution showed that hypofractionated thoracic radiotherapy (HypoTRT) with concurrent etoposide/platinum chemotherapy yielded favorable survival in patients with limited-stage small cell lung cancer (LS-SCLC). The present study retrospectively compared the survival outcomes, failure patterns and toxicities between groups of LS-SCLC patients treated with conventionally fractionated thoracic radiotherapy (ConvTRT) or HypoTRT combined with chemotherapy. METHODS: Medical records of LS-SCLC patients between January 2010 and December 2013 at Fudan University Shanghai Cancer Center were retrospectively reviewed. All patients treated with chemotherapy and ConvTRT (2 Gy per fraction daily, DT ≥ 56 Gy) or HypoTRT (2.5 Gy per fraction daily, DT = 55 Gy) were eligible for analysis. Progression-free survival (PFS) and overall survival (OS) were generated for different populations using the Kaplan-Meier method and compared using the log-rank test. Comparisons of failure patterns and toxicity were analyzed using the χ 2 test. RESULTS: A total of 170 patients treated with HypoTRT (n = 69) or ConvTRT (n = 101) were eligible for analysis. The median PFS and OS were 13.7 and 25.3 months, respectively, in the ConvTRT cohort, which was similar to the HypoTRT cohort (PFS 18.2 months, p = 0.991, and OS 27.2 months, p = 0.698), with a median follow-up of 30 months. Multivariate analysis revealed that PCI and TNM stage were prognostic factors for PFS and that PCI was prognostic for OS. The patterns of failure (stratified by local-regional recurrence, distant metastasis or both as first relapse) were similar between the dose cohorts (p = 0.693, p = 0.330, p = 0.572). Distant metastasis remained the main failure pattern. The brain was the most frequent remote failure site, followed by bone, liver and adrenal gland. PCI improved the 2-year survival rate from 46.1% to 70.0% and the 2-year PFS rate from 20.9% to 45.3%, respectively (p < 0.001). Grade ≥3 esophagitis and pneumonitis occurred in 9.9% and 11.9%, respectively, of the patients in the ConvTRT cohort and in 11.6% and 10.0%, respectively, of those in the HypoTRT cohort (p = 0.815). CONCLUSION: This retrospective analysis demonstrated that HypoTRT or ConvTRT combined with etoposide/platinum chemotherapy yielded statistically similar survival, treatment failure outcomes, and toxicity profiles. PCI correlated with improved PFS and OS.

Electroacupuncture prevents cognitive impairments by regulating the early changes after brain irradiation in rats.

Cognitive impairments severely affect the quality of life of patients who undergo brain irradiation, and there are no effective preventive strategies. In this study, we examined the therapeutic potential of electroacupuncture (EA) administered immediately after brain irradiation in rats. We detected changes in cognitive function, neurogenesis, and synaptic density at different time points after irradiation, but found that EA could protect the blood-brain barrier (BBB), inhibit neuroinflammatory cytokine expression, upregulate angiogenic cytokine expression, and modulate the levels of neurotransmitter receptors and neuropeptides in the early phase. Moreover, EA protected spatial memory and recognition in the delayed phase. At the cellular/molecular level, the preventative effect of EA on cognitive dysfunction was not dependent on hippocampal neurogenesis; rather, it was related to synaptophysin expression. Our results suggest that EA applied immediately after brain irradiation can prevent cognitive impairments by protecting against the early changes induced by irradiation and may be a novel approach for preventing or ameliorating cognitive impairments in patients with brain tumors who require radiotherapy.

Phase 2 study of accelerated hypofractionated thoracic radiation therapy and concurrent chemotherapy in patients with limited-stage small-cell lung cancer.

PURPOSE: To prospectively investigate the efficacy and toxicity of accelerated hypofractionated thoracic radiation therapy (HypoTRT) combined with concurrent chemotherapy in the treatment of limited-stage small-cell lung cancer (LS-SCLC), with the hypothesis that both high radiation dose and short radiation time are important in this setting. METHODS AND MATERIALS: Patients with previously untreated LS-SCLC, Eastern Cooperative Oncology Group performance status of 0 to 2, and adequate organ function were eligible. HypoTRT of 55 Gy at 2.5 Gy per fraction over 30 days was given on the first day of the second or third cycle of chemotherapy. An etoposide/cisplatin regimen was given to 4 to 6 cycles. Patients who had a good response to initial treatment were offered prophylactic cranial irradiation. The primary endpoint was the 2-year progression-free survival rate. RESULTS: Fifty-nine patients were enrolled from July 2007 through February 2012 (median age, 58 years; 86% male). The 2-year progression-free survival rate was 49.0% (95% confidence interval [CI] 35.3%-62.7%). Median survival time was 28.5 months (95% CI 9.0-48.0 months); the 2-year overall survival rate was 58.2% (95% CI 44.5%-71.9%). The 2-year local control rate was 76.4% (95% CI 63.7%-89.1%). The severe hematologic toxicities (grade 3 or 4) were leukopenia (32%), neutropenia (25%), and thrombocytopenia (15%). Acute esophagitis and pneumonitis of grade ≥3 occurred in 25% and 10% of the patients, respectively. Thirty-eight patients (64%) received prophylactic cranial irradiation. CONCLUSION: Our study showed that HypoTRT of 55 Gy at 2.5 Gy per fraction daily concurrently with etoposide/cisplatin chemotherapy has favorable survival and acceptable toxicity. This radiation schedule deserves further investigation in LS-SCLC.

Simultaneous integrated boost intensity-modulated radiotherapy in esophageal carcinoma: early results of a phase II study.

PURPOSE: The safety and efficacy of using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for patients with esophageal squamous cell carcinoma were evaluated in a single-institution phase II setting. METHODS AND MATERIALS: Between June 2007 and October 2009, 45 patients underwent concurrent chemoradiotherapy (n = 27) or radiotherapy alone (n = 18). Two planning target volumes (PTV) were defined for the SIB: PTVC and PTVG, with prescribed doses of 50.4 Gy to the PTVC (1.8 Gy/fraction) and 63 Gy to the PTVG (2.25 Gy/fraction), both given in 28 fractions. RESULTS: At a median follow-up interval of 20.3 months, the 3-year overall survival (OS) and progression-free survival (PFS) rates were 42.2 and 40.7 %, respectively. The median overall survival time was 21 months; locoregional control rates were 83.3 % at 1 year and 67.5 % at 3 years. According to CTCAE (version 3.0) criteria, none of the patients developed grade 4-5 toxicity. The most common grade 2 and 3 radiation-related toxicity was radiation esophagitis, occurring in 64 % of all patients (but only 13 % as grade 3). No patient developed grade > 2 pulmonary complications. CONCLUSION: SIB-IMRT is a feasible therapeutic approach for esophageal carcinoma patients and provides encouraging locoregional control with a low toxicity profile. Further investigations should focus on dose escalation and optimization of the combination with systemic therapies.

Patterns of local-regional failure in completely resected stage IIIA(N2) non-small cell lung cancer cases: implications for postoperative radiation therapy clinical target volume design.

PURPOSE: To analyze patterns of local-regional failure (LRF) for completely resected stage IIIA(N2) non-small cell lung cancer (NSCLC) patients treated in our hospital and to propose a clinical target volume (CTV) for postoperative radiation therapy (PORT) in these patients. METHODS AND MATERIALS: From 2005 to 2011, consecutive patients with pT1-3N2 NSCLC who underwent complete resection in our hospital but who did not receive PORT were identified. The patterns of first LRF were assessed and evaluated as to whether these areas would be encompassed by our proposed PORT CTV. RESULTS: With a median follow-up of 24 months, 173 of 250 patients (69.2%) experienced disease recurrence. Of the 54 patients with LRF as the first event, 48 (89%) had recurrence within the proposed PORT CTV, and 6 (11%) had failures occurring both within and outside the proposed CTV (all of which occurred in patients with right-lung cancer). Ninety-three percent of failure sites (104 of 112) would have been contained within the proposed PORT CTV. For left-sided lung cancer, the most common lymph node station failure site was 4R, followed by 7, 4L, 6, 10L, and 5. For right-sided lung cancer, the most common site was station 2R, followed by 10R, 4R, and 7. CONCLUSIONS: LRF following complete surgery was an important and potentially preventable pattern of failure in stage IIIA(N2) patients. Ipsilateral superior mediastinal recurrences dominated for right-sided tumors, whereas left-sided tumors frequently involved the bilateral superior mediastinum. Most of the LRF sites would have been covered by the proposed PORT CTV. A prospective investigation of patterns of failure after PORT (following our proposed CTV delineation guideline) is presently underway and will be reported in a separate analysis.

Variation in background intensity affects PET-based gross tumor volume delineation in non-small-cell lung cancer: the need for individualized information.

PURPOSE: Efficient tumor volume delineation by the combined use of PET/CT scanning is necessary for the proper treatment of non-small cell lung cancer (NSCLC). To understand the effect of variation in background intensity on PET-based gross tumor volume (GTV) delineation, we determined the background standard uptake values (SUVs) in normal lung, aorta (blood pool), and liver tissues and determined GTVs using different methods. METHODS: Thirty-seven previously untreated patients with pathologically confirmed NSCLC underwent PET/CT scanning with (18)F-fluorodeoxyglucose ((18)F-FDG). To obtain (18)F-FDG uptake values in normal tissues, regions of interest in the lung lobes (left upper, left lower, right upper, right middle, and right lower), aorta, and liver zones (left, intermediate, and right) were measured. The coefficient of variation (CV) of the SUV was measured for each normal structure. The CT-based GTV (GTV(CT)) was considered as the standard to which all PET-based GTVs were compared, and the correlation coefficient was analyzed to compare GTV obtained by the various delineation methods. Linear and logarithmic regression analyses were used to determine the relationship between GTV(CT) and GTV(PET). RESULTS: Normal lung tissue showed a significantly lower SUV and less stability than tissue of the aorta or liver. For the lung, aorta, and liver, the maximum SUV (SUV(max)) was 0.82 ± 0.32, 2.35 ± 0.37, and 3.24 ± 0.50 (CV: 38.79%, 15.82%, and 15.30%) and average SUV (SUV(ave)) was 0.49 ± 0.18, 1.68 ± 0.32, and 2.34 ± 0.36 (CV: 36.38%, 18.92%, and 15.44%), respectively. The SUVs of the lung varied from lobe to lobe. The GTV delineation method using the SUV(ave) of the lung lobe in which the tumor was found as background in the source-to-background ratio (SBR) method showed the best correlation with the volume of CT-based GTV (r=0.81). CONCLUSIONS: Our results show vast variation in the SUV among normal tissues, as well as in the different lung lobes. The tumor volume delineated using the SBR method correlated well with the CT-based tumor volume. We conclude that it is reasonable and precise to contour GTV in patients with NSCLC after taking into account the background intensity of the lung lobe in which the tumor is found.

A phase II trial of accelerated hypofractionated three-dimensional conformal radiation therapy in locally advanced non-small cell lung cancer.

PURPOSE: The aim of this study is to evaluate the safety and efficacy of accelerated hypofractionated radiotherapy (HypoRT) combined with sequential chemotherapy in locally advanced non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: A total of 34 patients with stage III NSCLC were enrolled. All patients received accelerated HypoRT (initially 50Gy/20 fractions, then a fraction dose of 3Gy) using three-dimensional conformal radiation therapy (3D-CRT), omitting elective nodal irradiation (ENI), to a total dose of 65-68Gy. All patients received two cycles of induction chemotherapy; 1-2 cycles of consolidation chemotherapy were given to 31 patients. The primary outcome measure was a profile of radiation toxicity. The secondary endpoints included overall survival (OS), progression-free survival (PFS), locoregional PFS (LR-PFS) and the pattern of initial failure. RESULTS: Radiation toxicity was minimal. The median and 3-year OS, PFS were 19.0 months, 32.1%; 10.0 months, 29.8%, respectively. The 1-, 2-, and 3-year LR-PFS were 69.6%, 60.9% and 60.9%, respectively. No patient experienced isolated elective nodal failure as the first site of failure. CONCLUSION: This study suggests that accelerated HypoRT using 3D-CRT omitting ENI can be used in combination with sequential chemotherapy in locally advanced NSCLC.

Loss of neuronal protein expression in mouse hippocampus after irradiation.

The effects of radiation on neurons are incompletely characterized. We evaluated changes in the expression of neuronal nuclear and other proteins in the mouse hippocampus after 17-Gy whole-brain irradiation. Expression of neuronal nuclei (NeuN), neuron-specific enolas, prospero-related homeobox 1 (Prox1), calbindin D28k, and synaptophysin 1 in the CA1, CA3, and dentate gyrus of the hippocampus was determined by immunohistochemistry; neuronal numbers were estimated by design-based stereology. At 7 days after irradiation, there was a marked reduction of NeuN neurons in CA3. Stereologic estimates confirmed a significant reduction in NeuN neurons in CA3 at 7 days, in the dentate gyrus at 7 days, 3 weeks and 2 months, and in CA1 at 2 months compared with controls; neuron-specific enolase and prospero-related homeobox 1-positive neurons in the CA3 subregion were also decreased at 7 days. The numbers of granule and pyramidal cells identified by 4'6-diamidino-2-phenylindole nuclear staining, however, remained unchanged, and there were no changes in calbindin D28k or synaptophysin 1 immunoreactivity after irradiation. We conclude that irradiation may result in a temporary loss of neuronal protein expression in mouse hippocampus. These changes do not necessarily indicate loss of neurons and indicate the need for caution regarding the use of phenotypic markers such as NeuN to estimate changes in neuronal numbers after irradiation.

Role of intercellular adhesion molecule-1 in radiation-induced brain injury.

PURPOSE: To determine the role of intercellular adhesion molecule-1 (ICAM-1) in the pathogenesis of brain injury after irradiation (IR). METHODS AND MATERIALS: We assessed the expression of ICAM-1 in mouse brain after cranial IR and determined the histopathologic and behavioral changes in mice that were either wildtype (+/+) or knockout (-/-) of the ICAM-1 gene after IR. RESULTS: There was an early dose-dependent increase in ICAM-1 mRNA and protein expression after IR. Increased ICAM-1 immunoreactivity was observed in endothelia and glia of ICAM-1+/+ mice up to 8 months after IR. ICAM-1-/- mice showed no expression. ICAM-1+/+ and ICAM-1-/- mice showed similar vascular abnormalities at 2 months after 10-17 Gy, and there was evidence for demyelination and inhibition of hippocampal neurogenesis at 8 months after 10 Gy. After 10 Gy, irradiated ICAM-1+/+ and ICAM-1-/- mice showed similar behavioral changes at 2-6 months in open field, light-dark chamber, and T-maze compared with age-matched genotype controls. CONCLUSION: There is early and late upregulation of ICAM-1 in the vasculature and glia of mouse brain after IR. ICAM-1, however, does not have a causative role in the histopathologic injury and behavioral dysfunction after moderate single doses of cranial IR.