Current Status and Perspectives of Therapeutic Antibodies Targeting the Spike Protein S2 Subunit against SARS-CoV-2.

The global coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has devastated public health and the global economy. New variants are continually emerging because of amino acid mutations within the SARS-CoV-2 spike protein. Existing neutralizing antibodies (nAbs) that target the receptor-binding domain (RBD) within the spike protein have been shown to have reduced neutralizing activity against these variants. In particular, the recently expanding omicron subvariants BQ 1.1 and XBB are resistant to nAbs approved for emergency use by the United States Food and Drug Administration. Therefore, it is essential to develop broad nAbs to combat emerging variants. In contrast to the massive accumulation of mutations within the RBD, the S2 subunit remains highly conserved among variants. Therefore, nAbs targeting the S2 region may provide effective cross-protection against novel SARS-CoV-2 variants. Here, we provide a detailed summary of nAbs targeting the S2 subunit: the fusion peptide, stem helix, and heptad repeats 1 and 2. In addition, we provide prospects to solve problems such as the weak neutralizing potency of nAbs targeting the S2 subunit.

The function of SARS-CoV-2 spike protein is impaired by disulfide-bond disruption with mutation at cysteine-488 and by thiol-reactive N-acetyl-cysteine and glutathione.

Viral spike proteins play important roles in the viral entry process, facilitating attachment to cellular receptors and fusion of the viral envelope with the cell membrane. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to the cellular receptor angiotensin converting enzyme-2 (ACE2) via its receptor-binding domain (RBD). The cysteine residue at position 488, consisting of a disulfide bridge with cysteine 480 is located in an important structural loop at ACE2-binding surface of RBD, and is highly conserved among SARS-related coronaviruses. We showed that the substitution of Cys-488 with alanine impaired pseudotyped SARS-CoV-2 infection, syncytium formation, and cell-cell fusion triggered by SARS-CoV-2 spike expression. Consistently, in vitro binding of RBD and ACE2, spike-mediated cell-cell fusion, and pseudotyped viral infection of VeroE6/TMPRSS2 cells were inhibited by the thiol-reactive compounds N-acetylcysteine (NAC) and a reduced form of glutathione (GSH). Furthermore, we demonstrated that the activity of variant spikes from the SARS-CoV-2 alpha and delta strains were also suppressed by NAC and GSH. Taken together, these data indicate that Cys-488 in spike RBD is required for SARS-CoV-2 spike functions and infectivity, and could be a target of anti-SARS-CoV-2 therapeutics.

Wheat yellow mosaic virus resistant line, 'Kitami-94', developed by introgression of two resistance genes from the cultivar 'Madsen'.

'Kitahonami' is a soft red winter wheat (Triticum aestivum L.) cultivar that has high yield, good agronomic performance and good quality characteristics. It currently accounts for 73% of the wheat cultivation area of Hokkaido the northern island in Japan and 42% of Japan's overall wheat cultivation. However, this cultivar is susceptible to Wheat yellow mosaic virus (WYMV). WYMV has become widespread recently, with serious virus damage reported in Tokachi and Ohotsuku districts, which are the main wheat production areas in Hokkaido. Here, we report a new wheat breeding line 'Kitami-94', which was developed over four years by repeated backcrossing with 'Kitahonami' using DNA markers for WYMV resistance linked to the Qym1 and Qym2 from 'Madsen'. Basic maps of Qym1 and Qym2 were created and used to confirm that 'Kitami-94' reliably carried the two resistance genes. 'Kitami-94' demonstrated WYMV resistance, and had agronomic traits and quality equivalent to 'Kitahonami' except for higher polyphenol oxidase activity and lower thousand grain weight. 'Kitami-94' may be useful for elucidating the mechanism of WYMV resistance in the background of 'Kitahonami', and for developing new cultivars.

SARS-CoV-2 Spike Protein Mutation at Cysteine-488 Impairs Its Golgi Localization and Intracellular S1/S2 Processing.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to the cellular receptor-angiotensin-converting enzyme-2 (ACE2) as the first step in viral cell entry. SARS-CoV-2 spike protein expression in the ACE2-expressing cell surface induces cell-cell membrane fusion, thus forming syncytia. To exert its fusogenic activity, the spike protein is typically processed at a specific site (the S1/S2 site) by cellular proteases such as furin. The C488 residue, located at the spike-ACE2 interacting surface, is critical for the fusogenic and infectious roles of the SARS-CoV-2 spike protein. We have demonstrated that the C488 residue of the spike protein is involved in subcellular targeting and S1/S2 processing. C488 mutant spike localization to the Golgi apparatus and cell surface were impaired. Consequently, the S1/S2 processing of the spike protein, probed by anti-Ser-686-cleaved spike antibody, markedly decreased in C488 mutant spike proteins. Moreover, brefeldin-A-mediated endoplasmic-reticulum-to-Golgi traffic suppression also suppressed spike protein S1/S2 processing. As brefeldin A treatment and C488 mutation inhibited S1/S2 processing and syncytia formation, the C488 residue of spike protein is required for functional spike protein processing.

Direct Inhibition of SARS-CoV-2 Spike Protein by Peracetic Acid.

Peracetic acid (PAA) disinfectants are effective against a wide range of pathogenic microorganisms, including bacteria, fungi, and viruses. Several studies have shown the efficacy of PAA against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, its efficacy in SARS-CoV-2 variants and the molecular mechanism of action of PAA against SARS-CoV-2 have not been investigated. SARS-CoV-2 infection depends on the recognition and binding of the cell receptor angiotensin-converting enzyme 2 (ACE2) via the receptor-binding domain (RBD) of the spike protein. Here, we demonstrated that PAA effectively suppressed pseudotyped virus infection in the Wuhan type and variants, including Delta and Omicron. Similarly, PAA reduced the authentic viral load of SARS-CoV-2. Computational analysis suggested that the hydroxyl radicals produced by PAA cleave the disulfide bridges in the RBD. Additionally, the PAA treatment decreased the abundance of the Wuhan- and variant-type spike proteins. Enzyme-linked immunosorbent assay showed direct inhibition of RBD-ACE2 interactions by PAA. In conclusion, the PAA treatment suppressed SARS-CoV-2 infection, which was dependent on the inhibition of the interaction between the spike RBD and ACE2 by inducing spike protein destabilization. Our findings provide evidence of a potent disinfection strategy against SARS-CoV-2.

Analysis of treatment process time for real-time-image gated-spot-scanning proton-beam therapy (RGPT) system.

We developed a synchrotron-based real-time-image gated-spot-scanning proton-beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot-scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated-spot-scanning proton-beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot-scanning proton therapy with a gating function can be achieved in approximately 30-min time slots.

IV crystalloid fluid for acute alcoholic intoxication prolongs ED length of stay.

OBJECTIVES: Acute alcohol intoxication is often treated in emergency departments by intravenous crystalloid fluid (IVF), but it is not clear that this shortens the time to achieving sobriety. The study aim was to investigate the association of IVF infusion and length of stay in the ED. METHODS: This single-center retrospective cohort study was conducted in Japan and included patients aged ≥20years of age and treated for acute alcohol intoxication without or with IVF. The primary outcome was the length of the ED stay and the treatments were compared by time-to-event analysis. RESULTS: A total of 106 patients, 42 treated without IVF and 64 with IVF. The baseline characteristics of the two groups were similar. Kaplan-Meier analysis and the generalized Wilcoxon test found no significant difference between the two treatments in the time to ED discharge. The median time was 189 (IQR 160-230) minutes without IVF and 254.5 (203-267 minutes with IVF; p=0.052). A Cox proportional hazards regression model adjusted for potential confounding variables found that patients treated with IVF were less likely to be discharged earlier than those treated without IVF (HR 0.54, 95% CI: 0.35-0.84, p=0.006). CONCLUSIONS: IVF for treatment of acute alcoholic intoxication prolonged ED length of stay even after adjustment for potential confounders. Patients given IVF for acute alcohol intoxication should be selected with care.

Oligo-recurrence predicts favorable prognosis of brain-only oligometastases in patients with non-small cell lung cancer treated with stereotactic radiosurgery or stereotactic radiotherapy: a multi-institutional study of 61 subjects.

BACKGROUND: To investigate the prognostic value of oligo-recurrence in patients with brain-only oligometastases of non-small cell lung cancer (NSCLC) treated with stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT). METHODS: Patients treated with SRS or SRT for brain-only NSCLC oligometastases in 6 high-volume institutions in Japan between 1996 and 2008 were reviewed. Eligible patients met 1), 2), and 4) or 1), 3), and 4) of the following: 1) NSCLC with 1 to 4 brain metastases on magnetic resonance imaging (MRI) treated with SRS or SRT; 2) control of the primary lesions (thorax) at the time of SRS or SRT for brain metastases (patients meeting this criterion formed the oligo-recurrence group); 3) with SRS or SRT for brain metastases, concomitant treatment for active primary lesions (thorax) with curative surgery or curative stereotactic body radiotherapy (SBRT), or curative chemoradiotherapy (sync-oligometastases group); and 4) Karnofsky performance status (KPS) ≥70. RESULTS: The median overall survival (OS) of all 61 patients was 26 months (95 % CI: 17.5-34.5 months). The 2-year and 5-year overall survival rates were 60.7 and 15.7 %, respectively. Stratified by oligostatus, the sync-oligometastases group achieved a median OS of 18 months (95 % CI: 14.8-21.1 months) and a 5-year OS of 0 %, while the oligo-recurrence group achieved a median OS of 41 months (95 % CI: 27.8-54.2 months) and a 5-year OS of 18.6 %. On multivariate analysis, oligo-recurrence was the only significant independent factor related to a favorable prognosis (hazard ratio: 0.253 (95 % CI: 0.082-0.043) (p = 0.025). CONCLUSIONS: The presence of oligo-recurrence can predict a favorable prognosis of brain-only oligometastases in patients with NSCLC treated with SRS or SRT.

Overcoming antibody-resistant SARS-CoV-2 variants with bispecific antibodies constructed using non-neutralizing antibodies.

A current challenge is the emergence of SARS-CoV-2 variants, such as BQ.1.1 and XBB.1.5, that can evade immune defenses, thereby limiting antibody drug effectiveness. Emergency-use antibody drugs, including the widely effective bebtelovimab, are losing their benefits. One potential approach to address this issue are bispecific antibodies which combine the targeting abilities of two antibodies with distinct epitopes. We engineered neutralizing bispecific antibodies in the IgG-scFv format from two initially non-neutralizing antibodies, CvMab-6 (which binds to the receptor-binding domain [RBD]) and CvMab-62 (targeting a spike protein S2 subunit epitope adjacent to the known anti-S2 antibody epitope). Furthermore, we created a bispecific antibody by incorporating the scFv of bebtelovimab with our anti-S2 antibody, demonstrating significant restoration of effectiveness against bebtelovimab-resistant BQ.1.1 variants. This study highlights the potential of neutralizing bispecific antibodies, which combine existing less effective anti-RBD antibodies with anti-S2 antibodies, to revive the effectiveness of antibody therapeutics compromised by immune-evading variants.

Multiple-antibiotic-resistant Helicobacter pylori infection eradicated with a tailor-made quadruple therapy.

In 2008, a 44-year-old woman with mild epigastralgia diagnosed as having Helicobacter pylori-positive chronic gastritis without peptic ulcer underwent eradication therapy with lansoprazole (LPZ), amoxicillin (AMPC) and clarithromycin (CAM) for 7 days, but it failed, so treatment with rabeprazole, AMPC, and metronidazole (MNZ) for another 7 days was given, but it also failed. She was then prescribed a modified, 14-day sequential therapy of LPZ and AMPC with an increased dose of CAM followed by MNZ supplement, but the infection was still not eradicated. The H. pylori was cultured and examined for antibiotic susceptibility with the agar dilution method and was found to be resistant to CAM, MNZ, and levofloxacin, and non-sensitive to AMPC, namely multiple-antibiotic-resistant, although sensitive to minocycline. The CYP2C19 genotype of the patient was an extensive metabolizer (G681A: G/A, G636A: G/G). In 2010, she gave informed consent for a 14-day, tailor-made, modified classical (or modified high-dose PPI + AMPC) quadruple therapy comprising 30 mg LPZ, 500 mg AMPC and 500 mg bismuth subnitrate, qid, and 100 mg minocycline, bid. Two months later, her urea breath test was negative. Histology and bacterial culture were still negative 1 year after the therapy. She did not have any adverse events during or after the novel therapy, nor did she feel any further epigastralgia.

Gastric volvulus suspected by POCUS finding in the emergency department.

We described a case of a man in his 90s with gastric volvulus of which point-of-care ultrasound (POCUS) contributed to a rapid diagnosis. The patient had Borchardt's triad and POCUS showed a distended and fluid-filled stomach, which allowed us to strongly suspect gastric volvulus even prior to the abdominal CT scan. Gastric volvulus is a rare but life-threatening condition that may lead to tissue ischaemia and perforation. Therefore, a prompt diagnosis is extremely important. This case suggests that POCUS can be a powerful tool when clinicians suspect gastric volvulus.

The Association Between Early Administration of Noninvasive Ventilation and Short-Term Outcome for Acute Heart Failure.

Background Acute decompensated heart failure (ADHF) is a life-threatening disease that requires emergent intervention. Although noninvasive positive pressure ventilation (NPPV) is crucial for treating ADHF, the earliest time point for administering NPPV remains unknown. In this study, we hypothesized that early NPPV administration for patients with acute heart failure in the emergency department (ED) would lead to a better outcome. Methodology This is a single-center retrospective cohort study at an ED of a community hospital in Japan. The data were collected from consecutive patients who were administered NPPV for ADHF in the ED from April 2016 to September 2018. The primary exposure was the timing of NPPV administration (within 30 minutes versus over 30 minutes after arrival). The primary outcome was 30-day mortality. Results A total of 115 patients were included in this study. Overall, the median age was 78 (interquartile range [IQR] = 70-84 years), and 63 (54.9%) patients were male. The median time from the arrival at the ED to NPPV administration for the patients was 14 minutes (IQR = 8-30 minutes). Overall, 72% (83/115) of the patients were categorized as early administration group (<30 minutes). The total 30-day mortality was 7.0% (8/115), and the total tracheal intubation rate was 11% (13/115). Early NPPV administration for patients with ADHF was associated with lower 30-day mortality (3.6% vs. 16%; p = 0.04) and shorter length of oxygenation (four days vs. seven days; p < 0.01). Multivariate logistic regression test showed that 30-day mortality was significantly lower in the early treatment group (adjusted odds ratio = 0.19; 95% confidential interval = 0.04-0.90). Conclusions Although further investigation is needed, early NPPV administration for patients with ADHF in the ED was associated with lower 30-day mortality.

Spectra of functional gastrointestinal disorders diagnosed by Rome III integrative questionnaire in a Japanese outpatient office and the impact of overlapping.

BACKGROUND AND AIMS: The aim of this study was to establish the spectra of functional gastrointestinal disorders (FGID) in a Japanese outpatient office in Rome III. METHODS: The Rome III Diagnostic Questionnaire for Adult Functional GI Disorders was translated into Japanese and an automated analyzing program was made according to the scoring algorithm of the questionnaire. Among 1378 patients who visited the outpatient office of the Social Insurance Shiga Hospital between May 2007 and April 2009, 112 serial patients who had symptoms possibly originating from the gastrointestinal (GI) tract, but did not have evidence of organic disease, were recruited. The subjects answered the questionnaire, and the answers were analyzed with the automatic analyzer. RESULTS: During the study period, 94 of the 112 patients were diagnosed as having active FGID. Non-overlapping FGID was diagnosed in 41 (43.6%) of those. Of the 41 non-overlapping FGID patients, the most frequent diagnosis was irritable bowel syndrome (IBS) in 13 patients. Including overlapping cases, 165 FGID were diagnosed in 94 patients. The most frequent diagnosis was IBS in 33 patients (35.1%), the second was functional dyspepsia (FD) in 29 (30.9%) and the third was functional constipation in 21 (22.3%). The most frequent FGID overlapping with IBS was FD (36.4%), and the most frequent FGID overlapping with FD was IBS (41.4%). Of the 29 FD patients, 20 (69.0%) had functional bowel disorders. CONCLUSION: The most frequent FGID was IBS in both overlapping and non-overlapping FGID patients. IBS and FD were the most frequent combinations in overlapping FGID. Most cases of FD are possibly parts of functional bowel disorders.

Clinical outcomes of stereotactic brain and/or body radiotherapy for patients with oligometastatic lesions.

OBJECTIVE: Several recent studies have shown that oligometastatic disease has curative potential, although it was previously considered to signal a patient's last stage of life. Stereotactic body radiotherapy has been available for extra-cranial metastases in addition to stereotactic cranial radiotherapy for brain metastases. The aim of the present study was to retrospectively evaluate the clinical outcomes of stereotactic radiotherapy for patients with oligometastatic lesions. METHODS: Between 1999 and 2008, 41 patients with five or fewer detectable metastases were treated with stereotactic radiotherapy at our institution. The treated oligometastatic lesions were in the brain, lung and adrenal glands. RESULTS: With a median follow-up period of 20 months, the 3-year overall survival, progression-free survival, local control and distant control rates were 39%, 20%, 80% and 35%, respectively, and the respective 5-year rates were 28%, 20%, 80% and 35%. The median survival time was 24 months. According to interval to recurrence, the 3- and 5-year overall survival rates were 19% and 10%, respectively, for patients with <12 months (n = 18), compared with 53% and 40% for those with > or =12 months (n = 23) (P = 0.006). CONCLUSIONS: Precise stereotactic radiotherapy was effective in controlling oligometastatic lesions for patients with a median survival time of 24 months. Interval to recurrence may impact the overall survival rate and should be included in the stratification criteria in a prospective randomized trial to investigate the benefits of stereotactic radiotherapy for patients with oligometastases.

[Multifocal extranodal non-Hodgkin lymphoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy of pancreas head].

A 66-year-old-woman was hospitalized with acute pancreatitis, obstructive jaundice, and tumor of the upper arm in September, 2008. At first, we diagnosed primary pancreatic cancer involving left lung and hilar lymph node, left brachial muscle metastasis and dissemination to the left pleura, but the histological diagnosis of the upper arm tumor was diffuse large B-cell lymphoma. In addition, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy from the pancreatic tumor showed diffuse large B-cell lymphoma, the same as the upper arm tumor. We experienced a rare case of multifocal extranodal non-Hodgkin lymphoma and EUS-FNA was useful for the diagnosis pancreatic tumor.

[CD5-positive B-cell prolymphocytic leukemia].

CD5 is a T-cell marker that is expressed in mature B cell malignancies and other B cell chronic lymphoproliferative disorders, but the biologic function of CD5 is unknown. We report a 68-year-old woman with B-cell prolymphocytic leukemia (B-PLL) expressing CD5 antigen. On admission, jaundice and hepatosplenomegaly were noted. Hematological examination demonstrated a platelet count of 2.8 x 10(4)/microl and a white blood cell count of 19,900/microl with 69% PLL cells. Surface marker analysis of the PLL cells was positive for CD5, CD19, CD20, sIgM, and was negative for CD23, and cyclin D1 was negative in immunostaining.

Pulmonary Oligometastases Treated by Stereotactic Body Radiation Therapy: A Nationwide Survey of 1,378 Patients.

AIM: This study was performed to confirm the superior overall survival (OS) after pulmonary oligo-recurrence compared to pulmonary sync-oligometastases in a large nationwide study. PATIENTS AND METHODS: Patients that met the following criteria were included: 1 to 5 lung-only metastases at the beginning of stereotactic body radiation therapy (SBRT) was performed between January 2004 and June 2015, and the biological effective dose (BED) of SBRT was 75 Gy or more. The parameters included in the analyses were age, gender, ECOG PS, primary lesion, pathology, oligoetastatic state, SBRT date, chemotherapy before SBRT, chemotherapy concurrent SBRT, chemotherapy after SBRT, maximum tumor diameter, number of metastases, field coplanarity, dose prescription, BED10, OTT of SBRT. RESULTS: In total, 1,378 patients with 1,547 tumors were enrolled. Oligo-recurrence occurred in 1,016 patients, sync-oligometastases in 118, and unclassified oligometastases in 121. The three-year OS was 64.0% for oligo-recurrence and 47.5% for sync-oligometastasis (p<0.001). In the multivariate analysis, the hazard ratio (HR) for sync-oligometastases versus oligo-recurrence was 1.601 (p=0.014). Adverse events of Grade 5 were occurred in 3 patients. CONCLUSION: This is the first nationwide to indicate that the OS of patients with pulmonary oligo-recurrence is better than that of patients with sync-oligometastases.

New D-dimer threshold for Japanese patients with suspected pulmonary embolism: a retrospective cohort study.

BACKGROUND: In the diagnosis of pulmonary embolism (PE), the D-dimer threshold is based on studies conducted in Western countries, where the incidence rate is 5 times higher than that in Asian countries, including Japan. If we could elevate the D-dimer threshold based on the low pre-test probability in the Japanese population, we could omit the computed tomography pulmonary angiography (CTPA) which might lead to radiation exposure and contrast-induced nephropathy. Therefore, we aimed to determine a new D-dimer threshold specific to Japanese individuals. METHODS: We conducted a retrospective cohort study at an emergency department in Japan, using medical charts collected from January 2013 to July 2017. We included patients whose D-dimer were measured for suspicion of PE with low or intermediate probability of PE and CTPA were performed. The primary outcome was failure rate of the new D-dimer threshold, defined as the rate of PE detected by CTPA among patients with D-dimer under the new threshold ranging from 1000 to 1500 µg/L by 100. The new D-dimer threshold was appropriate if the upper limit of 95% confidence interval of the failure rate of PE was approximately 3%. RESULTS: In 395 patients included, the number of patients with PE was 24 (the prevalence was 6.1%). If the D-dimer threshold was 1100 µg/L, the failure rate was 0% (0/119), the upper limit of the 95% confidence interval of the failure rate was 3.1%, and 30% (119/395) of the CTPA might be omitted. CONCLUSION: The new D-dimer threshold could safely exclude PE. This result can be generalized to other Asian populations with a lower incidence of PE. Further prospective studies will be needed.

Combination of FDG-PET and FMISO-PET as a treatment strategy for patients undergoing early-stage NSCLC stereotactic radiotherapy.

BACKGROUND: We investigated the prognostic predictive value of the combination of fluorodeoxyglucose (FDG)- and fluoromisonidazole (FMISO)-PET in patients with non-small cell lung carcinoma (NSCLC) treated with stereotactic body radiation therapy (SBRT). PATIENTS AND METHODS: We prospectively examined patients with pathologically proven NSCLC; all underwent FDG and FMISO PET/CT scans before SBRT. PET images were acquired using a whole-body time-of-flight PET-CT scanner with respiratory gating. We classified them into recurrent and non-recurrent groups based on their clinical follow-ups and compared the groups' tumor diameters and PET parameters (i.e., maximum of the standardized uptake value (SUVmax), metabolic tumor volume, tumor-to-muscle ratio, and tumor-to-blood ratio). We performed univariate analysis to evaluate the impact of the PET variables on the patients' progression-free survival (PFS). We divided the patients by thresholds of FDG SUVmax and FMISO SUVmax obtained from receiver operating characteristic analysis for assessment of recurrence rate and PFS. RESULTS: Thirty-two NSCLC patients (19 male and 13 females; median age, 83 years) were enrolled. All received SBRT. At the study endpoint, 23 patients (71.9%) were non-recurrent and nine patients (28.1%) had recurrent disease. Significant between-group differences were observed in tumor diameter and all the PET parameters, demonstrating that those were significant predictors of the recurrence in all patients. In the 22 patients with tumors > 2 cm, tumor diameter and FDG SUVmax were not significant predictors. Thirty-two patients were divided into three patterns from the thresholds of FDG SUVmax (6.81) and FMISO SUVmax (1.89); A, low FDG and low FMISO (n = 14); B, high FDG and low FMISO (n = 8); C, high FDG and high FMISO (n = 10). No pattern A patient experienced tumor recurrence, whereas two pattern B patients (25%) and seven pattern C patients (70%) exhibited recurrence. A Kaplan-Meier analysis of all patients revealed a significant difference in PFS between patterns A and B (p = 0.013) and between patterns A and C (p < 0.001). In the tumors > 2 cm patients, significant differences in PFS were demonstrated between pattern A and C patients (p = 0.002). CONCLUSION: The combination of FDG- and FMISO-PET can identify patients with a baseline risk of recurrence and indicate whether additional therapy might be performed to improve survival.