Fiducial marker position affects target volume in stereotactic lung irradiation.

PURPOSE: Real-time tracking systems of moving respiratory targets such as CyberKnife, Radixact, or Vero4DRT are an advanced robotic radiotherapy device used to deliver stereotactic body radiotherapy (SBRT). The internal target volume (ITV) of lung tumors is assessed through a fiducial marker fusion using four-dimensional computed tomography (CT). It is important to minimize the ITV to protect normal lung tissue from exposure to radiation and the associated side effects post SBRT. However, the ITV may alter if there is a change in the position of the fiducial marker with respect to the tumor. This study investigated the relationship between fiducial marker position and the ITV in order to prevent radiation exposure of normal lung tissue, and correct target coverage. MATERIALS AND METHODS: This study retrospectively reviewed 230 lung cancer patients who received a fiducial marker for SBRT between April 2015 and September 2021. The distance of the fiducial marker to the gross tumor volume (GTV) in the expiratory (dex ) and inspiratory (din ) CT, and the ratio of the ITV/V(GTVex ), were investigated. RESULTS: Upon comparing each lobe, although there was no significant difference in the ddiff and the ITV/V(GTVex ) between all lobes for dex  < 10 mm, there was significant difference in the ddiff and the ITV/V(GTVex ) between the lower and upper lobes for dex ≥ 10 mm (p < 0.05). Moreover, there was significant difference in the ddiff and the ITV/V(GTVex ) between dex ≥10 mm and dex  < 10 mm in all lung regions (p < 0.05). CONCLUSION: The ITV that had no margin from GTVs increased when dex was ≥10 mm for all lung regions (p < 0.05). Furthermore, the increase in ITV tended to be greater in the lower lung lobe. These findings can help decrease the possibility of adverse events post SBRT, and correct target coverage.

Stereotactic body radiotherapy for second primary lung cancer and intra-parenchymal lung metastasis in patients previously treated with surgery: evaluation of indications and predictors of decreased respiratory function.

BACKGROUND: The adaptation criteria for administration of stereotactic body radiotherapy (SBRT) to patients with lung cancer who previously underwent surgery and subsequently developed a second primary lung cancer (SPLC) or intra-parenchymal lung metastasis (IPLM) are controversial, unlike the criteria for repeat surgery. We aimed to evaluate the feasibility of SBRT for these patients. Factors associated with decreased respiratory function were also evaluated. MATERIAL AND METHODS: Sixty-nine patients with 89 lesions who underwent SBRT between 2008 and 2017 were analyzed. Of these, 29 were diagnosed with SPLC while the remaining 40 had IPLM. The distribution of histological types was as follows: squamous cell carcinoma (n = 13 lesions); adenocarcinoma (n = 25); non-small cell carcinoma (n = 1); unknown histological type (n = 49). The prescribed doses to the planning target volume (PTV) were 50 Gy in five fractions for 85 lesions and 60 Gy in 10 fractions for four lesions at PTV mean. RESULTS: Over a median follow-up period of 55 months, the 4-year overall survival and local control rates were 50.3% and 87.6%, respectively. Six patients experienced grade 2 radiation pneumonitis and one experienced grade 3. Two patients experienced grade 5 pulmonary fibrosis. Decreased respiratory function was observed in 10 patients (15.1%). On multivariate analysis, the presence of pulmonary disease before SBRT was the only statistically significant factor associated with decreased respiratory function. CONCLUSIONS: SBRT is safe and feasible in patients with SPLC or IPLM previously treated surgically. Pre-existing pulmonary disease was a predictive factor for decreased respiratory function.

[18F]Fluorodeoxyglucose uptake by positron emission tomography predicts outcomes for oropharyngeal and hypopharyngeal cancer treated with definitive radiotherapy.

This study evaluated the prognostic significance of the maximum standardized uptake value of the primary site (pSUVmax) in 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans of patients with oropharyngeal or hypopharyngeal cancer who were treated using definitive radiotherapy. The study included 86 patients who were primarily treated with radiotherapy for oropharyngeal or hypopharyngeal cancer. Sixty-nine patients underwent concurrent chemotherapy. The associations between pre-treatment pSUVmax and treatment outcomes were evaluated. The most appropriate pSUVmax cut-off value for predicting disease-free survival (DFS) and local control (LC) was selected using receiver operating characteristic (ROC) curves. The median follow-up time for surviving patients was 60 months, while the median survival time in the entire patient cohort was 55 months. A pSUVmax cut-off value of 9.0 showed the best discriminative performance. Five-year OS and DFS rates were 65.9% and 60.0%, respectively. In univariate analyses, pSUVmax (p = 0.009), T-stage (p = 0.001), N-stage (p = 0.039), and clinical stage (p = 0.017) were identified as significant prognostic predictors for DFS. The multivariate analysis did not identify any statistically significant factors, but the association between pSUVmax and DFS was borderline significant (p = 0.055). Interestingly, pSUVmax was predictive of local controllability in T1-T2 disease (p = 0.024), but there was no significant association for T3-T4 disease (p = 0.735). In this study, pSUVmax was predictive of DFS and LC in patients with oropharyngeal or hypopharyngeal cancer that was treated with definitive radiotherapy. pSUVmax was strongly associated with LC in T1-T2 disease.

Hypofractionated stereotactic radiotherapy for brain metastases from lung cancer : Evaluation of indications and predictors of local control.

AIM: To evaluate the efficacy and toxicity of hypofractionated stereotactic radiotherapy (HSRT) for brain metastases (BMs) from lung cancer, and to explore prognostic factors associated with local control (LC) and indication. PATIENTS AND METHODS: We evaluated patients who were treated with linac-based HSRT for BMs from lung cancer. Lesions treated with stereotactic radiosurgery (SRS) in the same patients during the same periods were analysed and compared with HSRT in terms of LC or toxicity. There were 53 patients with 214 lesions selected for this analysis (HSRT: 76 lesions, SRS: 138 lesions). For HSRT, the median prescribed dose was 35 Gy in 5 fractions. RESULTS: The 1­year LC rate was 83.6 % in HSRT; on multivariate analysis, a planning target volume (PTV) of <4 cm(3), biologically effective dose (BED10) of ≥51 Gy, and adenocarcinoma were significantly associated with better LC. Moreover, in PTVs ≥ 4 cm(3), there was a significant difference in LC between BED10 < 51 Gy and ≥ 51 Gy (p = 0.024). On the other hand, in PTVs < 4 cm(3), both HSRT and SRS had good LC with no significant difference (p = 0.195). Radiation necrosis emerged in 5 of 76 lesions (6.6 %) treated with HSRT and 21 of 138 (15.2 %) lesions treated with SRS (p = 0.064). CONCLUSION: Linac-based HSRT was safe and effective for BMs from lung cancer, and hence might be particularly useful in or near an eloquent area. PTV, BED10, and pathological type were significant prognostic factors. Furthermore, in BMs ≥ 4 cm(3), a dose of BED ≥ 51 Gy should be considered.

FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT.

OBJECTIVE: To evaluate the accuracy of PET/CT using (18)F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). METHODS: One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. RESULTS: The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). CONCLUSION: FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. KEY POINTS: • FDG-PET/CT is a more accurate post-treatment surveillance tool than ceCT for HNSCC. • FDG-PET/ceCT was useful, irrespective of the time interval after the last treatment. • FDG-PET/ceCT showed high negative predictive value and limited positive predictive value. • The added value of ceCT at FDG-PET/CT is minimal and likely not clinically relevant.

Transcriptional profile of tomato roots exhibiting Bacillus thuringiensis-induced resistance to Ralstonia solanacearum.

KEY MESSAGE: Activation of SA-dependent signaling pathway and suppression of JA-dependent signaling pathway seem to play key roles inB. thuringiensis-induced resistance toR. solanacearumin tomato plants. Bacillus thuringiensis, a well-known and effective bio-insecticide, has attracted considerable attention as a potential biological control agent for the suppression of plant diseases. Treatment of tomato roots with a filter-sterilized cell-free filtrate (CF) of B. thuringiensis systemically suppresses bacterial wilt caused by Ralstonia solanacearum through systemic activation of the plant defense system. Comparative analysis of the expression of the Pathogenesis-Related 1(P6) gene, a marker for induced resistance to pathogens, in various tissues of tomato plants treated with CF on their roots suggested that the B. thuringiensis-induced defense system was activated in the leaf, stem, and main root tissues, but not in the lateral root tissue. At the same time, the growth of R. solanacearum was significantly suppressed in the CF-treated main roots but not in the CF-treated lateral roots. This distinct activation of the defense reaction and suppression of R. solanacearum were reflected by the differences in the transcriptional profiles of the main and lateral tissues in response to the CF. In CF-treated main roots, but not CF-treated lateral roots, the expression of several salicylic acid (SA)-responsive defense-related genes was specifically induced, whereas jasmonic acid (JA)-related gene expression was either down-regulated or not induced in response to the CF. On the other hand, genes encoding ethylene (ET)-related proteins were induced equally in both the main and lateral root tissues. Taken together, the co-activation of SA-dependent signaling pathway with ET-dependent signaling pathway and suppression of JA-dependent signaling pathway may play key roles in B. thuringiensis-induced resistance to R. solanacearum in tomato.

Targeting Anterior Commissure Involvement with Hyperfractionated Radiotherapy for T1-T2 Squamous Cell Carcinoma of the Glottic Larynx.

Anterior commissure is involved in about 20% of early-stage glottic squamous cell carcinomas (EGSCCs). Treatment outcomes and prognostic factors for EGSCC with anterior commissure involvement (ACI) were evaluated by focusing on hyperfractionated radiotherapy (74.4 Gy in 62 fractions). One-hundred and fifty-three patients with T1-T2 EGSCC were included in this study. The median total doses for T1a, T1b, and T2 were 66, 74.4, and 74.4 Gy, respectively. Overall, 49 (32%) patients had T1a, 38 (25%) had T1b, and 66 (43%) had T2 disease. The median treatment duration was 46 days. The median follow-up duration was 5.1 years. The 10-year overall and cause-specific survival rates were 72% and 97%, respectively. The 10-year local control rates were 94% for T1a, 88% for T1b, and 81% for T2 disease. Local control rates in patients with ACI were slightly better than those in patients without ACI with T1a and T1b diseases; however, the difference was not significant. The 10-year laryngeal preservation rate was 96%. Six patients experienced grade 3 mucositis, and four patients had grade 3 dermatitis. Hyperfractionated radiotherapy was effective for T1 disease with ACI, but insufficient for T2 disease with ACI. Our treatment strategy resulted in excellent laryngeal preservation.

A viral satellite RNA induces yellow symptoms on tobacco by targeting a gene involved in chlorophyll biosynthesis using the RNA silencing machinery.

Symptoms on virus-infected plants are often very specific to the given virus. The molecular mechanisms involved in viral symptom induction have been extensively studied, but are still poorly understood. Cucumber mosaic virus (CMV) Y satellite RNA (Y-sat) is a non-coding subviral RNA and modifies the typical symptom induced by CMV in specific hosts; Y-sat causes a bright yellow mosaic on its natural host Nicotiana tabacum. The Y-sat-induced yellow mosaic failed to develop in the infected Arabidopsis and tomato plants suggesting a very specific interaction between Y-sat and its host. In this study, we revealed that Y-sat produces specific short interfering RNAs (siRNAs), which interfere with a host gene, thus inducing the specific symptom. We found that the mRNA of tobacco magnesium protoporphyrin chelatase subunit I (ChlI, the key gene involved in chlorophyll synthesis) had a 22-nt sequence that was complementary to the Y-sat sequence, including four G-U pairs, and that the Y-sat-derived siRNAs in the virus-infected plant downregulate the mRNA of ChlI by targeting the complementary sequence. ChlI mRNA was also downregulated in the transgenic lines that express Y-sat inverted repeats. Strikingly, modifying the Y-sat sequence in order to restore the 22-nt complementarity to Arabidopsis and tomato ChlI mRNA resulted in yellowing symptoms in Y-sat-infected Arabidopsis and tomato, respectively. In 5'-RACE experiments, the ChlI transcript was cleaved at the expected middle position of the 22-nt complementary sequence. In GFP sensor experiments using agroinfiltration, we further demonstrated that Y-sat specifically targeted the sensor mRNA containing the 22-nt complementary sequence of ChlI. Our findings provide direct evidence that the identified siRNAs derived from viral satellite RNA directly modulate the viral disease symptom by RNA silencing-based regulation of a host gene.

Comparative study of sub-second temporal resolution 4D-MRI and 4D-CT for target motion assessment in a phantom model.

To develop and investigate the feasibility of sub-second temporal resolution volumetric T1-weighted four-dimensional (4D-) MRI in comparison with 4D-CT for respiratory-correlated motion assessment using an MRI/CT-compatible phantom. Sub-second high temporal resolution (0.5 s) gradient-echo T1-weighted 4D-MRI was developed using a volumetric acquisition scheme with compressed sensing. An MRI/CT-compatible motion phantom (simulated liver tumor) with three sinusoidal movements of amplitudes and two respiratory patterns was introduced and imaged with 4D-MRI and 4D-CT to investigate the geometric accuracy of the target movement. The geometric accuracy, including centroid position, volume, similarity index of dice similarity coefficient (DSC), and Hausdorff distance (HD), was systematically evaluated. Proposed 4D-MRI achieved a similar geometric accuracy compared with 4D-CT regarding the centroid position, volume, and similarity index. The observed position differences of the absolute average centroid were within 0.08 cm in 4D-MRI and 0.03 cm in 4D-CT, less than the 1-pixel resolution for each modality. The observed volume difference in 4D-MRI/4D-CT was within 0.73 cm3 (4.5%)/0.29 cm3 (2.1%) for a large target and 0.06 cm3 (11.3%)/0.04 cm3 (11.6%) for a small target. The observed DSC values for 4D-MRI/4D-CT were at least 0.93/0.95 for the large target and 0.83/0.84 for the small target. The maximum HD values were 0.25 cm/0.31 cm for the large target and 0.21 cm/0.15 cm for the small target. Although 4D-CT potentially exhibit superior numerical accuracy in phantom studies, the proposed high temporal resolution 4D-MRI demonstrates sub-millimetre geometric accuracy comparable to that of 4D-CT. These findings suggest that the 4D-MRI technique is a viable option for characterizing motion and generating phase-dependent internal target volumes within the realm of radiotherapy.

Prognostic Value of Radiomics Analysis of Skeletal Muscle After Radical Irradiation of Esophageal Cancer.

BACKGROUND/AIM: Sarcopenia is an independent survival predictor in several tumor types. Computed tomography (CT) is the standard measurement for body composition assessment. Radiomics analysis of CT images allows for the precise evaluation of skeletal muscles. This study aimed to construct a prognostic survival model for patients with esophageal cancer who underwent radical irradiation using skeletal muscle radiomics. PATIENTS AND METHODS: We retrospectively identified patients with esophageal cancer who underwent radical irradiation at our institution between April 2008 and December 2017. Skeletal muscle radiomics were extracted from an axial pretreatment CT at the third lumbar vertebral level. The prediction model was constructed using machine learning coupled with the least absolute shrinkage and selection operator (LASSO). The predictive nomogram model comprised clinical factors with radiomic features. Three prediction models were created: clinical, radiomics, and combined. RESULTS: Ninety-eight patients with 98 esophageal cancers were enrolled in this study. The median observation period was 57.5 months (range=1-98 months). Thirty-five radiomics features were selected by LASSO analysis, and a prediction model was constructed using training and validation data. The average of the accuracy, specificity, sensitivity, and area under the concentration-time curve for predicting survival in esophageal cancer in the combined model were 75%, 92%, and 0.86, respectively. The C-indices of the clinical, radiomics, and combined models were 0.76, 0.80, and 0.88, respectively. CONCLUSION: A prediction model with skeletal muscle radiomics and clinical data might help determine survival outcomes in patients with esophageal cancer treated with radical radiotherapy.

Durvalumab Plus Concurrent Radiotherapy for Treatment of Locally Advanced Non-Small Cell Lung Cancer: The DOLPHIN Phase 2 Nonrandomized Controlled Trial.

Importance: Administration of durvalumab after concurrent chemoradiotherapy is the standard treatment of unresectable, locally advanced non-small cell lung cancer (NSCLC); however, 20% to 30% of patients do not receive durvalumab because of adverse events (AEs) during concurrent chemoradiotherapy. In addition, radiotherapy and immunotherapy have a synergistic effect. Objective: To investigate the efficacy and safety of durvalumab immunotherapy plus concurrent radiotherapy followed by maintenance with durvalumab therapy for treatment of locally advanced NSCLC without chemotherapy. Design, Setting, and Participants: The multicenter, single-arm DOLPHIN (Phase II Study of Durvalumab [MEDI4736] Plus Concurrent Radiation Therapy in Advanced Localized NSCLC Patients) nonrandomized controlled trial was performed by 12 institutions in Japan from September 13, 2019, to May 31, 2022. Participants in the primary registration phase included 74 patients with programmed cell death ligand 1 (PD-L1)-positive, unresectable, locally advanced NSCLC. The current analyses were conducted from June 1, 2022, to October 31, 2022. Interventions: Patients received radiotherapy (60 Gy) in combination with concurrent and maintenance durvalumab immunotherapy, 10 mg/kg every 2 weeks, for up to 1 year. Main Outcomes and Measures: The primary end point of the rate of 12-month progression-free survival (PFS), as assessed by an independent central review, was estimated using the Kaplan-Meier method and evaluated with 90% CIs calculated using the Greenwood formula. The key secondary end points were PFS, objective response rate, treatment completion rate, and AEs. Results: Data from 35 patients (median [range] age, 72 [44-83] years; 31 [88.6%] men) were included in the full analysis set of the evaluable population. The 12-month PFS rate was 72.1% (90% CI, 59.1%-85.1%), and the median PFS was 25.6 months (95% CI, 13.1 months to not estimable) at a median follow-up of 22.8 months (range, 4.3-31.8 months). Scheduled radiation therapy was completed in 97.1% of patients. The confirmed objective response rate was 90.9% (95% CI, 75.7%-98.1%), and the treatment completion rate was 57.6% (95% CI, 39.2%-74.5%). Among 34 patients evaluated in the safety analysis set, AEs of grade 3 or 4 occurred in 18 patients (52.9%), and of grade 5 in 2 patients (5.9%). Pneumonitis or radiation pneumonitis of any grade occurred in 23 patients (67.6%), and of grades 3 or 4 in 4 patients (11.8%). Conclusions and Relevance: Findings from this phase 2 nonrandomized controlled trial indicate that durvalumab immunotherapy combined with curative radiotherapy for patients with PD-L1-positive, unresectable, locally advanced NSCLC is a promising treatment with tolerable AEs and is appropriate as a study treatment for phase 3 clinical trials. Trial Registration: Japan Registry of Clinical Trials ID: jRCT2080224763.

Predicting factors of symptomatic radiation pneumonitis induced by durvalumab following concurrent chemoradiotherapy in locally advanced non-small cell lung cancer.

BACKGROUND: Concurrent chemoradiotherapy (CCRT) followed by durvalumab is the standard of care for unresectable locally-advanced non-small cell carcinoma (LA-NSCLC). However, a major concern about administration of durvalumab after CCRT is whether the incidence of symptomatic radiation pneumonitis (RP) may increase or not. In the present analysis, we report the initial results of CCRT followed by durvalumab in patients with LA-NSCLC in a real-world setting with focus on predicting factors for symptomatic RP. METHODS: Patients who were pathologically diagnosed as NSCLC and initiated treatment with CCRT followed by durvalumab between July 2018 to December 2019 were eligible for this study. Patients were included if they completed the planned CRT course and administered at least one course of durvalumab. We retrospectively investigated the preliminary survival outcome and incidence and predicting factors for symptomatic RP. RESULTS: Of the 67 patients who planned CCRT, 63 patients completed the entire CCRT course. Of these, 56 patients proceeded to consolidation with durvalumab. The median time to eternal discontinuation of durvalumab was 9.7 months. The cumulative proportion of the patients who exhibited symptomatic RP was 30, 40 and 44% at 3, 6 and 12 months, respectively. In multivariate analyses, pulmonary fibrosis score and lung V40 were significant predictive factors for symptomatic RP (p < 0.001, HR: 7.83, 95% CI: 3.38-18.13, and p = 0.034, HR: 3.17, 95% CI: 1.09-9.19, respectively). CONCLUSIONS: Pulmonary fibrosis sore and lung V40 were significant predictive factors for symptomatic RP. We should be cautious about the administration of durvalumab for patients having subclinical pulmonary fibrosis. To our best knowledge, this is one of the first report showing the predictive value of high dose volumes to the lung in patients with LA-NSCLC who received CCRT followed by durvalumab.

Risk-managed production of bioactive recombinant proteins using a novel plant virus vector with a helper plant to complement viral systemic movement.

A plant viral vector has the potential to efficiently produce recombinant proteins at a low cost in a short period. Although recombinant proteins can be also produced by transgenic plants, a plant viral vector, if available, may be more convenient when urgent scale-up in production is needed. However, it is difficult to use a viral vector in open fields because of the risk of escape to the environment. In this study, we constructed a novel viral vector system using a movement-defective Cucumber mosaic virus (CMV) vector, which is theoretically localized in the inoculated cells but infects systemically only with the aid of the transgenic helper plant that complements viral movement, diminishing the risk of viral proliferation. Interestingly, the helper plant systemically infected with the vector gave strong cross-protection against challenge inoculation with wild-type CMVs. Using CMV strains belonging to two discrete CMV groups (subgroups I and II), we also improved the system to prevent recombination between the vector and the transgene transcript in the helper plant. We here demonstrate the expression of an anti-dioxin single chain variable fragment (DxscFv) and interleukin-1 receptor antagonist (IL1-Ra) in Nicotiana benthamiana by this viral vector confinement system, which is applicable for many useful high-quality recombinant proteins.

Efficacy of Spacers in Radiation Therapy for Locally Advanced Pancreatic Cancer: A Planning Study.

BACKGROUND/AIM: We aimed to investigate the dosimetric effects of a spacer placed between the pancreas and surrounding gastrointestinal structures in intensity-modulated radiation therapy (IMRT) planning to provide more effective radiation therapy for locally advanced pancreatic cancer (LAPC). PATIENTS AND METHODS: Treatment planning was performed for six patients with LAPC based on computed tomography images without spacers and with 5-mm or 10-mm spacers virtually inserted under the supervision of a hepatobiliary pancreatic surgeon. The prescription dose was 63 Gy in 28 fractions. RESULTS: With the exception of one case of pancreatic head cancer, planning target volume receiving ≥95% of the prescribed dose (PTV V95) was achieved by 90% or more by inserting a spacer, and by 95% or more in all 3 cases of pancreatic body and tail cancer by inserting a 10-mm spacer. CONCLUSION: IMRT with appropriate spacer placement may help provide high-dose treatment for LAPC and improve associated patient outcomes.

Risk factors for osteoradionecrosis of the jaw in patients with head and neck squamous cell carcinoma.

BACKGROUND: To evaluate factors associated with osteoradionecrosis of the jaw (ORNJ) in patients with head and neck squamous cell carcinoma (HNSCC), focusing on jaw-related dose-volume histogram (DVH) parameters. METHODS: We retrospectively reviewed the medical records of 616 patients with HNSCC treated with curative-intent or postoperative radiation therapy (RT) during 2008-2018. Patient-related (age, sex, history of smoking or alcohol use, diabetes mellitus, performance status, pre-RT dental evaluation, pre- or post-RT tooth extraction), tumor-related (primary tumor site, T-stage, nodal status), and treatment-related (pre-RT surgery, pre-RT mandible surgery, induction or concurrent chemotherapy, RT technique) variables and DVH parameters (relative volumes of the jaw exposed to doses of 10 Gy-70 Gy [V10-70]) were investigated and compared between patients with and without ORNJ. The Mann-Whitney U test was used to compare RT dose parameters. Univariate and multivariate Cox regression analyses were used to assess factors associated with ORNJ development. Kaplan-Meier analyses were performed for cumulative ORNJ incidence estimation. RESULTS: Forty-six patients (7.5%) developed ORNJ. The median follow-up duration was 40 (range 3-145) months. The median time to ORNJ development was 27 (range 2-127) months. DVH analysis revealed that V30-V70 values were significantly higher in patients with than in those without ORNJ. In univariate analyses, primary tumor site, pre-RT mandible surgery, post-RT tooth extraction, and V60 > 14% were identified as important factors. In multivariate analyses, V60 > 14% (p = 0.0065) and primary tumor site (p = 0.0059) remained significant. The 3-year cumulative ORNJ incidence rates were 2.5% and 8.6% in patients with V60 ≤ 14% and > 14%, respectively (p < 0.0001), and 9.3% and 1.4% in patients with oropharyngeal or oral cancer and other cancers, respectively (p < 0.0001). CONCLUSIONS: V60 > 14% and oropharyngeal or oral cancer were found to be independent risk factors for ORNJ. These findings might be useful to minimize ORNJ incidence in HNSCC treated with curative RT.

The feasibility of transcatheter arterial chemoembolization following radiation therapy for hepatocellular carcinoma.

BACKGROUND: Technological developments have led to an increased usage of external-body radiotherapy (RT) for the treatment of hepatocellular carcinoma (HCC). Transcatheter arterial chemoembolization (TACE) may be required later in patients treated with RT because of the high recurrence rate and multinodular presentation of HCC. However, despite the risk of liver function impairment, the cumulative liver damage correlated with TACE following a hepatic RT has not been adequately assessed. PURPOSE: To evaluate the feasibility of TACE following RT for HCC. MATERIALS AND METHODS: Sixty-seven patients with HCC who underwent TACE after RT were retrospectively evaluated between 2012 and 2018. We assessed increases in Child-Turcotte-Pugh (CTP) by ≥2 points at 1 month, the incidence of major complications, survival duration, and short-term mortality within 6 months after TACE. Furthermore, we evaluated the predictive factors for liver function impairment and short-term mortality. RESULTS: Eight patients experienced a CTP increase ≥2 points at 1 month. There were no cases of liver abscesses or bilomas. Nine patients died within 6 months following TACE. The mean liver dose (MLD) was a significant predictor of liver function impairment at 1 month (p = 0.042). Low liver functional reserve, distant metastasis (p = 0.037), MLD (p = 0.046), TACE type (p = 0.025), and TACE within 3 months following RT (p = 0.007) were significant predictors of short-term mortality. CONCLUSIONS: Despite the feasibility of TACE following RT, clinicians should pay attention to impaired pretreatment liver function, following high dose RT, and the short duration between RT and TACE.

Rationale and Design for a Multicenter, Phase II Study of Durvalumab Plus Concurrent Radiation Therapy in Locally Advanced Non-Small Cell Lung Cancer: The DOLPHIN Study (WJOG11619L).

Durvalumab (anti-programmed cell death ligand-1) administration after concurrent chemoradiotherapy (cCRT) has improved the survival of patients with unresectable, locally advanced (LA) stage III non-small cell lung cancer (NSCLC). Some patients are unable to complete cCRT and cannot receive immunotherapy due to poor performance status based on adverse events after cCRT. Immunotherapy plays an important role in anti-programmed cell death ligand-1 (PD-L1)-positive advanced NSCLC and is replacing chemotherapy. In addition, radiotherapy and immunotherapy have been reported to have a synergistic effect. This Phase II, multicenter study (DOLPHIN, WJOG11619L, JapicCTI-194840) is designed to assess the efficacy and safety of durvalumab plus concurrent curative radiation therapy for PD-L1-positive unresectable LA-NSCLC without chemotherapy. Unresectable LA stage III NSCLC patients aged 20 years or older with a World Health Organization/Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 and PD-L1 positivity are enrolled. The patients will receive curative radiation therapy (60 Gy) plus durvalumab 10 mg/kg every 2 weeks (q2w) for up to 12 months until there is evidence of disease progression (PD) or unacceptable toxicity. The primary endpoint is the 12-month progression-free survival rate as assessed by an independent central review. The secondary endpoints are progression-free survival, overall survival, objective response rate, treatment completion rate, and safety. Recruitment began in September 2019.

Exosome-mediated radiosensitizing effect on neighboring cancer cells via increase in intracellular levels of reactive oxygen species.

The precise mechanism of intercellular communication between cancer cells following radiation exposure is unclear. Exosomes are membrane­enclosed small vesicles comprising lipid bilayers and are mediators of intercellular communication that transport a variety of intracellular components, including microRNAs (miRNAs or miRs). The present study aimed to identify novel roles of exosomes released from irradiated cells to neighboring cancer cells. In order to confirm the presence of exosomes in the human pancreatic cancer cell line MIAPaCa­2, ultracentrifugation was performed followed by transmission electron microscopy and nanoparticle tracking analysis (NanoSight) using the exosome­specific surface markers CD9 and CD63. Subsequent endocytosis of exosomes was confirmed by fluorescent microscopy. Cell survival following irradiation and the addition of exosomes was evaluated by colony forming assay. Expression levels of miRNAs in exosomes were then quantified by microarray analysis, while protein expression levels of Cu/Zn­ and Mn­superoxide dismutase (SOD1 and 2, respectively) enzymes in MIAPaCa­2 cells were evaluated by western blotting. Results showed that the uptake of irradiated exosomes was significantly higher than that of non­irradiated exosomes. Notably, irradiated exosomes induced higher intracellular levels of reactive oxygen species (ROS) and a higher frequency of DNA damage in MIAPaCa­2 cells, as determined by fluorescent microscopy and immunocytochemistry, respectively. Moreover, six up­ and five downregulated miRNAs were identified in 5 and 8 Gy­irradiated cells using miRNA microarray analyses. Further analysis using miRNA mimics and reverse transcription­quantitative PCR identified miR­6823­5p as a potential candidate to inhibit SOD1, leading to increased intracellular ROS levels and DNA damage. To the best of our knowledge, the present study is the first to demonstrate that irradiated exosomes enhance the radiation effect via increasing intracellular ROS levels in cancer cells. This contributes to improved understanding of the bystander effect of neighboring cancer cells.

HC-Pro, a potyvirus RNA silencing suppressor, cancels cycling of Cucumber mosaic virus in Nicotiana benthamiana plants.

The mixed infection of Cucumber mosaic virus (CMV) and a potyvirus has been known to increase CMV titer in Nicotiana benthamiana plants, resulting in synergistic viral symptoms. We found that among three potyviruses--Potato virus Y (PVY), Turnip mosaic virus (TuMV), and Clover yellow vein virus (C1YVV)--synergistic effects on CMV (or a recombinant CMV vector) titers were most efficiently induced by a co-infection with PVY in N. benthamiana plants. In addition, the helper component-proteinase (HC-Pro) gene of PVY expressed by transgenic plants, which is a viral RNA silencing suppressor, was sufficient to cancel the cycling pattern of CMV titer, resulting in increased levels of overall CMV accumulation. Surprisingly, we found that the levels of CMV and the foreign protein expressed from the CMV vector were much higher in the HC-Pro-transgenic plants than the levels detected in the plants mixed-infected with CMV and PVY. The mechanism for canceling the cyclic infection of CMV by the HC-Pro protein alone is discussed in view of the interaction between RNA silencing and HC-Pro, as well as the possible involvement of the 3a protein.

Novel artifact-robust and highly visible zinc solid fiducial marker for kilovoltage x-ray image-guided radiation therapy.

PURPOSE: To develop a novel biocompatible solid fiducial marker that prevents radiopaque imaging artifacts and also maintains high imaging contrast for kilovoltage x-ray image-guided radiation therapy. METHODS: The fiducial marker was made of pure zinc. An in-house water-equivalent phantom was designed to evaluate artifacts and visibility under various simulated treatment scenarios. Image artifacts were quantitatively assessed in terms of the metal artifact index (MAI) on kilovoltage computed tomography (CT) and cone-beam CT (CBCT) scans. Marker visibility was evaluated on two types of kilovoltage planar x-ray images in terms of the contrast-to-background ratio (CBR). Comparisons with a conventional gold fiducial marker were conducted. RESULTS: The use of zinc rather than a gold marker mitigates imaging artifacts. The MAI near the zinc marker decreased by 76, 79, and 77 % in CT, and by 77 (81), 74 (80), and 79 (85) % in CBCT full-fan (half-fan) scans, when using one-, two-, and three-marker phantom settings, respectively. The high-contrast part of the zinc marker exhibited CBRs above 2.00 for 28/32 exposures under four (lung, tissue, low-density bone, and high-density bone) different simulation scenarios, making its visibility comparable to that of the gold marker (30/32 exposures with CBRs > 2.00). CONCLUSIONS: We developed a biocompatible, artifact-robust, and highly visible solid zinc fiducial marker. Although further evaluation is needed in clinical settings, our findings suggest its feasibility and benefits for kilovoltage x-ray image-guided radiation therapy.