BACKGROUND:Prospective data on definitive radiotherapy alone for early-stage oropharyngeal cancer (OPC) are limited. JCOG1208 evaluated intensity-modulated radiation therapy (IMRT) alone with reduced prophylactic nodal irradiation in selected patients with early-stage OPC. MATERIALS AND METHODS:JCOG1208 was a prospective, multi-institutional, single-arm study that enrolled patients aged 20-80 years with T1-2 N0-1 M0 OPC of the tonsil, base of tongue, or soft palate according to the UICC 7th edition. Concurrent chemotherapy was not permitted. Patients received two-step adaptive IMRT to 70 Gy in 35 fractions, including 46 Gy to the initial target volumes followed by a 24 Gy boost. The primary endpoint was 3-year overall survival (OS), with a predefined threshold of 80 %. RESULTS:Fifty-seven patients were enrolled. Median follow-up was 6.8 years. Three-year OS was 93.0 % (95 % CI, 82.4-97.3 %), and 5-year OS was 87.6 % (95 % CI, 75.8-93.9 %). Five-year progression-free survival and loco-regional progression-free survival were 77.0 % and 78.8 %, respectively. No recurrences occurred solely within omitted prophylactic nodal regions. Most patients with progression had p16-negative/unknown disease and/or smoking history. Grade ≥ 3 late adverse events were observed in one patient. CONCLUSIONS:IMRT alone with reduced prophylactic nodal irradiation showed encouraging long-term survival in selected patients with early-stage OPC, with no failures solely within omitted prophylactic nodal regions. However, progression patterns suggest that careful patient selection based on p16/HPV status and smoking history is essential when considering radiotherapy alone. TRIAL REGISTRATION:UMIN-CTR UMIN000014274.

Introduction: Chemoradiotherapy (CRT) followed by durvalumab is the standard of care for unresectable locally advanced NSCLC. Limited prospective data have been reported on intensity-modulated radiotherapy (IMRT)–adapted CRT in the immunotherapy era. Methods: In this multicenter prospective observational study, patients underwent IMRT-adapted CRT (platinum-doublet chemotherapy plus 60 Gy IMRT in 30 fractions under a prespecified radiation protocol), followed by consolidative durvalumab. The primary outcome was the durvalumab introduction rate within 42 days post-CRT. Results: Thirty-two patients with unresectable locally advanced NSCLC were enrolled between November 2019 and February 2021. Among the 28 evaluable cases, durvalumab was introduced in 24 (85.7%, 90% confidence interval: 70.2%–95.0%) of 28 patients after CRT, achieving the primary end point. All 29 patients who received IMRT completed the scheduled 60 Gy radiotherapy dose. One year of durvalumab treatment was completed in 12 of 24 patients (50%). In the 24 patients who were durvalumab-introduced, the median progression-free survival and overall survival were 20.9 (95% confidence interval: 6.9–not evaluable) months and not reached, respectively. Two-year progression-free survival and overall survival rates were 44% and 73%, respectively. Among the 29 patients in the safety analysis set, there were no treatment-related deaths or grade 4 nonhematological adverse events. Pneumonitis grade 1 was observed in 13 patients (45%), grade 2 in seven (24%), and grade 3 in one (3%). Conclusions: High durvalumab introduction rate was reported after the completion of IMRT-adapted CRT under a prespecified radiation protocol. Its efficacy has been suggested, with favorable safety profiles, including a low incidence of severe pneumonitis. Trial Registration: University Hospital Medical Information Network database ID: UMIN000038366

INTRODUCTION:Neoadjuvant chemo-immunotherapy is one of the standard treatment options for resectable stage II to III NSCLC. Nevertheless, this treatment yielded insufficient local control in the CheckMate 816 trial. We hypothesized that adding radiotherapy could improve local control, thereby improving survival outcomes. METHODS:Eligible patients had clinical T1 to T3 or T4 (tumor size) N2 stage IIIA to B NSCLC (American Joint Committee on Cancer version 8), pathologically confirmed as N2 without extranodal invasion. Patients received concurrent chemoradiotherapy (carboplatin [area under the curve = 2] and paclitaxel [40 mg/m2] on days 1, 8, 15, 22, and 29, with 50 Gy radiation over 25 d) and durvalumab (1500 mg) on days 1 and 29, followed by surgical resection within two to six weeks. After surgery, durvalumab adjuvant therapy was administered for up to one year. The primary endpoint was major pathologic response (MPR: ≤10% viable tumor), with secondary endpoints being pathologic complete response, progression-free survival (PFS), overall survival (OS), and safety. RESULTS:From January 2020 through February 2022, 31 patients were enrolled from 10 Japanese institutions. The MPR rate was 63% (90% confidence interval: 47%-78%), which met the primary endpoint, and the pathologic complete response rate was 23%. At a median follow-up of 28 months, the two-year PFS and OS rates were 43% and 76%, respectively. Grade 3 or 4 adverse events occurred in 48% of cases, including one treatment-related death. CONCLUSIONS:Compared with recently published results of peri-operative chemo-immunotherapy trials, this treatment regimen had a higher MPR rate. Nevertheless, this benefit did not necessarily translate into improved PFS or OS.

BACKGROUND AND PURPOSE:Hypothyroidism is a recognized late adverse event following radiotherapy for head and neck cancer (HNC). In the JCOG1008 trial, we treated patients with high-risk HNC with postoperative chemoradiotherapy. We aimed to elucidate factors associated with hypothyroidism by analyzing the JCOG1008 data. MATERIALS AND METHODS:In 2012-2018, 261 patients from 28 institutions were enrolled in JCOG1008. Thyroid function tests were conducted to assess hypothyroidism, including free thyroxine (FT4) and thyroid-stimulating hormone assays. Hypothyroidism was defined as Grade 2 or higher in CTCAE v4.0. Various clinical and dosimetric parameters were analyzed. In radiotherapy, there were no dose constraints for the thyroid. Multivariable analysis was conducted on these variables to identify predictive factors for hypothyroidism. RESULTS:The analysis included 162 patients (57 with 3D-CRT and 105 with IMRT), with a median follow-up of 4.7 years (0.3-9.3 years). Among these, 27 (16.7 %) developed hypothyroidism within 2 years after radiotherapy. In a multivariable analysis, the weekly cisplatin [OR=7.700 (CI: 1.632-36.343, p = 0.010)] and baseline FT4 [OR=0.009 (CI: <0.001-0.313, p = 0.010)] were significantly associated with hypothyroidism in the IMRT group. Regarding dosimetric characteristics, V60Gy [OR=1.069 (CI: 0.999-1.143, p = 0.054)] was potentially associated with the development of hypothyroidism. CONCLUSION:The study revealed that the incidence of hypothyroidism within 2 years after postoperative chemoradiotherapy for high-risk HNC was 16.7 % based on analytical results from prospective clinical trials.

The present study aimed to evaluate whether an adapted plan with Ethos (TM) could be used for pharyngeal cancer. Ten patients with pharyngeal cancer who underwent chemoradiotherapy with available daily cone-beam computed tomography (CBCT) data were included. Simulated treatments were generated on the Ethos (TM) treatment emulator using CBCTs every four to five fractions for two plans: adapted and scheduled. The simulated treatments were divided into three groups: early (first-second week), middle (third-fourth week), and late (fifth-seventh week) periods. Dose-volume histogram parameters were compared for each period between the adapted and scheduled plans in terms of the planning target volume (PTV) (D98%, D95%, D50% and D2%), spinal cord (Dmax and D1cc), brainstem (Dmax) and ipsilateral and contralateral parotid glands (Dmedian and Dmean). The PTV D98%, D95% and D2% of the adapted plan were significantly higher than those of the scheduled plans in all periods, except for D98% in the late period. The adapted plan significantly reduced the spinal cord Dmax and D1cc compared with the scheduled plan in all periods. Ipsilateral and contralateral parotid glands Dmean of the adapted plan were lower than those of scheduled plan in the late period. In conclusion, the present study revealed that the adapted plans could maintain PTV coverage while reducing the doses to organs at risk in each period compared with scheduled plans.

Chemoradiotherapy has been considered as one of the standard treatment options for clinical T1bN0M0 esophageal squamous cell carcinoma with organ preservation. However, 20% of patients develop locoregional recurrence after chemoradiotherapy, which requires salvage treatment including salvage surgery and endoscopic resection. Salvage surgery can cause complications and treatment-related death. Interestingly, chemoradiotherapy with elective nodal irradiation has been reported to reduce the locoregional recurrence of advanced esophageal squamous cell carcinoma. Hence, we are conducting a clinical trial to confirm whether modified chemoradiotherapy with elective nodal irradiation was superiority to that without elective nodal irradiation for the patients with cT1bN0M0 esophageal squamous cell carcinoma. The primary endpoint is major progression-free survival, defined as the time from randomization to the date of death or disease progression, excluding successful curative resection through salvage endoscopic resection. We plan to enroll 280 patients from 54 institutions over 4 years. This trial has been registered in the Japan Registry of Clinical Trials (jRCTs031200067).

Background: We clarified the dose difference between the anisotropic analytical algorithm (AAA) and Acuros XB (AXB) with increasing target's air content using a virtual phantom and clinical cases. Materials and methods: Whole neck volumetric modulated arc therapy (VMAT) plan was transferred into a virtual phantom with a cylindrical air structure at the center. The diameter of the air structure was changed from 0 to 6 cm, and the target's air content defined as the air/planning target volume (PTV) in percent (air/PTV) was varied. VMAT plans were recalculated by AAA and AXB with the same monitor unit (MU) and multi-leaf collimator (MLC) motions. The dose at each air/PTV (5%-30%) was compared between each algorithm with D98%, D95%, D50% and D2% for the PTV. In addition, MUs were also compared with the same MLC motions between the D95% prescription with AAA (AAA_D95%), AXB_D95%, and the prescription to 100% minus air/PTV (AXB_D100%-air/PTV) in clinical cases of head and neck (HNC). Results: When air/PTV increased (5-30%), the dose differences between AAA and AXB for D98%, D95%, D50% and D2% were 3.08-15.72%, 2.35-13.92%, 0.63-4.59%, and 0.14-6.44%, respectively. At clinical cases with air/PTV of 5.61% and 28.19%, compared to AAA_D95%, the MUs differences were, respectively, 2.03% and 6.74% for AXB_D95% and 1.80% and 0.50% for AXB_D100%-air/PTV. Conclusion:The dose difference between AAA and AXB increased as the target's air content increased, and AXB_D95% resulted in a dose escalation over AAA_D95% when the target's air content was >= 5%. The D100%-air/PTV of PTV using AXB was comparable to the D95% of PTV using AAA.

4030 Background: The standard treatment for advanced esophageal cancer is preoperative chemoradiotherapy (CRT) followed by surgery or definitive CRT (NCCN Guideline 2022 ver5). CRT has the advantage of preserving organs and functions and the prognosis for patients achieved complete response by CRT is good. However, it is currently impossible to predict the outcomes of CRT before treatment. We have performed RNA expression analysis of pre-treatment biopsy specimens of esophageal cancer and identified several intrinsic molecular subtypes, as well as E-type (high expression of squamous markers) with good prognosis for CRT and M2-type (high expression of stromal markers) with poor prognosis for CRT (US patent No 10,969,390 B2). Herein, we performed an integrated analysis to confirm the relationship between intrinsic expression molecular subtype classification and prognosis in the pooled population from two prospective cohort studies (UMIN000043637). Methods: Two cohort studies were as follows; 1) single institute prospective cohort study conducted at National Cancer Center Hospital East (n=157, UMIN-C000000459), 2) multicenter prospective cohort study conducted at 10 institutions (n=226, UMIN000016141). A total 383 cases met inclusion criteria and the Affymetrix U331Plus 2 panel (47,104 transcripts, 38,572 genes) was used to identify E-type and M2-type. The clinical course and outcome were blinded for subtype classification. Treatment was performed as usual at each institution, and treatment details and outcomes were examined by subtype. Results: Among 383 patients, 181 and 164 patients were treated by CRT and surgery, respectively. Ninety-nine percent (n=342) were squamous cell carcinoma. Stage I/II/III/IV were 13/61/86/21 and 17/63/81/3 in CRT group and surgery group, respectively. Among them, 76 (22%), 100 (29%), 169 (49%) patients were classified as E, M2 and others, respectively. Among the patients treated by CRT, CR rate of E-type and M2-type were 62.8% (95% CI, 47.8-75.7) and 33.3% (95% CI, 21.9-47.1) (p=0.006). The 5-year progression free survival (PFS) and overall survival (OS) rates of CRT group was 50.5% (95% CI, 34.7-64.4) and 59.8% (95% CI, 42.6-73.3) for E-type vs. 23.0% (95% CI, 12.0-36.2) and 29.0% (95%CI, 16.8-42.4) for M2-type, with statistically significant difference (p=0.011, p=0.003). Cox regression analysis showed that crude HR for PFS and OS of E vs M2 were 0.50 (95% CI, 0.296-0.859, p=0.012) and 0.41 (95% CI, 0.226-0750, p=0.004), respectively. In contrast, E and M2-type did not show the survival difference in surgery group. Conclusions: For the first time in the world, we confirmed that expression molecular subtype of esophageal cancer has the potential to predict the outcomes of CRT. The results may provide precision medicine in the selection of treatment for esophageal cancer.

This study aimed to reveal the long-term outcomes and late toxicities (> 5 years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC). Data from 43 patients (median age, 55 years; range, 17–72 years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5 years after IMRT. A total dose of 70 (range, 66–70) Gy was delivered in 35 (33–35) fractions with concurrent cisplatin chemotherapy. The median follow-up duration was 119 (range, 61.5–242.1) months. Three patients developed locoregional failure at 79, 92, and 149 months after IMRT, respectively. Of these, 2 patients died of disease progression at 136 and 153 months after IMRT. One patient died of aspiration pneumonia 141 months after IMRT, despite salvage of the recurrent tumor by re-irradiation. In addition, one patient died of aspiration pneumonia 62 months after the IMRT. Thus, the 10-year overall survival, progression-free survival, and locoregional control rates were 98

Background/Aim: This study compared two types of parallel-plate ionization chamber to clarify the pitfalls of dosimetry in electron radiation therapy. Materials and Methods: The ion recombination correction factor and polarity effect correction factor, sensitivity, and percentage depth doses (PDDs) of PPC05 and PPC40 parallel-plate ionization chambers were compared in a small-field electron beam. The output ratios were measured for 4-20 MeV electron beams with field sizes of 10 cm x 10 cm, 6 cm x 6 cm, and 4 cm x 4 cm. Furthermore, the films were placed in water and positioned in the beam with their surface perpendicular to the beam axis, and lateral profiles were obtained for each beam energy and each field. Results: Regarding PDDs, at depths greater than the peak dose, the percentage depth dose for PPC40 was smaller than that for PPC05 in small fields and at beam energies greater than 12 MeV, which could be attributed to the lack of lateral electron equilibrium at small depths and multiple scattering events at large depths. The output ratio of PPC40 was approximately 0.025-0.038, which was lower than that of PPC05 in a 4 cm x 4 cm field. For large fields, the lateral profiles were similar, regardless of the beam energy, however, for small fields, the flatness of the lateral profile was beam energy dependent. Conclusion: The PPC05 chamber, which has a smaller ionization volume, is therefore more suitable than the PPC40 chamber for small-field electron dosimetry, in particular at high beam energies.

We performed daily cone-beam computed tomography (CBCT) to determine the impact of rectal gas on the movements of prostate and seminal vesicles (SVs). We aimed to determine the relationship between planning target volume (PTV) margins and rectal gas. In 30 treatments of 15 prostate cancer patients, excessive rectal gas was removed and CBCT images were analyzed. Image registration between planning CT and daily CBCT images before and after rectal gas removal was performed for pelvic bone and prostate matching. The couch movement distance between each matching was considered the prostate movement. In addition, we measured SV tip movement between each matching. The anterior–posterior movement of the prostate before rectal gas removal (3.1 ± 2.9 mm) was significantly greater than that after rectal gas removal (1.2 ± 1.2 mm; p < 0.01). The left–right and superior–inferior movements were similar regardless of the presence or absence of rectal gas. The SV movement distances before and after rectal gas removal were 11.0 ± 5.8 mm and 4.6 ± 3.8 mm, respectively (p < 0.01), in pelvic bone matching, and 8.0 ± 4.2 mm and 3.8 ± 3.2 mm, respectively (p < 0.01), in prostate matching. After rectal gas removal, the SV position did not differ significantly between each matching. In 26 of the 30 treatments, SV movement distance in the presence of rectal gas was >6 mm, which is the minimum PTV margin at our institution. In comparison, after rectal gas removal and prostate matching, only 6 treatments demonstrated an SV movement distance of >6 mm. In the presence of rectal gas, the SVs require greater PTV margins than the prostate. Rectal gas removal should be considered if the movement distance on prostate matching is greater than the minimum PTV margin at treating institution.

Background and purpose: In this study, fluoromisonidazole positron emission tomography (F-MISO PET/ CT) was used to evaluate tumor hypoxia and re-oxygenation in patients with lung tumors treated with stereotactic body radiation therapy (SBRT).Materials and methods: Patients with T1-2 N0 lung cancer were included in this study. The prescribed dose was 48-52 Gy in four fractions. F-MISO PET/CT was performed twice, before SBRT and 1-3 days after the first irradiation. The maximum standardized uptake value (SUVmax) and tumor/muscle ratio (TMR) were evaluated as indicators of hypoxia. The threshold for hypoxia was defined as a TMR of 1.30 or more.Results: Between 2016 and 2021,15 patients were included. Pre-treatment tumor hypoxia was observed in nine tumors (60 %). TMR in all six tumors without pre-treatment hypoxia rose after single high-dose irradiation. In contrast, TMR in six of nine tumors with pre-treatment hypoxia dropped after irradiation, suggesting re-oxygenation. Although no local recurrence was noted, regional and/or distant relapses were seen in four patients (27 %). Of these, three had tumors with abnormal F-MISO uptake. The remain-ing patient had a tumor without signs of hypoxia on pre-treatment PET/CT. The 2-year progression free survival of patients with tumors with and without pre-treatment hypoxia were 30 % and 63 %, respec-tively (p = 0.319).Conclusion: Tumor hypoxia reduced after single high-dose irradiation. Tumor with F-MISO uptake seems to be an unfavorable prognostic factor in lung SBRT.(c) 2023 The Authors. Published by Elsevier B.V. Radiotherapy and Oncology 180 (2023) 109491 This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Supplementary Table S1 from IL12RB2 and ABCA1 Genes Are Associated with Susceptibility to Radiation Dermatitis

This study assessed the efficacy of chemoradiotherapy for squamous cell carcinoma of the anal canal (SCCAC). Patients with T1-4N0-3M0 SCCAC received chemoradiotherapy with 5-fluorouracil (5-FU, 800 mg/m(2)/day, 96-h infusion) and mitomycin-C (MMC, 10 mg/m(2) bolus). Patients treated with 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) were administered 36.0 Gy in 20 fractions or 49.5 Gy in 33 fractions for elective nodal irradiation and 59.4 Gy in 33 fractions for primary tumor and metastatic nodal irradiation. The sample size was considered sufficient to estimate 95% confidence intervals (CIs) for the true 2-year disease-free survival (DFS) within a width of +15% when the expected true 2-year DFS was 70%. The primary endpoint was 2-year DFS. The secondary endpoints were 2-year overall survival (OS), locoregional control (LC), colostomy-free survival (CFS) and adverse events. Thirty-one patients were enrolled between January 2014 and July 2019. The median follow-up was 33.3 months (range, 16.2-65.8 months). Among the 31 patients, 13%, 32%, 16% and 39% had stage I, II, IIIA and IIIB disease, respectively. Thirty patients were treated with IMRT. Complete response (CR) was achieved in 27 patients. The 2-year DFS, OS, LC and CFS rates were 77.4% (95% CI, 58.4-88.5%), 93.5% (95% CI, 76.6-98.3%), 83.9% (95% CI, 65.5-92.9%) and 80.6% (95% CI, 61.9-90.8%), respectively. One patient experienced grade 3 late adverse events; however, no grade >= 4 late adverse events occurred. Good DFS with a low rate of late adverse events was observed. Chemoradiotherapy with 5-FU and MMC was effective for SCCAC.

Purpose: We previously reported the primary results of JCOG0701, a randomized, multicenter, phase 3, noninferiority trial comparing accelerated fractionation (Ax) to standard fractionation (SF) for early glottic cancer. In the primary results, although the similar efficacy of 3-year progression-free survival and toxicity of Ax compared with SF was observed, the nonin-feriority of Ax was not confirmed statistically. To evaluate the long-term follow-up results of JCOG0701, we conducted JCOG0701A3 as an ancillary study of JCOG0701.Methods and Materials: In JCOG0701, 370 patients were randomly assigned to receive SF of 66 to 70 Gy (33-35 fractions; n = 184) or Ax of 60 to 64.8 Gy (25-27 fractions; n = 186). The data cutoff date for this analysis was in June 2020. Overall sur-vival, progression-free survival, and late adverse events including central nervous system ischemia were analyzed.Results: With a median follow-up period of 7.1 years (range, 0.1-12.4), progression-free survival of the SF and Ax arms were 76.2% and 78.2% at 5 years and 72.7% and 74.8% at 7 years (P = .44). OS of the SF and Ax arms were 92.7% and 89.6% at 5 years and 90.8% and 86.5% at 7 years (P = .92). Among 366 patients with a protocol treatment, the cumulative incidence of late adverse events of the SF and Ax arms were 11.9% and 7.4% at 8 years (hazard ratio, 0.53; 95% CI, 0.28-1.01; P = .06). Cen-tral nervous system ischemia of grade 2 or higher was observed in 4.1% for the SF arm and 1.1% for the Ax arm (P = .098).Conclusions: After long-term follow-up, Ax showed comparable efficacy to SF and a tendency for better safety. Ax may be suitable for early glottic cancer because of its convenience in minimizing treatment time, cost, and labor.(c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)