A Nomogram to Predict Pathological Axillary Status in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

PURPOSE/OBJECTIVE(S)

This study aimed to identify factors influencing axillary pathological complete response (pCR) and to develop a predictive nomogram to evaluate axillary pCR rate in breast cancer patients treated with neoadjuvant chemotherapy (NAC).

MATERIALS/METHODS

A total of 2368 patients who received NAC and mastectomy between 2000 and 2014 from 12 grade A tertiary hospitals in China were analyzed retrospectively. The patients treated in three cancer hospitals (training set, n = 1629) were used to construct the nomogram based on multivariate logistic regression analyses. The nomograph was validated by the area under the receiver operating characteristic curve (AUC) and calibration curve in patients from 9 other general hospitals (validation set, n = 739).

RESULTS

The nomogram incorporated seven predicting factors including NACT cycles, response to NACT, clinical T stage, clinical N stage, grade, LVI, and molecular subtype. The AUC for the training set and validation set were 0.762 and 0.802, respectively. In addition, the calibration curve also showed good agreement between the nomogram-based predictions and the actual observations.

CONCLUSION

A nomogram was established to predict the status of axillary lymph nodes in breast cancer patients after NAC. The predictive model performed well both in the training set and external validation set.

Identification and Validation of a Ferroptosis Prognostic Model for Prostate Cancer Patients through Screening the TCGA and scRNA-seq Datasets

PURPOSE/OBJECTIVE(S)

Ferroptosis is currently a common mode of programmed cell death, and the induction of ferroptosis is a new strategy and idea for current tumor therapy. Therefore, the signaling pathways and genes regulated by ferroptosis are significant markers for current malignant tumor therapy. To construct a prognostic model for predicting the survival prognosis of prostate cancer (PCa) based on the molecules and markers related to ferroptosis, we combined with differentially expressed genes (DEGs) in PCa patients, and further analyze the correlation between this risk score and immune cell infiltration. Finally, to validate the expression of risk genes and analyze the expression and localization of risk genes in using the datasets of single cell RNA-sequencing (scRNA-seq).

MATERIALS/METHODS

Firstly, we screened the DEGs in PCa patients by the expression profiles of TCGA database. Meanwhile, we collected the information of ferroptosis regulatory genes from FerrDb, and these two parts were intersected. Then the impact of genes on the survival and prognosis of PCa patients was confirmed and selected by LASSO regression, further screening of molecules and fitting the risk format. And the efficacy of the model was evaluated by ROC curves. The immune cell infiltration of PCa tissues was predicted using TIMER. Last, the scRNA-seq of PCa (GSM5155455, GSM3735993) were carried to reveal the expression of risk molecules in different cell types. Besides, the expression of risk molecules was validated using PCa cell lines.

RESULTS

We found a total of 259 DEGs associated with ferroptosis in PCa tissues. After LASSO regression, we screened DRD5, LINC00336, ACSF2, RRM2, NOX1, GDF15, ALB, MIOX, and NOX4 as variables to establish a prognostic model, and the specific risk scores was calculated following this format: Risk score = (-1.9465)*DRD5+(-1.6806)*LINC00336+(0.3045)*ACSF2+(0.4747)*RRM2+(-0.2815)*NOX1+(-0.1871)* GDF15+(0.1846)*ALB+(0.2676)*MIOX+(0.1648)*NOX4 (lambda.min = 0.0032), with a 10-yr AUC value of 0.751 (95% CI, 0.549-0.953). Furthermore, we discovered the higher the scores, the fewer CD8+ T cells infiltrated as predicting, showing a negative relationship. By testing the gene sets of scRNA-seq forPCa, we discovered that RRM2, GDF15, ALB, and MIOX were mainly expressed in tumor cells, T cells, B cells and neutrophils of PCa tissues, and not in endothelial cells. Finally, we detected differences in protein expression of RRM2, GDF15, and MIOX in PCa cell lines compared to normal prostate cancer epithelium by WB.

CONCLUSION

We constructed a novel prognostic model for PCa based on ferroptosis-related genes, which showed better predictive validity. And we analyzed the cellular expression of risk genes by scRNA-seq, which will be explored future in relation to prostate cancer radiotherapy.

A novel mini-open sublay hernioplasty combined with D10 mesh for primary lumbar hernia: a retrospective analysis of 48 cases

BACKGROUND

The aim of this study was to explore the safety and efficacy of a novel mini-open sublay hernioplasty with D10 mesh for primary lumbar hernias.

METHODS

This retrospective study included 48 patients with primary lumbar hernias who underwent mini-open sublay hernioplasty with D10 mesh from January 2015 to January 2022 in our hospital. Observation indicators were intraoperative measured diameter of hernia ring defect, operation time, length of hospital stay, postoperative follow-up, complications, postoperative visual analog scale (VAS) score, chronic pain.

RESULTS

The operations were completed successfully in all 48 cases. The mean diameter of hernia ring was 2.66 ± 0.57 cm (range 1.5-3.0 cm), the mean operation time was 41.54 ± 13.21 min (range 25-70 min), the intraoperative blood loss was 9.89 ± 6.16 ml (range 5-30 ml), and the mean hospital stay was 3.14 ± 1.53 days (range 1-6 days). The mean preoperative and postoperative VAS scores at 24 h were 0.29 ± 0.53 (range 0-2) and 2.52 ± 0.61 (range 2-6), respectively. All cases were followed-up for 53.4 ± 24.3 months (range 12-96 months) without seroma, hematoma, incision or mesh infection, recurrence, and obvious chronic pain.

CONCLUSION

A novel mini-open sublay hernioplasty with D10 mesh for primary lumbar hernias is safe and feasible. Its efficacy in the short term is favorable.

The Predictive Value of Circulating Exosomal PD-L1 in Cervical Cancer Immunotherapy

PURPOSE/OBJECTIVE(S)

Programmed death ligand 1 (PD-L1) expression was wildly used as a predictor of immune Check-Point Inhibitors (ICIs) efficiency. However, emerging results showed that PD-L1 was of great heterogeneity in sampling time and site. Recently, some studies found that exosomal PD-L1(ExoPD-L1) was related to ICIs response. In this study, we aimed to explore the predictive value of ExoPD-L1 in ICIs treatment of cervical cancer (CC) for the first time.

MATERIALS/METHODS

A total of 40 primarily diagnosed CC patients who accepted radical radiotherapy (RT) from March 2021 to October 2022 were included. The consecutive tumor sample were collected before and during RT. Another 37 advanced CC patients who accepted ICIs combination therapy from June 2020 to October 2022 were enrolled in this study. Blood samples were collected from each participant before and during treatment. Exosomes were derived by differential centrifugation, which was further identified by Western blot (WB) (CD9/TSG101/Calnexin), transmission electron microscope analysis and nanoparticle tracking analysis. ExoPD-L1 detection was conducted by enzyme-linked immuno-sorbent assay (ELISA). The knockout of PD-L1 was conducted via CRISPR/Cas9 assay and the overexpress of PD-L1 was conducted by lentiviral transfection. CD8+ T cells were extracted from murine spleen by CD8+ T Cell Isolation Kit. Immune cells and cytokines markers were detected by multicolor flow cytometry.

RESULTS

The consecutive detection of PD-L1 showed a dynamic change during RT. Compared with the level before RT, PD-L1 expression elevated in most patients (87.5%, 35/40) after RT. And the responders (n = 18) had elevated ExoPD-L1 level at the first two circles in the ICIs combination therapy (P<0.001). Whereas the level of pre-treatment ExoPD-L1 couldn't stratified clinical responders and non-responders (P = 0.181). The median follow-up time was 14.13 months. The mPFS in increased group vs. decreased group: not reach vs.11.02 months (P = 0.025, HR: 0.218, 0.052-0.913). Continuous blood sampling of mice models also found that effective therapeutic intervention could increase ExoPD-L1 in the early stage. The combination of exosome inhibitor GW4869 and anti-PD-1 further inhibited tumor growth. Mice were injected with external ExoPD-L1OE and ExoPD-L1KO. The results showed that ExoPD-L1OE suppressed body immunity and promoted tumor growth. The results of flow cytometry showed that ExoPD-L1OE inhibited CD8+ T cells from releasing interferon-and granzyme B. And ExoPD-L1OE also suppressed the CD8+ T cells proliferation in murine spleen. The coculture of CD8+ T cells and exosomes in vitro also confirmed the above conclusion.

CONCLUSION

Compared with unstable and impressionable tumoral PD-L1, ExoPD-L1 seems to be better predictor for the efficacy of immunotherapy in CC, which was with easy accessibility and continuation. Exosome PD-L1 played an immunosuppressive role by inhibiting the proliferation and functional factor release of CD8+ T cell.

Evaluating the Effects of Bone Marrow Sparing Radiotherapy on Acute Hematologic Toxicity for Patients with Locoregionally Advanced Cervical Cancer: A Prospective Phase II Randomized Controlled Trial

PURPOSE/OBJECTIVE(S)

Bone marrow sparing intensity modulated radiotherapy (BMS-IMRT) can reduce the incidence of acute hematologic toxicity (HT) for locoregionally advanced cervical cancer (LACC) patients receiving concurrent chemoradiotherapy (CCRT), but the norm has been controversial. The purpose of the study was to evaluate the effects of bone marrow (BM) V40 <25% on decreasing the incidence of acute HT in a prospective clinical trial.

MATERIALS/METHODS

A total of 242 LACC patients were recruited from May 2021 to May 2022, who were evenly randomized into BMS-IMRT group and standard IMRT group according to a computer-generated random number list. All patients received pelvic irradiation with concurrent cisplatin (40 mg/m2 weekly), followed by brachytherapy. For patients in BMS-IMRT group, the outer contour of pelvic bone, lumbar spine and left and right femur heads were additionally delineated as a surrogate for BM, and V40 <25% was prescribed. Blood counts were tested weekly, of which nadirs during external beam radiotherapy (EBRT) were graded to assess acute HT as primary observation index. Second observation index were dosimetric parameters of EBRT plan from the dose volume histograms (DVHs). Binary logistic regression model and receiver operating characteristic (ROC) curve were used for predictive value analysis.

RESULTS

Baseline demographic, disease and treatment characteristics were all balanced between BMS-IMRT group and standard IMRT group. BMS-IMRT was associated with a lower incidence of grade ≥2 and grade ≥3 acute HT, leukopenia and neutropenia (72.70% vs 90.90%, P <0.001*; 16.50% vs 65.30%, P <0.001*; 66.10% vs 85.10%, P = 0.001*; 13.20% vs 54.50%, P <0.001*; 37.20% vs 66.10%, P <0.001*; 10.70% vs 43.80%, P <0.001*). Plan target volume (PTV) for all patients satisfied the clinical requirement of V(100%) ≥95%, and conformity and homogeneity were both comparable between 2 groups. BMS also decreased dose delivered to the organs at risk (OARs) including rectum, bladder and left and right femur head. Univariate and multivariate analyses showed that BM V40 was an independent risk factor for grade ≥3 acute HT (odds ratio [OR] = 2.734, 95% confidence interval [CI] = 1.959-3.815, P <0.001*). Cutoff value was 25.036% and area under the curve (AUC) was 0.786. The nomogram was constructed, which was rigorously evaluated and internally cross-validated, showing good predictive performance.

CONCLUSION

BM V40 <25% can reduce the risks of acute HT for LACC patients receiving CCRT while the dose delivery of target volume and other normal tissues were not compromised. With great practicality and applicability, BM V40 <25% is a promising strategy, making BMS-IMRT widespread especially in the area where application of image guided radiotherapy (IGRT) such as 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET)/CT is not popularized. Chinese clinical trial registry (ChiCTR2200066485).

Proton Radiation Therapy for Stage IIA/IIB Testicular Seminoma

PURPOSE/OBJECTIVE(S)

Testicular seminoma affects young men and is associated with very favorable prognosis. The evolution in treatment paradigm has focused on minimizing acute and especially late toxicities. Following orchiectomy, while surveillance is favored in Stage I patients, radiotherapy (RT) is a standard treatment option for de novo or relapsed stage IIA or select non-bulky stage IIB disease. Despite low doses, standard RT fields to paraaortic and pelvic lymphatics using x-rays exposes a large volume of uninvolved normal tissue/viscera to excess dose. This young patient population is especially vulnerable to risks of late RT toxicities including secondary malignancy. Proton beam therapy (PBT) has dosimetric advantage over x-ray-based RT due to lack of exit dose, and comparative dosimetric/modeling studies show significant sparing of uninvolved abdominal/pelvic organs. However, there is scant reported clinical data at this time for PBT. We review our early institutional outcomes with PBT for testicular seminoma.

MATERIALS/METHODS

Single institution retrospective review from a tertiary care center of patients treated with PBT from 2013-2022 for testicular seminoma. Recurrence free (RFS) and overall survival (OS) were calculated from the completion of PBT. Toxicities were graded (Gr) using CTCAE v5.0.

RESULTS

Four patients underwent PBT, median age 39 (range 36-47). All were Stage I at diagnosis (pT1b n = 3; pT2 n = 1) and were treated for recurrent stage II disease (IIA n = 3; IIB n = 1) at a median of 34 months from orchiectomy (range 3 - 74 months). Nodal extent included 2 with multiple paraaortic nodes, 1 with solitary paraaortic node and 1 with solitary pelvic node. PBT was delivered with pencil-beam scanning, treating paraaortic + ipsilateral pelvic fields (20 Gy in 10 fractions), then sequential boost to involved nodes (10 -16 Gy in 5-8 fractions). Typically, PA or posterior oblique fields were used to minimize dose to out-of-field abdominal/pelvic viscera. Treatment was well tolerated with minimal acute toxicities: fatigue Gr 1 (n = 3), nausea Gr 1 (n = 3). No Gr 2 or higher acute toxicities or significant late toxicities were observed. At median follow up of 30 months (range 3 - 54), no recurrences were observed, and RFS and OS were 100%. Two patients are without evidence of disease > 4 years post-treatment.

CONCLUSION

In this case series, PBT for retroperitoneal and pelvic metastases in Stage IIA/IIB testicular seminoma was associated with oncologic efficacy with minimal toxicity. PBT reduces unnecessary dose to abdominal/pelvic organs compared to x-ray techniques, which is advantageous in young patients who have anticipated long-term survival. This is one of the few series reporting clinical outcomes of PBT in the management of seminoma. Randomized comparisons with x-ray approaches are impractical given the relatively low volume of patients receiving RT in modern seminoma management, so it is essential to report and track longitudinal outcomes across institutions to validate this approach.

Safety and Efficacy of Radiotherapy Combined with Chemotherapy for Recurrent Metastatic Renal Pelvic and Ureteral Carcinoma

PURPOSE/OBJECTIVE(S)

To retrospectively investigate the safety and efficacy of radiotherapy combined with systemic chemotherapy for recurrent metastatic renal pelvic and ureteral carcinoma.

MATERIALS/METHODS

A total of 109 patients were enrolled in this study, including 44 patients in the Radio-chemotherapy group and 65 patients in the Chemotherapy group. Propensity score matching (PSM) was used to balance the clinical baseline characteristics of the two groups by 1:1 matching. Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS) before and after matching. Prognostic factors were analyzed by Cox proportional risk model. Treatment-related adverse events were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0.

RESULTS

The median follow-up time was 14.5 months. Multivariate analysis showed that radiotherapy was a good independent prognostic factor for OS in patients with recurrent metastatic renal pelvic and ureteral carcinoma (HR: 0.327, 95% CI: 0.157∼0.680, P = 0.003). After matching, there were 40 patients in the Radio-chemotherapy group and 40 patients in the Chemotherapy group, and the median PFS and median OS in the Radio-chemotherapy group were better than those in the Chemotherapy group (PFS: 10.4 months vs. 6.7 months, P = 0.035; OS: 43.5 months vs. 18.8 months, P<0.001). The 1-year OS and 2-year OS of the Radio-chemotherapy group were higher than those of the Chemotherapy group (1-year OS: 88.1% vs. 70.4%; 2-year OS: 81.1% vs. 39.3%). In addition, in the Radio-chemotherapy group, patients treated with radiotherapy before first-line chemotherapy failure had longer PFS than those treated with radiotherapy after chemotherapy failure (median PFS: 15.7 months vs. 6 months, P = 0.003). There was no significant difference in the incidence of grade 3∼4 toxicities between the Radio-chemotherapy group and the Chemotherapy group (52.3% vs. 50.8%, P = 0.878).

CONCLUSION

For patients with advanced renal pelvic and ureteral carcinoma, adding radiotherapy on the basis of systemic chemotherapy is well tolerable and expected to bring long-term survival benefits to patients, and the benefits of early interventional radiotherapy may be more obvious.

Radiotherapy Resistance in Prostate Cancer Cells: AKR1C3 Inhibition of Ubiquitinated Degradation of Nrf2 through Interaction with KEAP1

PURPOSE/OBJECTIVE(S)

Radiotherapy is the most fundamental treatment for prostate cancer (PCa), and although radiotherapy for overall PCa patients is effective, poor prognosis and resistance to multiple treatments regimes in some highly malignant PCa, such as those with high Gleason Scores (GS) (≥9), are important bottlenecks limiting the improvement of treatment outcomes for clinical. AKR1C3 is a key PCa resistance gene that our team identified previously, but the induction of the specific mechanism of radiotherapy resistance has not been fully revealed and understand.

MATERIALS/METHODS

To analyze the correlation between its expression level and clinical radiotherapy, we used the gene expression profiles data of PCa patients in TCGA database. We generated a stepwise increase of radiotherapy dose to established PCa radiotherapy resistant cell lines and detect the AKR1C3 expression level. In addition, to explore the molecular mechanism of AKR1C3 induced prostate cancer radiation tolerance through functional enrichment analysis. Then, to treat cells with cycloheximide and the protein stability of the Nrf2 was detected. Last, the protein ubiquitination level was assayed by co-immunoprecipitation (co-IP) after treatment with MG132. Finally, protein-protein interactions were identified using co-IP to mine possible binding molecules.

RESULTS

By analyzing the expression profiles data of PCa patients in the TCGA database, we found that in the population of PCa patients treated with radiotherapy, all patients with high AKR1C3 expression died after radiotherapy, suggesting that high AKR1C3 expression may be a biomarker of resistance to radiation. Accordingly, AKR1C3 expression levels showed a positive correlation with GS score, which may be a symbol for patients with highly malignant PCa. A PCa radiotherapy resistant cell line was constructed by a stepwise increase of ionizing radiation (IR) dose, and the total IR dose of radiotherapy was 84Gy, which reached the dose of radical radiotherapy for prostate cancer. The expression of AKR1C3 was further detected by RT-qPCR and WB, and it was found that the expression of AKR1C3 was significantly up-regulated in the resistant cell line, accompanied by milder DNA damage. What's more, by GSEA functional enrichment analysis, we discovered that AKR1C3 overexpression might be related with intracellular oxidative stress damage. After CHX treatment, the protein stability of Nrf2 was significantly enhanced in AKR1C3 overexpression groups than control groups. And the administration of MG132 showed the same results, indicating that the ubiquitinated degradation of Nrf2 was inhibited in AKR1C3 overexpression groups. Further by co-IP, we found that Nrf2 was less ubiquitinated in the cytoplasm after AKR1C3 overexpression, and AKR1C3 could bind Keap1.

CONCLUSION

In sum, we found that AKR1C3 can bind with Keap1 leading to reduced ubiquitination level of Nrf2, causing upregulation of Nrf2 expression and providing new insights into PCa radiotherapy resistance.

Prediction of Response to Neoadjuvant Chemoradiotherapy Combined with Pembrolizumab in Esophageal Squamous Cell Carcinoma with CT/FDG PET Radiomic Signatures Based on Machine Learning Classification

PURPOSE/OBJECTIVE(S)

PALACE-1 trial has confirm that the addition of pembrolizumab to neoadjuvant chemoradiotherapy (NCRT) improves the pathological complete response(pCR) for esophageal squamous cell carcinoma (ESCC), which might be a novel treatment strategy for ESCC. In the present study, we aim to establish a machine learning model to predict the local response to NCRT+ pembrolizumab for ESCC by using pretreatment 18-fluorodeoxyglucose positron emission tomography (FDG PET) and contrast-enhanced plan CT images.

MATERIALS/METHODS

A total of 65 cases treated with NCRT+ pembrolizumab followed by surgery were prospectively enrolled for analysis from 2019-2022. Each patient contains a contrast-enhanced plan CT and FDG PET images. 52 patients were randomly divided into training set and 13 patients were used as test set. The Extraction of radiomics features was performed using an open-source Python library PyRadiomics automatically. Features were computed according to the radiologist-drawn ROIs on both CT and PET images. In the feature selection stage least absolute shrinkage and selection operator (LASSO) was utilized on CT features and PET features separately. Four different machine learning models were implemented: Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF) and XGBoost (XGB). The features selected by LASSO regression were used as model input and the output of the model is "pCR" or "non-pCR". To find the optimal parameter, the 5-fold cross-validation method was used in the training stage. In this study, we use accuracy, sensitivity and specificity as the metrics to evaluate the performance of the model on the testing cohort. The predictive performance of the model was assessed using the area under curve (AUC) of the receiver operating characteristics curve (ROC).

RESULTS

Of the 65 cases treated with NCRT+pembrolizumab, 35 patients archived pCR (53.8%), and 30 archived non-pCR. 1684 radiomics features were extracted from each case, and half of them (842 features) were from CT and others were from PET. Among the machine learning models mentioned above SVM achieves the most promising performance on the evaluation metrics. Accuracy, sensitivity, specificity and AUC score on test set were 0.692, 0.833, 0.571 and 0.786 for CT features and 0.615, 0.667, 0.571 and 0.762 for PET features, respectively. For CT+FDG PET fused features accuracy, sensitivity, specificity and AUC score on test set were 0.769, 0.667, 0.857 and 0.833.

CONCLUSION

In this study, we performed several different machine learning models to predict the response to NCRT+ pembrolizumab among ESCC based on the extracted radiomics features from CT and FDG PET images. The best-performing model based on radiomics features of CT and PET images could identify non-pCR to NCRT + pembrolizumab in EC patients.

Clinicopathologic Features of Prostate Cancer with Mesorectal Lymph Node Involvement on PSMA or Fluciclovine PET/CT

PURPOSE/OBJECTIVE(S)

Advanced PET imaging has shown more prevalent mesorectal lymph node (LN) involvement in prostate cancer than previously appreciated. The clinical features predicting risk for mesorectal involvement are not well established and the prognostic impact is unclear. This may have implications on management including radiotherapy field design. This study aims to identify clinical and pathologic characteristics associated with mesorectal involvement identified on PSMA or fluciclovine PET/CT.

MATERIALS/METHODS

We conducted a single institution retrospective review of prostate cancer patients with F-18 fluciclovine, F-18 piflufolastat, or Ga-68 gozetotide PET between January 2020 and 2023 demonstrating tracer-avid mesorectal LN in the setting of newly diagnosed disease (ND) or biochemical failure after curative-intent therapy (BF). Clinical characteristics, pathologic findings, and early clinical outcomes were reviewed.

RESULTS

We identified 16 ND and 34 BF patients with uptake in at least one mesorectal LN on PET. For ND patients, clinical features at initial diagnosis were median PSA of 35.2 (range 9.6-659), median grade group 5, and 87% with clinical or radiographic T3/T4 disease. Radiographic PET staging among ND patients (excluding mesorectal LNs) were 19% N0M0, 25% N1M0, 56% as N1M1. For BF patients, clinical features at initial diagnosis were median PSA 9.2 (range 4.1-90) and median grade group 4. Primary treatment was prostatectomy in most (91%), with a high rate of high-risk features: 68% pT3-4, 28% pN1, and 32% had persistent detectable postop PSA. Radiographic PET staging among BF patients (excluding mesorectal LNs) were 29% N0M0, 38% N1M0, 12% N0M1, and 21% as N1M1. High-risk histologic features (cribriform, intraductal, ductal, or neuroendocrine) were identified in 88% of ND and 48% BF patients. Of these patients, 86% had cribriform pattern. Median PSA prior to PET for ND and BF patients was 37.0 (range 8.5-659) and 1.9 (0.2-11.1). Median interval from initial therapy to PET for BF patients was 4.4yr (range 0.2-19.7). Median follow-up post-PET was 8.7mo (range 3.4-29) for ND and 8.8mo (range 0-76) for BF patients. Of patients with M0 PET staging, none of the 7 ND patients developed DMs, and 1 of 23 BF patients developed DM after 4 yrs.

CONCLUSION

In this analysis of prostate cancer patients with mesorectal involvement, we found a high incidence of high grade, T3-4 disease, and cribriform pattern, especially in ND patients. For BF patients, there was a high incidence of pT3-4 and pN1 disease at time of initial treatment. Overall, most patients had concurrent regional nodal disease on PET. Longer follow up of clinical outcomes and comparison to high-risk patients without mesorectal LN involvement is needed to understand the prognostic significance and predictors of mesorectal LN spread. Additional studies are needed to identify patients at highest risk in whom elective coverage of mesorectal lymphatics with elective pelvic nodal RT may be warranted.

Maintenance Therapy for Recurrent or Metastatic Cervical Cancer: A Multicenter, Cohort Study

PURPOSE/OBJECTIVE(S)

Maintenance therapy with alternative agents after chemotherapy was shown to improve the overall survival in some advanced cancers such as breast cancer, lung cancer, ovarian cancer and so on. However, maintenance therapy is not accepted as the standard treatment for recurrent/metastatic cervical cancer. Aim of this study is to elucidate the efficacy of maintenance therapy in cervical cancer and to explore the factors associated with the prognosis of recurrent or metastatic cervical cancer.

MATERIALS/METHODS

In this multicenter cohort study, we retrospectively collected patients with a diagnosis of either recurrent or stage IVB cervical cancer to receive first-line chemotherapy with or without maintenance therapy. Patients did not have disease progression with first-line chemotherapy and were divided into maintenance therapy group (Arm A) and conventional chemotherapy group (Arm B). Information on clinical characteristics, metastasis information, treatment outcome and survival of patients was collected using an electronic medical record system. The endpoints of the study were OS and PFS. Data were analyzed for general characteristics and survival using statistical software, and the results were considered statistically significant at P < 0.05.

RESULTS

Between January 2019 and July 2021, a total of 270 patients were enrolled from 6 institutions in China. 26 patients were excluded because of short treatment cycles (less than 3 cycles). Finally, a total of 66 patients in Arm A and 178 patients in Arm B were analyzed for survival. The addition of maintenance significantly prolonged overall survival. Overall survival at 3 year was 50.1% in Arm A and 27.8% in Arm B (median overall survival, ≥36 months vs. 22 months; P<0. 001). The median progression-free survival was 21 months in Arm A and 14 months in Arm B (P = 0.025). Univariate survival analysis showed that age, maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were associated with PFS. Further multifactorial analysis showed that maintenance therapy, combined radiotherapy, and number of extra-pelvic metastases were independent prognostic factors for patients with recurrent or metastatic cervical cancer.

CONCLUSION

The addition of maintenance therapy significantly prolonged overall survival as well as progression-free survival in patients with recurrent or metastatic cervical cancer and did not increase the incidence of serious adverse events. It is time to consider maintenance therapy as the standard treatment after conventional chemotherapy for recurrent or metastatic cervical cancer, rather than waiting for disease progression.

Treatment Outcomes of Concurrent Nimotuzumab with Intensity Modulated Radiotherapy in Advanced Nasopharyngeal Carcinoma Patients Unfit for Concurrent Chemoradiotherapy: A Single Institute Experience

PURPOSE/OBJECTIVE(S)

To assess the safety and efficacy of intensity-modulated radiotherapy (IMRT) combined with nimotuzumab for patients with locally advanced nasopharyngeal carcinoma (LA-NPC) medically unfit to receive concomitant chemotherapy.

MATERIALS/METHODS

From 2016.6 to 2020.9, 34 newly diagnosed patients with local-regional advanced NPC medically unfit for concurrent chemoradiation had undergone definitive radiotherapy and were retrospectively evaluated. All patients were treated with IMRT combined treatment modality of nimotuzumab with or without cisplatin-based induction chemotherapy. Nimotuzumab was administered concurrently with IMRT at a weekly dose of 200 mg. Acute and late radiation-related toxicities were evaluated based on the Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 during and after IMRT. The Kaplan-Meier method was used for survival analysis. Univariate and multivariate prognostic analyses were performed by using the Cox proportional hazard model.

RESULTS

The median follow-up time for the entire group was 15 months (range 5 to 55 months). At the time of this analysis, a total of 2 cases developed loco-regional recurrence. In addition, 4 patients developed distant metastasis. There was a total of 5 deaths: 3 patients died from distant metastasis, 1 patient died from the progression of loco-regional disease after recurrence, and the causes of death for the additional 1 case was a nasopharyngeal ulcer and deadly bleeding. The 1-year OS rate of the whole cohort was 87.9%, and the 1-year LFFR, DFFR, and PFS rates were 100%, 91.0%, and 91.0%, respectively. During the period of concurrent nimotuzumab and IMRT, no grade 3-4 hematologic toxicities and dermatitis were observed. Grade 3-4 radiotherapy-related oral mucositis was reported in 7 patients (20.6%). No infusion reaction was observed. No acneiform eruptions were found among these patients. The most commonly observed late complication was xerostomia. The degree of dry mouth in most patients was mild-to-moderate at the time of the last follow-up. Finally, 7 patients developed either unilateral or bilateral hearing impairment. One female patient experienced a nasopharyngeal ulcer and deadly bleeding after 5 months of completion of radiotherapy.

CONCLUSION

Concurrent nimotuzumab with IMRT for the treatment of LA-NPC was well tolerated, with encouraging survival data, and it could be an effective treatment alternative for patients with LA-NPC medically unfit for concomitant chemotherapy. Further clinical trials are needed to confirm these findings.

Quality Assurance of Protocol Compliance in a Multicenter Randomized Trial Investigating the Role of Hypofractionated Comprehensive Reginal Nodal Irradiation in Node-Positive Breast Cancer (HARVEST)

PURPOSE/OBJECTIVE(S)

The HARVEST trial (NCT03829553) is a phase III, multicenter, randomized clinical trial to explore efficacy and safety of hypofractionated irradiation (HFI) involving regional nodal irradiation (RNI, including internal mammary nodes, IMN) in N+ breast cancer patients treated with mastectomy or breast conserving surgery (BCS). Current study aims to analyze the dosimetric quality assurance so as to evaluate the compliance to the trial protocol.

MATERIALS/METHODS

Eligible patients were randomly assigned (1:1) to receive conventional fractionated irradiation (CFI: 50 Gy/25Fx) or HFI (40.05 Gy/15Fx), which is delivered to ipsilateral chest wall or whole breast (CW/WB) with tumor bed boost (HFI: 10.68 Gy/4Fx; CFI: 10 Gy/5Fx) and comprehensive RNI (supra/infraclavicular nodes and IMN in each patient, lower axilla if indicated) by using IMRT technique. The plan quality was evaluated based on dose distribution, dose volume histogram (DVH) and field parameters. The target coverage, including planning target volume of CW/WB (PTV1) and tumor bed (PTV2) and doses of the organs at risk (OARs) were evaluated. The LQ model was used to convert doses of OARs in HFI group using α/β = 3 Gy (EQD23) for comparison.

RESULTS

Between Feb 21, 2019 and Feb 14, 2022, 801 patients were enrolled at 8 centers with 401 and 400 in CFI and HFI group, respectively. There were 182 patients received BCS and 387 patients were with more than three positive lymph nodes. In the CFI group, the D90 and V45 of PTV1 reached the prescribed dose in 70.6% and 96.0% of the patients, respectively. In the HFI group, the D90 and V36 of PTV1 reached the prescribed dose in 87.8% and 95.5% of the patients, respectively. When the tumor bed was irradiated, the D90 of PTV2 reached the prescribed dose in 95.6% in the CFI group and 100% in the HFI group, respectively. The mean D90 of PTV1 and PTV2 were 50.09±0.65 Gy and 60.63±0.91 Gy in CFI group while 40.11±0.56 Gy and 50.79±2.03 Gy in HFI group. For OARs constraints, protocol compliance was all above 95% (heart: 95.3%; ipsilateral lung: 95.5%; contralateral lung: 97.1%; humeral head: 98.2% and spinal cord: 100%) with no significant difference between CFI and HFI groups. For patients with left-sided breast cancer, the Dmean of the heart was 5.10±1.75 Gy vs. 4.59±1.86 Gy (EQD23) in CFI and HFI groups (p = 0.51), respectively. No significant differences in Dmean of the heart (1.45±0.71 Gy vs. 1.33±0.77 Gy (EQD23), p = 0.40) was found either between two groups in right-sided patients. The differences were significant in the Dmean of the ipsilateral lung (13.37±1.99 Gy vs. 11.17±3.50 Gy (EQD23), p<0.01), contralateral lung (0.88±0.73 Gy vs. 0.74±0.61 Gy (EQD23), p<0.01) and the ipsilateral humeral head (15.27±7.62 Gy vs. 13.05±6.19 Gy (EQD23), p<0.01) and the Dmax of spinal cord (21.40±8.82 Gy vs. 19.47±7.99 Gy (EQD23), p = 0.05) between CFI and HFI groups.

CONCLUSION

A high degree of compliance with protocol dose constraints was found for treatment plans in the HARVEST trial and doses to the most of OARs decreased in HFI group.

Establishing a Risk Stratification Model to Identify Clinically High-Risk N0 Breast Cancer Who Could Benefit from Regional Nodal Irradiation: A Single Institute Analysis

PURPOSE/OBJECTIVE(S)

The adverse clinical features for pN0 BC patients significantly varies and there is no established clinical risk stratification system to identify those "high-risk" pN0 BC patients who might benefit from RNI. The purpose of this real-world study was to investigate the risk factors for developing recurrence among patients with pathological T1-3N0 breast cancer (BC) treated with breast-conserving surgery (BCS) followed by whole breast irradiation alone (WBI) and identify those clinically high-risk BCs who could benefit from regional nodal irradiation (RNI).

MATERIALS/METHODS

Female BC patients treated from 2009 to 2016 were retrospectively reviewed. The disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method, and survival differences were compared with the log-rank test. Univariate and multivariate analysis was performed using Cox logistic regression analysis. An external validation was conducted by using SEER database.

RESULTS

A total of 622 BC patients treated with BCS+WBI alone were included. With a median follow-up of 82 months, the 7-year OS and DFS for the entire cohort was 97% and 91%, respectively. Multivariable Cox analysis indicated that tumor size (p = 0.006), tumor location (p = 0.033), lymphovascular invasion (LVI) status (p = 0.0028) and Ki-67 index (p = 0.051) were independent risk factors for DFS, while only tumor size was the only independent risk factors for OS (p = 0.029). A scoring system was developed using these four factors and the 7-year DFS and OS were 97% and 96% for patients with 0-1 risk factors, 95% and 82% for patients with ≥2 risk factors (p<0.0001 for DFS, and p = 0.0063 for OS). Based on tumor size and tumor location, an external validation by demonstrated that the 7-year OS was 90% and 88% for patients with 0-1 risk factor, which was significantly better than those defined as high-risk BC patients (82%, p<0.0001).

CONCLUSION

By using our institute database, we establish a risk stratification system for identifying sub-group of pN0 BC patients, who are at high risk for developing recurrence. The results of our study support tailored RT decision-making according to individual risks, which needed to be confirmed in further studies.

Outcomes of Targeted Therapy Plus Immunotherapy and High-Dose Stereotactic Ablative Body Radiotherapy (SABR) for Metastatic Renal Cell Cancer Patients

PURPOSE/OBJECTIVE(S)

Stereotactic ablative body radiotherapy (SABR) is one of the treatment options for metastatic renal cell carcinoma (mRCC) but is limited by a lack of data to evaluate targeted therapy plus immunotherapy concurrently with high-dose SABR to multiple sites. We evaluated the safety and disease control for mRCC patients who concurrently received the above tri-modality treatment.

MATERIALS/METHODS

Patients were treated with SABR (40-70 Gy/5-10 fractions) for small lesions or partial-SABR (tumor center boosted with 6-8 Gy/3-5 fractions with 50-60 Gy/20-25 fractions to the whole tumor volume) for bulky tumors or tumors adjacent to critical organs. When SABR/partial-SABR was not feasible, a moderate fractionated radiotherapy plan, usually 60Gy/20 fractions were applied. of Targeted therapy plus immunotherapy (PD-1 inhibitor) was not interrupted during or after radiotherapy (RT). Adverse events (AEs) were evaluated. Disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were calculated. The PFS1 was defined as the first progression since the start of RT. The PFS2 was defined as the second progression after the second RT course, if new metastases occurred after first RT were all re-irradiated, and the systemic therapy was not changed. The Kaplan-Meier method was used for time-to-event endpoints.

RESULTS

A total of 51 patients, with a median age of 57 yr, were enrolled. The median follow-up was 12 months. There were 75% of patients with intermediate-risk and 18% with favorable-risk disease. 61% of the patients were oligometastatic. 71% had clear cell renal cancer. There were 241 metastases while 161 (67%) were irradiated. 80% of the lesions received SABRP/partial SABR. 1 patient with 14 lesions irradiated received proton therapy. All the surviving patients are continuing using targeted therapy while 81% patients complete at least 1-year PD-1 therapy. 10 patients (20%) had grade 3 drug-related AEs: pneumonitis (n = 2), elevated alanine transaminase (n = 4), myositis (n = 1), hand-foot syndrome myositis (n = 1), enteritis (n = 1), fatigue (n = 1). There were 1 grade 4 AEs of upper gastrointestinal bleeding. No grade 3-5 RT-related AEs was found. ORR and DCR for irradiated lesion were 51% and 98%. Median OS and PFS2 was not reached. Median PFS1 was 14(6-22) months. Estimated 1- and 2-yr OS, PFS1 and PFS2 were 90% and 90%, 56% and 38%, 74% and 51% respectively. Univariate analysis showed that an PFS1 benefit was found in patients who received radiation before systemic therapy failure (p = 0.038).

CONCLUSION

We investigated the high-dose RT in combination of concurrent targeted and immunotherapy in patients with metastatic RCC. We found that this treatment regimen was well tolerated, with good cancer control. Early use of high-dose RT to multi-lesions may improve PFS. Partial-SABR for bulky lesions close to critical organs could be safely and effectively applied under certain circumstances. These encouraging findings warrant further investigation.

Outcomes of recurrent incisional hernia repair by open and laparoscopic approaches: a propensity score-matched comparison

PURPOSE

Recurrent incisional hernias are challenging, and their surgical outcomes have not been well studied. We aimed to analyze the outcomes of recurrent incisional hernia repair in a propensity score-matched cohort study on laparoscopic intra-peritoneal onlay mesh repair (lap. IPOM) versus open sublay repair.

METHODS

All consecutive patients who had undergone open sublay repair and lap. IPOM of recurrent incisional hernia between January 2015 and December 2021 at a tertiary hernia center was identified. One-to-one propensity score matching was used to achieve a balanced exposure groups at baseline.

RESULTS

Of 255 patients, 85/95 with open sublay repair were matched to 85/160 with lap. IPOM. Before matching, the open sublay group had significantly larger hernia defects (6.3 cm vs. 5.0 cm) than the lap. IPOM group. Other major baseline imbalances were also found in body mass index (BMI), obesity and European Hernia Society (EHS) width classification. The pre-match results showed that the lap. IPOM group had significantly shorter operative time (median 75 vs. 95 min) and shorter postoperative hospital stay (median 8 vs. 11 days) compared with the open sublay group. Wound infection (8.4% vs. 1.9%) and hematoma (5.3% vs. 0.6%) occurred more frequently after open sublay repair. After matching, baseline characteristics were well balanced. The recurrence rate and incidence of complications were comparable between the two groups. However, the post-match analysis still showed that lap. IPOM was associated with decreased length of postoperative stay.

CONCLUSION

The outcomes of recurrent incisional hernia surgery after lap. IPOM and open sublay repair appear similar, except that the former had shorter length of postoperative stay. However, the poor outcomes were more likely associated with the unfavorable risk profiles, such as larger defect size, rather than the procedure technique itself.

The Role of Radiotherapy in Patients with Refractory Hodgkin Lymphoma after Brentuximab Vedotin and -/or Immune Checkpoint Inhibitors

PURPOSE/OBJECTIVE(S)

Brentuximab vedotin (BV) and immune checkpoint inhibitors (ICIs) had important roles in the treatment of relapse or refractory (R/R) Hodgkin lymphoma (HL). Treatment of refractory disease after BV and -/or ICIs remains a challenge. This study was conducted to evaluate the efficacy and safety of radiotherapy for R/R HL after failure to BV or ICIs.

MATERIALS/METHODS

We retrospectively analyzed patients in two institutions with R/R HL who had failed after first-line therapy, and were refractory to BV or ICIs, and received radiotherapy (RT) thereafter. The overall response rate (ORR), duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 19 patients were enrolled. First-line systemic therapy consisted of ABVD (84.2%), AVD + ICIs (10.5%) and BEACOPP (5.3%), respectively. After first-line therapy, 15 patients (78.9%) were refractory, and 4 patients (21.1%) relapsed. After diagnosis of R/R HL, 8 patients (42.1%) received BV, and 17 patients (89.5%) received ICIs. RT was delivered in all 19 patients who failed after BV or ICIs. In 16 efficacy-evaluable patients, the ORR and CR rate were 100% and 100%. The median DOR was 17.2 months (range, 7.9 to 46.7 months). 3 patients progressed at outside of the radiation field. The in-field-response rate was 100%. The 12-month PFS and OS were 84.4% and 100%, respectively. No patients were reported with sever adverse events.

CONCLUSION

This study concluded that radiotherapy was effective and safe for refractory HL after BV or ICIs. Further prospective studies were warranted.

Treatment Outcomes and Prognostic Factors of Chemotherapy Combined with Radiotherapy for Patients with Stage I-II Nasal-Type Natural Killer/T-Cell Lymphoma

PURPOSE/OBJECTIVE(S)

The purpose of this study was to assess the treatment outcome and the potential prognostic factors for patients with stage I-II nasal ENKTL treated with radiotherapy (RT) combined chemotherapy (CT).

MATERIALS/METHODS

From July, 2005 to January, 2019, 118 eligible patients were retrospective included in the study. Among the 118 patients, 84 were male and 34 were female. The median age was 45 years (range: 14-77 years). According to the Ann Arbor staging system, 66 patients had stage I disease (Primary tumor invasion (PTI) was present in 29 patients), and 52 patients had stage II disease. B symptoms were observed in 61 patients. The Eastern Cooperative Oncology Group (ECOG) performance score was 0 to 1 in 88 patients. Cervical lymph node involvement was observed in 51 patients. The primary lesions were located in the nasal cavity in 92 cases and in the Waldeyer ring in 26 cases. Five patients had received RT followed by CT (RT + CT), 20 patients had received CT followed by RT (CT + RT), 90 patients had received CT followed by RT, again followed by CT (CT+RT+CT), and 3 patients had received concurrent chemoradiotherapy (CRT) (1 patient received CRT + CT, other 2 patients received CT+CRT+CT). Patients were irradiated with a median dose of 50 Gy (range, 24-61.2). All patients received chemotherapy, 91 received non-anthracycline-based chemotherapy, whereas 27 patients received anthracycline-based chemotherapy. The median number of courses of chemotherapy was four (range: 1-10). Patients were scored as having low-risk disease (n = 50), intermediate-risk disease (n = 60) or high-risk disease (n = 8) according to the prognostic index of natural killer cell lymphoma (PINK).

RESULTS

Among the 118 patients, after initial therapy, the complete response (CR) rate was 82.2% (n = 97), and the partial response (PR) rate was 11.0% (n = 13). The stable disease (SD) rate was 2.5% (n = 3), and the progressive disease (PD) rate was 4.2% (n = 5). With a median follow-up of 43 months (range, 4-201) after irradiation, the 3-year PFS and OS were 76.9% and 82.9%, respectively. The 3-year OS rate was 75.0% for RT + CT, 70.0% for CT + RT, 87.1% for CT + RT+ CT, and 50.0% for CRT (P = 0.052). Three-year OS and PFS were 88.6% and 83.4%, respectively, for non-anthracycline-based chemotherapy regimen compared to 61.6% (P = 0.001) and 58.4% (P = 0.003), respectively, for the anthracycline-based chemotherapy regimen. Three-year OS and PFS were 84.0% and 79.0%, respectively, for patients receiving high-dose RT (≥50 Gy, n = 111) compared to 71.4% (P = 0.076) and 71.4% (P = 0.228), respectively, for low-dose RT (<50 Gy, n = 7). In multivariate analysis, adverse factors associated with OS in our study were chemotherapy regimen and response to RT and CT (P = 0.047, <0.001).

CONCLUSION

Radiotherapy combined with chemotherapy reported promising response rate and a favorable survival for patients with stage I-II nasal ENKTL. Anthracycline-based chemotherapy regimen and no remission after RT and CT were adverse factors of OS.

Gastrointestinal Toxicity Following Proton and Photon Radiation for Prostate Cancer in Patients with Inflammatory Bowel Disease

PURPOSE/OBJECTIVE(S)

Inflammatory bowel disease (IBD) has been considered a relative contraindication for radiation for prostate cancer (PC) due to concern for gastrointestinal (GI) toxicity. Modern radiation planning techniques such as intensity modulated radiation therapy (IMRT) have resulted in a significant decrease in GI toxicity in the general PC population. Several published case series have suggested overall excellent outcomes using IMRT in PC patients with IBD. Proton therapy (PT) with improved dosimetric sparing of bowel and rectum may offer additional benefit, but to our knowledge, there is no published data assessing outcomes after PT in PC patients with IBD. We report our institutional experience treating PC patients with IBD with both PT and IMRT.

MATERIALS/METHODS

We identified patients with an IBD diagnosis treated for PC at our institution from 2012-2022 with either IMRT or PT. Baseline clinical characteristics were captured, along with radiation parameters, including dose, fractionation, inclusion of pelvic nodes, and use of a rectal spacer. IBD specifics captured included type of IBD, use of IBD medication, and pre radiation colonoscopy findings when available. Early and late GI toxicities were captured via retrospective chart review and graded per the Common Terminology Criteria for Adverse Events (CTCAE) version 5.

RESULTS

Eighteen patients with IBD were treated with RT for PC at our institution, including 10 with ulcerative colitis, 7 with Crohn's disease, and 1 with IBD NOS. Nine of these patients were treated with PT and 9 with IMRT. Most were treated with conventional fractionation (n = 14) and the rest with moderate hypofractionation. Fourteen received primary RT to an intact prostate, and the rest received salvage RT. In four patients, the pelvic nodes were also treated. Rectal spacers were used for 8 patients. Nine of the patients were on IBD medications, and of the 15 patients with records of pre-RT colonoscopy, only 1 demonstrated inflammatory findings, which were noted in the ileum. Median follow-up was 3.5 years (1-6) Acute grade (Gr)1 GI toxicity was seen in 6(33%) patients with diarrhea and proctitis. No patients developed acute Gr 2 GI toxicity, and 1 patient developed acute Gr 3 diarrhea and proctitis. This patient had asymptomatic Crohn's disease prior to IMRT, not on medication, and was treated to the prostate and pelvic nodes. Late Gr 1 GI toxicity was seen in 4 (22%) patients. Median time to late GI toxicity was 9.5 months. No patients developed late Gr 2 or higher GI toxicity.

CONCLUSION

Modern radiation techniques including IMRT and PT are well tolerated in PC patients with well-controlled IBD. Larger studies with longer follow up would be helpful to further characterize these patients' outcomes. In the meantime, IMRT and PT should be considered as treatment options in patients with well-controlled IBD.

Improving Interfraction Robustness for IMPT Treatment Planning for Lung Cancer Using Multiple-CT Incorporated Robust Optimization

PURPOSE/OBJECTIVE(S)

Dose deterioration due to motion-induced density variation is a major concern in intensity-modulated proton therapy (IMPT) for lung cancer. Robust optimization is capable to address the intrafraction motion issue but not the interfraction variation. This study aims to investigate the potential of a new robust optimization technique of IMPT in mitigating the interfraction variation of lung cancer patients.

MATERIALS/METHODS

Two optimization techniques were used to create an IMPT plan for a lung cancer case, one was conventional robust optimization (ROcon) considering the perturbation of 3 mm setup uncertainty and 3.5% range uncertainty, and the other was multiple-CT incorporated robust optimization (ROmul) considering one more perturbation quantified using the end-of-inhalation-phase (T0) and end-of-exhalation-phase (T50) CTs. The ROcon plan was optimized on the average-intensity-projection (AIP) planning CT (pCT), and the ROmul plan was optimized on the AIP, T0, and T50 pCTs. The dose prescription was 40 Gy (RBE) in 5 fractions. The patient underwent a verification 4DCT (vCT) scan on six successive days. Both plans were recalculated on the T0 pCT, T50 pCT, and AIP vCT. The dose to the target and organ at risk of the ROcon and ROmul plans on pCT and vCT were compared.

RESULTS

Compared with the ROcon plan, the ROmul plan reduced the deviation of target coverage by greater than 50% in presence of intrafraction motion (ROmul:0.38-0.88%, ROcon:1.90-2.23%) and interfraction variation (ROmul: 0.62-1.63% vs ROcon:0.50-2.75%) while meeting the dose criteria on the planning AIP CT. As for the dose to the organ at risk, the ROmul plan had a slightly high lung V20 (0.3%) than did the ROcon plan on the AIP pCT. The deviations in lung V20 of the ROmul plan (mean 0.15%) on the vCTs were similar to that of the ROcon plan (mean 0.17%).

CONCLUSION

This study indicates that dose variation of an IMPT plan can be reduced in presence of interfraction variation along the treatment course by combining conventional robust optimization and novel multiple-CT optimization using only the planning CT.

[A single-center retrospective study of percutaneous drainage clinical characteristics of grade B and C postoperative pancreatic fistula and determination of the optimal intervention time]

Objective: To classified the fluid location of of grade B and C postoperative pancreatic fistula (POPF) and propose processing flow. Methods: Data from 232 patients who underwent pancreatic surgery from January 2018 to December 2022 at Department of General Surgery & Hepato-billo-pancreatic,Beijing Hospital were collected retrospectively. Forty-six patients who suffered from grade B and C POPF underwent ultrasound-guided drainage. There were 32 males and 14 females, with an age of (60.2±13.7)years (range:18 to 85 years). The imaging data of postoperative CT were collected and the the fluid location was classified. Then analyzed the drainage status when patents were diagnosed as POPF. Machine learning was performed and a random forest model was applied to construct the relationship between intervention time and mortality. The optimal intervention time was calculated. The patients were then divided into early and late intervention groups and clinical data and outcomes were compared using the t test,Mann-Whitney U test, χ2 test or Fisher's exact test between the two groups. Results: Based on the results of the random forest model, the optimal puncture time was within 5.38 days after the diagnosis of POPF. Based on the optimal time, 21 patients were subsumed into early intervention group and 25 patients were subsumed into late intervention group. The location of fluid collection was classified into four types: peripancreatic (32.7%,15/46), extra-pancreatic and epigastric (41.3%,19/46), extra-pancreatic and hypogastic (13.0%,6/46) and diffused (13.0%,6/46). The status of the drainage included normal in 10 patients (21.8%), displaced drain in 18 patients (39.1%) and drain removed or blocked in 18 patients (39.1%). The perioperative mortality rate was 19.0% (4/21) in the early intervention group and 8.0%(2/25) in the late. The late intervention group had significantly higher rates of positive drainage fluid cultures (88.0%(22/25) vs. 42.9%(10/21), χ2=10.584, P=0.001), secondary surgery (24.0%(6/25) vs. 0(0/21), P=0.025), and readmission within 90 days(32.0%(8/25) vs. 4.8%(1/21),χ2=5.381, P=0.020) than the early group, and a significantly longer postoperative hospital stay(M(IQR))(24(20)days vs. 39(53)days,Z=3.023,P=0.003). Conclusions: The location of the POPF fluid collection is classified into four types. Early radiological evaluation can detect abdominal effusion promptly,and early puncture and drainage will be beneficial in improving outcomes in these patents.

Nodal Response to Neo-Adjuvant Systemic Therapy Predicts Prognosis of cN3c Breast Cancer Patients Receiving Multidisciplinary Therapy

PURPOSE/OBJECTIVE(S)

cN3c breast cancer with ipsilateral supraclavicular (SCV) lymph nodal (SCLN) metastasis has a dismal prognosis. We investigated the survival outcomes, patterns and risks of recurrence in those patients after multidisciplinary therapy, as well as the predictors of candidates for SCV area boosting.

MATERIALS/METHODS

Consecutive cN3c breast cancer patients without distant metastases from January 2009 to December 2020 in our institution were retrospectively reviewed. Based on nodal response to neoadjuvant therapy (NAT), patients were categorized into three groups: clinical complete response (cCR) not achieved in SCLN (Group A, n = 66), SCLN cCR but axillary node (ALN) did not achieve pathological complete response (pCR, Group B, n = 34), cCR in SCLN and pCR in ALN (Group C, n = 13).

RESULTS

The median follow-up time was 32.7 months (range, 21.9-53.3months). The 5-year overall survival (OS) and recurrence-free survival (RFS) rates were 64.6% and 43.7% respectively. Multivariate analysis showed cumulative SCV dose and ypT stage, ALN response and SCV response to NAT were significantly associated with OS and RFS respectively. The 3-year for patients receiving the cumulative SCV dose of ≥60 Gy versus <60 Gy was 81.3% versus 69.0% (P = 0.042). Compared with Group A or B, Group C showed significantly improved RFS (3y-RFS: 53.8% vs 73.6% vs 100%, p = 0.003) and a numerically longer OS (3y-OS: 73.4% vs 86.7% vs 100%, p = 0.089). Meanwhile, Group C showed the lowest rate of DM as first failure (37.9 % vs 23.5% vs 0 in group A, B and C, respectively, p = 0.010). In patients of Group A, the 3-year OS rates for patients receiving the cumulative SCV dose of ≥60 Gy versus <60 Gy was 78.0% versus 57.3% (p = 0.029).

CONCLUSION

Nodal response to NAT is an independent prognostic factor for survival and pattern of failure. cN3c breast cancer patients with SCLN cCR and ALN pCR after NAT are potentially curable. A cumulative SCV dose of ≥60 Gy is positively associated with improved OS, especially in patients of SCLN without achieving cCR. Our data supports the perspective of optimizing radiotherapeutic strategy based on nodal response.

A Ferroptosis Microneedle Integrated Wireless Implanted Photodynamic Therapy Pellet for Cancer Treatment

PURPOSE/OBJECTIVE(S)

Effective, non-toxic, and targeted induction of lung cancer cell death is urgently needed. The goal of this research is to create a new implantable battery-free therapeutic pellet with integrated drug microneedles that allows for wireless photodynamic therapy (PDT) and targeted release of a ferroptosis inducer (Imidazole ketone erastin, IKE) into tumor tissue.

MATERIALS/METHODS

A wireless power unit, μ-LED illuminant, a flexible control circuit, and an IKE-stored biodegradable microneedle enclosed in polydimethylsiloxane (PDMS) were all built into an integrated therapeutic pellet. Lung cancer cells were used to illustrate the in vitro viability and molecular biological processes of this system. Therapeutic pellet implanted into the LLC xenograft C57BL/6 model. PDT was conducted by 660 nm laser irradiation after injecting a photosensitizer (Chlorin e6, Ce6) and targeted IKE released into the tumor. Systematically analyzing the therapeutic effects on lung cancer and toxic side-effects.

RESULTS

The PDT-IKE group reduced cellular viability by 90% compared to the control group at the cellular level. In mouse model studies, the PDT-IKE group suppressed tumors at 78.8%, three or four times greater than the PDT (26.6%) or IKE (19.2%) group alone. The PDT-IKE group also controlled IKE release more precisely with heated electrodes, reducing nephrotoxicity and improving safety. Moreover, the combination of PDT and IKE can effectively cause ferroptosis in tumor cells, both in vivo and in vitro.

CONCLUSION

A new implantable battery-free therapeutic pellet was designed for wireless PDT with integrated IKE microneedles to induce obvious ferroptosis in lung cancer. The proposed pellet would provide a promising strategy for cancer treatment.

Initial Report of a Randomized Trial Comparing Conventional vs. Novel Treatment Planning Technique to Ameliorate Immunosuppression from Lung SBRT

PURPOSE/OBJECTIVE(S)

SBRT is highly effective against early-stage non-small cell lung cancer. Radiation Therapy (RT) is known to modulate the immune system and contribute to the generation of anti-tumor T cells and stimulate T cell infiltration into tumors. However, this anti-tumor activity is offset by radiation-induced immunosuppression (RIIS) which results in lower tumor control and survival. Lymphocytes are highly radiosensitive and RIIS means destroying existing as well as newly created cytotoxic and helper T lymphocytes. We hypothesized that optimizing RT treatment planning by considering circulating blood and lymphatics as a critical Organ at Risk (OAR) may mitigate RIIS.

MATERIALS/METHODS

We conducted an IRB approved NCI funded clinical trial for 50 early-stage lung cancer patients treated with SBRT alone, from 2020 to 2023, to investigate the ability to reduce RIIS by reducing dose to circulating blood and lymphatics with the aid of a predictive algorithm. All SBRT plans adhered to treatment parameters from RTOG 0813 (central) or RTOG 0915 (peripheral). Patients were randomized to two arms: experimental optimization for RIIS (to reduce dose to blood and lymphatic rich organs) versus standard SBRT planning (without optimization for RIIS). Peripheral blood samples were collected at baseline, end of Tx, 4 weeks and 6 months post Tx. Patients with baseline absolute lymphocyte counts (ALC) less than 0.5x109 cells/L were ineligible for the trial. Data acquired for all blood cell types as well as lymphocyte sub populations CD3+, CD4+, CD8+, CD19+, CD56+. Two sample t-test was used to determine the statistical significance between the cohorts at the time points.

RESULTS

The standard arm had an ALC reduction of 28% at one week post Tx and a nadir at 4 weeks with a 34% reduction. Absolute percentage reductions in ALC from baseline in the optimized arm compared to the standard arm are: end of treatment point (13%, p = 0.03), 4 weeks (12%, p = 0.08), 6 months (15%, p = 0.1), and all three time points together 13% (p = 0.001). ALC recovery appears to be faster in the optimized arm. Radiation induced suppression of all blood cell types are also reduced in the optimized arm with respect to standard arm (relative percentages): ALC (34%), WBC (47%), RBC (46%), platelets (40%), monocytes (100%), and neutrophils (62%) at 4-week mark. Average percentage reductions on integral doses, and V5 (volume receiving a 5 Gy dose) of optimized compared to standard plans are: aorta: 26%, 41% heart: 8%, 33%, vena cava: 32%, 52%, T spine: 51%, 81%, lymph nodes: 35%, 57%, total lung- ITV: 1.6%, 1%, body: 10%, 14%.

CONCLUSION

For the first time, we have shown that it is possible to reduce RIIS in a statistically significant manner, compared to standard of care, via optimized RT planning using a predictive model. This has implications in increasing the efficacy of immunotherapy by preserving the existing tumor reactive T cells in the immune system to enhance anti-tumor activity, and in reducing hospitalizations and improving survival.

Assessing the feasibility of SUVindex (a metric derived from FDG PET/CT) for the diagnosis of polymyalgia rheumatica

AIM

To evaluate the feasibility of standard uptake value (SUV) index (ratio lesional maximum SUV [SUVmax] to liver mean SUV [SUVmean]) as a metabolic parameter for diagnosing polymyalgia rheumatica (PMR).

MATERIALS AND METHODS

A retrospective group of patients with PMR and controls with symptoms similar to PMR but diagnosed with other diseases. Semiquantitative and qualitative analysis of 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) uptake at 18 sites was undertaken for all patients. The diagnostic value of positron-emission tomography/computed tomography (PET/CT) for PMR was assessed by R software using logistic regression and a generalised additive model (GAM). All images were examined independently by two nuclear medicine physicians with extensive work experience.

RESULTS

The characteristic sites of PMR were the ischial tuberosity, interspinous bursa, periarticular hip, and symphysis pubis enthesis. The area under the curve (AUC) of the characteristic site SUV index was 0.930, and the best cut-off value was 1.685 with a sensitivity of 84.6% and a specificity of 92.6%. After adjusting for potential confounders, the probability of PMR diagnosis increased as the characteristic site SUV index increased and there was a nonlinear correlation between the two. When the characteristic site SUV index was ≥2.56, the probability of PMR gradually reached the threshold effect, which was as high as 90% or more.

CONCLUSION

The characteristic site SUV index is an independent factor for diagnosing PMR, and PMR should be highly suspected when it is ≥ 1.685. Nonetheless, it is important to note that these findings are based on an initial retrospective single-centre study and require external validation and further prospective evaluation before being translated into clinical practice.