Results Of Radiotherapy Research Articles

Proton and carbon ion radiotherapy for operable early-stage lung cancer; a prospective nationwide registry

Background and purposeTo investigate the toxicity and survival outcomes of proton and carbon ion radiotherapy for patients with operable early-stage lung cancer who are eligible for lobectomy. Materials and methodsThis multicenter nationwide prospective cohort study included patients with operable early-stage lung cancer. Proton and carbon ion radiotherapy was performed according to the schedule stipulated in the unified treatment policy. Progression-free survival (PFS), overall survival (OS) and treatment-related toxicities were evaluated. ResultsA total of 274 patients were enrolled and included in efficacy and safety analyses. The most common tumor type was adenocarcinoma (44 %), while 105 cases (38 %) were not histologically confirmed or diagnosed clinically. Overall, 250 (91 %) of the 274 patients had tumors that were peripherally situated, while 138 (50 %) and 136 (50 %) patients were treated by proton and carbon ion radiotherapy, respectively. The median follow-up time for all censored patients was 42.8 months (IQR 36.7–49.0). Grade 3 or severe treatment-related toxicity was observed in 4 cases (1.5 %). Three-year PFS was 80.5 % (95 % CI: 75.7 %–85.5 %) and OS was 92.5 % (95 % CI: 89.3 %–95.8 %). Pathological confirmation and clinical stage were factors significantly associated with PFS, while tumor location and particle-ion type were not. Meanwhile, clinical stage was significantly associated with OS, but pathological confirmation, tumor location, and particle-ion type were not. ConclusionsParticle therapy for operable early-stage lung cancer resulted in excellent 3-year OS and PFS in each subset. In this disease context, proton and carbon ion beam therapies are feasible alternatives to curative surgery.

OTHR-03. DEVELOPMENT OF PANORAMA: AN ASSESSMENT TOOL FOR PEDIATRIC NEURO-ONCOLOGY SERVICE DELIVERY CAPACITY

Abstract BACKGROUND To enhance the quality of care available for children with central nervous system (CNS) tumors across the world, a systematic evaluation of service delivery capacity is needed to identify gaps in pediatric neuro-oncology and prioritize interventions. To that end, we created the PediAtric Neuro-Oncology Resource AssesMent Aid (PANORAMA) tool. METHODS PANORAMA development consisted of three phases: operationalization, consensus building, and piloting. PANORAMA was designed to have domains that capture the elements of the pediatric neuro-oncology care continuum using assessments which were weighted according to their importance. Responses were ordinally scored to reflect adequacy of satisfaction. PANORAMA was revised based on feedback at various phases to improve its relevance, usability, and clarity. RESULTS The operationalization phase identified thirteen domains using 252 questions. The consensus phase included validating the identified domains, questions, and scoring by fifteen experts (six pediatric oncologists, three radiation oncologists, two neurosurgeons, two radiologists, and two pathologists). The validated PANORAMA domains were national context, hospital infrastructure, organization and service integration, human resources, financing, laboratory, neurosurgery, diagnostic imaging, pathology, chemotherapy, radiotherapy, supportive care, and patient outcomes. Seventy-six questions were added during the expert review. PANORAMA was piloted at thirteen institutions in twelve countries, representing diverse patient care contexts. Face validity was assessed using the correlation between the estimated score by respondents and calculated PANORAMA scores for each domain (r = 0.67, p <0.0001). Piloting eliminated two questions. CONCLUSIONS PANORAMA was developed following a systematic approach, leading to a relevant tool to evaluate the core elements of pediatric neuro-oncology service capacity. PANORAMA will be distributed to facilitate quantitative evaluation of institutional services, allowing for prioritization and benchmarking with centers at the local, regional, and international levels.

Clinical factors predicting the outcome of salvage radiotherapy for patients with biochemical recurrence after radical prostatectomy.

It remains unclear which patients with biochemical recurrence after prostatectomy are most suitable for salvage radiotherapy. We evaluated the parameters related to outcomes. We retrospectively evaluated patients who underwent salvage therapy for biochemical recurrence after prostatectomy between 2005 and 2019. This study aimed to evaluate biochemical recurrence-free survival (bRFS) after salvage radiotherapy and elucidate the parameters associated with bRFS. The bRFS rate was calculated using the Kaplan-Meier method, and the parameters associated with bRFS were evaluated using Cox regression analysis. This study included 67 patients treated with salvage radiotherapy with a median age of 67years at salvage radiotherapy. The median follow-up period after salvage radiotherapy was 7.3years. The 5-year bRFS rate following salvage radiotherapy was 47.1%. Univariate analysis showed that PSA doubling time < 6months, positive surgical margin, and pathological Gleason score ≥ 8 were significantly associated with shorter bRFS (p < 0.001, p = 0.036, p = 0.047, respectively). Multivariable analysis showed that a PSA doubling time < 6months and positive surgical margins were significantly associated with shorter bRFS (p = 0.001 and p = 0.018, respectively). No serious adverse events were observed. In our hospital, approximately half of the patients are under long-term control with salvage radiotherapy. A PSA doubling time of < 6months and positive surgical margins were suggested to be associated with poor outcomes of salvage radiotherapy.

3D printed dosimeter incorporating leuco-crystal violet and PMMA

This paper describes the development of 3D-printed dosimeters made from radiochromic materials. Incorporating polymethyl methacrylate (PMMA) as a transparent polymer matrix and leuco-crystal violet as a radiochromic dye, these dosimeters exhibit a color change when exposed to radiation. This change provides a way to visualize and measure three-dimensional dose distributions, which is important for the accurate verification of radiation doses in radiotherapy. The use of 3D printing technology allows these dosimeters to approximate human organ geometries, which may contribute to safer and more effective radiotherapeutic applications. The dosimeters can be customized into various shapes and sizes, are lightweight, and cost-effective, making them appropriate for use in both clinical and research settings in radiotherapy. The fabrication process is detailed, and the dosimeters have been tested at doses up to 100 Gy in X-ray irradiation and analyzed for dose distribution. Bragg-peak measurements from carbon beam irradiation illustrate the dosimeters' capability to detect peak radiation doses with a spatial resolution of approximately 1 mm. These findings indicate the potential of these 3D printed dosimeters to improve the accuracy of radiation delivery, which could positively impact patient outcomes in radiotherapy.

Androgen Deprivation Therapy and Outcomes After Radiation Therapy in Black Patients With Prostate Cancer

Prostate cancer in Black men compared with White men may be more sensitive to radiation therapy resulting in better outcomes in equal-access settings. The outcomes of androgen-deprivation therapy (ADT) vs radiation therapy itself remains uncharacterized. To quantify any outcome modification by receipt of ADT on the association between Black race and prostate cancer outcomes following radiation therapy. This was a retrospective, nationwide cohort study of Black and White patients treated in the US Veterans Healthcare system between 2000 and 2020 receiving definitive radiation for localized prostate cancer. Data were analyzed from January 2000 to December 2020. Patient self-identified race and use of ADT defined as any gonadotrophin-releasing hormone agonist or antagonist prescription within 6 months of radiation. Biochemical recurrence (BCR) from time of completion of radiation therapy (prostate-specific antigen nadir plus 2 ng/mL) and development of metastatic disease or prostate cancer mortality (PCSM) from time of recurrence. A total of 26 542 patients (8716 Black men with median [IQR] age of 64 [59-69] years and 17 826 White men with median [IQR] age of 67 [62-72] years) received definitive radiation therapy for nonmetastatic prostate cancer and had complete staging and follow-up data. A total of 5144 patients experienced BCR (3384 White and 1760 Black patients). The cumulative incidence of BCR at 10 years was not significantly different between Black and White men (1602 [22.14%] vs 3099 [20.13%], respectively) with multivariable hazard ratio (HR) of 1.03 (95% CI, 0.97-1.09; P = .33). In men receiving ADT, Black men had an HR for BCR of 0.90 (95% CI, 0.82-0.99; P = .03) compared with White men, and in men not receiving ADT, Black men had an HR of 1.13 (95% CI, 1.05-1.22; P = .002). Black race was associated with a decreased risk of developing metastatic disease (HR, 0.90; 95% CI, 0.82-0.98; P = .02) or PCSM (subdistribution HR, 0.72; 95% CI, 0.63-0.82; P < .001) from time of biochemical recurrence. Black patients treated with radiation appear to specifically benefit from the addition of ADT with regard to biochemical control. Additionally, BCR in Black men results in a lower rate of metastatic disease and death from prostate cancer. Future analyses of radiosensitivity in Black men should evaluate for the possibility of outcome modification by ADT.

A Population-Based Tumor-Volume Model for Head and Neck Cancer During Radiation Therapy With a Dynamic Oxygenated Compartment

PurposeWith the coming era of digital wisdom medical technology, mathematical modelling of tumor becomes a key step to optimize and realize precision radiotherapy. The purpose of this study is to develop a mathematical model for simulating the change of head-and-neck tumor (HN) volume during radiotherapy. Methods and MaterialsA formula is developed to describe the dynamic change of oxygenated compartment within a tumor, which is combined with the LPL model to describe various cell processes during radiotherapy, including potentially lethal lesion repair and misrepair, cell proliferation/loss, and tumor reoxygenation. Parameter sensitivity analysis is performed to evaluate the impacts of the lesion-related and repair-related biological factors on radiotherapy outcome. ResultsWe tested our model on 14 available HN cancer patients and compared the performance with three other models. The mean error of our model for the twelve good fit cases is 12.2%, which is considerable smaller than that of the LQ model (19.7%), GLQ model (19.1%) and FLCP model (16.6%). Correlation analysis results reveal that for small tumors, there is a positive correlation (correlation coefficient r=0.9416) between hypoxic fraction and tumor volume, whereas the correlation becomes negative and not significant (r=−0.4365) for large tumors. It is demonstrated from sensitivity analysis that the production rate of lethal lesions (ηl) has a far greater impact on tumor volume than other parameters. The hypoxic fraction has insignificant impact on tumor volume, but it has notable influence on the volume of surviving cells. The final volume of surviving cells athf=0.5 is almost 8 ×102 times that of hf=0.01. The potentially lethal lesion-related parameters (ηpl,εpl, ε2pl) have rather small impacts (<1%) on both tumor volume and the volume of surviving cells, which indicates that the repaired and misrepaired sublethal cells only take up a small portion of the total cancer cell population. ConclusionsA population-based tumor-volume model for HN cancer during radiotherapy with a dynamic oxygenated compartment was developed in this study. Comprehensively considering the damage process of tumor cells caused by radiation therapy, the accurate prediction of the volume change of head-and-neck tumors during treatment has been revealed. Meanwhile, various cell activities and their principles in the process of anti-tumor treatment were reflected, and it has positive clinical reference significance for radiobiology.

Survival outcomes of concurrent radiotherapy and toripalimab versus radiotherapy alone for elderly patients with postoperative head and neck squamous cell carcinoma unfit for cisplatin.

6099 Background: For elderly patients with locally advanced head and neck squamous cell carcinoma (HNSCC), the role of postoperative concurrent chemotherapy was controversial since the intolerable toxicities and increased acute mortality, thus, radiotherapy alone was recommended. We aimed to assess if addition of toripalimab (anti-PD-1) to radiotherapy could improve treatment outcomes for this patient population. Methods: This trial was an, open-label, phase 2, randomized study.We randomly assigned (1:1) patients aged&gt;65 years, with ECOG Performance Status(PS) of 0–2, and with postoperative Stage III-IV (AJCC 8th Staging system) HNSCC unfit for cisplatin to concurrent radiotherapy (60-66Gy) and toripalimab (240mg on D0, D21 and D42)(RT+PD-1 group) or radiotherapy alone(RT group). The primary endpoint was 2-year disease free survival (DFS). It is hypothesized to detect a difference between arms of 45%-65% in 2-year DFS. Results: Between September 2020 and May 2023, 87 patients were randomly assigned (43 in RT+PD-1 group and 44 in RT group). The median age were 71.0 years (range 66-81) for the RT+PD-1 group and 72.5 years (range 67-80 years) for RT group. In the RT+PD-1 group, 35 (81.4%) patients received at least one dose of toripalimab; 38 (88.3%) patients in the RT+PD-1 group and 36 (81.8%) patients in the RT group complete the planed radiation dose. Median follow-up was 24 months in both arms. The 2-year DFS was 55.3% with RT+PD-1 and 51.2% with RT alone (p=0.866), and the 2-year OS was 63.3% with RT+PD-1 and 78.4% with RT alone(p=0.557). In RT+PD-1 group, 18(41.8%) patients were CPS≥20%; 2-year DFS was 72.2% in patients with CPS≥20%, which was 53.8% in patients with CPS&lt;20 (p=0.412). Conclusions: The primary objective of prolonging DFS with concurrent radiotherapy and toripalimab in elderly patients unfit for cisplatin with locally advanced HNSCC was not met. For patients with CPS≥20, further study still warranted to evaluate the benefit of toripalimab in this patient setting. Biomarker analysis is still ongoing. Clinical trial information: NCT04523883 .

Outcomes of combined immunotherapy and palliative radiotherapy in patients with recurrent/metastatic head and neck cancers.

e18002 Background: Immunotherapy has revolutionized the treatment for recurrent/metastatic head and neck cancers (R/M HNC). It is uncertain whether the combination of immunotherapy and radiotherapy can provide survival benefits for R/M HNC. Methods: This study included patients with R/M HNC who underwent immunotherapy in our institute from November 2018 to October 2022. All patients received intravenous PD-1 inhibitors every 3 weeks. Palliative radiotherapy was administered to localized lesions for symptomatic treatment purposes in addition to systemic therapies. Tumor response was evaluated using RECIST1.1 criteria. The primary outcome measures were progression-free survival (PFS) and overall survival (OS). Other outcome measures were disease control rate (DCR) and objective response rate (ORR). The Kaplan-Meier method was utilized for survival analysis, and univariate and multivariate Cox regression analysis was conducted to identify prognostic factors associated with PFS and OS. Results: We included 129 R/M HNC patients. The median follow-up time was 14.0 months. The median number of immunotherapy courses received was 4 (range: 1-60). During immunotherapy, 43 patients received palliative radiotherapy, targeting primary tumors, lymph nodes, metastasis in liver, lung, bone, and other sites. Following the treatments, 16 (12.4%) patients achieved complete response (CR), 44 (34.1%) achieved partial response (PR), 35 (27.1%) had stable disease (SD), and 34 (26.4%) had progressive disease (PD). The ORR was 46.5% and the DCR was 73.6%. The group receiving immunotherapy combined with palliative radiotherapy had higher ORR (65.1% vs 37.2%, p = 0.005) and DCR (90.7% vs 65.1%, p = 0.004) than those without palliative radiotherapy. The PFS (15.0 months vs 4.0 months, p = 0.0027) and OS (not reached vs 26.0 months, p = 0.036) were improved in patients receiving palliative radiotherapy compared to those not. Patients who had received prior radiotherapy (n = 81) had a shorter PFS (4.0 months vs 14.0 months, p = 0.014), while there was no difference in OS (p = 0.16). We further showed that patients had better PFS (20.0 months vs 2.0 months; p &lt; 0.0001) and OS (43 months vs 17 months; p = 0.0043) when they received more than 4 cycles of immunotherapy. At the same time, our findings demonstrated that immunotherapy combined with nanoparticle albumin‐bound (nab-) paclitaxel-based regimens may prolong PFS (14.0 months vs 4.0months vs 2.5months, p = 0.0055) than gemcitabine-based regimens and other regimens. Conclusions: In patients with R/M HNC, the combination of immunotherapy and palliative radiotherapy demonstrates a synergistic effect, resulting in survival benefits. Prior radiotherapy might compromise patients’ PFS. Increasing the number of immunotherapy cycles and combining with nab-paclitaxel chemotherapy may improve patient survival.

Utilization patterns and outcomes of radiotherapy for patients with germ cell tumor relapsing with brain metastases, with a focus on stereotactic radiosurgery.

Utilization patterns and outcomes of radiotherapy for patients with germ cell tumor relapsing with brain metastases, with a focus on stereotactic radiosurgery.

MRI-Linac radiation therapy outcomes in patients with prostate, breast and other advanced malignancies.

e13811 Background: MR-guided radiation therapy offers an innovative approach, providing superior soft tissue contrast that enables clinicians to deliver higher doses to the target site with fewer fractions. The objective of the study is to assess objective response rates and adverse effects related to a community-based single-institution experience with the ViewRay MRIdian. Methods: An IRB-approved registrational trial was conducted at the Providence Cancer Institute starting May 2020, with data cutoff of September 2023. All patients treated underwent MR screening, and the target site(s) were treated using hypofractionated radiation therapy in ≤5 fractions. The primary endpoint was to assess adverse effects attributed to radiation therapy. Secondary measures included local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS), and change in prostate-specific antigen (PSA) for patients treated definitively for prostate cancer. The assessments were performed under the guidance of experienced radiation oncologists. Results: From May 2020 to September 2023, n=257 patients received treatment on the MRIdian with a median follow-up of 430 days [range 4-1221 days]. One and 2-year LRFS was 92% and 87%, and excluding prostate and breast cancer, 83% and 70%. Definitive prostatestereotactic body radiation therapy(SBRT) was delivered to 117 patients and significantly reduced PSA (mean difference -6.27, p&lt;0.0001), with no local failures to date. One and 2-year DMFS was 75% and 67%, though if excluding definitive prostate SBRT and partial breast irradiation, these were 48% and 33%. The OS rate at 1 and 2 years was 86% and 76%. Excluding prostate and breast cancer, the 1 and 2-year OS was 74% and 55%. Grade 3+ adverse events possibly or definitely attributable to radiation therapy were noted in 5% (n=13/257) of patients, including 2 possible treatment-associated deaths (bowel perforation following liver SBRT, and respiratory failure following lung SBRT and trastuzumab-deruxtecan systemic therapy). Conclusions: Our institutional experience with the MRIdian demonstrated high levels of local control, while overall survival was driven by out-of-field failures. Serious adverse events were infrequent, but more common in abdominal targets highlighting the need for careful planning and tight organs at risk (OAR) constraints, particularly if systemic therapy is delivered soon after radiation.

Outcomes of definitive carbon-ion radiotherapy for cT1bN0M0 esophageal squamous cell carcinoma.

A recent phase I/II study determined the optimal dose of definitive carbon-ion radiotherapy (CIRT) for cT1bN0M0 esophageal cancer. This study aimed to further confirm the efficacy and feasibility of the recommended dose fractionation of CIRT with long-term follow-up results in a larger sample size. This single center retrospective study evaluated patients with cT1bN0M0 esophageal squamous cell carcinoma treated with the recommended dose fractionation of 50.4Gy relative biological effectiveness in 12 fractions, between 2012 and 2022. Thirty-eight patients underwent CIRT at our hospital. Although eight (21.1%) patients were older than 80years, 15 (39.5%) had high surgical risk, and seven (18.4%) were at high risk for chemotherapy, all patients underwent CIRT as scheduled. Grade 3 esophagitis occurred in eight (21.1%) patients and grade 3 pneumonia in one (2.6%) patient in this study, but no grade 4 adverse events occurred. The only grade 3 late adverse event was pneumonia in one patient (2.6%). The 5-year overall survival rate, local control rate, and disease-free survival rates were 76.6% (95% CI, 90.9-62.4), 74.9% (95% CI, 90.7-59.0), and 66.4% (95% CI, 83.3-49.5), respectively. Additionally, post CIRT recurrence was as follows: seven (18.4%) patients had recurrence in another part of the esophagus, three (7.9%) in the primary site, three (7.9%) in lymph nodes outside the irradiated area, and one (2.6%) patient had liver metastasis. Our study demonstrates that CIRT using the recommended dose fractionation is feasible and effective for cT1bN0M0 esophageal squamous cell carcinoma.

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy.

Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent. To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC. All patients with LARC treated at a single tertiary hospital who underwent proctectomy after completing TNT were included. Patients were excluded if adequate details of TNT were not available in the electronic medical record. A total of 53 patients with LARC were included. Thirty-nine patients (73.5%) received LCRT and 14 (26.4%) received SCRT. Forty-nine patients (92.5%) were clinical stage III (cN1-2) prior to treatment. The average lymph node yield after proctectomy was 20.9 for SCRT and 17.0 for LCRT (P = .075). Of the 49 patients with clinically positive nodes before treatment, 76.9% of those who received SCRT and 72.2% of those who received LCRT achieved pN0 disease after TNT. Additionally, there were no significant differences in rates of pathologic complete response between patients who received SCRT and LCRT, 7.1% and 12.8%, respectively (P = .565). Pathologic outcomes of patients with LARC treated with SCRT or LCRT, as part of TNT, may be similar. Further prospective trials are needed to assess long-term clinical outcomes and to determine best treatment protocols.

Radiotherapy and immunology.

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Higher HIF-1alpha Level in Cervical Cancer Worsen the Outcome of Radiotherapy in Stage IIIB Squamous Cell Carcinoma of the Cervix

Higher HIF-1alpha Level in Cervical Cancer Worsen the Outcome of Radiotherapy in Stage IIIB Squamous Cell Carcinoma of the Cervix

Valuation of advanced Dosimetry in Transarterial Radioembolization of Hepatocellular Carcinoma with 90Y microspheres

Objective : The aim of our study was to analyze the relationships between tumor (T) and normal tissue (N) absorbed dose in relation to the clinical outcomes in hepatocellular carcinoma (HCC) patients treated with 90Y microspheres. Materials and methods : After transarterial radioembolization of HCC with 90Y microspheres, 62 patients (10 females: 52 males, mean age 68.2±8.2 years) were imaged using a four-ring, time-of-flight (TOF), PET/CT system. Low dose, non-diagnostic CT images from PET/CT were utilized for localization of the 90Y microspheres and attenuation correction of PET images. Response assessment was conducted using mRECIST criteria on MRI one month post treatment and subsequently every three months after 90Y treatment. Results : Among 62 patients, mean liver, tumor, and normal tissue doses (mean ± SD) were 51.38±23.32 Gy, 682.60±785.19 Gy and 45.54±21.19 Gy, respectively. Out of these patients, 39 exhibited complete response (CR), 11 showed partial response (PR), 2 had stable disease (SD), and 10 showed progression of the disease (PD). For CR+PR patients the mean T was 824.63±833.10 Gy, whereas for PD patients, the mean T was significantly lower at 205.70±183.22 Gy. The mean liver and normal tissue doses were comparable; for CR+PR patients had liver and normal tissue doses of 51.01±22.55 Gy and 45.18±20.68 Gy, respectively, and for PD patients, these values were 54.34±26.73 Gy and 49.10±22.97 Gy, respectively. Conclusion : Despite not considering the partial volume effect and having a limited number of PD cases, our data indicates a statistically significant lower (P = 0.0001) tumor dose in patients with disease progression compared to those with complete and partial response. These results suggest that post-therapy personalized, and image-based dosimetry provides promising predictive outcomes in 90Y microsphere radiation therapy for liver cancers.

Association between tumor cell in air space and treatment outcomes in early-stage lung cancer treated with stereotactic body radiation therapy

Background and purposeSpread-through air space (STAS) is an unfavorable factor in patients with lung cancer treated with surgery. However, the relationship between the treatment outcomes of stereotactic body radiation therapy (SBRT) for lung cancer and STAS has not been adequately investigated. This study aimed to evaluate the impact of tumor cells in the air space (TCIAS), which show a STAS burden, on treatment outcomes in patients with early-stage lung cancer treated with SBRT. Materials and methodsData of patients who underwent SBRT for early-stage lung cancer treated with SBRT were retrospectively reviewed. The influence of the TCIAS status on local progression-free (LPF), regional failure-free (RFF), distant failure-free (DFF), progression-free survival (PFS), and overall survival (OS) rates was assessed using univariate and multivariate analyses. ResultsOverall, 68 patients were included. The median follow-up time was 24.3 months. For patients positive/negative for TCIAS, the 2-year LPF, RFF, DFF, PFS, and OS rates were 81.4 %/91.1 %, 73.7 %/96.2 %, 55.9 %/75.3 %, 55.0 %/84.6 %, and 67.8 %/92.2 %, respectively. In the multivariate analysis, TCIAS-positive was a significant unfavorable factor for RFF (hazard ratio [HR]: 4.10; 95 % confidence interval [CI]: 1.04–16.16, p = 0.04), DFF (HR: 2.61, 95 % CI: 1.03–6.57, p = 0.04), and PFS (HR: 2.36; 95 % CI: 1.05–5.30, p = 0.04). By contrast, TCIAS-positive was not a significant risk factor for LPF and OS. ConclusionTCIAS-positive is an unfavorable factor for regional and distant failure after SBRT. TCIAS status may be useful in predicting the treatment outcome of SBRT for early-stage lung cancer.

Orbital radiotherapy with combined intravenous methylprednisolone and mycophenolate mofetil in moderate-to-severe thyroid eye disease

PurposeTo report the clinical outcomes of orbital radiotherapy (ORT) with combined intravenous methylprednisolone (IVMP) and mycophenolate mofetil (MMF) in thyroid eye disease (TED) patients with restrictive myopathy. DesignProspective comparative case series of patients managed at The Chinese University of Hong Kong from 2015 to 2021. MethodsThe primary outcome was the change in Gorman diplopia score at 52 weeks. Secondary outcomes were the changes in extraocular muscle motility (EOMy), area of extraocular muscle (EOM) on MRI, exophthalmos, and marginal reflex distance (MRD) 1 and MRD2 at 52 weeks. ResultsA total of 40 (29 females) TED patients, medium age 56 years, were treated with the double regimen: combined IVMP and MMF (17) or triple regimen: IVMP, MMF, and ORT (23). The triple group has a higher age (P = 0.028). Sex, smoking history, thyroid, and pre-treatment orbital status were comparable between the 2 groups. EOMy improved more after the triple regimen(P = 0.026). Nine patients from the triple group showed a significant reduction in the size of the inferior rectus (both eyes: P < 0.05), while five from the double group showed no significant reduction of any EOM on MRI. The improvement of CAS, diplopia score, exophthalmos, MRD1, and MRD2 were similar. No patient reported any severe or organ-threatening side effects from IVMP, MMF, or ORT requiring discontinuation of treatment. ConclusionThe triple regimen demonstrates better structural and functional outcomes in TED-related restrictive myopathy. Future randomized clinical trials are warranted to clarify the adjuvant role of ORT in this specific indication of TED management.

Dietary fibre supplementation enhances radiotherapy tumour control and alleviates intestinal radiation toxicity

BackgroundNon-toxic approaches to enhance radiotherapy outcomes are beneficial, particularly in ageing populations. Based on preclinical findings showing that high-fibre diets sensitised bladder tumours to irradiation by modifying the gut microbiota, along with clinical evidence of prebiotics enhancing anti-cancer immunity, we hypothesised that dietary fibre and its gut microbiota modification can radiosensitise tumours via secretion of metabolites and/or immunomodulation. We investigated the efficacy of high-fibre diets combined with irradiation in immunoproficient C57BL/6 mice bearing bladder cancer flank allografts.ResultPsyllium plus inulin significantly decreased tumour size and delayed tumour growth following irradiation compared to 0.2% cellulose and raised intratumoural CD8+ cells. Post-irradiation, tumour control positively correlated with Lachnospiraceae family abundance. Psyllium plus resistant starch radiosensitised the tumours, positively correlating with Bacteroides genus abundance and increased caecal isoferulic acid levels, associated with a favourable response in terms of tumour control. Psyllium plus inulin mitigated the acute radiation injury caused by 14 Gy. Psyllium plus inulin increased caecal acetate, butyrate and propionate levels, and psyllium alone and psyllium plus resistant starch increased acetate levels. Human gut microbiota profiles at the phylum level were generally more like mouse 0.2% cellulose profiles than high fibre profiles.ConclusionThese supplements may be useful in combination with radiotherapy in patients with pelvic malignancy.C3P3Z-i-BEWcsPG8U_9P4fVideo

Enhancing online dose distribution reconstruction in radiotherapy through sparse sampled rotating fiber arrays and deep learning

A optical fiber array dosimeter based on radiation-induced luminescence can be used in two-dimensional dose distribution measurements. However, using rotating fiber arrays introduces challenges in terms of online monitoring and variations in detector performance due to the long data acquisition time. This study aims to propose and demonstrate a novel method for online fast reconstruction of two-dimensional dose distributions in radiation therapy using projection data obtained from sparsely sampled rotating fiber arrays. The projection data were processed in both the projection and image domains to achieve restoration and noise reduction by deep learning techniques. The performance of the proposed method was evaluated using simulation data obtained by Monte Carlo toolkit Geant4 and experimental data obtained from a medical accelerator. Results showed that the method can successfully reconstruct dose distribution through sparse sampling and reduce the measurement time to one-sixth of the original. The peak signal-to-noise ratio, root mean square error, and structural similarity index were 23.72, 2.68, and 0.95, respectively. Additionally, the 3%/3 mm gamma pass rate reached 98.4% under specific irradiation conditions with a dose of at least 10% of the maximum dose. The integration of sparse sampling techniques, rotating fiber arrays, and deep learning techniques offers new possibilities for the fast and efficient reconstruction of two-dimensional dose distributions, ensuring high-quality radiotherapy outcomes.

A Retrospective Study of Clinical Outcomes for Patients with Esophageal Cancer Who Were Treated with Radiotherapy Alone

Introduction: Patients with esophageal cancer who are in a poor general condition receive radiotherapy alone, but outcomes are often unsatisfactory. The aim of this study was to clarify recent outcomes of radiotherapy alone for esophageal cancer. Methods: Patients who underwent 50 Gy or more of radiotherapy without chemotherapy were retrospectively reviewed. Endpoints were overall survival (OS), disease-specific survival (DSS), local control (LC), and progression-free survival (PFS). Survival curves were drawn using the Kaplan-Meier method, and predictors were analyzed using the Cox proportional hazards model. Results: Sixty-nine patients were included. The median follow-up period was 17.9 months. The 5-year OS, DSS, LC, and PFS rates were 33.2%, 49.8%, 46.2%, and 16.8%, respectively. In the multivariate Cox proportional hazard model, clinical stage was a significant predictor for OS (hazard ratio [HR]: 4.42, 95% confidence interval [CI]: 1.80–11.17, p = 0.001), DSS (HR: 2.08, 95% CI: 1.43–3.12, p = 0.0001), LC (HR: 1.86, 95% CI: 1.28–2.74, p = 0.001), and PFS (HR: 1.65, 95% CI: 1.25–2.18, p = 0.0004). Radiation dose was a significant predictor for LC (HR: 0.87, 95% CI: 0.78–0.97, p = 0.018) and tumor location was a significant predictor for PFS (HR: 1.55, 95% CI: 1.10–2.19, p = 0.018). In subgroup analysis, the 5-year OS, DSS, LC, and PFS rates for stage I were 60.0%, 80.0%, 71.9%, and 46.1%, respectively. Conclusions: Stage, radiation dose, and tumor location are significant predictors for outcomes. Patients with stage I esophageal cancer can be cured by radiotherapy alone.