Modern Radiotherapy Techniques Research Articles

Hypofractionated radiotherapy with simultaneous tumor bed boost (Hi-RISE) in breast cancer patients receiving upfront breast-conserving surgery: study protocol for a phase III randomized controlled trial.

The effectiveness and safety of moderately hypofractionated radiotherapy (HFRT) in patients undergoing breast-conserving surgery (BCS) has been demonstrated in several pivotal randomized trials. However, the feasibility of applying simultaneous integrated boost (SIB) to the tumor bed and regional node irradiation (RNI) using modern radiotherapy techniques with HFRT needs further evaluation. This prospective, multi-center, randomized controlled, non-inferiority phase III trial aims to determine the non-inferiority of HFRT combined with SIB (HFRTsib) compared with conventional fractionated radiotherapy with sequential boost (CFRTseq) in terms of five-year locoregional control rate in breast cancer patients undergoing upfront BCS. A total of 2904 participants will be recruited and randomized in a 1:1 ratio into the HFRTsib and CFRTseq groups. All patients will receive whole breast irradiation, and those with positive axillary nodes will receive additional RNI, including internal mammary irradiation. The prescribed dose for the HFRTsib group will be 40Gy in 15 fractions, combined with a SIB of 48Gy in 15 fractions to the tumor bed. The CFRTseq group will receive 50Gy in 25 fractions, with a sequential boost of 10Gy in 5 fractions to the tumor bed. This trial intends to assess the effectiveness and safety of SIB combined with HFRT in early breast cancer patients following BCS. The primary endpoint is locoregional control, and the results of this trial are expected to offer crucial evidence for utilizing HFRT in breast cancer patients after BCS. This trial was registered at ClincalTrials.gov (NCT04025164) on July 18, 2019.

Comparative Analysis of External and Internal Radiotherapy- Dependent Plans in Patients with Gynecological Cancer.

Radiotherapy plays a key role in the treatment of gynecological cancer. Modern radiotherapy techniques with external beams (e-RT) are applied in a broad spectrum of gynecological cancer cases. However, high radiation doses, affecting normal tissue adjacent to cancer, represent the main disadvantage of e-RT regimens. For this reason, brachytherapy (BT), an internal beam-based technique (i-RT), is suggested following e-RT. Our purpose was to compare e-RT plans using volumetric-modulated arc therapy (VMAT) with those using 3D conformal techniques (3D-CRT) and compare BT plans guided by 3D or 2D imaging based on the potential corresponding toxicity levels. In this preliminary, non-randomized comparative retrospective study, 15 females suffering gynecological cancer were enrolled. Modern e-RT and i-RT (BT) techniques were applied. Concerning e-RT, D95/D99/rectum 2cc/bladder 2cc and small intestine 2cc were measured and compared; in i-RT, rectum 2cc/bladder 2cc were measured and compared. The median dose to the planning target volume in VMAT was 97.4 Gy compared with 92.9 Gy in 3D-CRT. Τhe rectum received almost 5 Gy less in VMAT compared to 3D-CRT (median of 43.5 Gy vs. 48.6 Gy; p=0.001). In the bladder, dose differences were minimal, while the small intestine received 47.6 Gy in VMAT (p=0.001). Regarding 3D-BT, the rectum received 63.1 Gy compared with 49.9 Gy (p=0.009) in 2D-BT. Concerning the bladder, mean 2D-BT and 3D-BT doses were 71.9 and 65 Gy, respectively, differing non-significantly. VMAT was found to be superior to 3D-CRT, especially in dose distribution, volume coverage and protection of critical organs. Similarly, 3D-BT should be preferred over 2D-BT due to critical advantages.

Dose-volume metric-based prediction of radiotherapy-induced lymphocyte loss in patients with non-small-cell lung cancer treated with modern radiotherapy techniques

Background and PurposeRadiation-induced lymphopenia (RIL) is a common side effect of radiotherapy (RT) that may negatively impact survival. We aimed to identify RIL predictors in patients with non-small-cell lung cancer (NSCLC) treated intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) Materials and MethodsWe retrospectively analysed data of 306 patients who underwent radical RT for NSCLC. Absolute lymphocyte count (ALC) loss was evaluated for each patient by fitting an exponential decay curve to data from first 45 days since treatment start, and percentage ALC loss relative to baseline was calculated based on area under the decay curve and baseline ALC. We compared IMRT and VMAT treatment plans and used linear regression to predict ALC loss. ResultsALC decreased during RT in the whole patient group, while neutrophil counts remained stable and decreased only in those treated with concurrent chemoradiotherapy (CRT). Percentage ALC loss ranged between 11.0–77.8 % and was more strongly than lymphocyte nadir correlated with dose-volume metrics for relevant normal structures. We found evidence for the association of high radiation dose to the lungs, heart and body with percentage ALC loss, with lung volume exposed to 20–30 Gy being most important predictors in patients treated with IMRT. A multivariable model based on CRT use, baseline ALC and first principal component (PC1) of the dose-volume predictors showed good predictive performance (bias-corrected R2 of 0.40). ConclusionPercentage lymphocyte loss is a robust measure of RIL that is predicted by baseline ALC, CRT use and dose-volume parameters to the lungs, heart and body.

Exclusion of non-Involved uterus from the target volume (EXIT-trial): An individualized treatment for locally advanced cervical cancer using modern radiotherapy and imaging techniques followed by completion surgery

Background and purposeChemoradiotherapy followed by brachytherapy is the standard of care for locally advanced cervical cancer (LACC). In this study, we postulate that after omitting an iconographical unaffected uterus (+12 mm distance from the tumour) from the treatment volume is safe and that no tumour will be found in the non-targeted uterus (NTU) leading to reduction of high-dose volumes of surrounding organs at risk (OARs) Material and MethodsIn this single-arm phase 2 study, two sets of target volumes were delineated: one standard-volume (whole uterus) and an EXIT-volume (exclusion of non-tumour-bearing parts of the uterus with a minimum 12 mm margin from the tumour). All patients underwent chemoradiotherapy targeting the EXIT-volume, followed by completion hysterectomy. In 15 patients, a plan comparison between two treatment plans (PTV vs PTV_EXIT) was performed. The primary endpoint was the pathological absence of tumour involvement in the non-targeted uterus (NTU). Secondary endpoints included dosimetric impact of target volume reduction on OARs, acute and chronic toxicity, overall survival (OS), locoregional recurrence-free survival (LRFS), and progression-free survival (PFS). ResultsIn all 21 (FIGO stage I: 2; II: 14;III: 3; IV: 2) patients the NTU was pathologically negative. Ssignificant reductions in Dmean in bladder, sigmoid and rectum; V15Gy in sigmoid and rectum, V30Gy in bladder, sigmoid and rectum; V40Gy and V45Gy in bladder, bowel bag, sigmoid and rectum; V50Gy in rectum were achieved. Median follow-up was 54 months (range 7–79 months). Acute toxicity was mainly grade 2 and 5 % grade 3 urinary. The 3y- OS, PFS and LRFS were respectively 76,2%, 64,9% and 81 %. ConclusionMRI-based exclusion of the non-tumour-bearing parts of the uterus at a minimum distance of 12 mm from the tumour out of the target volume in LACC can be done without risk of residual disease NTU, leading to a significant reduction of the volume of surrounding OARS treated to high doses.

Clinical Outcomes of Salvage Microsurgical Resection after Radiation Therapy for Sporadic Vestibular Schwannomas

Abstract Background The purpose of this study was to evaluate clinical outcomes after salvage microsurgery for vestibular schwannoma (VS) treated initially with modern radiotherapy techniques as compared to those treated with primary microsurgical resection. Methods Patients who underwent microsurgical resection of sporadic VS undergoing a translabyrinthine approach at a single academic skull base tertiary referral center were included. Baseline and postoperative dynamic gait index, functional gait assessment, House–Brackmann facial nerve grading, and completeness of resection were prospectively recorded. Results Of the 265 patients reviewed, 21 (7.9%) patients underwent prior radiation. Median age of the cohort was 55 years (interquartile range: 51–63). The likelihood of achieving a gross total resection was significantly lower for radiated as compared to nonradiated patients (odds ratio: 0.18, 95% confidence interval: 0.05–0.53, p = 0.004) when controlling for tumor size. Radiated patients had better postoperative facial nerve function on the first postoperative day, but this difference was not significant at long-term follow-up. Radiated patients had lower preoperative postural stability scores than nonradiated patients on FGA (26 vs. 23, p = 0.035). Postoperatively, radiated patients had comparable outcomes compared to nonradiated patients when controlling for age and tumor size. Conclusions Compared to patients with VS treated with surgery alone, previously radiated patients are less likely to achieve gross total resection in the salvage setting. Radiated patients scored better on facial nerve outcomes compared to nonradiated patients in the initial postoperative period but demonstrated similar long-term outcomes.

Study of PRESAGE® dosimeter for end-to-end 3D radiotherapy verification using an anthropomorphic phantom with bespoke dosimeter insert.

Modern radiotherapy techniques have advanced and become more sophisticated. End-to-end 3D verification of the complex radiotherapy dose distribution in an anthropomorphic phantom can ensure the accuracy of the treatment delivery. The phantoms commonly used for dosimetry are homogeneous solid water phantom which lacks the capability to measure the 3D dose distribution for heterogeneous tissues necessary for advanced radiotherapy techniques. Therefore, we developed an end-to-end 3D radiotherapy dose verification system based on MAX-HD anthropomorphic phantom (Integrated Medical Technologies Inc., Troy, New York) with bespoke intracranial insert for PRESAGE® dosimeter. In this study, several advanced radiotherapy treatment techniques of various levels of complexity; 3D-CRT, IMRT and VMAT treatment, were planned for a 20mm diameter of a spherical target in the brain region and delivered to the phantom. The dosimeters were read out using an in-house developed optical computed tomography (OCT) imaging system known as 3DmicroHD-OCT. It was found that the measured dose distribution of the PRESAGE® when compared with the measured dose distribution of EBT film and Monaco TPS has a maximum difference of less than 3% for 3D-CRT, IMRT and VMAT treatment plans. The gamma analysis results of PRESAGE® in comparison to EBT film and Monaco TPS show pass rates of more than 95% for the criteria of 3% dose difference and 3mm distance-to-agreement. This study proves the capability of PRESAGE® and bespoke MAX-HD phantom in conjunction with the 3DmicroHD-OCT system to measure 3D dose distribution for end-to-end dosimetry verification.

The impact of advancing the standard of care in radiotherapy on operational treatment resources.

To demonstrate the impact of implementing hypofractionated prescription regimens and advanced treatment techniques on institutional operational hours and radiotherapy personnel resources in a multi-institutional setting. The study may be used to describe the impact of advancing the standard of care with modern radiotherapy techniques on patient and staff resources. This study uses radiation therapy data extracted from the radiotherapy information system from two tertiary care, university-affiliated cancer centers from 2012 to 2021. Across all patients in the analysis, the average fraction number for curative and palliative patients was reported each year in the decade. Also, the institutional operational treatment hours are reported for both centers. A sub-analysis for curative intent breast and lung radiotherapy patients was performed to contextualize the impact of changes to imaging, motion management, and treatment technique. From 2012 to 2021, Center 1 had 42214 patient plans and Center 2 had 43252 patient plans included in the analysis. Averaged over both centers across the decade, the average fraction number per patient decreased from 6.9 to 5.2 (25%) and 21.8 to 17.2 (21%) for palliative and curative patients, respectively. The operational treatment hours for both institutions increased from 8h 15 min to 9h 45 min (18%), despite a patient population increase of 45%. The clinical implementation of hypofractionated treatment regimens has successfully reduced the radiotherapy workload and operational treatment hours required to treat patients. This analysis describes the impact of changes to the standard of care on institutional resources.

Nasopharyngeal carcinoma in children: a challenging disease in a middle-income country, Tunisia

Background: This study aimed to assess the epidemiological, clinical, and therapeutic aspects and prognosis of juvenile nasopharyngeal carcinoma in Tunis country.
 Materials and Methods: This study included 68 patients, younger than 18 years of age. All the patients had a clinical and para-clinical tumoral assessment. The study of survival and prognostic factors was done after a descriptive analysis. These prognostic factors were studied through uni and multivariate analysis.
 Results: The median age was 14.7 years and the sex ratio was 2 male to 1 female. The average time to first consultation was 4 months. Rhinological signs were the most frequent symptom for consultation (n= 41). The T3-T4 tumors accounted for 78% of patients and there was a lymph node invasion stage N2-N3 in 63% of cases. Non-metastatic patients had radiotherapy associated with chemotherapy in 97% of cases. Metastatic patients received hypofractionated radiotherapy on bone metastasis, and first-line chemotherapy followed by radiotherapy on the primitive tumor and lymph node areas in case of good response to chemotherapy ( n= 2). The mean follow-up was 94 months; 78% of these patients were alive and in complete remission, 19% were in therapeutic failure, and 16% of them had metachronous metastases. The five-year-overall survival was 95%. Hyposialia and skin dystrophy were the most frequent late complications.
 In univariate analyses, significant prognostic factors were cranial nerve invasion, intracranial invasion, and infra-temporal fossa invasion. In multivariate analysis, the most parsimonious model associated extension to the infratemporal fossa, endo-cranial extension, and initial therapeutic modality (treatment failures were less frequent with neoadjuvant chemotherapy (p= 0.22)). 
 Conclusion: Treatment of nasopharyngeal carcinoma in children consists of chemotherapy and radiotherapy. Synchronous or metachronous metastases are common in this patient population. Modern radiotherapy techniques, including conformal radiotherapy with intensity modulation, are promising and could overcome toxicities in long-term survivors.

Does lower dose pilocarpine have a role in radiation-induced xerostomia in the modern radiotherapy era? A single-center experience based on patient-reported outcome measures.

This study aims to investigate the efficacy of lower dose pilocarpine in alleviating late dry mouth symptoms in head and neck cancer patients received radiotherapy. Eighteen head and neck cancer patients experiencing persistent dry mouth were enrolled in this study. All participants started pilocarpine treatment a median of 6months post-radiotherapy. Initially, patients received pilocarpine at 5mg/day, with a gradual increase to the recommended dose of 15mg/day. A Patient-Reported Outcome Measurement (PROMs) questionnaire assessed symptoms' severity related to hyposalivation. All patients reported symptomatic dry mouth above grade 2 before starting the medication. Pilocarpine treatment continued based on patients' self-assessment, with a median duration of 12months (range, 3-36months). The median daily maintenance dose was 10mg (range, 5 to 20mg). Total PROMs scores significantly decreased following medication, from 13 points (range 7-18 points) to 7 points (range 4-13 points) (p = 0.001). Significant improvements were observed in questions related to dry mouth (p < 0.001), water intake during eating (p = 0.01), carrying water (p = 0.01), taste (p < 0.001), and water intake during speech (p < 0.001). Initial and maintenance doses of pilocarpine were lower, and the duration of pilocarpine usage was shorter in patients treated with intensity-modulated radiation therapy compared to conformal radiotherapy (12months vs. 25months, p = 0.04). Pilocarpine may be considered at doses lower for late-term dry mouth. With modern radiotherapy techniques effectively preserving the parotid gland, short-term use may be recommended in these patients. Future studies may enhance the development of a more robust patient selection criteria model.

Does Breast Surgery Type Alter Incidental Axillary Irradiation? A Dosimetric Analysis of the "Sentinel Envahi et Randomisation du Curage" SERC Trial.

An incidental axillary dose of adjuvant radiotherapy using tangential beams is usually given after breast-conserving surgery for breast cancer. The goal of this sub-study was to evaluate this incidental dose in the setting of post-mastectomy radiotherapy (PMRT) according to two different radiotherapy techniques. Patients participating in a randomized SERC trial who received PMRT in a single center were included. We collected the incidental axillary dose delivered to the Berg level 1 using different dosimetric parameters and compared two techniques using Student's t-test: three-dimensional conformal radiotherapy (3D-CRT) and volumetric arc therapy (VMAT). We analyzed radiotherapy plans from 52 patients who received PMRT from 2012 to 2021. The mean dose delivered to the Berg level 1 was 37.2 Gy. It was significantly higher with VMAT than with 3D-CRT-43.6 Gy (SD = 3.1 Gy) versus 34.8 Gy (SD = 8.6 Gy) p < 0.001. Eighty-four percent of the Berg level 1 was covered by 40 Gy isodose in the VMAT group versus 55.5% in the 3D-CRT group p < 0.001. On the Berg level 1, PMRT gives a dose at least equivalent to the one given by post-breast-conserving surgery radiotherapy, making it possible to limit completion axillary lymph node dissections in select pN1a patients treated with a mastectomy. Modern radiotherapy techniques like VMAT tend to increase this incidental dose.

Setup margins based on the inter- and intrafractional setup error of left-sided breast cancer radiotherapy using deep inspiration breath-hold technique (DIBH) and surface guided radiotherapy (SGRT).

The use of volumetric modulated arc therapy (VMAT), simultaneous integrated boost (SIB), and hypofractionated regimen requires adequate patient setup accuracy to achieve an optimal outcome. The purpose of this study was to assess the setup accuracy of patients receiving left-sided breast cancer radiotherapy using deep inspiration breath-hold technique (DIBH) and surface guided radiotherapy (SGRT) and to calculate the corresponding setup margins. The patient setup accuracy between and within radiotherapy fractions was measured by comparing the 6DOF shifts made by the SGRT system AlignRT with the shifts made by kV-CBCT. Three hundred and three radiotherapy fractions of 23 left-sided breast cancer patients using DIBH and SGRT were used for the analysis. All patients received pre-treatment DIBH training and visual feedback during DIBH. An analysis of variance (ANOVA) was used to test patient setup differences for statistical significance. The corresponding setup margins were calculated using the van Herk's formula. The intrafractional patient setup accuracy was significantly better than the interfractional setup accuracy (p<0.001). The setup margin for the combined inter- and intrafractional setup error was 4, 6, and 4mm in the lateral, longitudinal, and vertical directions if based on SGRT alone. The intrafractional error contributed ≤1mm to the calculated setup margins. With SGRT, excellent intrafractional and acceptable interfractional patient setup accuracy can be achieved for the radiotherapy of left-sided breast cancer using DIBH and modern radiation techniques. This allows for reducing the frequency of kV-CBCTs, thereby saving treatment time and radiation exposure.

Embracing Personalized Strategies in Radiotherapy for Nasopharyngeal Carcinoma: Beyond the Conventional Bounds of Fields and Borders.

Radiotherapy is the primary treatment modality for non-metastatic nasopharyngeal carcinoma (NPC) across all TN-stages. Locoregional control rates have been impressive even from the 2D radiotherapy (RT) era, except when the ability to deliver optimal dose coverage to the tumor is compromised. However, short- and long-term complications following head and neck RT are potentially debilitating, and thus, there has been much research investigating technological advances in RT delivery over the past decades, with the primary goal of limiting normal tissue damage. On this note, with a plateau in gains of therapeutic ratio by modern RT techniques, future advances have to be focused on individualization of RT, both in terms of dose prescription and the delineation of target volumes. In this review, we analyzed the guidelines and evidence related to contouring methods, and dose prescription for early and locoregionally advanced (LA-) NPC. Next, with the preference for induction chemotherapy (IC) in patients with LA-NPC, we assessed the evidence concerning radiotherapy adaptations guided by IC response, as well as functional imaging and contour changes during treatment. Finally, we discussed on RT individualization that is guided by EBV DNA assessment, and its importance in the era of combinatorial immune checkpoint blockade therapy with RT.

Dosimetric Comparison of Hippocampal Sparing Whole Brain Radiotherapy by Volumetric Modulated Arc Therapy, Linac-based Intensity-modulated Radiation Therapy and 3-D Conformal Radiation Therapy: A Cross-sectional Study

Introduction: Brain metastases are treated with Whole-Brain Radiotherapy (WBRT) using the 3-D Conformal Radiation Therapy (3DCRT) technique. Attempts have been made to perform dosimetric analysis of WBRT with hippocampal sparing using 3DCRT, Volumetric Modulated Arc Therapy (VMAT), and Linac-based Intensity Modulated Radiation Therapy (linac-based IMRT), anticipating technical challenges during contouring and treatment planning. Aim: To perform a dosimetric analysis and comparison ofhippocampal sparing cranial irradiation by 3DCRT, VMAT, and IMRT treatment plans in brain metastases patients. Materials and Methods: The analytical cross-sectional dosimetric study was conducted from November 2022 to September 2023 at Government Medical College, Kottayam, Kerala, India. Ten patients treated for brain metastases with WBRT using 3DCRT were considered for dosimetric analysis. The Planning Target Volume (PTV) dosimetry and hippocampal dosimetry were studied for all ten patients. The important dosimetric parameters included volume receiving 100% dose, Target Coverage (TC), Homogeneity Index (HI) in PTV dosimetry, the mean hippocampal dose, and maximal hippocampal dose in hippocampal dosimetry. The hippocampus and hippocampal avoidance volume were contoured. Treatment plans for 3DCRT, VMAT, and Linac-based IMRT were generated for each patient’s prescription dose of 30 Gy in 10 fractions. The non-parametric Kruskal-Wallis test was used for data analysis. Results: The mean whole brain Planned Target Volume (PTV) was 1190 cm3 . The mean hippocampal avoidance volume was 30 cm3 , which occupied 2.5% of the whole brain PTV. The average median dose received by the hippocampus was 30.05 Gy, 17.1 Gy, and 17.5 Gy for 3DCRT, Linac-based IMRT, and VMAT, respectively. The mean dose for the hippocampus was 31.03 Gy, 17.7 Gy, and 17.5 Gy for 3DCRT, Linac-based IMRT, and VMAT, respectively (p&lt;0.001). VMAT offered better hippocampal sparing compared to IMRT and 3DCRT. On average, VMAT offered a 2% improvement, and 3DCRT offered a 5% improvement in TC compared to IMRT. The HI of 3DCRT was 0.09, IMRT 0.199, and VMAT 0.150. Conclusion: VMAT and LINAC-based IMRT permit hippocampal-sparing WBRT with adequate target volume coverage and acceptable homogeneity when compared to 3DCRT plans. Thus, the dosimetric study suggests that modern radiotherapy techniques should be advocated for hippocampal-sparing WBRT.

KRŪTIES VĖŽIO RADIOTERAPIJA TAIKANT INOVATYVŲ GILAUS KVĖPAVIMO KONTROLĖS METODĄ: KLINIKINIAI VAKARŲ LIETUVOJE SUKAUPTOS PATIRTIES ASPEKTAI

Radiation therapy is an important part of breast cancer treatment, reducing local recurrence and improving overall survival. About 1,500 cases of breast cancer are diagnosed in Lithuania every year. About 30% of all newly diagnosed cancers in women are breast cancer, and about 80% of early-stage breast cancers are treated with radiotherapy. New modern radiation techniques have been evaluated with a better understanding of the effects of radiation on the heart. The article reviews the implementation of the deep inhalation breath hold technique in the clinical practice of Klaipėda University Hospital. The purpose of this article is to analyse the results of the first two years after the implementation of the new methods. Assessing the importance of radiotherapy, the author reveals the importance of the innovative deep breathing method in the article, and shares the experience she has gathered. At the same time, scientific and practical assumptions are made that, after the introduction of innovative radiotherapy technologies into practice, new opportunities for optimising the treatment of patients by individualising it open up. The results of the study reveal the need for a prospective cohort study in order to optimise patient education, clarify selection criteria, and increase the availability of modern radiotherapy services. The presentation of this method in an interdisciplinary environment of social and health care specialists allows specialists to familiarise themselves with the achievements of oncological radiotherapy in west Lithuania.

Results of treatment of recurrent growth and metastasis of anaplastic gliomas

Anaplastic glioma is one of the most dangerous and serious brain tumors. Modern microsurgery, radiation, chemotherapy, and other all-encompassing therapeutic techniques can lead to inadequate clinical treatment results for gliomas. High dose re-irradiation with concurrent chemotherapy is a workable treatment option for patients with metastases and recurrent anaplastic gliomas, even when significant treatment volumes are being employed to target non-enhancing tumor components. The issue of glioma metastasis is likewise unsettled and poorly understood. Single serial observations of high-grade glioma metastases are reported in the international literature, with glioblastoma accounting for the majority of these cases. Isolated cases of anaplastic glioma metastasis have been recorded in the majorit y of observations.

A Comparison of 3D Conformal and Deep Inspiratory Breath Holding vs. 4D-CT Intensity-Modulated Radiation Therapy for Patients with Left Breast Cancer.

Multimodality is required for the treatment of breast cancer. Surgery, radiation (RT), and systemic therapy were traditionally used. Pharmacotherapy includes different drug mechanisms, such as chemotherapy, hormone therapy, and targeted therapies, alone or in combination with radiotherapy. While radiation offers numerous benefits, it also has certain harmful risks. such as cardiac and pulmonary toxicity, lymphedema, and secondary cancer. Modern radiation techniques have been developed to reduce organs at risk (OAR) doses. This study is a prospective feasibility trial conducted at the Fayium Oncology Center on patients with left breast cancer receiving adjuvant locoregional radiotherapy after either breast conservative surgery (BCS) or modified radical mastectomy (MRM). This study aimed to assess the proportion of patients who are fit both physically and intellectually to undergo breast radiotherapy using the deep inspiratory breath-holding (DIBH) technique, comparing different dosimetric outcomes between the 3D dimensional conformal with DIBH and 4D-CT IMRT plans of the same patient. D95 of the clinical target volume (CTV) of the target is significantly higher in the 3D DIBH plan than in the IMRT plan, with an average of 90.812% vs. 86.944%. The dosimetry of the mean heart dose (MHD) in the 4D-CT IMRT plan was significantly lower than in the 3D conformal with the DIBH plan (2.6224 vs. 4.056 Gy, p < 0.0064), and no significant difference between the two plans regarding mean left anterior descending artery (LAD) (14.696 vs. 13.492 Gy, p < 0.58), maximum LAD (39.9 vs. 43.5 Gy, p < 0.35), and V20 of the ipsilateral lung (18.66% vs. 16.306%, p < 0.88) was observed. Internal mammary chain (IMC) irradiation was better in the 4D-CT IMRT plan. Radiotherapy of the breast and chest wall with the 4D-CT IMRT technique appears not to be inferior to the 3D conformal with the DIBH technique and can be used as an alternative to the 3D conformal with the DIBH technique in patients meeting the exclusion criteria for performing the DIBH maneuver concerning coverage to target volumes or unacceptably high doses to OAR.

Ultra-Hypofractionated Involved Site Radiation Therapy (ISRT) As Salvage or Bridging Therapy in Aggressive Non-Hodgkin Lymphomas

Introduction: Conventional fractionated radiation treatment (RT) to a total dose of 40-50 Gy in 20-25 fractions is typically recommended in the ‘definitive’ intent treatment of aggressive chemorefractory non-Hodgkin lymphoma. However, during the time of COVID-19, recommendations for hypofractionated courses (5-13 fractions) arose (Yahalom et al Blood 2020) as modern radiation techniques should allow similar total doses to be delivered safely in far fewer fractions. Our aim is to evaluate the outcomes and toxicities of ultra-hypofractionated (&amp;lt;/=5 fractions) ‘definitive’ ISRT in aggressive non-Hodgkin lymphomas to see if this may be an acceptable alternate recommendation beyond COVID-19. Methods: We conducted an IRB-approved, retrospective review of all aggressive non-Hodgkin lymphoma patients treated at our institution with ‘definitive’ intent (40-50 Gy EQD2 with an α/β of 10) ultra-hypofractionated ISRT between April 2020 and July 2023. Demographic, disease-specific, and treatment-related variables were collected. Primary outcomes include objective response rate (ORR), defined as complete (CR) or partial response (PR) on post-RT positron emission tomography (PET) scans using the Lugano classification, local failure (LF), and radiation-related toxicity per CTCAE v5. Secondary outcomes include overall disease control and survival. Results: 26 ultra-hypofractionated radiation treatments were identified from 23 unique patients who were treated with ‘definitive’ intent ISRT (39.1% salvage, 30.4% early-salvage post CAR-T, and 30.4% bridging to SCT or CAR-T). The most common dose was 30 Gy in 5 fractions (96%); all patients were treated with IMRT with SBRT-type immobilization and image guidance as clinically indicated. The most common diagnosis was DLBCL (91%). 10/23 (43%) patients were female, the majority (82%) were ECOG 0-1 performance status, and the average age at time of RT was 68.9 years. 39% had all FDG-avid sites at the time of radiation treated. The median follow-up was 8.3 months (range 0.3-27.9 months). 26% of patients had acute radiation related toxicities, which were all grade 1-2 with the most common being fatigue (30%). There were no grade 3-4 toxicities, and no subacute or long-term toxicities. Initial local ORR was 20/21, or 95% (86% CR and 10% PR), while initial overall ORR was 12/21, or 57% (52% CR and 5% PR). At time of last follow up, only 1/24 (4%) of irradiated sites had local failure (2 data points N/A), with a TTLF of 1.5 months. 62% of patients had disease progression, with median time to disease progression of 1.5 months. At time of last follow up, 48% were dead, with a median time to death of 6.6 months. Conclusions: Ultra-hypofractionated ISRT in the ‘definitive’ intent treatment of aggressive non-Hodgkin lymphomas has excellent local tumor control and appears to be safe with minimal acute and subacute toxicities. In addition to patient convenience and cost effectiveness, short-course ISRT allows patients to quickly move on to next-line therapy when indicated. Prospective studies and long-term follow up are needed to further validate this as an alternative radiation treatment option.

Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma.

To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery. Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As asecondary endpoint, reported toxicity was assessed. Atotal of 34localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31patients. Grade3 side effects were experienced by 26.7% of patients and there were no grade4 or 5events observed. Median PFS was 19months. Median OS was 20months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008). IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as acomponent of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

Cardiac radiation dose is associated with inferior survival but not cardiac events in patients with locally advanced non-small cell lung cancer in the era of immune checkpoint inhibitor consolidation

PurposeWe assessed the association of cardiac radiation dose with cardiac events and survival post-chemoradiation therapy (CRT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) after adoption of modern radiation therapy (RT) techniques, stricter cardiac dose constraints, and immune checkpoint inhibitor (ICI) consolidation. Methods and MaterialsThis single-institution, multi-site retrospective study included 335 patients with LA-NSCLC treated with definitive, concurrent CRT between October 2017 and December 2021. All patients were evaluated for ICI consolidation. Planning dose constraints included heart mean dose < 20 Gy (<10 Gy if feasible) and heart volume receiving ≥ 50 Gy (V50Gy) < 25 %. Twenty-one dosimetric parameters for three different cardiac structures (heart, left anterior descending coronary artery [LAD], and left ventricle) were extracted. Primary endpoint was any major adverse cardiac event (MACE) post-CRT, defined as acute coronary syndrome, heart failure, coronary revascularization, or cardiac-related death. Secondary endpoints were: grade ≥ 3 cardiac events (per CTCAE v5.0), overall survival (OS), lung cancer-specific mortality (LCSM), and other-cause mortality (OCM). ResultsMedian age was 68 years, 139 (41 %) had baseline coronary heart disease, and 225 (67 %) received ICI consolidation. Proton therapy was used in 117 (35 %) and intensity-modulated RT in 199 (59 %). Median LAD V15Gy was 1.4 % (IQR 0–22) and median heart mean dose was 8.7 Gy (IQR 4.6–14.4). Median follow-up was 3.3 years. Two-year cumulative incidence of MACE was 9.5 % for all patients and 14.3 % for those with baseline coronary heart disease. Two-year cumulative incidence of grade ≥ 3 cardiac events was 20.4 %. No cardiac dosimetric parameter was associated with an increased risk of MACE or grade ≥ 3 cardiac events. On multivariable analysis, cardiac dose (LAD V15Gy and heart mean dose) was associated with worse OS, driven by an association with LCSM but not OCM. ConclusionsWith modern RT techniques, stricter cardiac dose constraints, and ICI consolidation, cardiac dose was associated with LCSM but not OCM or cardiac events in patients with LA-NSCLC.

Comparative Analysis of Intensity Modulation Radiation Therapy and Volumetric Modulation Arc Therapy in Brain Tumor Cases to Minimize Radiation Dose to Organs at Risk

Radiotherapy technique is a systematic radiation planning method or procedure used for cancer treatment in the field of radiotherapy. Modern radiotherapy techniques allow the delivery of high doses at target volumes without dose escalation to at-risk organs, offering the possibility of better local control while maintaining a good quality of life. This study aims to analyze the difference in Treatment Planning System (TPS) results between Intensity Modulation Radiation Therapy (IMRT) and Volumetric Modulation Arc Therapy (VMAT) techniques in irradiation of brain tumors with Glioblastoma cases based on the dose received by the target volume and Organ at risk, as well as the results of the isodose curve. The research design used was Cross-Sectional and qualitative analysis. Data was obtained from simulation results in the Treatment Planning System (TPS) as a Dose Volume Histogram (DVH) by conducting Literature Studies, Observations, Documentation, and FGD Techniques. This research will be conducted in July 2023 at the Radiation Oncology Installation of Siloam MRCCC Hospital Semanggi. A study was conducted on 11 patients with brain tumors who received radiation therapy with IMRT or VMAT techniques. The results of this study showed no significant difference in dose received by the target volume and dose of Organ at risk in both techniques in statistical tests, but based on the average results descriptively showed that the VMAT technique was better than the IMRT technique. This is indicated by the dose received by the target volume according to the plan.