3-dimensional Conformal Radiotherapy Research Articles

Prospective Evaluation of the Efficacy of Neoadjuvant Chemotherapy Followed by Hypofractionated Radiotherapy in Inoperable Oral Cavity Squamous Cell Carcinoma

<h3>Purpose/Objective(s)</h3> We aim to evaluate the role of neoadjuvant chemotherapy followed by hypofractionated radiotherapy in locally advanced unresectable OCSCC in terms of acute toxicity and efficacy. <h3>Materials/Methods</h3> 10 patients with locally advanced (T4a-T4b and N0 or N1-N2) inoperable OCSCC with good performance status were recruited in this single arm prospective study between December 2020-january 2022. All patients received 2 cycles of NACT (paclitaxel 175 mg /m² on D-1, cisplatin 75 mg / m² on D1 and D2 in divided doses) every three weekly followed by Hypofractionated Radiotherapy (RT), delivered by 3-dimensional conformal radiotherapy plan with a dose of 55Gray (Gy) in 22 fractions at 2.5Gy per fraction delivered 5 days a week in two phases. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and response was evaluated by WHO response criteria. The primary and secondary endpoints were clinical response rate and acute toxicity, respectively. Statistical analysis was done using statistical software. <h3>Results</h3> All patients received 2 cycles of NACT. Median RT dose was 55Gy. overall treatment time (OTT) was 98 days (95-120). Median Duration of follow up was 10 months (8-13 months). Patients' characteristics are summarized in table 1. All the patients completed their treatment as per protocol. Weekly assessment of toxicity was done and recorded during radiotherapy. Patients having dysphagia (grade >2) was 40% (4) and patients having dysphagia (grade ≤ 2) was 60% (6). Patients having oral mucositis (grade >2) was 50% (5) and those having (grade ≤ 2) was 50% (5). Radiation dermatitis more than grade 2 was not observed in any patient. No patient developed grade-4 radiation toxicity. All patients were regularly followed up for response assessment both clinically and radiologically. At median follow up of 10 month, 20% (2) patients had complete response (CR), 70% (7) patients had partial response (PR) and 10% (1) had progressive disease (PD). <h3>Conclusion</h3> Neoadjuvant chemotherapy followed by hypofractionated radiotherapy in locally advanced unresectable OCSCC shows acceptable acute radiation toxicity and good efficacy.

Comment on Ivanov et al. Ultra-Hypofractionated vs. Moderate Fractionated Whole Breast Three Dimensional Conformal Radiotherapy during the COVID-19 Pandemic. Medicina 2022, 58, 745.

I read the paper by Ivanov et al. [...].

Immunotherapy-Induced Rectovaginal Fistula After Prior Reirradiation for Recurrent Cervical Cancer in a Pelvic Lymph Node

A 48-year-old woman received a diagnosis of American Joint Committee on Cancer stage IIIB (cT1b2N1M0), International Federation of Gynecology and Obstetrics stage IB2 cervical squamous cell carcinoma. She received concurrent weekly cisplatin and 3-dimensional conformal radiation therapy (4-field box) to the whole pelvis (including the common iliac nodes) to a dose of 45 Gy in 25 fractions, followed by a sequential boost of 9 Gy in 5 fractions to the involved 3- × 2-cm left external iliac lymph node (total dose 54 Gy), and intracavitary brachytherapy using tandem and ovoids to a total dose of 28 Gy in 4 fractions prescribed to the cervical high-risk clinical target volume (defined on computed tomography [CT] and magnetic resonance imaging [MRI]).

A network meta-analysis of curative effect of different treatment methods on patients with brain metastasis of breast cancer.

Background:Breast cancer (BC) is a malignant tumor with the highest incidence rate worldwide, and its incidence of breast cancer brain metastases is increased in recent years. Although significant progress has been made in the systematic treatment of BC that of breast cancer brain metastases is still very difficult. Organically integrating local and systemic therapies remains an urgent problem to be solved. In this study, a network meta-analysis was performed to collect the treatment effects of different treatment measures on patients with BC brain metastasis in recent years, evaluate and screen the current best clinical treatment scheme, and assist doctors in formulating clinical treatment schemes.Methods:Keywords were used to search databases, such as the Chinese Journal Full-text Database, VIP Chinese Science and Technology Journal Full-text Database (VP-CSJFD), Wanfang Data Journal Paper Resources (Wangfang), PubMed, the Cochrane Library, and EMBASE. The retrieval period was from the establishment of each database to February 2022. Qualified randomized controlled studies were screened according to the inclusion and exclusion criteria, and Stata 16 software was adopted for mesh meta-analysis of binary variable data. Using R4 0.2 software, and calling GeMTC and JAGS packages in R software, the Bayesian network model analysis of survival data was completed.Conclusion:Combined with overall response rate, disease control rate, and overall survival, whole-brain radiation therapy + 3-dimensional conformal radiation therapy + Che may be the intervention measure with the highest objective remission rate for patients with brain metastasis of BC, besides, it may also be the intervention measure of the highest disease control rate in patients after treatment. In contrast, WBRT + Che may be the intervention with the lowest overall survival risk ratio after treatment.

The efficacy profiles of concurrent chemoradiotherapy with intensity-modulated radiotherapy followed by durvalumab in patients with unresectable stage III non–small cell lung cancer: A multicenter retrospective cohort study

PurposeIntensity-modulated radiotherapy (IMRT) is currently used more commonly than 3-dimensional conformal radiation for definitive thoracic radiation. We examined the efficacy profiles of concurrent chemoradiotherapy (CCRT) with IMRT after durvalumab became clinically available. MethodsWe reviewed the clinical records of patients with stage III non-small cell lung cancer (NSCLC) treated with CCRT and IMRT at seven centers in Japan and investigated relapse and survival from May 2018 to December 2019. The primary endpoint of this report was progression-free survival (PFS). ResultsAmong 107 patients enrolled in the study, 87 were sequentially administered durvalumab. From CCRT commencement, patients were followed up for a median period of 29.7 months. The median PFS at the end of the CCRT was 20.7 months. Among the 87 patients, 58 experienced disease relapses, of whom 36 (62.1 %) had distant metastases. Multivariate Cox regression analysis revealed that a favorable response to CCRT, a radiation dose ≥ 62 Gy, and stage IIIA NSCLC were associated with prolonged PFS (all P = 0.04). Multivariate logistic regression by landmark analysis revealed that mortality risk factors were durvalumab treatment duration ≤ 11.7 months, a lower maximum grade of immune-related adverse events, FEV1 < 2805 mL, and radiation dose < 62 Gy (P = 0.01, 0.01, 0.03, and 0.04, respectively). ConclusionsIn patients with NSCLC receiving CCRT using IMRT, long PFS was associated with a better response to CCRT, stage IIIA NSCLC, and an increased radiation dose. The duration of durvalumab consolidation also played an essential role in the survival of patients receiving CCRT with IMRT. (250 words)

Comparison of acute gastrointestinal toxicities between 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy including prophylactic regions in chemoradiotherapy with S-1 for pancreatic cancer-importance of dose volume histogram parameters in the stomach as the predictive factors.

The purpose of this study was to compare acute gastrointestinal (GI) toxicities in patients who underwent 3-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in chemoradiotherapy (CRT) with S-1 including prophylactic regions for pancreatic cancer. We also investigated the predictive factor of acute GI toxicities in dose volume histogram (DVH) parameters. Patients who received CRT with S-1 for pancreatic cancer between January 2014 and March 2021 were included. Radiotherapy (RT) with a total dose of 50-54 Gy was delivered. We examined the differences in the frequencies of acute GI toxicity of grade 2 or higher and DVH parameters of the stomach (ST) and duodenum (DU) between the 3DCRT group and the IMRT group. The RT-related predictive factors of acute GI toxicities were investigated by univariate and multivariate analyses. There were 25 patients in the 3DCRT group and 31 patients in the IMRT group. The frequencies of acute GI toxicity of G2 or higher were 36% in the 3DCRT group and 9.7% in the IMRT group (p = 0.035). ST V50 was the most predictive factor (p = 0.001), and the incidences of acute GI toxicity of G2 or higher in ST V50 ≥ 4.1 cc and < 4.1cc were 43.7% and 7.7%, respectively. ST V40 was also a significant predictive factor of acute GI toxicity (p = 0.002). IMRT could reduce acute GI toxicities in CRT with S-1 including prophylactic regions for pancreatic cancer. Acute GI toxicities may be affected by moderate to high doses to the ST.

Overview of breast cancer external beam radiation therapy in Ghana: Towards the establishment of a national standardized treatment guidelines for improved patient care

Background and purposeThis paper reports on results from the foremost national survey on external beam radiation therapy (EBRT) treatment practice at the three radiotherapy (RT) facilities in Ghana. It is to survey the current EBRT treatment protocols and its resources available in the country for breast cancer treatment. Results are intended to form the foundation for future clinical research into developing standardized institutional and/or National breast cancer treatment planning guidelines. This will introduce uniformity into EBRT protocols across the three facilities in the country for their breast cancer patients. Materials and methodsThe survey was conducted with two online-based questionnaires; a general questionnaire that targeted radiation oncology professionals working in the three RT facilities in Ghana and a follow-up specifically for the radiation oncologists. The first survey was rolled out from 21st August 2020 to 31st December 2020. The second survey was conducted from 15th February 2021 to 31st March 2021 after the initial analysis of the responses from the first survey. The first questionnaire had 54 general EBRT breast cancer treatment questions. The second questionnaire had 14 questions focusing on dose fractionation regimens, definition of treatment targets and organs at risk (OAR) delineation. ResultsThe Google web-based questionnaires had in total 11 responses from the targeted radiation oncologists, medical physicists, and radiation therapists working in the three radiotherapy facilities in the country. The facility response rate was 100% for the survey as there were participation from all three RT facilities. CT-based breast planning was considered standard and used in all three facilities. Reference markers to aid patient positioning and target delineations were employed during simulations. Majority of the relevant OAR associated with breast EBRT were very well defined. 3 dimensional conformal radiotherapy (3DCRT) planning with forward-planning field-in-field (FP-FIF) technique has become the preferred planning of choice. From this survey, there were three medical linear accelerators (Linacs) and two Cobalt-60 (Co-60) treatment units used in treating an average of 750 breast cancer patients annually. ConclusionResults from the survey gave an in-depth overview of the current state of EBRT resources available in the treatment and management of breast cancer in Ghana. Minor protocol variations amongst the facilities were observed. However, there were strong consensus amongst the facilities regarding majority of their current existing protocols and possible future techniques/technology implementation.

Tattoo-Free Setup for Patients With Breast Cancer Receiving Regional Nodal Irradiation

PurposePatients undergoing regional nodal irradiation (RNI) with either 3-dimensional conformal radiation therapy (3DCRT) planning or volumetric modulated arc therapy (VMAT) receive permanent tattoos to assist with daily setup alignment and verification. With the advent of surface imaging, tattoos may not be necessary to ensure setup accuracy. We compared the accuracy of conventional tattoo-based setups to those without reference to tattoos. Methods and MaterialsForty-eight patients receiving RNI at our institution from July 2019 to December 2020 were identified. All patients received tattoos per standard of care. Twenty-four patients underwent setup using tattoos for initial positioning followed by surface and x-ray imaging. A subsequent 24 patients underwent positioning using surface imaging followed by x-ray imaging without reference to tattoos. Patient cohorts were balanced by treatment technique and use of deep inspiration breath hold. Treatment (including setup and delivery) time and x-ray–based shifts after surface imaging were recorded. ResultsAmong patients in the tattoo group receiving 3DCRT RNI, the average treatment time per fraction was 21.35 versus 19.75 minutes in the 3DCRT RNI no-tattoo cohort (P = .03). Mean 3D vector shifts for patients in the tattoo cohort were 5.6 versus 4.4 mm in the no-tattoo cohort. The average treatment time per fraction for the tattoo VMAT RNI cohort was 23.16 versus 20.82 minutes in the no-tattoo VMAT RNI cohort (P = .08). Mean 3D vector shifts for the patients in the tattoo VMAT cohort were 5.5 versus 7.1 mm in the no-tattoo VMAT cohort. Breath hold technique and body mass index did not affect accuracy in a consistent or clinically relevant way. ConclusionsUsing a combination of surface and x-ray imaging, without reference to tattoos, provides excellent accuracy in alignment and setup verification among patients receiving RNI for breast cancer, regardless of treatment technique and with reduced treatment time. Skin-based tattoos are no longer warranted for patients receiving supine RNI.

Dosimetric Comparison Study of Three Dimensional Conformal Radiotherapy (3DCRT) Versus Different Intensity Modulated Radiotherapy (IMRT) Techniques in Prostate Cancer Treatment

The KDU Journal of Multidisciplinary Studies (KJMS) is published biannually, by the Faculty of Graduate Studies, General Sir John Kotelawala Defence University, Sri Lanka. KJMS is an international open access and peer reviewed journal which publishes high quality original research papers from multi-disciplinary and interdisciplinary approaches.

THE INCIDENCE OF RADIATION PNEUMONITIS IN BREAST CANCER PATIENTS WHO RECEIVED RADIOTHERAPY USING 3-DIMENSIONAL TECHNIQUES

Background: According to the 2018 Global Cancer Observatory from the World Health Organization (WHO), breast cancer is the most common cancer in Indonesia. 3-dimensional conformal radiotherapy (3D-CRT) is one of the breast cancer treatment planning. Effect of radiation on the lungs can cause radiation pneumonitis. The incidence rate of pneumonitis in breast cancer patients who received radiotherapy using 3D-CRT techniques from several researchers is still varied and there is no accurate data yet at RSUP Dr. Kariadi.Objective: To determine the incidence of pneumonitis in breast cancer patients undergoing breast cancer 3D-CRT.Methods: The research design used in this study was cross sectional. The subject is chosen by consecutive sampling methods. The independent variables of this study was 3D breast cancer radiation therapy, while the dependent variable was radiation pneumonitis. This hypothesis test on this study is analyzed with chi-square test.Results: Forty one subjects were included in this study, two subjects were found with a picture of pneumonitis on chest radiographs. The incidence of radiation pneumonitis in breast cancer patients who received radiotherapy using 3-dimensional techniques was 4.9%. There is no significant relationship between breast cancer radiation therapy 3-dimensional techniques on the incidence of pneumonitis. And there was no significant difference in the proportion of pneumonitis in patients with breast cancer locations on the right and left sides.Conclusion: The incidence of radiation pneumonitis in breast cancer patients who received radiotherapy using a 3-dimensional technique is 4.9%. Keywords: 3 Dimensional Technique Radiotherapy, Breast Cancer, Radiation Pneumonitis

A dosemetric and radiobiological impact of VMAT and 3DCRT on lumbosacral plexuses, an underestimated organ at risk in cervical cancer patients.

BackgroundThe purpose of this study was to evaluate dosimetric and radiobiological difference between volumetric modulated arc therapy (VMAT) and 3-dimensional conformal radiotherapy (3DCRT) in organ at risk (OAR) lumbosacral plexus (LSP) in cervical cancer patients.Materials and methods30 patients of cervical cancer who were treated using 3DCRT or VMAT along with chemotherapy followed by brachytherapy were enrolled. LSP was delineated retrospectively. Dosimetric and radiobiological difference was evaluated. Patients were followed for radiation induced lumbosacral plexopathy (RILSP).ResultsMedian follow-up was 12 months (3–16 months). 53.3% of patients were treated by 3DCRT and 46.7% by VMAT. The mean (±SD) LSP volume: 119.03 ± 15 cm3. The mean volume percentages (%) of the LSP: V5, V10, V20, V30, V40, V50, V55, and V60 were 100%, 99.8%, 99.2%, 94.3%, 84.03%, 59.7%, 0%, 0%, respectively. All patients received doses to the LSP in excess of 50 Gy, one patient received 55 Gy. A statistically significant difference was observed in the median value of V20, V30, V40, V50, D50, P2, P4, P7, P8, P9, and P10 across two different techniques of radiotherapy — VMAT and 3DCRT. None of the patients presented with RILSP. NTCP value was less in VMAT plans compared to 3DCRT, which is also statistically significant.ConclusionRILSP is a rare and often refractory complication of pelvic radiotherapy. Advance radiotherapy technique with proper OAR delineation and constraint can prevent the occurrence of RILSP. VMAT has potential benefits for the probability of dose reduction in LSP. Further studies are required focusing on dose distribution in LSP–OAR and radiotherapy modality.

Prospective study to compare the dose distribution and acute toxicity of three-dimentional conformal radiation therapy with intensity-modulated radiation therapy for post-mastectomy radiotherapy in carcinoma breast

Though adjuvant radiotherapy has an established role in the treatment of carcinoma breast, there is concern regarding irradiation to heart and lung, more on left sided disease. Intensity Modulated Radiation Therapy (IMRT) modulates the intensity of the radiation beams with better accuracy, sparing surrounding normal organs. But it increases integral dose to normal healthy tissues compared to 3-Dimensional Conformal Radiation Therapy (3DCRT). So, our study was aimed at comparing the dosimetry and acute toxicity profile of 3DCRT and IMRT in post-mastectomy patients. In study arm patients received radiotherapy with IMRT and in control arm with 3DCRT, radiation dose being 50 Gy in 25 fractions for 5 weeks for both the arms. We compared the dosimetric data for Planning Target Volume (PTV) and Organ At-risk (OAR) by both techniques along with acute toxicity profile. Dosimetric parameter of PTV coverage V95 and V107 were significantly better in IMRT than 3DCRT (p-value &lt;0.0001). IMRT showed better homogeneity index (0.14 Gy vs 0.26 Gy) and conformity index was also better for IMRT (0.94 Gy vs 0.74 Gy, p-value 0.0028). The mean value of heart V25 in left sided disease was significantly lower in IMRT than 3DCRT (22.59 and 25.64, p value 0.01). V20 of ipsilateral lung was numerically less in IMRT though not significant (31.44 vs 35.3). But low dose volume was significantly more in IMRT, as seen by higher V5 of heart and ipsilateral lung. To conclude, IMRT has better PTV coverage and better sparing of organs at risk with more homogenous and conformal plans than 3DCRT. Keywords: adjuvant radiotherapy; IMRT; 3DCRT; carcinoma breast

Risk of second brain tumour after radiotherapy for pituitary adenoma or craniopharyngioma: a retrospective, multicentre, cohort study of 3679 patients with long-term imaging surveillance

Radiotherapy is a valuable treatment in the management algorithm of pituitary adenomas and craniopharyngiomas. However, the risk of second brain tumour following radiotherapy is a major concern. We assessed this risk using non-irradiated patients with the same primary pathology and imaging surveillance as controls. In this multicentre, retrospective cohort study, 4292 patients with pituitary adenoma or craniopharyngioma were identified from departmental registries at six adult endocrine centres (Birmingham, Oxford, Leeds, Leicester, and Bristol, UK and Ferrara, Italy). Patients with insufficient clinical data, known genetic predisposition to or history of brain tumour before study entry (n=532), and recipients of proton beam or stereotactic radiotherapy (n=81) were excluded. Data were analysed for 996 patients exposed to 2-dimensional radiotherapy, 3-dimensional conformal radiotherapy, or intensity-modulated radiotherapy, and compared with 2683 controls. Over 45 246 patient-years, second brain tumours were reported in 61 patients (seven malignant [five radiotherapy, two controls], 54 benign [25 radiotherapy, 29 controls]). Radiotherapy exposure and older age at pituitary tumour detection were associated with increased risk of second brain tumour. Rate ratio for irradiated patients was 2·18 (95% CI 1·31-3·62, p<0·0001). Cumulative probability of second brain tumour was 4% for the irradiated and 2·1% for the controls at 20 years. Irradiated adults with pituitary adenoma or craniopharyngioma are at increased risk of second brain tumours, although this risk is considerably lower than previously reported in studies using general population controls with no imaging surveillance. Our data clarify an important clinical question and guide clinicians when counselling patients with pituitary adenoma or craniopharyngioma on the risks and benefits of radiotherapy. Pfizer.

A comparison of dosimetry and clinical outcomes in patients receiving photon external beam therapy to the pelvis: A two-year experience with 6MV and 10MV photon energies in cervical cancer patients at Parirenyatwa Radiotherapy Centre in Harare, Zimbabwe.

e18768 Background: Radiotherapy efficacy depends on the ability of the treatment machine to deliver optimal radiation dose to target volume while sparing normal tissue using different techniques. The photon energy determines penetrative power. Higher photon energies are generally preferred over low photon energies when treating deep tumours using 3-dimensional conformal radiotherapy (3DCRT). In most low income settings, availability of higher energies (≥10MV) is limited. Elsewhere protocols do not recommend use of lower energies for deep pelvic tumours. There is paucity of data comparing 10MV and 6MV photon energy plans and outcomes for treatment of pelvic tumours with 3DCRT. This study aimed to compare dosimetric and clinical tumour outcomes between the two photon energies which are available in our setting when treating locally advanced cervical cancer (LACC). Methods: We retrospectively analysed medical records for LACC patients who received definitive concurrent chemoradiotherapy (CCRT) at Parirenyatwa Group of Hospitals Radiotherapy Centre for the period between 1st January 2017 and 31st December 2018. Patient’s treatment plans were stratified into two arms according to the photon energies used (10MV and 6MV) and their respective dosimetric and clinical tumour outcomes at three months post-treatment were compared. Results: A total 875 cervical cancer patients were seen during the study period, of these 82 met the inclusion criteria and were evaluated. Out of these, 20(24.4%) and 62(75.6%) patients were planned and/or treated with 10MV and 6MV photon energy respectively. The differences in minimum doses to the planned target volume and dose homogeneity index between the two photon energies were statistically significant (p-values 0.027 and 0.028 respectively), whereas the other dosimetric parameters (maximum &amp; average doses to the planned target volume, conformity index and maximum doses to rectum, bladder, femoral heads and bowel) were not statistically significant (p-values of 0.245, 0.309, 0.130, 0.19, 0.35 and 0.42, and 0.16 respectively). Complete clinical tumour response at 3 months post treatment was 95% in the 10 MV arm compared to 91% in the 6 MV arm. Conclusions: This study showed that the dosimetric and clinical tumour outcomes in LACC patients receiving 3DCRT definitive CCRT using 10MV or 6MV photon energy in our setting are comparable. Follow-up prospective studies to further characterise the application of these photon energies in resource constrained settings is recommended.

Which radiotherapy technique is better for neoadjuvant treatment of rectal cancer: A dosimetric comparison

Objective: Our aim was to compare helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) plans with 3-dimensional conformal radiotherapy (3D-CRT) considering the planning target volume (PTV) and organs at risk (OARs) in rectal cancer patients treated with neoadjuvant radiotherapy. Patients and Methods: Thirty patients, previously treated with intensity modulated radiotherapy (IMRT) or 3D-CRT from January 2014 to February 2020 were selected and 3 plans were generated for each patient using VMAT, HT and 3D-CRT. Dosimetric comparisons were made for each plan regarding PTV and OARs. Integral dose (ID) was calculated and beam on times were analyzed. Results: The homogeneity index (HI) was significantly better in HT plans compared with VMAT and 3D-CRT plans (p<0.001), conformity index (CI) was better in VMAT plans. For small bowel, high doses were higher in 3D-CRT plans (p <0.001). HT produced lower doses for the bladder as compared to VMAT and 3D-CRT (p<0.005). The mean and maximum doses of bilateral femoral heads were higher in 3D-CRT plans. Beam on times were longer and IDs were higher in HT plans (p<0.001). Conclusion: Both VMAT and HT improved target homogeneity and conformity and decreased OAR doses compared to 3D-CRT. Although, VMAT was the best method to decrease ID, HT produced better bladder sparing.

Ultra-Hypofractionated vs. Moderate Fractionated Whole Breast Three Dimensional Conformal Radiotherapy during the COVID-19 Pandemic.

Background and Objectives: Reducing time of treatment during COVID-19 outbreaks has been recommended by the leading Radiation Oncology societies. Still minimizing radiation induced tissue toxicity is one of the most important issues in breast cancer patients. The study aimed to investigate compliance, clinical and dosimetry normal tissue toxicity, and cosmetic results between moderated and ultra-fractionated regimes for breast cancer patients during COVID-19 pandemic. Materials and Methods: This pilot prospective randomized study included 60 patients with early breast cancer after preserving surgery, 27 patients advocated to ultra-hypofractionated whole-breast three dimensional (3D) conformal radiotherapy of 26 Gy in 5 fractions over 1 week and 33 patients with moderate fractionated breast 3D conformal radiotherapy patients between March 2020 and July 2020, during the COVID pandemic outbreak. The compliance to treatment, dosimetric parameters, acute and late skin toxicity, subcutaneous tissue toxicity, cosmetic results and clinical follow up for 18 months for the two regimes were analyzed and compared. Results: When two regimes were compared 5 fraction group had significantly lower prevalence of newly infected cases of SARS-CoV-2 and thus delayed/interrupted treatment (p = 0.05), comparable grade 1 CTCAE v5, acute skin toxicity (p = 0.18), Grade 1 Radiation Morbidity Scoring Scheme (RESS) subcutaneous tissue toxicity (p = 0.18), Grade 1 RESS late skin toxicity (p = 0.88) and cosmetic results (p = 0.46). Dosimetric results reveled that patients in 5 fraction group received significantly lower median ipsilateral lung doses (p < 0.01) in addition to left breast cancer patients that received significantly lower median heart dose (p < 0.01) and median left anterior descending artery (LAD) dose (p < 0.01). Conclusion: Ultra-hypofractionated radiotherapy for breast cancer is comparable to moderate hypofractionation regimen regarding grade 1 acute skin toxicity, grade 1 subcutaneous tissue toxicity, late skin toxicity and cosmetic results. Application of ultra-hypofractionated radiotherapy with significantly lower radiation doses for lung and heart could be crucial in reducing the risk of acute/late pulmonary and heart radiation-induced toxicity.

Intensity-Modulated Radiotherapy Associated With Improved Survival Outcome in Anal Cancer.

PurposeTo describe the survival and toxicity outcome from a single-centre experience in patients with squamous cell cancer of the anal canal (SCC-AC), related to the impact of technological advances in diagnostics and radiation techniques.Material and MethodsA retrospective cohort study was performed after the approval of the institutional ethical committee (EK 478-21). We identified 142 patients in our registry, who received radical treatment for SCC-AC between 2000 and 2020. Fifty-five patients had FDG PET/CT for initial staging and target volume delineation, 87.33% received concomitant chemoradiotherapy (CRT), 64 patients were treated with 3-dimensional conformal radiotherapy (3DRT) between 2000-2009, and 78 patients with intensity-modulated radiotherapy (IMRT) between 2009-2020. Endpoints for the analysis included locoregional relapse-free survival (LRFS), disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS). Acute and late toxicities were also reported.ResultsAt a median follow-up of 31.2 months, the median overall survival was 135 months, 5-year LRFS was 73.1%, 5-year DFS was 65.3%, and 5-year CSS was 75.3%. The use of IMRT was associated with shorter treatment duration. In the univariate analysis, IMRT was associated with significantly improved DFS and CSS for the whole cohort and significantly improved DFS, OS, and CSS for patients who received CRT. In the multivariate analysis, IMRT was associated with the improvement of all survival paraments. The use of FDG PET/CT did not translate into an improvement in the survival outcomes in both univariate and multivariate analyses. Grade-3 and more dermatological toxicities occurred less frequently, but hematological toxicities were more frequent in the IMRT-group. Late side effects and colostomies were less frequently reported in the IMRT group.ConclusionThe use of IMRT in the management of SCC-AC was associated with improvement of the oncological outcomes with improved toxicity profiles in this long-term single-centre experience.

Intensity-Modulated Radiotherapy and Three-Dimensional Conformal Radiotherapy Combined with Intracavitary Posterior Radiotherapy for the Treatment of Medium-Term and Advanced Cervical Cancer: Efficacy, Safety and Prognostic Factors.

ObjectiveTo explore the efficacy, safety, and prognostic factors of intensity modulated radiation therapy (IMRT) and three dimensional conformal radiation therapy (3D-CRT) combined with intracavitary posterior radiotherapy for medium-term and advanced cervical cancer.MethodsRetrospectively analyze the clinical data of 104 patients with medium-term and advanced cervical cancer who were treated in the radiotherapy department of our hospital from September 2015 to March 2017. According to the different radiotherapy techniques, they were divided into the IMRT combined with intracavitary posterior radiotherapy group (n = 52) and the 3D-CRT combined with intracavitary posterior radiotherapy group (n = 52). Observe and compare the short-term efficacy, occurrence of adverse reactions and overall survival rate of the two groups. The clinicopathological characteristics of the survival group and the death group were compared, and univariate analysis and multiple logistic regression models were used to analyze the relationship between the clinicopathological characteristics and the patient’s prognosis.ResultsThe total effective rate of IMRT combined with intracavitary posterior radiotherapy group was 96.15%, which was higher than that of 3D-CRT combined with intracavitary posterior radiotherapy group (88.46%), but the difference was not statistically significant (p > 0.05). The incidence of digestive system injury, thrombocytopenia, and radiation proctitis in the IMRT combined intracavitary posterior radiotherapy group was lower than that of the 3D-CRT combined intracavitary posterior radiotherapy group, and the differences were statistically significant (p < 0.05). The prognosis and survival of the two groups of patients were similar, and the difference was not statistically significant (p > 0.05). Pathological classification, clinical stage, and lymph node metastasis are independent influencing factors of 3-year prognosis in patients with medium-term and advanced cervical cancer (p < 0.05).ConclusionIMRT combined with intracavitary posterior radiotherapy is equivalent to 3D-CRT combined with intracavitary posterior radiotherapy, but it can reduce the incidence of adverse reactions in patients with medium-term and advanced cervical cancer, and has higher safety. Pathological typing, clinical staging, Lymph node metastasis were independent factor affecting the prognosis of patients. In clinical treatment, IMRT combined with intracavitary posterior radiotherapy is more recommended as a treatment plan for patients with medium-term and advanced cervical cancer.

The prognostic significance of pretreatment squamous cell carcinoma antigen levels in cervical cancer patients treated by concurrent chemoradiation therapy and a comparison of dosimetric outcomes and clinical toxicities between tomotherapy and volumetric modulated arc therapy

BackgroundTo analyze the prognostic factors associated with stage IB-IVA cervical cancer in patients who underwent concurrent chemoradiation therapy (CCRT) and to compare the clinical toxicities and dosimetric parameters of organs at risk between the different radiotherapy techniques.MethodsThis retrospective study enrolled 93 patients with stage IB-IVA cervical cancer who underwent definitive CCRT between April 2009 and December 2017. Nine patients (9.7%) received 3DCRT, 43 patients (46.2%) underwent VMAT, and 41 patients (44.1%) received tomotherapy, and all of them followed by brachytherapy using a 2D planning technique. The treatment outcomes and related prognostic factors were analyzed. We also compared the clinical toxicities and dosimetric parameters between the different techniques used for the last 30 patients.ResultsWith a median follow-up of 52.0 months, the 5-year overall survival (OS), progression-free survival (PFS), locoregional recurrence–free survival (LRRFS), and distant metastases–free survival (DMFS) were analyzed. In a Cox proportional hazards regression model, pretreatment SCC Ag > 10 ng/mL was a significant prognostic factor for PFS (hazard ratio [HR] 2.20; 95% confidence interval [CI] 1.03–4.70; P = 0.041), LRRFS (HR, 3.48; 95% CI 1.07–11.26; P = 0.038), and DMFS (HR 2.80; 95% CI 1.02–7.67; P = 0.045). Increasing the rectal volume receiving a radiation dose exceeding 30 Gy (V30 of rectum; odds ratio [OR] 1.15; 95% CI 1.10–1.30; P = 0.03) was associated with a higher possibility of ≥ Grade 2 acute radiation therapy (RT)-related diarrhea. The median rectal V30 values were 56.4%, 97.5%, and 86.5% for tomotherapy, 3-dimensional conformal radiation therapy (3DCRT), and volumetric modulated arc therapy (VMAT), respectively (P < 0.001). In addition, the chance of experiencing ≥ Grade 2 acute diarrhea were 10.0%, 66.7%, and 54.5% for tomotherapy, 3DCRT, and VMAT, respectively (P = 0.029).ConclusionsPatients with pretreatment SCC Ag ≤ 10 ng/mL have better PFS, LRRFS, and DMFS than those with pretreatment SCC Ag > 10 ng/mL. The rectal V30 is a significant predictor of severe acute diarrhea. Tomotherapy significantly decreased the rectal V30, reducing the severity of acute RT-related diarrhea during external beam RT.Trial registration This study was approved by the institutional review board at Kaohsiung Medical University Hospital. The registration number is KMUHIRB-E(I)-20190054 and retrospectively registered on 2019/3.

128P The role of volumetric modulated arc therapy in left breast cancer

Three dimensional conformal radiotherapy (3D-CRT) has long been used as a standard treatment for early stage breast cancer. However, the homogeneity, conformity in the target volume (PTV), and the dose to nearly organs at risk (OAR) was a concern. Using field-in-field as intensity modulation improved the homogeneity and conformity in the PTV, yet the dose to OARs still require further improvement. In this study, we aimed at analyze the dose volumetric parameters (DVP) of 3D-CRT and VMAT plan to identify a better for left breast cancer, in particular dose reduction to heart and the left anterior descending artery (LAD).