3D Conformal Radiotherapy Research Articles

VMAT in Prostate Cancer: Experience at the RABAT INO national Oncology Institute

Study object : To report the experience of the external radiotherapy department of the RABAT National Institute of Oncology in the conformal irradiation of prostate cancers with intensity modulation of the volumetric modulated arc therapy (VMAT). Materials and methods: This is a retrospective study conducted in the external radiotherapy department between January 2017 and December 2021. All patients with prostate cancer were included. Those with immediate metastatic disease at the time of diagnosis were excluded. For 441 patients, respecting dose constraints in organs at risk of toxicity. VMAT was the technique used in all our patients. Results and statistical analysis: A total of 441 prostate cancer patients were treated in our department. The median age at diagnosis was 72 years, with an average consultation time of 8 months. Mean PSA: 59 ng/ml (range 5.03 to 403 ng/ml). Pelvic MRI was performed in 94% of patients. Three of our patients were classified as oligo-metastatic. The predominant histological type was ADK in 100% of cases. Tumors were classified according to the current Amico and NCCN classifications. Treatment consisted of a combination of external radiotherapy and hormone therapy in 97% of cases, and exclusive radiotherapy in 3% of cases. In terms of therapeutic tolerance, 66% of patients experienced acute toxicities of all kinds, and 45% of patients experienced late toxicities. Complete remission was achieved in 100% of patients, with a mean PSA Nadir of 0.09 ng/ml. Overall recurrence-free survival was 94%, with a relapse rate of 6%. Conclusion : VMAT is an effective technique for treating prostate cancer, with a better rate of locoregional control and reduced toxicity than 3D conformal radiotherapy.

Assessing parotid gland function through diffusion weighted MRI during and post-radiotherapy in head and neck cancer patients

ObjectivesThe purpose of this study was to evaluate the usefulness of apparent diffusion coefficient (ADC) variation in irradiated parotid glands during and after 3D conformal radiotherapy (3DCRT). Materials and methodsThis study enrolled 15 head and neck cancer (HNC) patients who were treated with 3DCRT underwent diffusion weighted imaging (DWI) at rest and after gustatory stimulation in three time points as follows: before, during (one day after receiving the mean dose 26 Gy) and 6 months after the end of radiotherapy (RT). Salivary Ejection Fraction (SEF) data was also obtained from salivary gland scintigraphy (SGS) at the same three time points as MRI. Mean ADC at rest and after stimulation (ADCr, ADCs) and SEF were extracted from parotid region for three time points. Finally, SEF and changes of ADC over time at rest and after stimulation and in each time point were compared. ResultsDifference between mean ADCr before RT and during RT was not significant (p = 0.12). The ADCr values were significantly higher after RT than before RT (p = 0.003) and during RT (after dose 26 Gy) (p = 0.001). The difference between ADCr and ADCs in each time point showed that there is significant difference between ADCr and ADCs before RT (p = 0.005). Difference between these parameters after RT was also significant (p = 0.05). Non-significant difference (p = 0.21) between ADCr and ADCs during RT was observed. The result of SEF also was significantly lower after RT than during (p = 0.008) and before RT (p = 0.001). ConclusionMean ADC values could be used as a surrogate marker to characterize the parotid function in different stages of RT.

3D gamma analysis between treatment plans for nominally beam‐matched medical linear accelerators using PyMedPhys

AbstractBeam‐matched linear accelerators (linacs) enable flexible patient scheduling and efficient treatment delivery in the event of unexpected machine downtime. The purpose of this study was to test the feasibility of 3D gamma index as an additional metric beyond standard measurement‐based comparisons for more efficient evaluation of treatment plans between linacs with nominally matched beam models to ensure safe patient transfer. Seventeen 3D conformal radiotherapy (3DCRT) plans and thirty‐six volumetric‐modulated radiation therapy (VMAT) plans for different disease sites were selected from the original linac. An in‐house script was used to automatically create new plans for the target linac and calculate dose using parameters of the original plans. 3D gamma analysis was performed to compare plan dose distributions between the target and original linacs using PyMedPhys. The 2%/2 mm gamma pass (γ≤1) rate was >99.99% for all 3DCRT plans. The median 1%/1 mm pass rate was 99.86% but two cases failed (< 90%). For VMAT plans, the median and minimum 2%/2 mm gamma pass rates were 99.43% and 93.81%. For 1%/1 mm, the median pass rate was 92.02% but ten cases failed. The results indicated using 3D gamma index can enhance the confidence and add an extra layer for safe patient transfer.

Monte Carlo study of organ doses and related secondary cancer risk estimations for patients undergoing prostate radiotherapy: Algerian population-based study

The present study aimed to assess organ doses and the associated cancer risks related to secondary radiation (photons and neutrons) exposure during 3D Conformational Radiotherapy (3D-CRT) for patients with prostate cancer in Algeria. To this purpose, a detailed geometric Monte Carlo (MC) modeling of the LINAC, combined with a hybrid whole-body phantom was carried out. The secondary radiation doses were calculated in patient's organs, both within and outside the field. The obtained doses were used to estimate the Lifetime Attributable Risks (LARs) for cancer incidence for out of field organs, using the Biological Effects of Ionizing Radiation VII (BEIR VII) risk model, considering the exposure age range according to the age of the treated patients in Algeria. The survival information and baseline cancer risks were based on relevant statistics for the Algerian population. The results revealed that secondary radiation equivalent doses mostly depend on the distance of organs from the treated volume. The highest and lowest equivalent doses of 5.77 mSv/Gy and 0.24 mSv/Gy were recorded in the small intestine and ocular lens, respectively. LARs decreased as the age of exposure increased, with the highest estimated value per 100,000 individuals identified at a 35-year exposure age (88 for the colon and 15 for the intestine). Conversely, the lowest risks were found at 70 years of age, specifically in rib bone and leg bone with value of (0). The current research could contribute to establishing a database concerning the incidence of secondary cancers induced by radiotherapy during 3D-CRT for prostate cancer in Algeria.

PDOC-05 MULTIPLE ISOCENTRE VMAT PLANNING FOR PAEDIATRIC CRANIOSPINAL IRRADIATION USING THE HALCYON LINEAR ACCELERATOR

Abstract Paediatric brain tumours constitute the leading cause of cancer specific deaths worldwide. Many patients require craniospinal irradiation (CSI), one of the most technically demanding techniques in radiotherapy. Many LMIC centres have installed Varian Halcyon® linear accelerators and require a technique to execute CSI safely. This study evaluates a multiple isocentre VMAT planning strategy for CSI. The Halcyon is a ring based linac with a single 6MV flattening filter free (FFF) photon beam, a stacked and staggered double MLC for beam shaping and modulation, and no movable collimator jaws. Multiple isocentres are required for treatment fields longer than 28 cm. Paediatric CSI requires dose to be delivered to the entire thecal sac incorporating whole brain as well as entire spinal cord, resulting in long planning target volumes. In addition to the length of the treatment field, CSI treatments are complex due to the change in geometry of the target and the patient body over the length of the treatment field. Traditional 3D conformal radiotherapy techniques (3DCRT) require multiple isocentres with field matching and junction feathering. VMAT offers an alternative, but also require multiple fields to achieve coverage. A Halcyon based three isocentre VMAT technique was investigated and evaluated according to the QUANTEC criteria. Portal dosimetry quality assurance was performed on all fields to ensure they were clinically deliverable. High quality paediatric CSI VMAT treatments can be delivered on the Halcyon, using three isocentres with automatic feathering applied in field overlap regions. Two full arcs and one support arc were used for the brain area, with two posterior partial arcs per spine isocentre, each covering a total of 140 degrees posteriorly to limit integral dose and dose to the lungs and kidneys. Imaging and setup is required for every isocentre further than 8cm/10cm (Halcyon V2/V3 respectively) from the previous isocentre.

Randomized Prospective Trial Comparing 2 Schedules of Hypofractionated Adjuvant Radiotherapy 3 Weeks Against One Week Fractionation Regimen in Females with Breast Cancer

Abstract Purpose Acceleration of radiotherapy in 5 fractions for breast cancer can reduce the burden of treatment especially in Low middle income countries. We report on acute toxicity after whole breast irradiation /chest wall irradiation ± nodal irradiation, QOL score & Local recurrence incidence with ultra- hypofractionation schedule compared to modest hypofractionation protocol. Material and Methods Acute toxicity and health-related quality of life (HRQoL) of 101 patients, randomized between a 15- or 5-fractions schedule, were collected, using the RTOG acute toxicity scoring system, EORTC QLQ-C30 and BR23 questionnaire. The prescribed dose to the breast was either 15∗2.67 Gy (40.05 Gy) or 5∗5.2 Gy (26 Gy),60.1% of patients received tumor boost divided in both arms, with prescribed dose 5∗200cGy with 3D conformal radiotherapy technique. Inclusion criteria were: T1–T3 invasive breast cancer with or without axillary involvement (N0-N1&N2) after breast conserving or modified radical surgery. Results A total of 101 patients included in the study. Median age was 53±10.29 years, most of the cases enrolled were stage II with 38 patients in arm 1 (26 Gy) and 26 in arm 2(40Gy),only 19 cases had stage III breast cancer with 14 cases included in arm 2,while nodal negative status reported in 49 cases. A significant difference was observed for acute skin toxicity after radiotherapy in favor of better tolerability for arm 1 (P value <0.0001),also patients in ultra hypofractionation arm reported significant lower score for symptom scale including breast pain (P value >0.0001),swollen breast (P value <0.0001),difficulty to move arm (P value=0.0001),swollen hand (P value <0.0001)and QOL deterioration was less also in ultra fractionation arm (P value <0.0001) and none of the cases in both arms had local recurrence till time of data collection (12-20 months follow up duration). Conclusion In this single institute study, acute toxicity of accelerated breast radiotherapy in 5 fractions over 5 days seems to compare favorably to hypofractionated breast radiotherapy in 15 fractions. Less radiation dermatitis, breast edema, breast pain, difficulty to move arm and swollen hand. Quality of life is also less disturbed and patients have a better future perspective, however longer time for follow up &larger enrolled numbers needed to confirm non inferiority of this approach.

Evaluating the Effects of Prostate Radiotherapy Intensified with Pelvic Nodal Radiotherapy and Androgen Deprivation Therapy on Myelosuppression: Single-Institution Experience.

Prostate cancer (PCa) management commonly involves the utilization of prostate radiotherapy (PRT), pelvic nodal radiotherapy (PNRT), and androgen deprivation therapy (ADT). However, the potential association of these treatment modalities with bone marrow (BM) suppression remains inadequately reported in the existing literature. This study is designed to comprehensively evaluate the risk of myelosuppression associated with PRT, shedding light on an aspect that has been underrepresented in prior research. We conducted a retrospective analysis of 600 patients with prostate cancer (PCa) treated with prostate radiotherapy (PRT) at a single oncology center between 2007 and 2017. Patients were categorized into four cohorts: PRT alone (n = 149), PRT + ADT, (n = 91), PRT + PNRT (n = 39), and PRT + PNRT + ADT (n = 321). To assess the risk of myelosuppression, we scrutinized specific blood parameters, such as hemoglobin (HGB), white blood cells (WBCs), neutrophils (NEUT), lymphocytes (LYM), and platelets (PLT) at baseline, mid-treatment (mRT), immediately post-RT (pRT), 1 month post-RT (1M-pRT), and 1 year post-RT (1Y-pRT). The inter-cohort statistical significance was evaluated with further stratification based on the utilized RT technique {3D conformal radiotherapy (3D-CRT), and intensity-modulated radiation therapy (IMRT)}. Significant statistical differences at baseline were observed in HGB and LYM values among all cohorts (p < 0.05). Patients in the PRT + PNRT + ADT cohort had significantly lower HGB at baseline and 1M-pRT. In patients undergoing ADT, BMS had a significant impact at 1M-pRT {odds ratio (OR) 9.1; 95% Confidence Interval (CI) 4.8-17.1} and at 1Y-pRT (OR 2.84; CI 1.14-7.08). The use of 3D-CRT was linked to reduced HGB levels in the PRT + PNRT + ADT group at 1 month pRT (p = 0.015). Similarly, PNRT significantly impacted BMS at 1M-pRT (OR 6.7; CI 2.6-17.2). PNRT increased the odds of decreased WBC counts at 1Y-pRT (OR 6.83; CI: 1.02-45.82). Treatment with any RT techniques (3D-CRT or IMRT), particularly in the PRT + PNRT and PRT + PNRT + ADT groups, significantly increased the odds of low LYM counts at all time points except immediately pRT (p < 0.05). Furthermore, NEUT counts were considerably lower at 1M-pRT (p < 0.05) in the PRT + PNRT + ADT group. PLT counts were significantly decreased by PRT + PNRT + ADT at mRT (OR 2.57; 95% CI: 1.42-4.66) but were not significantly impacted by the RT technique. Treatment with PRT, ADT, PNRT, and 3D-CRT is associated with BMS. Despite this statistically significant risk, no patient required additional interventions to manage the outcome. While its clinical impact appears limited, its importance cannot be underestimated in the context of increased integration of novel systemic agents with myelosuppressive properties. Longer follow-up should be considered in future studies.

Exploring the impact of field shape on predicted dose distribution in breast cancer patients using deep learning in radiation therapy

BackgroundGeometrical information such as field shape is essential for dose calculation in radiation therapy. However, new methods of dose prediction based on deep learning only use CT images and contouring of patients. The aim of this study is to develop a deep learning method for three-dimensional dose prediction for breast cancer radiotherapy using field shape as well as CT and contouring images of patients. MethodsA total of 150 breast cancer patients' data treated with 3D conformal radiation therapy (CRT) technique were used to train and test 3D-U-Res-F-Net model. The model inputs were CT images, patients' contouring and field shape. The network output was the corresponding the patients’ dose distribution. Then, the dosimetric parameters extracted from the dose volume histograms related to the planned and predicted dose distributions were compared and were statistically analysed with the paired-samples t-test. These parameters include Dmean and Dmax for planning target volume and organs at risk, D95%, D50%, V47.5Gy for PTV, V30Gy and V25Gy for heart and V20Gy for left lung. The gamma index with 3%/3 mm criteria was calculated for PTV and OARs. ResultsThe average absolute difference of the Dmean relative to the prescribed dose for the PTV, heart, left lung, right lung and spinal cord were 1.37 ± 0.4%, 2.02 ± 2%, 2.12 ± 1%, 0.37 ± 0.3% and 0.41 ± 0.3%, respectively. The average absolute difference of the Dmax relative to the prescribed dose for the PTV and OARs varied from 0.23 ± 0.2% to 2.04 ± 2%. The 3D gamma pass rate with 3mm/3% criteria for planning target volume, heart, left lung, right lung, spinal cord and body were 89 ± 3%, 91 ± 5%, 93 ± 5%, 99 ± 3%, 99 ± 1% and 96 ± 2% respectively. ConclusionsThe results of the proposed model demonstrate that there is no significant difference between the predicted and planned dose distributions. The deep learning model can directly predict the 3D dose distribution faster than treatment planning systems. Further studies with more patients and on other cancer sites are essential to fully validate the proposed method.

SEROLOGICAL OUTCOMES OF TREATMENT WITH 3D-CRT AND IMRT IN LOCALIZED PROSTATE CANCER.

Prostate cancer ranks the second most frequent cancer encountered worldwide in men. Radiotherapy has been effectively used to treat localized prostate cancer. Over the years more effective radiation techniques like 3D-Conformal Radiation Therapy (3D-CRT), Proton Therapy, Intensity Modulated Radiation Therapy (IMRT), and Brachytherapy has been evolved and effectively used to deliver radiation therapy. Herein, we compare serological outcomes of two radiation treatment techniques intensity modulated radiation therapy (IMRT) and 3- dimensional conformal radiation therapy (3DCRT) in localized prostate adenocarcinoma. It is a cohort study conducted at Department of Oncology, Dr Ziauddin Hospital, Karachi. Patients with localized prostate adenocarcinoma meeting the inclusion criteria were recruited from July 2016 to June 2022, underwent treatment with a total dose >74 Gy using two different advanced radiotherapy techniques, i.e., IMRT and 3D-CRT. Serum PSA levels were assessed prior to treatment, and 6 weeks and 12 months after treatment. Paired t-Test was applied to identify the difference in PSA levels before, and after the treatment. p-value less than 0.05 was taken as significant at 95% confidence interval. A total of 78 patients with 39 in each group. The mean age of patients in 3D-CRT group was 68±10 years while in IMRT group was 68±07 years. Six weeks after initiation of treatment, we observed that both the treatment methods, i.e., 3D-CRT and IMRT reduced the PSA levels significantly p-value = 0.001 respectively. There was no significant difference in the mean of PSA levels on 06th week and 12th months. Furthermore, the analysis of PSA levels at 12th months when compared with the baseline PSA levels came highly significant in both the groups as depicted in paired-t teat analysis of PSA levels with acceptable toxicity. Radiation therapy modalities 3D-CRT and IMRT both showed a significant serological response with minimal or acceptable gastrointestinal and genitourinary toxicities in the 3D-CRT group in comparison to the IMRT group. Although the sample size is relatively smaller, but the results of this study are encouraging to treat those patients on 3D-CRT, who cannot afford more expansive radiotherapy treatment technique like IMRT.

Analisis Distribusi Dosis pada Treatment Planning System Pasien Kanker Payudara dengan Sumber Foton 6 MV pada Instalasi Radioterapi Rumah Sakit X

The internship at X Hospital aimed to gain practical experience as a medical physicist over two months, particularly in the treatment planning system activities in the radiotherapy unit. Additionally, this internship aimed to evaluate the Dose Volume Histogram (DVH) and analyze the effectiveness of the isodose lines. The treatment planning system is a simulation of cancer or tumor treatment using radiation with 3D conformal radiotherapy (3D-CRT) techniques. The patient study object was a woman with post-mastectomy breast cancer who was to undergo adjuvant curative therapy. The prescribed dose was 50 Gy, divided into 25 fractions, using a 6 MV photon source. The irradiation was conducted with four fields, gantry angle 129° with collimator angle 270°, 310° with collimator angle 90°, 130° with collimator angle 0°, and 270° with collimator angle 0°, field size 14 x 14 cm, and irradiation distance of 100 cm. The TPS simulation results indicated that the dose received by the Planning Target Volume (PTV) covered more than 90% of the target volume (special treatment), while the dose received by the Organ at Risk (OAR) tended to be below the threshold limit, and the isodose lines ensured optimal radiation dose distribution to the breast cancer target area. This was demonstrated by the DVH curve.

Comparison of Photon Dose Distribution in Breast Cancer Using 3DCRT and Half Beam Techniques

Radiotherapy planning can be done with 3D Conformal Radiotherapy (3DCRT) and Half Beam. The success of radiotherapy planning is considered by comparing the isodose curve, Dose Volume Histogram (DVH), Organs At Risk (OAR), Homogeneity Index (HI), and Conformity Index (CI) obtained by the 3DCRT and Half Beam techniques. This study used data from 5 patients at the Radiotherapy Installation at A.W. Hospital. Sjahranie Samarinda with radiation planning of 5000 cGy (25×2 Gy) for breast cancer. The two radiation plans used gantry angles of 310˚ and 120˚. The calculated dose distribution value can be seen through the 90%, 95% PTV dose, and OAR absorbed dose. PTV doses of 90% and 95% in the 3DCRT technique covered the target well. The radiation dose values of the 3DCRT technique at PTV 90% were around 4860 cGy – 4930 cGy and PTV 95% were around 4750 cGy – 4840 cGy. Meanwhile, the Half Beam technique could not cover the target well. It was because the radiation dose values received by the Half Beam technique at 90% PTV were around 780 cGy – 4860 cGy and 95% PTV were around 2210 cGy – 5020 cGy. The OAR absorbed doses values for the 3DCRT and Half Beam techniques were still within the safe limits of tolerance according to QUANTEC. Meanwhile, the HI and CI values in the 3DCRT technique were closer to the rules of ICRU Report 83 of 2010 compared to the Half Beam technique. Therefore, from the values that have been obtained, the success rate of the radiotherapy planning process after measurements is shown in the 3DCRT technique. It has the value of more efficient dose calculations and can be used as a reference in optimizing dose distribution to patients.

Predictors of Clinical Hematological Toxicities under Radiotherapy in Patients with Cervical Cancer-A Risk Analysis.

Cervical cancer ranks third in frequency among female cancers globally and causes high mortality worldwide. Concurrent chemoradiotherapy improves the overall survival in cervical cancer patients by 6% but it can cause significant acute and late toxicities affecting patient quality of life. Whole pelvis radiotherapy doses of 10-20 Gy can lead to myelosuppression and to subsequent hematological toxicities since pelvic bones contain half of bone marrow tissue. A total of 69 patients with IB-IVB-staged cervical cancer have been included in this retrospective cohort study. We analyzed clinical adverse events and changes in blood cell counts (hemoglobin, neutrophils, leukocytes, and platelets) during radiation or chemoradiotherapy received at the Oncological Institute of Bucharest from 2018 to 2021. Decreases in hemoglobin levels of over 2.30 g/dL during treatment were associated with BMI > 23.2 kg/m2 (OR = 8.68, 95%CI = [1.01, 75.01]), age over 53 years (OR = 4.60 95%CI = [1.10, 19.22]), with conformational 3D irradiation (OR = 4.78, 95%CI = [1.31, 17.40]) and with total EQD2 of over 66.1 Gy (OR = 3.67, 95%CI = [1.02, 13.14]). The hemoglobin decrease rate of 0.07 g/dL/day was related to 95% isodose volume (OR = 18.00). Neutropenia is associated frequently with gastrointestinal side effects and with the bowel and rectal V45 isodoses (OR = 16.5 and OR = 18.0, respectively). Associations of total external and internal radiation dose with the time durations calculated from the initiation of treatment to the onset of hematological adverse reactions were also obtained. The maximum drop in leukocytes was observed before day 35 from the RT initiation in patients who underwent treatment with 3D conformal radiotherapy (OR = 4.44, 95%CI = [1.25, 15.82]). Neutrophil levels under 2.2 × 103/μL and thrombocyte levels under 131 × 103/μL during the follow-up period were associated with a total planned dose of 54 Gy to the pelvic region volume (OR = 6.82 and OR = 6.67, respectively). This study shows the existence of clinical and blood predictors of hematological adverse reactions in cervical cancer patients. Thus, patients who are in a precarious clinical situation, with low hematological values (but not yet abnormal), should be monitored during days 29-35 after the initiation of RT, especially if they are obese or over 53 years of age.

3121: Coronary arteries exposure in VMAT versus 3D conformal radiotherapy for thymic epithelial tumors

3121: Coronary arteries exposure in VMAT versus 3D conformal radiotherapy for thymic epithelial tumors

Erectile Dysfunction and Penile Bulb Dose Following Definitive Prostate Radiation Therapy

Background: Erectile dysfunction (ED) is a common side effect of prostate cancer treatment, affecting up to 50% of patients after radiation therapy. Objectives: This study aims to analyze the correlation between the dose received by the penile bulb (PB) and ED in men who underwent definitive radiation therapy for early-stage prostate cancer without androgen deprivation therapy. Methods: The study included 40 patients who received 3D conformal radiation therapy (3D-CRT) for localized prostate cancer and were reported to be potent before treatment, as determined by the International Index of Erectile Function (IIEF-15) questionnaire. The dose to the PB was measured using dose volume histograms (DVHs), and the IIEF-15 questionnaire was completed again 3 months after 3D-CRT. The Pearson correlation coefficient and linear regression test were used to examine the correlation between the ED score and PB doses. Statistical significance was considered if the P value was less than 0.05. Results: The mean age of the patients was 75.5 ± 5.70 years. The average ED score based on the questionnaire was 15 ± 10.55. Twenty percent of the patients had moderate ED, while 80% had mild ED (all patients reported a decrease in potency after 3D-CRT). However, the correlation between the ED score and the PB mean dose was not statistically significant. Conclusions: This study revealed ED in all prostate cancer patients after 3D-CRT, but no significant correlation was found between the dose received by the PB and radiotherapy-induced impotence.

Dosimetric and radiobiological advantages from deep inspiration breath-hold and free breath technique for left-sided breast radiation using 3DCRT, IMRT and Rapid Arc methods-a complete assessment.

The verification and use of the best treatment approach using 3D conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and Rapid Arc methods for left breast radiation with dosimetric and radiobiological characteristics. The use of custom-built Python software for the estimation and comparison of volume, mean dose, maximum dose, monitor units and normal tissue integral dose along with radiobiological parameters such as NTCP, tumor control probability, equivalent uniform dose and LKB's effective volume from 3DCRT, IMRT and Rapid Arc planning with deep inspiration with breath holding (DIBH) and free breadth (FB) techniques. Volume growth of three-fourth in DIBH compared with FB causes a decrease in cardiac doses and complications because the left lung expands, pulling the heart away from the chest wall and the treatment area. A tiny area of the left lung was exposed during treatment, which reduced the mean dose. There was little difference in the treatment approaches because the spinal cord was immobile in both techniques. Rapid Arc is the unmatched modality for left-sided breast irradiation with significant patient breath-hold, as shown by the comparison of dosimetric and radiobiological parameters from treatment techniques with a deep inspiration breath-hold approach.

Evaluating a hypofractionated radiotherapy schedule for prostate cancer at an institution in South Africa

Background: Hypofractionated radiotherapy (HFRT) in the treatment of prostate cancer (PCa) has logistical and cost advantages, especially in a resource constrained setting. Studies have demonstrated equivalent efficacy with HFRT schedules using Intensity Modulated Radiation Therapy (IMRT) as treatment modality. However, higher rates of acute and late gastrointestinal (GI) and genitourinary (GU) toxicity have been reported when compared to conventionally fractionated radiotherapy (CFRT). In this study, we evaluate the efficacy and toxicity rates of a HFRT schedule using 3D conformal radiotherapy (RT) as treatment modality.Aim: With this study, we aim to describe the safety and outcomes of a definitive HFRT schedule used for localised PCa. We hypothesise that there is no difference in the biochemical relapse rate and incidence rates of normal tissue toxicities between patients receiving CFRT and HFRT schedules.Setting: This RT schedule was used at Tygerberg Academic Hospital in South Africa for the treatment of localised prostate cancer.Methods: This is a retrospective study in which the records of patients diagnosed with localised PCa were reviewed. Patients were treated with either CFRT regimen to a total of 74Gy in 37 daily fractions for 5 days a week or a HFRT regimen to a total of 65Gy in 26 daily fractions for 4 days per week.Results: In all, 116 patients were included in the study with a median follow-up of 57.2 months from the start of RT. No statistically significant differences in overall survival (OS) and biochemical relapse-free survival were found between the two schedules. A significant difference in acute GI toxicity was observed, with a higher incidence noted in the HFRT schedule. No significant differences were observed in late GI toxicity or in early and late GU toxicities.Conclusion: This study observes a hypofractionated regimen using three-dimensional conformal radiation therapy (3DCRT) with similar efficacy and RT-related toxicities to CFRT.Contribution: The HFRT schedule used in this study could be useful in hospitals with limited access to resources.

Clinical Outcomes and Treatment Efficacy in Cervical Cancer Patients in the UAE: A Retrospective Cohort Study.

Background and objectives Cervical cancer remains a significant global health issue, particularly in low- and middle-income countries. While high-income countries have seen reduced incidence and mortality rates due to effective screening and HPV vaccination programs, these rates are still high in areas with limited healthcare infrastructure. In the United Arab Emirates (UAE), recent efforts are improving public health initiatives and awareness. This retrospective cohort study evaluates clinical outcomes and treatment efficacy in cervical cancer patients at a tertiary cancer center in Al Ain, Abu Dhabi. It analyzes treatment regimens, their effectiveness, and factors affecting survival, disease progression, and treatment completion. Methods and material The study included 275 cervical cancer patients treated between January 2008 and December 2021. Data were extracted from medical records, including demographic information, clinical characteristics, and treatment details. Statistical analyses, including Kaplan-Meier survival curves and Cramér's V correlation matrix, were used to evaluate survival outcomes and the relationships between various categorical variables. Results The mean age of patients was 48.88 years, with the majority being non-nationals, 221 (80.37%). Histopathologically, there were 234 (85.18%) cases of squamous cell carcinoma (SCC) and 33 (11.85%) cases of adenocarcinomas. The International Federation of Gynecology and Obstetrics (FIGO) staging indicated that 137 (49.80%) patients were in stage II and 60 (21.81%) were in stage III. Pelvic lymph node involvement was observed in 139 (50.54%) patients. The treatment modalities included surgery in 39 (14.18%) patients, 3D conformal radiotherapy (3D-CRT) in 247 (89.81%) patients, intensity-modulated radiation therapy (IMRT) in 11 (4.00%) patients, brachytherapy in 213 (77.45%) patients, and chemotherapy in 248 (90.18%) patients. The survival analysis showed no significant differences in survival among different treatment groups, as indicated by the Log-rank test (p = 0.4060). Conclusion The study highlights the demographic and clinical characteristics of cervical cancer patients in the UAE, emphasizing the prevalence of advanced-stage diagnoses and high-grade tumors. Despite significant efforts to improve screening and treatment, cervical cancer remains a concern in the UAE. The findings underscore the need for enhanced early detection and comprehensive treatment strategies. Addressing the study's limitations, such as the retrospective design and the absence of human papillomavirus (HPV) data, could further refine cervical cancer management and improve patient outcomes in future research.

Small cell cancer of the esophagus, treatment outcomes of a rare histological type

Purpose: To demonstrate treatment outcomes in two patients with small cell esophageal cancer. Cases reports. Patient M. was assigned to receive polychemotherapy (PC H) composed of etoposide 100 mg/ m2 intravenously on days 1–3 + cisplatin 80 mg/m2 on day 1, every 21 days for 6 cycles and lanreotide 120 mg subcutaneously, every 28 days, followed by chemoradiotherapy (CRT). The patient received 1 cycle of PCT , which was well tolerated. Then, the patient received a cycle of 3D-conformal radiation therapy concurrently with 2 cycles of chemotherapy: etoposide 120 mg/m2 + cisplatin 80 mg/m2. Chemoradiotherapy was well tolerated. Dysphagia regression to grade I was observed. Currently, the patient continues to receive treatment (etoposide 100 mg/ m2 intravenously on days 1–3 + cisplatin 80 mg/m2 on day 1, every 21 days for 6 cycles and lanreotide 120 mg subcutaneously, every 28 days) and tolerates it well. Patient A. was assigned to receive PCT with etoposide 120 mg/m2 + cisplatin 80 mg/m2. After 4 cycles of PCT , the follow-up CT images revealed disease progression (enlarged retroperitoneal lymph nodes). The patient underwent external bean radiation therapy to the primary tumor. Radiotherapy was relatively well tolerated. The patient underwent the course of radiation therapy relatively satisfactorily. Due to the progression of the disease, symptomatic treatment was assigned. The patient died 9 months after diagnosis. Conclusion. Small cell carcinoma of the esophagus is a rare histological type with poor prognosis. Concurrent platinum-based chemoradiotherapy allows achievement of stable disease and disease control.

Technologies of modern radiotherapy and development prospects. Quality assurance concept

At the clinic of the N.N. Blokhin National Medical Research Center of Oncology has been using the following conformal irradiation technologies for cancer patients that meet international standards for more than 13 years: 3D conformal radio therapy (3DCRT); intensity modulated radiotherapy (IMRT); volume modulated arc therapy (VMAT); stereotactic radiation technique (SRT); radiotherapy technique with breathing control, total therapeutic irradiation (TRT) technique followed by bone marrow transplantation. The technological complex with which these technologies are implemented has demonstrated an increase in the quality of radiation treatment for cancer patients. However, despite the “advancement” of technology, there are limitations in the ability to reduce dose loads on critical organs for a number of nosologies. Therefore, the prospects for the development of radiotherapy in Russia lie in the creation of several clinical centers for the use of heavy charged particles that have different physical and dosimetric characteristics and, from this point of view, carry other opportunities and prospects. There is great interest in flash therapy.

Short course irradiation in rectal cancer: Dosimetry study comparing 3D conformal radiotherapy versus intensity-modulated radiotherapy versus volumetric modulated arc therapy

The standard radiotherapy planning technique for locally advanced rectal cancer (LARC) was 3D Conformal Radiotherapy (3DCRT). Modern radiation delivery techniques, including Intensity-Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) techniques, have been developed in recent years in terms of dose delivery to the target while minimizing the dose to the organ at risk (OAR). The objective of this study was to identify the most suitable treatment plan technique from the available options of 3DCRT, IMRT and VMAT for LARC using short course radiotherapy (SCRT). Therefore, twenty-five adult patients with LARC in the last five-year period (2017–2021) were involved in this study. For each patient, three radiotherapy treatment plans were generated for dosimetric comparison of short course irradiation (25 Gy/5 fractions, which is the new standard of care) using Varian Eclipse software to generate 3DCRT in comparison with IMRT and VMAT plans. The conformity index (CI), the homogeneity index (HI), and the organs at risk (OAR), including bladder, small bowel, and femoral heads, were compared between the three plans. The results revealed that VMAT and IMRT plans had a higher level of conformity for the planning target volume (PTV) with 0.996 and 0.994, respectively, compared to the 3DCRT planning of 0.947 (both p < 0.005). The PTV dose distribution was less homogeneous with 3DCRT than with VMAT or IMRT plans. VMAT offered superior homogeneity to IMRT and 3DCRT plans with 1.055, 1.066, and 1.089, respectively (p < 0.005). The findings showed that VMAT is superior to IMRT and 3DCRT in almost all parameters, including dose distribution conformity and homogeneity of the target volume, as well as providing better OAR sparing in LARC patients.