Three-dimensional Conformal Radiotherapy Research Articles

Cribriform Pattern Is a Predictive Factor of PSA Recurrence in Patients Receiving Radiotherapy After Prostatectomy.

In prostate cancer, robotic total prostatectomy is a popular treatment modality. However, prostate-specific antigen (PSA) recurrence after prostate cancer surgery remains a concern. Salvage radiotherapy is commonly used to treat PSA recurrence, but the recurrence rate after salvage radiotherapy is high, highlighting the need for better predictive markers. This study aimed to retrospectively evaluate the association between cribriform pattern and PSA recurrence in patients receiving radiotherapy after radical prostatectomy. Data of 50 patients who underwent radiotherapy after total prostatectomy between January 2010 and May 2020 were retrospectively evaluated. The median age was 67 years. Among these patients, two cases involved postoperative irradiation, while 48 cases involved salvage irradiation after postoperative PSA recurrence. The median time from surgery to PSA recurrence was 38.3 months. The median radiation dose was 64 Gy in 32 fractions. Three-dimensional conformal radiation therapy was administered in 38 cases and intensity-modulated radiation therapy was used in 12 cases. Combined hormone therapy was administered in 21 cases. PSA levels were measured every 3 months after treatment. Statistical analysis between groups was performed by a t-test. The median follow-up period after radiotherapy was 31 months. No local recurrences were observed at the prostate bed, and no deaths related to prostate cancer were recorded during follow-up. However, 18 patients (36.0%) had PSA recurrence. The PSA recurrence rate based on the cribriform pattern was 17.6% in the none to moderate group (34 patients) and 75.0% in the severe cribriform pattern group (16 patients). The PSA recurrence rate was significantly higher in patients with a severe invasive cribriform pattern (p=0.001). No significant differences were observed in other histopathological characteristics. The cribriform pattern in surgical pathology specimens was found to be a useful predictor of PSA recurrence after postoperative radiotherapy.

Three-dimensional conformal radiation therapy with concurrent chemotherapy for stage III non-small cell lung cancer: protocol for a systematic review and meta-analysis

IntroductionLung cancer continues to be a common form of cancer worldwide and a primary contributor to cancer-related fatalities. Non-small cell lung cancer (NSCLC) is the most prevalent form, making up...

Effect of replanning boost radiotherapy plan in locally advanced unresectable middle to lower thoracic esophageal cancer

Thoracic bulky esophageal cancer shrinks during radiotherapy, changing the location and shape of the surrounding heart and lungs. The current study aimed to explore how replanning by volumetric-modulated arc radiotherapy (VMAT) and three-dimensional conformal radiotherapy (3DCRT) influences the target coverage and dose to organs at risk in locally advanced unresectable middle to lower thoracic esophageal cancer. We retrospectively collected CT simulation images of initial and boost radiotherapy plans for locally advanced unresectable thoracic esophageal cancer in 17 consecutive patients. First, we created boost plans of 20 Gy using 3DCRT and VMAT on the initially acquired CT images. Second, we replicated the process on CT images acquired after 20–40 Gy of radiotherapy. We then compared non-replanned boost radiotherapy plans with replanned boost plans. Replanned radiotherapy delivered more conformal doses to the target and reduced heart and lung doses. VMAT reduced more irradiated mean doses to the heart than 3DCRT in the case of replanning (1.7 and 1.1 Gy, p < 0.001). Replanning to accommodate tumor shrinkage during radiotherapy effectively lowers the irradiated doses to the heart and lungs in patients with locally advanced unresectable middle to lower thoracic esophageal cancer, especially those treated with VMAT.

466 - Dosimetric comparison between three-dimensional conformal radiation therapy, hybrid intensity-modulated radiation therapy and volumetric modulated arc therapy for left-breast cancer with lymph node involvement using breath-hold technique

466 - Dosimetric comparison between three-dimensional conformal radiation therapy, hybrid intensity-modulated radiation therapy and volumetric modulated arc therapy for left-breast cancer with lymph node involvement using breath-hold technique

Assessment of setup error in Three-Dimensional Conformal Radiotherapy (3-DCRT) during the treatment of patients with prostate or bladder cancers in Ayadi El-Mostakbal hospital (Alexandria, Egypt)

Assessment of setup error in Three-Dimensional Conformal Radiotherapy (3-DCRT) during the treatment of patients with prostate or bladder cancers in Ayadi El-Mostakbal hospital (Alexandria, Egypt)

Induction chemotherapy followed by standard chemoradiotherapy versus standard chemoradiotherapy alone in patients with locally advanced cervical cancer (GCIG INTERLACE): an international, multicentre, randomised phase 3 trial

Locally advanced cervical cancer is treated with chemoradiotherapy (standard of care), but many patients still relapse and die from metastatic disease. We investigated chemoradiotherapy with or without induction chemotherapy to determine whether induction chemotherapy improves both progression-free survival and overall survival. The INTERLACE trial was a multicentre, randomised phase 3 trial done at 32 medical centres in Brazil, India, Italy, Mexico, and the UK. Adults (aged ≥18 years) with locally advanced cervical cancer (FIGO 2008 stage IB1 disease with nodal involvement, or stage IB2, IIA, IIB, IIIB, or IVA disease) were randomly assigned (1:1), by minimisation, using a central electronic system, to standard cisplatin-based chemoradiotherapy (once-a-week intravenous cisplatin 40 mg/m2 for 5 weeks with 45·0-50·4 Gy external beam radiotherapy delivered in 20-28 fractions plus brachytherapy to achieve a minimum total 2 Gy equivalent dose of 78-86 Gy) alone or induction chemotherapy (once-a-week intravenous carboplatin area under the receiver operator curve 2 and paclitaxel 80 mg/m2 for 6 weeks) followed by standard cisplatin-based chemoradiotherapy. Stratification factors were recruiting site, stage, nodal status, three-dimensional conformal radiotherapy or intensity modulated radiotherapy, age, tumour size, and histology (squamous vs non-squamous). Primary endpoints were progression-free survival and overall survival within the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01566240, and EUDRACT, 2011-001300-35. Between Nov 8, 2012, and Nov 17, 2022, 500 eligible patients were enrolled and randomly assigned to the chemoradiotherapy alone group (n=250) or the induction chemotherapy with chemoradiotherapy group. Of 500 patients, 354 (70%) had stage IIB disease and 56 (11%) stage IIIB disease. Pelvic lymph nodes were positive in 215 (43%) patients. 230 (92%) patients who received induction chemotherapy had at least five cycles. Median interval between induction chemotherapy and chemoradiotherapy was 7 days. Four or more cycles of cisplatin were given to 212 (85%) participants in the induction chemotherapy with chemoradiotherapy group and to 224 (90%) of participants in the chemoradiotherapy alone group. 462 (92%) participants received external beam radiotherapy and brachytherapy with a median overall treatment time of 45 days. After a median follow-up of 67 months, 5-year progression-free survival rates were 72% in the induction chemotherapy with chemoradiotherapy group and 64% in the chemoradiotherapy alone group with a hazard ratio (HR) of 0·65 (95% CI 0·46-0·91, p=0·013). 5-year overall survival rates were 80% in the induction chemotherapy with chemoradiotherapy group and 72% in the chemoradiotherapy alone group, with an HR of 0·60 (95% CI 0·40-0·91, p=0·015). Grade 3 or greater adverse events were reported in 147 (59%) of 250 individuals in the induction chemotherapy with chemoradiotherapy group versus 120 (48%) of 250 individuals in the chemoradiotherapy alone group. Short-course induction chemotherapy followed by chemoradiotherapy significantly improves survival of patients with locally advanced cervical cancer. Cancer Research UK and University College London-University College London Hospitals Biomedical Research Centre.

Radiotherapy for hypopharyngeal carcinoma in Senegal: Experience of the main cancer care facility

Objectives: To describe the epidemiological, diagnostic, therapeutic, and prognostic factors associated with patients treated for hypopharyngeal carcinoma at the Radiotherapy Department of the National Hospital Center Dalal Jamm. Patients and Methods: Data from 50 consecutive patients treated for hypopharyngeal carcinoma between 2018 and 2022 were retrospectively analyzed. All patients received three-dimensional conformal radiotherapy (3DCRT) with or without chemotherapy. Epidemiological and diagnostic data, treatment details, and therapeutic outcomes were collected in an Excel 2016 database created for the study. Statistical analyses were performed using SPSS version 20.0. Overall survival estimates were generated using the Kaplan-Meier method. Statistical significance was considered at p = 0.05. Uni- and multivariate analyses were conducted to identify prognostic factors associated with survival. Results: The average age of the patients was 44 years (± 14.4 years), with a male-to-female ratio of 0.56. Sixteen percent of the patients were active smokers and 4% were alcohol consumers. The mean delay to the first consultation was 6 months, and dysphagia was the primary symptom (92%). The majority of patients (89.8%) were classified as stage IVa, and 10% had metastases at diagnosis. Treatment consisted of curative concurrent chemoradiotherapy (95.92%), preceded by induction chemotherapy in 58% of patients. A radiation dose of 70 Gy was utilized in 75% of cases. The 2-year overall survival rate was 25%. Multivariate analysis indicated that the presence of feeding gastrostomy (p=0.044), use of induction chemotherapy (p=0.012), and radiation dose less than 70 Gy (p=0.020) were associated with poorer survival. Conclusion: Concurrent chemoradiotherapy using 3D conformal techniques improved management, although outcomes remain unsatisfactory. Prospective cohort studies are imperative to identify specific risk factors in our population. Additionally, timely access to appropriate treatment modalities could enhance prognosis.

An efficacy of protection the organs at risks comparison between the intensitymodulated radiotherapy therapy (IMRT) and the three-dimensional conformal radiotherapy (3DCRT).

To compare the efficiency of three-dimensional conformal radiotherapy and intensity-modulated radiation therapy techniques. The cross-sectional study was conducted from February to August 2021 at Al-Amal National Hospital, Baghdad, Iraq, and comprised patients aged 19-45 years with cancerous head and neck tumours of size 2-7cm. All the patients underwent magnetic resonance imaging or computed tomography simulation scans. Treatment planning techniques used for each patient were three-dimensional conformal radiotherapy and intensitymodulated radiotherapy. After evaluating patterns, a better plan and treatment with an X-ray beam was chosen. Data was analysed using SPSS 24. The study involved thirty participants, with 17(57%) females and 13(43%) males, aged 19-45, and 28 patients having chemotherapy. Six out of thirty had craniotomy surgery. The intensity-modulated radiation therapy had a safer radiation dose than the three-dimensional conformal radiotherapy for spinal cord (p=0.3203), brain stem (p= 0.17924), right parotid gland (p=0.8556) and left parotid gland (p=0.2193). The three-dimensional conformal radiotherapy protected the organs better than intensity-modulated radiation therapy for left optic nerve (p=0.1227), right optic nerve (p=0.0032), left eye (p=0.3859), right eye (p=0.1189), left lens (p=0.0004), right lens (p=0.0001), optic chiasm (p=0.0320) and pituitary gland (p=0.9162). The intensity-modulated radiation therapy technique protected the spinal cord, brain stem, and right and left parotid glands. The three-dimensional conformal radiotherapy was safe for left and right optic nerves, left and right eyes, left and right lenses, optic chiasm and pituitary glands.

Intensity-modulated radiotherapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) as treatment plans for head and neck tumours.

To compare intensity-modulated radiation therapy with three-dimensional conformal radiation therapy 3DCRTwith respect to dose coverage for target volume. The cross-sectional study was conducted at Al-Amal National Hospital, Baghdad, Iraq, from November 2020 to March 2021 and comprised patients with head and neck cancerous tumours. The patients underwent computed tomography scans, and were subsequently subjected to three-dimensional conformal radiotherapy and intensity-modulated radiotherapy treatment planning techniques on the basis of Monaco 5.1. The oncologist selected the better plan depending on evaluation parameters for each patient who was then irradiated with X-ray treatment. Data was analysed using SPSS 24. There were 30 patients, 17 (57%) females and 13 (43%) males with the age range of 19-45 years. Of the total, 28 received chemotherapy and 6 patients underwent brain surgery. The intensity-modulated radiation therapy resulted in significant coverage of the tumour than the three-dimensional conformal radiation therapy in phase 1 (p<0.00001) and phase II (p=0.0023). The intensity-modulated radiation therapy technique achieved a lower homogeneity value (p=0.0004) and higher conformity value (p<0.00001) than three-dimensional conformal radiation therapy. In phase II, no significant homogeneity index was found between the two therapies (p=0.072). The intensity-modulated radiation therapy showed significantly better conformity compared to three-dimensional conformal radiation therapy (p<0.00001). The intensity-modulated radiation therapy significantly improved coverage, plan conformity, and humongous dose distribution for head and neck tumours compared to the three-dimensional conformal radiation therapy 3DCRT.

Assessment of prostate cancer radiotherapy using three-dimensional treatment planning technique.

To assess the available commercial treatment planning system using three-dimensional conformal radiation therapy with respect to treatment for prostate cancer patients. This is a cross-sectional study was conducted from June 2021 to February 2022 at the Baghdad Centre for Radiation Therapy and Nuclear Medicine, Baghdad, Iraq, and comprised patients with prostate cancer who were treated with 6MV or 10MV energy using three-dimensional conformal radiation therapy technique, and irradiated using a linear accelerator. The patents were divided into three treatment phases. The prescribed dose in Phase I was 5000 centigrade, in Phase II it was 1800 centigrade, and in Phase III it was 600 centigrade. The number of beams used was 5 and 7. Data was analysed using SPSS 24. Out of 35 patients, 10 (28.6%) in phase I, 15 (42.8%) in phase II, and 10 (28.6%) in phase III. The PTV dose of 5 and 7 beams 6MV energy at the centre was higher than at 1mm, 2mm, and 3mm p values = (0.351, 0.013*, 0.076, 0.295), respectively. Dose to the rectum comparing 6MV and 10MV for beams 5, and 7. The dose to the rectum on phase one at 6MV and 10MV was similar for 5 beams (p=0.611) and 7 beams (p=0.778). A significant difference was seen for 7 beams (p-value=0.008). Phase three showed significant variations in rectum dose at 6 MV and 10MV for 5 beams (p=0.0004). For bladder, a significant difference observed between the energies for 5 beams on phase one and three (p-value=<0.00001*, 0.002*), while at 7 beams only phase 3 were significant (p-value=0.041*). The three-dimensional conformal radiation therapy plan with 10MV energy and a higher number of beams gave a higher coverage of dose for prostate tumours and was found to be a safe dose for the rectum and bladder.

Multi-segments conformal plan optimization for head and neck cancer.

To evaluate better dose distribution with three-dimensional radiation therapy, and to compare it with multi-segmented treatment planning techniques in patients with head and neck cancer. The prospective study was conducted at the Baghdad Centre for Radiation Therapy and Nuclear Medicine, Baghdad, Iraq, and comprised data of 50 patients with head and neck cancerous tumours from June 2021 to February 2022. There were 35 (70%) females and 15(30%) males. The mean age was 47.31 ± 3.95 years (range 19 - 69 years The patients had undergone computed tomography simulation. The images were exported to Monaco 5.1 for contouring by the radiation oncologist. The data was then imported to XiO planning system. Each plan was repeated twice; once with three-dimensional conformal radiation therapy and the other with field-in-field technique. Data was analysed using SPSS 24. There were 50 patients whose data was analysed. The results showed significant differences between three-dimensional conformal radiation therapy and field-in-field techniques for dose coverage at 90% and 95% volumes (p<0.05). There was a significant difference between the two techniques for 2Gy dose (p<0.05), but the difference was not significant for 5Gy dose (p>0.05). The field-in-field treatment planning technique was found to be more effective than the threedimensional conformal radiation therapy technique.

A systematic review on the techniques, long-term outcomes, and complications of partial breast irradiation after breast-conserving surgery for early-stage breast cancer.

To evaluate the efficacy and safety of four techniques of partial breast irradiation (PBI) including interstitial brachytherapy (ISBT), balloon-based brachytherapy (BBT), Intraoperative radiotherapy (IORT) and three-dimensional conformal radiotherapy (3DCRT) in the treatment for early-stage breast cancer patients after breast-conserving surgery. A systematic search was performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed, Embase, Cochrane Library and Web of Science databases. The inclusion criteria were clinical trials and observational studies that reported on outcome measures of principal PBI techniques. The methodological quality of the included research data was assessed using bias risk assessment tool with the Methodological Index for Non-Randomized Studies (MINORS), and the research information were analyzed using data analysis software. Clinical studies were collected from the earliest available date until September 2023. Fifty-one studies were included, with a total sample size of 7708. The results of network meta-analysis (NMA) showed that ISBT can lower the local recurrence (SUCRA: 73.8%). In terms of reducing distant metastasis, 3DCRT may be the best choice (SUCRA: 52.5%). And IORT has the highest 5-year overall survival (SUCRA: 90%). Furthermore, ISBT also has the advantages of lowest risk with fat necrosis (SUCRA: 72.5%), infection (SUCRA: 78.3%) and breast pain (SUCRA: 86.2%). BBT may be the optimal solution for fibrosis (SUCRA: 76.9%) and hyperpigmentation (SUCRA: 66.7%). 3DCRT has lower incidence of telangiectasia (SUCRA: 56.7%) and better cosmetic result (SUCRA: 85%). Postoperative PBI treatment using ISBT after breast-conserving surgery in patients with early-stage breast cancer may be a more valuable choice based on the treatment efficacy and is associated with fewer late side-effects. Large-scale, prospective, long-term studies are warranted to clarify the role of different PBI techniques in selected patients.

Recurrence pattern of glioblastoma treated with intensity-modulated radiation therapy versus three-dimensional conformal radiation therapy.

To evaluate recurrence patterns of and survival outcomes in glioblastoma treated with intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3D-CRT). We retrospectively examined 91 patients with glioblastoma treated with either IMRT (n = 60) or 3D-CRT (n = 31) between January 2013 and December 2019. Magnetic resonance imaging showing tumor recurrence and planning computed tomography scans were fused for analyzing recurrence patterns categorized as in-field, marginal, and out-of-field based on their relation to the initial radiation field. The median overall survival (OS) was 18.9 months, with no significant difference between the groups. The median progression-free survival (PFS) was 9.4 months, with no significant difference between the groups. Patients who underwent gross total resection (GTR) had higher OS and PFS than those who underwent less extensive surgery. Among 78 relapse cases, 67 were of in-field; 5, marginal; and 19, out-of-field recurrence. Among 3D-CRT-treated cases, 24 were of in-field; 1, marginal; and 9, out-of-field recurrence. Among IMRT-treated cases, 43 were of in-field; 4, marginal; and 10, out-of-field recurrence. In partial tumor removal or biopsy cases, out-of-field recurrence was less frequent in the IMRT (16.2%) than in the 3D-CRT (36.3%) group, with marginal significance (p = 0.079). IMRT and 3D-CRT effectively managed glioblastoma with no significant differences in OS and PFS. The survival benefit with GTR underscored the importance of maximal surgical resection. The reduced rate of out-of-field recurrence in IMRT-treated patients with partial resection highlights its potential utility in cases with unfeasible complete tumor removal.

Executive Summary of the American Radium Society Appropriate Use Criteria for NSCLC in a Central/Ultracentral Location: Systematic Review and Guidelines

IntroductionDefinitive radiation therapy is considered standard therapy for medically inoperable early-stage NSCLC. Nevertheless, for patients with tumors located near structures such as the proximal tracheobronchial tree, esophagus, heart, spinal cord, and brachial plexus, the optimal management regimen is controversial. The objective was to develop expert multidisciplinary consensus guidelines on managing medically inoperable NSCLC located in a central or ultracentral location relative to critical organs at risk. MethodsCase variants regarding centrally and ultracentrally located lung tumors were developed by the 15-member multidisciplinary American Radium Society (ARS) Thoracic Appropriate Use Criteria (AUC) expert panel. A comprehensive review of the English medical literature was performed from January 1 1946 to December 31 2023 to inform consensus guidelines. Modified Delphi methods were used by the panel to evaluate the variants and procedures, with at least three rating points from median defining agreement/consensus. The guideline was then approved by the ARS Executive Committee and released for public comment per established ARS procedures. ResultsThe Thoracic ARS AUC Panel identified 90 relevant references and obtained consensus in all variants. Radiotherapy alone was considered appropriate, with additional immunotherapy to be considered primarily in the clinical trial setting. Hypofractionated radiotherapy in eight to 18 fractions was considered appropriate for ultracentral lesions near the proximal tracheobronchial tree, upper trachea, and esophagus. For other ultracentral lesions near the heart, great vessels, brachial plexus, and spine, or for non-ultracentral but still central lesions, five-fraction stereotactic body radiation therapy was also considered an appropriate option. Intensity-modulated radiotherapy was considered appropriate and three-dimensional–conformal radiotherapy inappropriate for all variants. Other treatment planning techniques to decrease the risk of overdosing critical organs at risk were also considered. ConclusionsThe ARS Thoracic AUC panel has developed multidisciplinary consensus guidelines for various presentations of stage I NSCLC in a central or ultracentral location.

Evaluation and Comparison of the Dose Received by the Mandible, Maxilla, and Teeth in Two Methods of Three-dimensional Conformal Radiation Therapy and Helical Tomotherapy.

Using three-dimensional conformal radiation treatment (3D-CRT) and helical tomotherapy (HT), this study examines and contrasts the dosage received by the mandible, maxilla, and teeth. Sixteen patients with head-and-neck cancer (H and NC) were the subject of treatment planning at the Seyyed Al-Shohada Hospital in Isfahan, Iran. This study examined target coverage quality, exposure of healthy tissue, and radiation delivery effectiveness. In terms of a number of measures, including D2%, D50%, Dmean, V95%, conformity index (CI), and homogeneity index (HI) for the planning target volume (PTV) and D2%, D98%, Dmean, V95%, CI, and HI for the nodal PTV, HT showed considerable gains over 3D-CRT. The brainstem, D1cc, and D10cc received considerably lower maximum dosages in HT. Measurements of the right and left cochleas (Dmean, V55, and Dmax) revealed decreases in HT, with Dmean revealing the most significant variations. The Dmean and Dmax values for HT significantly decreased in constrictors as well. In terms of several HT-related indicators, the larynx, optic chiasm, optic nerves, oral cavity, mandible, thyroid, and parotid glands all showed considerable decreases. The findings of the comparison of the two treatment approaches revealed that the HT method was more than 50% more effective than the 3D-CRT method in sustaining organs at risk (OARs) and the target volume dose. In general, dosimetric coverage, homogeneity, conformity indices, and the absence of cold and hot patches showed that HT produced targets with greater accuracy than 3D-CRT. In addition, HT outperformed 3D-CRT in protecting important structures (OARs). HT as a result has the potential to be a more effective method of treatment for those with H and NC and involvement of regional lymph nodes.

Dosimetric Comparison of Synchronous Bilateral Breast Cancer Treatments: Volumetric Modulated Arc Therapy vs. Three-Dimensional Conformal Radiotherapy

Dosimetric Comparison of Synchronous Bilateral Breast Cancer Treatments: Volumetric Modulated Arc Therapy vs. Three-Dimensional Conformal Radiotherapy

Three-Dimensional Conformal Radiotherapy Versus Image-Guided Intensity Modulated External Beam Radiotherapy in Locally Advanced Cervical Cancer: A Phase III Randomized Control Study

AimsThe standard treatment of locally advanced cervical carcinoma is radical chemoradiation followed by brachytherapy which has improved survival. Hence, a major concern is our attempt to reduce the incidence of acute and late toxicities. IMRT has been shown to reduce toxicities. In this study, we have compared 3DCRT with IG-IMRT using patient-specific margins to evaluate tumor control as well as OAR-related toxicities. Materials and MethodsThis was a single institution prospective phase III randomised control study including patients of squamous cell carcinoma of cervix (stage II–IIIB, FIGO 2009) without pelvic lymph node involvement. All patients were simulated using intermediate bladder filling protocol and those in the IG-IMRT arm, underwent additional scans with full and empty bladder to assess the range of internal motion and generate individualised ITV margin. EBRT dose of 46Gy/23#/4.5 weeks was delivered with weekly concurrent cisplatin followed by brachytherapy. All toxicities during EBRT and till 3 months post brachytherapy were considered acute toxicity. Post-treatment, patients were followed up every 2 months for first 2 years and then once every 6 months. Disease-related outcomes were assessed with clinical examination and symptom-directed imaging. ResultsTwo hundred patients were screened for inclusion and of them, 89 patients in 3DCRT and 84 patients in IG-IMRT arms were considered for final analysis. The baseline characteristics were comparable in both arms, majority of patients in both arms having stage II disease. For OARs, all dosimetric parameters were significantly better in the IG-IMRT arm. Acute radiation induced toxicities (dermatitis, genito-urinary and gastrointestinal toxicities) were significantly less in the IG-IMRT arm. The local, pelvic, and distant control were comparable in both arms. ConclusionBased on our experience, the use of IG-IMRT with patient-specific ITV margins results in reduction in acute OAR toxicities in patients without compromising on tumor control.

Adaptive radiotherapy (up to 74 Gy) or standard radiotherapy (66 Gy) for patients with stage III non-small-cell lung cancer, according to [18F]FDG-PET tumour residual uptake at 42 Gy (RTEP7–IFCT-1402): a multicentre, randomised, controlled phase 2 trial

Thoracic radiation intensification is debated in patients with stage III non-small-cell lung cancer (NSCLC). We aimed to assess the activity and safety of a boost radiotherapy dose up to 74 Gy in a functional sub-volume given according to on-treatment [18F]fluorodeoxyglucose ([18F]FDG)-PET results. In this multicentre, randomised, controlled non-comparative phase 2 trial, we recruited patients aged 18 years or older with inoperable stage III NSCLC without EGFR mutation or ALK rearrangement with an Eastern Cooperative Oncology Group performance status of 0-1, and who were affiliated with or a beneficiary of a social benefit system, with evaluable tumour or node lesions, preserved lung function, and who were amenable to curative-intent radiochemotherapy. Patients were randomly allocated using a central interactive web-response system in a non-masked method (1:1; minimisation method used [random factor of 0·8]; stratified by radiotherapy technique [intensity-modulated radiotherapy vs three-dimensional conformal radiotherapy] and by centre at which patients were treated) either to the experimental adaptive radiotherapy group A, in which only patients with positive residual metabolism on [18F]FDG-PET at 42 Gy received a boost radiotherapy (up to 74 Gy in 33 fractions), with all other patients receiving standard radiotherapy dosing (66 Gy in 33 fractions over 6·5 weeks), or to the standard radiotherapy group B (66 Gy in 33 fractions) over 6·5 weeks. All patients received two cycles of induction platinum-based chemotherapy cycles (paclitaxel 175 mg/m2 intravenously once every 3 weeks and carboplatin area under the curve [AUC]=6 once every 3 weeks, or cisplatin 80 mg/m2 intravenously once every 3 weeks and vinorelbine 30 mg/m2 intravenously on day 1 and 60 mg/m2 orally [or 30 mg/m2 intravenously] on day 8 once every 3 weeks). Then they concomitantly received radiochemotherapy with platinum-based chemotherapy (three cycles for 8 weeks, with once per week paclitaxel 40 mg/m2 intravenously and carboplatin AUC=2 or cisplatin 80 mg/m2 intravenously and vinorelbine 20 mg/m2 intravenously on day 1 and 40 mg/m2 orally (or 20 mg/m2 intravenously) on day 8 in 21-day cycles). The primary endpoint was the 15-month local control rate in the eligible patients who received at least one dose of concomitant radiochemotherapy. This RTEP7-IFCT-1402 trial is registered with ClinicalTrials.gov (NCT02473133), and is ongoing. From Nov 12, 2015, to July 7, 2021, we randomly assigned 158 patients (47 [30%] women and 111 [70%] men) to either the boosted radiotherapy group A (81 [51%]) or to the standard radiotherapy group B (77 [49%)]. In group A, 80 (99%) patients received induction chemotherapy and 68 (84%) received radiochemotherapy, of whom 48 (71%) with residual uptake on [18F]FDG-PET after 42 Gy received a radiotherapy boost. In group B, all 77 patients received induction chemotherapy and 73 (95%) received radiochemotherapy. At the final analysis, the median follow-up for eligible patients who received radiochemotherapy (n=140) was 45·1 months (95% CI 39·3-48·3). The 15-month local control rate was 77·6% (95% CI 67·6-87·6%) in group A and 71·2% (95% CI 60·8-81·6%) in group B. Acute (within 90 days from radiochemotherapy initiation) grade 3-4 adverse events were observed in 20 (29%) of 68 patients in group A and 33 (45%) of 73 patients in group B, including serious adverse events in five (7%) patients in group A and ten (14%) patients in group B. The most common grade 3-4 adverse events were febrile neutropenia (seven [10%] of 68 in group A vs 16 [22%] of 73 in group B), and anaemia (five [7%] vs nine [12%]). In the acute phase, two deaths (3%) occurred in group B (one due to a septic shock related to chemotherapy, and the other due to haemotypsia not related to study treatment), and no deaths occurred in group A. After 90 days, one additional treatment-unrelated death occurred in group A and two deaths events occurred in group B (one radiation pneumonitis and one pneumonia unrelated to treatment). A thoracic radiotherapy boost, based on interim [18F]FDG-PET, led to a meaningful local control rate with no difference in adverse events between the two groups in organs at risk, in contrast with previous attempts at thoracic radiation intensification, warranting a randomised phase 3 evaluation of such [18F]FDG-PET-guided radiotherapy dose adaptation in patients with stage III NSCLC. Programme Hospitalier de Recherche Clinique National 2014.

Experiences with Volumetric Modulated Arc Therapy (VMAT) for treating symptomatic peripheral joint osteoarthritis (OA) with Low Dose Radiotherapy (LDRT) – a case series

Introduction: Peripheral joint osteoarthritis (OA) in Australia is the third leading cause of life-years lost. Implant surgery is a great help, but patients who are waiting or are inoperable suffer. Low Dose Radiotherapy (LDRT) is well established in some countries. Three-dimensional conformal radiotherapy (3DCRT) is recommended. However, some departments may only have Volumetric Modulated Arc Therapy (VMAT). We present our experiences treating ten volumes of symptomatic OA treated with VMAT in nine consecutive patients to two months post-LDRT. Methods: The hypothesis was that LDRT using VMAT was feasible and effective at two months. Patient response data was collected prospectively. The Visual Analog Scale Pain (VASP) for pain was used. A Visual Analog Scale Mobility (VASM) was created for mobility. Bones within radiation oncologists (RO) skin marks around the joint were auto-contoured for clinical target volume (CTV) with 2 mm expansion to planning target volume (PTV). Treatment was titrated to clinical response. Phase 1 was 3 Gray (Gy) in 6 fractions at 2-3 fractions per week. There was RO review at 2 months post-phase 1 for consideration of phase 2. If no response, then phase 2 was 6 Gy in 6 fractions, if a partial response (PR), then a repeat of phase 1. A third phase similar to phase 2 was possible. RO follow-up was done 2 months after the last phase. Results: Nine consecutive patients, eight males and one female, average age of 69 years (60-84), with ten volumes of symptomatic OA were treated. Joints were three single knees, two cases of both knees, three cases of both hands, one hip and one carpometacarpal joint. They had suffered from OA for an average of eight years (1-20). All were on at least one systemic therapy. All were using some sort of local therapy or device. Eight had a PR to phase 1 and proceeded to phase 2. Two had an equivocal response. No patient had a third phase. Average VASP pain scores fell from baseline of 7.4 to 3.6 after phase 1, and to 2.3 after phase 2. Average VASM immobility scores fell from baseline of 6.9 to 4.4 after phase 1 and to 3.3 after phase 2. Conclusion: In this small Australian cohort LDRT using VMAT is feasible and clinically effective when measured at 2 months. More study is needed.

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.