Accelerated Radiation Therapy Research Articles

Patient Selection and Outcomes for Hypofractionated Accelerated Radiation and Concurrent Chemotherapy for Non–Small-Cell Lung Cancer

Purpose/ObjectivesAdoption of hypofractionated accelerated radiation therapy (HART) with concurrent chemotherapy has been limited by toxicity concerns. We aimed to describe outcomes of patients treated with HART and concurrent chemotherapy and to evaluate dosimetry to organs at risk to guide patient selection. Materials/MethodsWe evaluated a retrospective cohort of NSCLC patients treated with concurrent chemotherapy with HART (>2.2 Gy per fraction) or standard fractionated radiation therapy (SFRT; 2-2.2 Gy fractions). Dosimetric parameters to key organs at risk were compared, and toxicity, patterns of recurrence and survival were calculated for the cohorts. ResultsFifty-three patients treated with HART were compared with 100 patients treated with SFRT. Median dose per fraction for the HART cohort was 2.75 Gy (range 2.4-3 Gy). HART patients had significantly lower doses to the lung, heart, and esophagus due to patient selection. The HART group and had rates of grade 2+ pneumonitis (9.4 vs. 19%, P = .16) and grade 2+ esophagitis (20.8 vs. 45%, P < .01) that compared favorably to SFRT. Cumulative incidence of in-field recurrence trended lower in the HART cohort (7.6% vs. 23.1%, P = .058). Among the HART group, 88.7% (47/53) met the newly proposed lung constraints based on the degree of hypofractionation ConclusionIn select patients with favorable dosimetry to organs at risk, definitive HART with concurrent chemotherapy achieved excellent local control with low toxicity. These results are being used to inform a prospective study on the safety and efficacy of HART with concurrent chemotherapy for select NSCLC patients.

Randomized Controlled Trial of Hypofractionated vs. Normo-fractionated Accelerated Radiation Therapy with or without Cisplatin for Locally Advanced Head and Neck Squamous Cell Carcinoma (HYPNO)

Randomized Controlled Trial of Hypofractionated vs. Normo-fractionated Accelerated Radiation Therapy with or without Cisplatin for Locally Advanced Head and Neck Squamous Cell Carcinoma (HYPNO)

Study of Light Nuclei Activation in Human Blood During High-Energy Linear Accelerator (Linac) Radiation Therapy

Study of Light Nuclei Activation in Human Blood During High-Energy Linear Accelerator (Linac) Radiation Therapy

Long-Term Follow-up of a Randomized Controlled Trial on Accelerated Radiation Therapy Versus Standard Fractionated Radiation Therapy for Early Glottic Cancer (JCOG0701A3)

We previously reported the primary results of JCOG0701, a randomized, multicenter, phase III, non-inferiority trial comparing accelerated fractionation (Ax) to standard fractionation (SF) for early glottic cancer (GC). In the primary results, although the similar efficacy of 3-year PFS and toxicity of Ax compared with SF was observed, the non-inferiority of Ax was not confirmed statistically. To evaluate the long-term follow-up results of JCOG0701, we conducted JCOG0701A3 as an ancillary study of JCOG0701. In JCOG0701, 370 patients were randomly assigned to receive SF of 66-70 Gy (33-35 fractions) (n=184) or Ax of 60-64.8 Gy (25-27 fractions) (n=186). The data cutoff date for this analysis was in June 2020. Overall survival, progression-free survival, and late adverse events including central nervous system ischemia (CNSI) were analyzed. With median follow-up period of 7.1 years (range: 0.1-12.4), PFS of the SF and Ax arms were 76.2% and 78.2% at 5 years and 72.7% and 74.8% at 7 years (p=0.44). OS of SF and Ax arms were 92.7% and 89.6% at 5 years and 90.8% and 86.5% at 7 years (p=0.92). Among 366 patients with a protocol treatment, the cumulative incidence of late adverse events of SF and Ax arms were 11.9% and 7.4% at 8 years (HR: 0.53, 95% CI: 0.28-1.01, p=0.06). CNSI of Grade 2 or higher was observed in 4.1% for SF arms and 1.1% for Ax arm (p=0.098). After a long-term follow-up Ax showed comparable efficacy to SF and a tendency for better safety. Ax may be suitable for early GC because of its convenience in minimizing treatment time, cost, and labor.

Improving animal-specific radiotherapy quality assurance for kilovoltage X-ray radiotherapy using a 3D printed dog skull water phantom.

Accurate dose assessment during animal radiotherapy is beneficial for veterinary medicine and medical education. To visualize the radiation treatment distribution of orthovoltage X-ray equipment in clinical practice using Monte Carlo simulations and create a dog skull water phantom for animal-specific radiotherapy. EGSnrc-based BEAMnrc and DOSXYZnrc codes were used to simulate orthovoltage dose distributions. At 10, 20, 30, 40, 50, and 80 mm in a water phantom, the depth dose was measured with waterproof Farmer dosimetry chambers, and the diagonal off-axis ratio was measured with Gafchromic EBT3 film to simulate orthovoltage dose distributions. Energy differences between orthovoltage and linear accelerated radiotherapy were assessed with a heterogeneous bone and tissue virtual phantom. The animal-specific phantom for radiotherapy quality assurance (QA) was created from CT scans of a dog and printed with a three-dimensional printer using polyamide 12 nylon, with insertion points for dosimetry chambers and Gafchromic EBT3 film. Monte Carlo simulated and measured dose distributions differed by no more than 2.0% along the central axis up to a depth of 80 mm. The anode heel effect occurred in shallow areas. The orthovoltage radiotherapy percentage depth dose in bone was >40%. Build-up was >40%, with build-down after bone exit, whereas linear accelerator radiotherapy absorption changed little in the bone. A highly water-impermeable, animal-specific dog skull water phantom could be created to evaluate dose distribution. Animal-specific water phantoms and Monte Carlo simulated pre-treatment radiotherapy are useful QA for orthovoltage radiotherapy and yield a visually familiar phantom that will be useful for veterinary medical education.

TOXICITY AND TREATMENT OUTCOME OF ACCELERATED FRACTIONATION RADIOTHERAPY VERSUS CONVENTIONAL FRACTIONATED CONCOMITANT CHEMORADIATION IN LOCALLY ADVANCED CERVICAL CARCINOMA: A PROSPECTIVE STUDY

Objectives: The benefit of concurrent chemoradiation is often not achievable due to poor tolerance due to increased toxicity, which is a common problem in our setting, where a significant portion of carcinoma cervix patients presents at an elderly age, with medical comorbidities, and with poor performance status. In addition, many patients refuse chemotherapy. Accelerated radiation therapy remains one of the possible alternatives there. Hence, we would like to perform a prospective study to compare treatment results between Pure Accelerated Radiation versus Concomitant Chemoradiation in Locally Advanced Squamous Cell Carcinoma of Cervix. Methods: After the initial investigative work, a total of 62 histologically confirmed squamous cell carcinoma of cervix locally advanced stage (FIGO-stage IB2 to IVA.) with ECOG performance status 0–2 patients were randomized into two arms: Arm A (Study arm, n=30) – Patients received Six fractions per week of External Beam Radiotherapy without chemotherapy and Arm B (Control arm, n=32) patients received concurrent chemoradiation with Five fractions per week of radiation with Weekly Injection of Cisplatin at the dose of 40 mg/m2. Results: Overall response rates between the two arms were similar and statistically not significant (p=0.352). All acute late toxicities are similar in both arms except acute renal toxicity which is more in the control arm and the difference is statistically significant (p=0.005). Conclusions: In developing countries like India with limited treatment facilities, pure accelerated RT with brachytherapy, without concurrent chemotherapy, may be a good option and it can be viewed as an equally effective option for the elderly patients, the patients who refuse, those who have contraindications for chemotherapy, or have comorbidities. Further, multicenter, controlled, and Phase III trials will be needed to prove the benefit of the shortening overall treatment time and compare the efficacy with chemoradiation.

Locally advanced NSCLC: a plea for sparing the ipsilateral normal lung—prospective, clinical trial with DART-bid (dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily) by VMAT

BackgroundIn radiation treatment of locally advanced non-small cell lung cancer (LA-NSCLC), ‘margins’ from internal target volumes to planning target volumes in the range of 12 to 23 mm are reported, and avoiding exposure of the contralateral lung is common practice. We investigated prospectively an approach with tight margins (7 mm) and maximal sparing of the ipsilateral normal lung. Mature results for the first endpoint (pneumonitis) and further toxicities are reported.MethodsPrimary tumors were treated by VMAT with 73.8–90.0 Gy in positive correlation to tumor volumes, nodes with 61.2 Gy, a restricted volume of nodes electively with 45 Gy. Fractional doses of 1.8 Gy bid, interval 8 h. Before radiotherapy, two cycles platin-based chemotherapy were given. 12 patients finished maintenance therapy with Durvalumab. Median follow up time for all patients is 19.4 months, for patients alive 27.0 months (3.4–66.5 months).Results100 consecutive, unselected patients with LA-NSCLC in stages II through IVA were enrolled (UICC/AJCC, 8th edition). No acute grade 4/5 toxicity occurred. Pneumonitis grade 2 and 3 was observed in 12% and 2% of patients, respectively; lowering the risk of pneumonitis grade ≥ 2 in comparison to the largest study in the literature investigating pneumonitis in LA-NSCLC, is significant (p < 0.0006). Acute esophageal toxicity grade 1, 2 and 3 occurred in 12%, 57% and 3% of patients, respectively. Two patients showed late bronchial stricture/atelectasis grade 2. In two patients with lethal pulmonary haemorrhages a treatment correlation cannot be excluded. Median overall survival for all stage III patients, and for those with ‘RTOG 0617 inclusion criteria’ is 46.6 and 50.0 months, respectively.ConclusionsOverall toxicity is low. In comparison to results in the literature, maximal sparing the ipsilateral normal lung lowers the risk for pneumonitis significantly.Trial registrationEthics committee of Vorarlberg, Austria; EK-0.04-105, Registered 04/09/2017—Retrospectively registered. http://www.ethikkommission-vorarlberg.at

Pelvic U-Net: multi-label semantic segmentation of pelvic organs at risk for radiation therapy anal cancer patients using a deeply supervised shuffle attention convolutional neural network

BackgroundDelineation of organs at risk (OAR) for anal cancer radiation therapy treatment planning is a manual and time-consuming process. Deep learning-based methods can accelerate and partially automate this task. The aim of this study was to develop and evaluate a deep learning model for automated and improved segmentations of OAR in the pelvic region.MethodsA 3D, deeply supervised U-Net architecture with shuffle attention, referred to as Pelvic U-Net, was trained on 143 computed tomography (CT) volumes, to segment OAR in the pelvic region, such as total bone marrow, rectum, bladder, and bowel structures. Model predictions were evaluated on an independent test dataset (n = 15) using the Dice similarity coefficient (DSC), the 95th percentile of the Hausdorff distance (HD95), and the mean surface distance (MSD). In addition, three experienced radiation oncologists rated model predictions on a scale between 1–4 (excellent, good, acceptable, not acceptable). Model performance was also evaluated with respect to segmentation time, by comparing complete manual delineation time against model prediction time without and with manual correction of the predictions. Furthermore, dosimetric implications to treatment plans were evaluated using different dose-volume histogram (DVH) indices.ResultsWithout any manual corrections, mean DSC values of 97%, 87% and 94% were found for total bone marrow, rectum, and bladder. Mean DSC values for bowel cavity, all bowel, small bowel, and large bowel were 95%, 91%, 87% and 81%, respectively. Total bone marrow, bladder, and bowel cavity segmentations derived from our model were rated excellent (89%, 93%, 42%), good (9%, 5%, 42%), or acceptable (2%, 2%, 16%) on average. For almost all the evaluated DVH indices, no significant difference between model predictions and manual delineations was found. Delineation time per patient could be reduced from 40 to 12 min, including manual corrections of model predictions, and to 4 min without corrections.ConclusionsOur Pelvic U-Net led to credible and clinically applicable OAR segmentations and showed improved performance compared to previous studies. Even though manual adjustments were needed for some predicted structures, segmentation time could be reduced by 70% on average. This allows for an accelerated radiation therapy treatment planning workflow for anal cancer patients.

A "SHort course Accelerated RadiatiON therapy" (SHARON) During and Beyond the COVID-19 Pandemic.

A "SHort course Accelerated RadiatiON therapy" (SHARON) During and Beyond the COVID-19 Pandemic.

PO-0975 ICT Plus Simultaneous Modulated Accelerated Radiation Therapy in Non-operative SCCH/L

PO-0975 ICT Plus Simultaneous Modulated Accelerated Radiation Therapy in Non-operative SCCH/L

Blocking the GITR-GITRL pathway to overcome resistance to therapy in sarcomatoid malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma.

Clinical Outcomes in Patients With NFPAs Treated With Stereotactic Linear Accelerator Radiation Therapy

Abstract Background: Non-functioning pituitary adenoma (NFPAs) are benign tumors of the pituitary gland characterized by the absence of hormonal hypersecretion. Surgical treatment and fractionated stereotactic radiotherapy (FSRT) are necessary in majority of patients. NFPAs appear to cause higher mortality compared to the general population. Objective: To assess outcomes in patients with NFPAs treated with stereotactic linear accelerator radiation therapy. Material and Methods: Comparative, observational, longitudinal study, with prolective evaluation, from January 1987 to August 2019. Results: 264 patients (65.5% women and 34.5% men, mean age 43 ± 16 years) with a diagnosis of non-functional adenomas were evaluated. 30 patients received FSRT (14%), 93% were macroadenomas, and 80% of the cases were operated as a first line of treatment. The mean number of surgeries before radiotherapy was 1.2+-.847 (0-4). FSRT were used in 91.7% (n=21) because of post-surgical recurrence. Diabetes insipidus after surgery was transitory in 5.4%, and persistent in 4.0%. Hypopituitarism was identified in 59.4% before radiation (n=19), and in 13 patients (7.7%) after mean of 6.5+-5.5 years of FSRT. Dyslipidemia (62.0% vs. 45.9%), high blood pressure (16.5% vs. 23%), type 2 diabetes mellitus (10% vs. 77%) and heart failure (10% vs. 8.4%) were observed in the irradiated vs. non-irradiated groups, respectively (p&amp;lt;0.05). Conclusions: FSRT is a useful and safe strategy as an adjuvant treatment in patients with NFPA.

Induction Chemotherapy Plus Simultaneous Modulated Accelerated Radiation Therapy in Non-operative Hypopharyngeal and Supraglottic Laryngeal Squamous Cell Carcinoma: Long-Term Outcome of a Prospective Phase 2 Study.

Background: To evaluate the toxicities and long-term outcomes of induction chemotherapy (ICT) plus simultaneous modulated accelerated radiation therapy (SMART) in non-operative hypopharyngeal and supraglottic laryngeal squamous cell carcinoma (SCCH/L).Materials and Methods: This was a prospective phase 2 study. Patients diagnosed with SCCH/L, aged from 18 to 75, staged from III to IVB in accordance with the AJCC 2010 criteria, and refusing surgery were eligible. The patients were treated with 2–3 cycles of docetaxel-cisplatin-based ICT and SMART combined with 2–3 cycles of cisplatin-based concurrent chemotherapy. The prescription dose to the primary tumor and metastatic nodes was 69 Gy in 30 fractions. Acute and late toxicities were assessed according to the established Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria, and long-term outcomes were analyzed.Results: Between February 2013 and June 2015, 55 newly diagnosed SCCH/L patients were enrolled. No grade 2 or worse acute xerostomia was noted. The incidences of grade 3 acute dermatitis, oral mucositis, and pharyngoesophagitis were 12.7, 3.6, and 12.7%, respectively. The median follow-up time was 48 months (range 5.5–74 months). The main late toxicity was hoarseness or sore throat, with an incidence of 32.7%. The 5-year functional larynx-preservation survival was 51.5%. The 3- and 5-year locoregional control and overall survival were 58.2, 51.5, 63.6, and 54.1%, respectively.Conclusions: The ICT plus SMART with a regimen of 69 Gy/30 F for the treatment of SCCH/L demonstrated acceptable severe toxicity, satisfactory long-term outcomes, and laryngeal function preservation.

Efficacy of Function-Adapted Simultaneous Modulated Accelerated Radiation Therapy (FA-SMART) with Concurrent Chemotherapy in Patients with Locally Advanced Non–Small-Cell Lung Cancer: A Phase 2 Prospective Clinical Trial

To determine whether the function-adapted simultaneous modulated accelerated radiation therapy (FA-SMART) technique and concurrent weekly chemotherapy can improve treatment efficacy in patients with locally advanced non-small-cell lung cancer (NSCLC). In this single-arm phase 2 study (clinicaltrials.gov Identifier: NCT02573506), we enrolled patients with unresectable stage III NSCLC and an Eastern Cooperative Oncology Group performance status score of 0-1. Split-course thoracic radiotherapy was delivered using FA-SMART technique. Pulmonary function test (PFT) including the percentage-predicted forced expiratory volume in 1 second / forced vital capacity (FEV1/FVC %) and single-breath carbon monoxide diffusing capacity (DLCO %) was performed at baseline and after the interval. Patients were irradiated at 51Gy in 17 daily fractions in the first course. After the interval, patients who had non-progressive disease and an adequate pulmonary function (FEV1/FVC % ≥ 40% and DLCO % ≥ 45%) underwent adaptive re-planning, and were irradiated at 15∼18Gy in 5∼6 daily fractions as a boost. Concurrent chemotherapy consisted of weekly docetaxel and nedaplatin. The primary endpoint was progression-free survival (PFS). The Kaplan-Meier method and log-rank tests were performed for survival analysis. Adverse events were graded according to the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE 4.0). A total of 89 patients were enrolled and analyzed. Eighty-three patients (93.3%) completed two courses of RT at a total dose of 66∼69Gy. The median follow-up was 26 months (range, 12∼51 months) on living patients. Median PFS was 12.0 months (95% CI, 7.8∼16.2 months) and the PFS rates were 47.8% (95% CI, 37.2∼58.4%) at 1 year and 35.0% (95% CI, 24.0∼46.0%) at 3 years. Median OS was 27.0 months (95% CI, 14.3∼39.7 months) and the OS rates were 74.2% (95% CI, 65.2∼83.2%) at 1 year and 43.1% (95% CI, 30.6∼55.6%) at 3 years. Grade ≥3 acute esophagitis was observed in 15(16.9%) patients. Grade ≥3 acute and late pneumonitis was observed in 7(7.9%) and 3(3.3%) patients respectively. DLCO was significantly reduced after the first course of RT (6.62 vs 5.79 mmol/min/kPa, p = 0.016). Patients with better interval DLCO % had significantly better OS (DLCO % ≥80% vs 60-79% vs 45-59% vs <45%, 2-year OS was 72.4% vs 45.3% vs 42.1% vs 0, p = 0.008). Interval DLCO % also correlated significantly with the incidence of grade 3 acute pneumonitis (p = 0.005). The split-course FASMART with concurrent chemotherapy has apparently improved survival with no loss in palliation or increased morbidity in patients with LANSCLC. PFT, DLCO in particular, is a necessary indicator for evaluation of irradiation boost after interval. Patients with favorable lung function after treatment interval would benefit more from intensive CCRT regimen, which should be taken into account for future study design.

Advanced head and neck cancer in older adults: Results of a short course accelerated radiotherapy trial

ObjectivesTo assess the feasibility and safety of a repeated SHort course Accelerated RadiatiON therapy (SHARON) regimen in the palliative setting of Head and Neck (H&N) cancer in older adults. Material and MethodsPatients with histological confirmed H&N cancers, age ≥ 80 years, expected survival >3 months, and Eastern Cooperative Oncology Group (ECOG) performance status of ≤3 were enrolled. Patients were treated in cohorts of six patients: a total dose of 20 Gy was delivered in 2 consecutive days with a twice-daily fractionation (5 Gy per fraction) and at least 8-h interval. If no Grade 3 toxicity was registered, a second enrollment started with another cohort of six patients to whom were administered two cycles (total dose of 40 Gy). The primary endpoint was to evaluate the feasibility of the two cycles of treatment. Secondary endpoints were evaluation of symptoms control rate, symptoms-free survival (SFS), and Quality of Life (QoL) scores. ResultsSeventeen consecutive patients (median age: 85 years) were treated. Nine patients were treated with one cycle and 8 patients with two cycles. No G3 toxicity was reported in either cohort. With a median follow-up time of 4 months, 3-month SFS in the first and second cohorts was 83.3%, and 87.5%, respectively. The overall palliative response rate was 88%. Among 13 patients reporting pain, 8 (61.5%) showed an improvement or resolution of their pain. ConclusionRepeated short course accelerated radiotherapy in a palliative setting of H&N cancers is safe and well-tolerated in older adults.

Neo-adjuvant chemotherapy followed by either continuous hyper-fractionated accelerated radiation therapy week-end less or conventional chemo-radiotherapy in locally advanced NSCLC-A randomised prospective single institute study.

Better locoregional control and increased overall survival by continuous hyper fractionated accelerated radiotherapy have been shown in unresectable nonsmall cell lung carcinoma (NSCLC). Dose escalation and neoadjuvant chemotherapy (NACT) along with continuous hyperfractionated accelerated radiotherapy week end-less (CHARTWEL) were also tried for improved survival. In this present study, we compared the results of NACT followed by CHARTWEL against NACT followed by conventional concurrent chemo-radiation therapy. The aim of this study is to compare the locoregional control and toxicities in NSCLC Stage IIIA and B in both arms. Randomized, prospective single-institutional study with a study population comprising all locally advanced unresectable NSCLC patients enrolled in 2014 at our institute. All enrolled patients were randomized into two arms-CHARTWEL and concomitant chemo-radiotherapy (CCRT), after three weeks of the fourth cycle of NACT. In CHARTWEL arm 30 patients received two-dimensional radiotherapy (RT) 58.5 Gy/39 fr/2.5 weeks while in CCRT arm 30 received 66 Gy/33 fr/6.5 weeks. Disease response was evaluated at 6 months and toxicity assessment during and after treatment completion. Data were analyzed using tools such as percentage, mean, Chi-square test and P value. Chi-square and P value was calculated by statistical online software (http://quantpsy.org). 28% of patients in study arm and 20% in control arm had complete response at 6 months after RT. Locoregional disease control was observed in 44% in study arm and 32% in control arm of patients. There was no statistical difference in grades of toxicities or overall survival (OS)/disease-free survival except persistent esophagitis Grade III seen in two patients of study arm. Study suggests that CHARTWEL in combination with NACT is an effective strategy to treat patients with locally advanced lung cancer with the advantage of a smaller dose and shorter duration. Although large multivariate studies still needed.

MRI Connecting Functions and Anatomy: A New Bridge for Radiotherapy

Advances in medical devices have allowed the use of CT, MRI, and PET-CT for the diagnosis of tumors and the detailed evaluation of the extent of lesions. For several decades, CT has been established as the gold standard modality for the treatment planning of radiotherapy, while MRI has emerged as a tool to evaluate the functional characteristics of tumors without radiation exposure. To further optimize precision radiation therapy, we should consider how functional images can be used in the workflow for radiation therapy. In this regard, MRI, as a modality without the need for a contrast agent, may allow more frequent scans and more detailed dose painting, such as increasing the dose to viable lesion parts while reducing the dose to less aggressive parts. Thus, a more personalized treatment based on precision radiation medicine might be realized. In recent years, MR-Linac systems (MRI integrated linear accelerator radiation therapy systems) have been applied in clinical settings by fusing MRI with Linac planning, and further development of radiation therapy utilizing MRI-derived functional images is expected. The use of MR-Linac techniques allows the characteristics of the tumor to be evaluated in more detail before treatment, and the treatment planning can be modified according to the position and characteristics of the tumor (which may change daily during irradiation) to avoid harming normal tissue. Compared with conventional cone beam CT, MR-Linac can offer MR images with much better contrast of soft tissue for image-guided radiation therapy, even when acquired at 0.35 T. A multicenter study of liver tumors using MR-Linac was recently reported. In current tumor imaging, various MRI sequences can be used to evaluate tumor functional information such as tumor heterogeneity, cell density, microenvironment, angiogenesis, necrosis, hypoxic status, and microstructure. In this article, we introduce state-of-the-art acquisition methods for MRI imaging, and discuss how the functional information obtained from these imaging methods can be useful for radiation therapy.

Prospective Randomized Study of Accelerated Radiation Therapy (PRART)

Prospective Randomized Study of Accelerated Radiation Therapy (PRART)

Short-Course 2-Dimensional Radiation Therapy in the Palliative Treatment of Esophageal Cancer in a Developing Country: A Phase II Study (Sharon Project)

PurposePatients with locally advanced and metastatic esophageal cancer are usually affected by cancer-related symptoms, which worsen their performance status and quality of life. The aim of this study was to determine the efficacy of short-course accelerated radiation therapy for symptomatic palliation in a low resourced setting where only a 2-dimensional radiation therapy (RT) technique was available. Methods and MaterialsA phase II trial based on Simon’s 2-stage design was planned. A total dose of 12 Gy in 4 fractions, twice per day, over 2 days, ≥8 hours apart, using a 2-dimensional conventional RT technique was delivered with a Cobalt 60 unit (Equinox, Best Theratronics, Ottawa, Ontario). Symptoms were graded using the International Atomic Energy Agency scoring system. ResultsA total of 17 patients were treated (male/female = 10/7; median age, 50.0 years; range, 27-78 years; histology: 6 adenocarcinomas and 11 squamous cell carcinomas; tumor site: 4 gastresophageal junction and 13 esophagus). The most frequent baseline symptoms were dysphagia or regurgitation (100%), odynophagia (76%), and chest or back pain (53%). At 1 month after RT, all patients were alive with palliative response rates (complete plus partial) for dysphagia, regurgitation, odynophagia, and chest or back pain of 76%, 82%, 69%, and 56%, respectively. No patients presented acute ≥G3 toxicity. ConclusionsShort-course accelerated radiation therapy treatment, planned and delivered using a conventional 2-dimensional RT technique, was effective and well tolerated for the symptomatic palliation of locally advanced or metastatic esophageal cancer. This schedule may be useful for RT centers in developing countries to reduce treatment times, costs, and patient waiting times before treatment.

Economic evaluation of linear accelerator radiation therapy for patients with malignant tumors at hospitals in China

Objective To make a cost-effectiveness analysis for stereotactic radiotherapy and intensity-modulated radiotherapy using linear accelerators against malignant tumors, then to provide references for choosing a more cost-effective radiotherapy for the patient. Methods Basic information of patients subject to radiotherapy(gender, age, date of admission, days of hospital stay), hospitalization cost, admission diagnosis, clinical outcomes among others of 320 patients with malignant tumors(lung tumor, head and neck tumor, bone metastases, liver tumor)were collected from Hubei, Guangxi and Fujian provinces.The cost of hospitalized radiotherapy and treatment effect of these patients were compared to identify the more cost effective of the two methods. Results The effective rates of stereotactic radiotherapy and intensity-modulated radiotherapy were 99.1%(108/109) and 97.2%(205/211) respectively, and the difference was not significant(P>0.05). The average hospitalization cost of treatment of the two groups was 37 545.56 yuan and 48 159.05 yuan respectively; the cost-effectiveness ratio was 37 886.54 and 49 546.35 respectively. Conclusions The short-term effects of stereotactic and intensity-modulated radiotherapy are similar, but the cost of intensity-modulated radiotherapy is higher.The minimum cost analysis shows that stereotactic radiotherapy is more cost effective. Key words: Radiotherapy planning, computer-assisted; Stereotactic orientation; Intensity adjustment; Effect; Cost effectiveness