Longitudinal Costs of Image-Guided Intensity-Modulated Radiation Therapy Versus Three-Dimensional Conformal Radiation: Lessons From Phase III PARCER Trial for Shaping Resource-Stratified Guidelines in Low- and Middle-Income Countries.

PURPOSE: The PARCER trial provided level I evidence for image-guided intensity-modulated radiation therapy (IG-IMRT) in patients with cervical cancer. Further information regarding long-term financial impact is imperative for adoption into the National Cancer Grid of India cervical cancer resource-stratified guidelines. METHODS: Patient data from the PARCER trial were analyzed to evaluate the cost implications of transitioning to IG-IMRT. Lacking differences in outcomes between the three-dimensional conformal radiation (3D-CRT) and IG-IMRT, differences in treatment costs, adverse event incidence, and toxicity management costs were examined. The overall financial impact was estimated by adding the treatment costs, toxicity management, and wage loss. This was extrapolated nationally to determine if a transition to IG-IMRT would be feasible for the Indian health care system. RESULTS: Of the 300 patients in the PARCER trial, 93 faced grades ≥2 adverse events (3D-CRT = 59, IG-IMRT = 34). Patients in the 3D-CRT and IG-IMRT arms spent an average of 2.39 years and 1.96 years in toxicity, respectively. The average toxicity management and the yearly financial impact per patient were, respectively, 1.50 and 1.44 times higher for 3D-CRT patients compared with IG-IMRT patients. Extrapolation to the national level showed that treatment with 3D-CRT led to a 2.88 times higher cost ratio when compared with treatment with IG-IMRT. CONCLUSION: Although the initial costs of IG-IMRT are high, on the basis of longitudinal data, it is financially inefficient to treat with 3D-CRT. Resource-stratified guidelines should include longitudinal health intervention costs rather than solely initial costs for policy decisions to implement advanced radiation technology.

Methodology for small animals targeted irradiations at conventional and ultra-high dose rates 65 MeV proton beam.

As part of translational research projects, mice may be irradiated on radiobiology platforms such as the one at the ARRONAX cyclotron. Generally, these platforms do not feature an integrated imaging system. Moreover, in the context of ultra-high dose-rate radiotherapy (FLASH-RT), treatment planning should consider potential changes in the beam characteristics and internal movements in the animal. A patient-like set-up and methodology has been implemented to ensure target coverage during conformal irradiations of the brain, lungs and intestines. In addition, respiratory cycle amplitudes were quantified by fluoroscopic acquisitions on a mouse, to ensure organ coverage and to assess the impact of respiration during FLASH-RT using the 4D digital phantom MOBY. Furthermore, beam incidence direction was studied from mice µCBCT and Monte Carlo simulations. Finally,in vivodosimetry with dose-rate independent radiochromic films (OC-1) and their LET dependency were investigated. The immobilization system ensures that the animal is held in a safe and suitable position. The geometrical evaluation of organ coverage, after the addition of the margins around the organs, was satisfactory. Moreover, no measured differences were found between CONV and FLASH beams enabling a single model of the beamline for all planning studies. Finally, the LET-dependency of the OC-1 film was determined and experimentally verified with phantoms, as well as the feasibility of using these filmsin vivoto validate the targeting. The methodology developed ensures accurate and reproducible preclinical irradiations in CONV and FLASH-RT without in-room image guidance in terms of positioning, dose calculation andin vivodosimetry.

Comprehensive geriatric assessment predicts radiation-induced acute toxicity in prostate cancer patients.

PURPOSE: The purpose of the present prospective study was to evaluate the significance of geriatric conditions measured by a comprehensive geriatric assessment (GA) for the prediction of the risk of high-grade acute radiation-induced toxicity. METHODS: A total of 314 prostate cancer patients (age ≥ 65 years) undergoing definitive radiotherapy at a tertiary academic center were included. Prior to treatment, patients underwent a GA. High-grade toxicity was defined as acute toxicity grade ≥ 2 according to standard RTOG/EORTC criteria. To analyze the predictive value of the GA, univariable and multivariable logistic regression models were applied. RESULTS: A total of 40 patients (12.7%) developed acute toxicity grade ≥ 2; high grade genitourinary was found in 37 patients (11.8%) and rectal toxicity in 8 patients (2.5%), respectively. Multivariable analysis revealed a significant association of comorbidities with overall toxicity grade ≥ 2 (odds ratio [OR] 2.633, 95% confidence interval [CI] 1.260-5.502; p = 0.010) as well as with high-grade genitourinary and rectal toxicity (OR 2.169, 95%CI1.017-4.625; p = 0.045 and OR 7.220, 95%CI 1.227-42.473; p = 0.029, respectively). Furthermore, the Activities of Daily Living score (OR 0.054, 95%CI 0.004-0.651; p = 0.022), social status (OR 0.159, 95%CI 0.028-0.891; p = 0.036), and polypharmacy (OR 4.618, 95%CI 1.045-20.405; p = 0.044) were identified as independent predictors of rectal toxicity grade ≥ 2. CONCLUSION: Geriatric conditions seem to be predictive of the development of high-grade radiation-induced toxicity in prostate cancer patients treated with definitive radiotherapy.

Economical Evaluation of Prostate Cancer Treatment Using Intensity-Modulated Radiation Therapy, 3-Dimensional Conformal Radiation Therapy and Radical Prostatectomy: A Systematic Review.

OBJECTIVES: Prostate cancer is a common form of cancer among men worldwide. The objective of this study was to conduct a systematic review of the economic evaluations of prostate cancer treatment strategies. METHODS: This systematic review was conducted using multiple electronic databases up to May 2021. English-language economic evaluation studies that compared intensity-modulated radiation therapy (IMRT), 3-dimensional conformal radiation therapy (3DCRT), and radical prostatectomy (RP) were included. The studies were evaluated using the Consolidated Health Economic Evaluation Reporting Standards checklist. The search yielded 1151 potentially relevant publications, which were screened based on the title and abstract. After the removal of duplicates, 55 studies remained, and 9 studies were screened in full text. Finally, textual data were analyzed manually using by-content analysis method. RESULTS: All studies were cost-effective and evaluated quality-adjusted life year as the efficacy indicator. The studies were conducted from either payers' or health systems' perspectives, and the time horizon varied from 5 to 20 years. We included only full economic evaluation studies. The use of IMRT in comparison with 3DCRT was evaluated in 6 studies, based on which IMRT increased health and reduced side effects of treatment. According to incremental cost-effectiveness ratio (ICER) results, IMRT was more cost-effective than 3DCRT. Three studies evaluated the use of RP in comparison with radiotherapy. Based on these studies, radiotherapy was more effective than RP. CONCLUSION: IMRT was found to be more cost-effective than 3DCRT in all 6 studies compared with the threshold. Radiotherapy was found to be more effective than RP. However, long-term clinical trial studies are needed to confirm these findings and to provide more definitive conclusions.

The cost effectiveness of intensity-modulated radiation therapy and three-dimensional conformal radiotherapy in the treatment of head and neck cancers.

PURPOSE: Intensity-modulated radiotherapy is developed as a replacement for 3-dimensional conformal radiation therapy. Considering the difference in costs and effectiveness of these interventions, the aim of this study was to compare the cost effectiveness of intensity-modulated radiation therapy and three-dimensional conformal radiotherapy in the treatment of head and neck cancer in east of Iran. METHODS: A Markov model including six states based on xerostomia and dysphagia was developed to estimate the incremental cost effectiveness ratio from the perspective of societal. Cost and quality of life data were collected from 97 respondents via a checklist and EuroQol-5Dimension questionnaire. The robustness of results was examined by deterministic and probabilistic sensitivity analysis. All analysis were conducted with Treeage software. RESULTS: The results of this study showed that the cost and quality adjusted life years for 3-dimensional conformal radiation therapy were 9209.76 and 3.63 respectively. However, the cost and quality adjusted life years for intensity-modulated radiotherapy were 12562.90 and 3.17 respectively. Therefore, 3-dimensional conformal radiation therapy produced 0.45 more quality adjusted life years than intensity-modulated radiotherapy and saved $3353. According to the incremental cost effectiveness ratio, 3-dimensional conformal radiation therapy as compared to intensity-modulated radiotherapy saved $7367.27 per quality adjusted life years. These results confirmed by sensitivity analysis. CONCLUSION: This study concluded that in the treatment of head and neck cancer, the 3-dimensional conformal radiation therapy method appears to be cost-effective when compared with intensity-modulated radiotherapy.

Comparing Risk for Second Primary Cancers After Intensity-Modulated vs 3-Dimensional Conformal Radiation Therapy for Prostate Cancer, 2002-2015.

Importance: Compared with 3-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) can spare nearby tissue but may result in increased scatter radiation to distant normal tissue, including red bone marrow. It is unclear whether second primary cancer risk varies by radiotherapy type. Objective: To evaluate whether radiotherapy type (IMRT vs 3DCRT) is associated with second primary cancer risk among older men treated for prostate cancer. Design, Setting, and Participants: In this retrospective cohort study of a linked database of Medicare claims and Surveillance, Epidemiology, and End Results (SEER) Program population-based cancer registries (2002-2015), male patients aged 66 to 84 diagnosed with a first primary nonmetastatic prostate cancer from 2002 to 2013, as reported to SEER, and who received radiotherapy (IMRT and/or 3DCRT without proton therapy) within the first year following prostate cancer were identified. The data were analyzed from January 2022 through June 2022. Exposure: Receipt of IMRT and 3DCRT, based on Medicare claims. Main Outcomes and Measures: The association between radiotherapy type and development of a subsequent hematologic cancer at least 2 years after prostate cancer diagnosis or a subsequent solid cancer at least 5 years after prostate cancer diagnosis. Hazard ratios (HRs) and 95% CIs were estimated using multivariable Cox proportional regression. Results: The study included 65 235 2-year first primary prostate cancer survivors (median [range] age, 72 [66-82] years; 82.2% White patients) and 45 811 5-year survivors with similar demographic characteristics (median [range] age, 72 [66-79] years; 82.4% White patients). Among 2-year prostate cancer survivors (median [range] follow-up, 4.6 [0.003-12.0] years), 1107 second hematologic cancers were diagnosed (IMRT, 603; 3DCRT, 504). Radiotherapy type was not associated with second hematologic cancers overall or any specific types evaluated. Among 5-year survivors (median [range] follow-up, 3.1 [0.003-9.0] years), 2688 men were diagnosed with a second primary solid cancer (IMRT, 1306; 3DCRT, 1382). The overall HR for IMRT vs 3DCRT was 0.91 (95% CI, 0.83-0.99). This inverse association was restricted to the earlier calendar year period of prostate cancer diagnosis (HR2002-2005 = 0.85; 95% CI, 0.76-0.94; HR2006-2010 = 1.14; 95% CI, 0.96-1.36), with a similar pattern observed for colon cancer (HR2002-2005 = 0.66; 95% CI, 0.46-0.94; HR2006-2010 = 1.06; 95% CI, 0.59-1.88). Conclusions and Relevance: The results of this large, population-based cohort study suggest that IMRT for prostate cancer is not associated with an increased risk of second primary cancers, either solid or hematologic, and any inverse associations may be associated with calendar year of treatment.

Safety in radiation oncology (SAFRON): Learning about incident causes and safety barriers in external beam radiotherapy.

PURPOSE: Safety in Radiation Oncology (SAFRON) is a reporting and learning system on radiotherapy and radionuclide therapy incidents and near misses. The primary aim of this paper is to examine whether any discernible patterns exist in the causes of reported incidents and safety barriers within the SAFRON system concerning external beam radiotherapy. METHODS AND MATERIALS: This study focuses on external beam radiotherapy incidents, reviewing 1685 reports since the inception of SAFRON until December 2021. Reports that did not identify causes of incidents and safety barriers were excluded from the final study population. RESULTS: Simple two-dimensional radiotherapy or electron beam therapy were represented by 97 reports, three-dimensional conformal radiotherapy by 39 reports, modulated arc therapy by 12 reports, intensity modulated radiation therapy by 11 reports, stereotactic radiosurgery by 4 reports, and radiotherapy with protons or other particles by 1 report, while for 92 of them, no information on treatment method had been provided. Most of the reported incidents were minor incidents and were discovered by the radiation therapist. Inadequate direction/information in staff communication was the most frequently reported cause of incident, and regular independent chart check was the most common safety barrier. CONCLUSIONS: The results indicate that the majority of incidents were reported by radiation therapists, and the majority of these incidents were classified as minor. Communication problems and failure to follow standards/procedures/practices were the most frequent causes of incidents. Furthermore, regular independent chart checking was the most frequently identified safety barrier.

Outcomes Following SBRT vs. IMRT and 3DCRT for Older Patients with Stage IIA Node-Negative Non-Small Cell Lung Cancer > 5 cm.

BACKGROUND: To describe outcomes and compare the effectiveness of stereotactic body radiotherapy (SBRT) versus 3-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) in patients with stage IIA lymph node-negative (N0) non-small cell lung cancer (NSCLC) tumors > 5 cm. METHODS: We used the SEER-Medicare database (2005-2015) to identify patients > 65 years with stage IIA (AJCC TNM7) N0 NSCLC > 5 cm tumors who were treated with SBRT, IMRT, and 3DCRT. We used propensity score methods with inverse probability weighting to compare lung cancer-specific survival (LCSS), overall survival (OS), and toxicity. RESULTS: Of 584 patients, 88 (15%), 140 (24%), and 356 (61%) underwent SBRT, IMRT, and 3DCRT, respectively. The SBRT group was older (P = .004), had more comorbidities (P = .02), smaller tumors (P = .03), and more adenocarcinomas (P < .0001). We found a trend towards higher median unadjusted OS with SBRT compared to IMRT and 3DCRT (19 vs. 13 and 14 months, respectively, P = .37). In our propensity score-adjusted analyses, SBRT was significantly associated with better OS and LCSS compared to IMRT (HROS: 0.78, 95% CI: 0.68-0.89, HRLCSS: 0.70, 95% CI: 0.60-0.81) and 3DCRT (HROS: 0.81, 95% CI: 0.72-0.93, HRLCSS: 0.80, 95% CI: 0.68-0.93). SBRT-treated patients also had lower overall adjusted complication rates compared to IMRT (OR: 0.74, 95% CI: 0.55-0.99) and 3DCRT (OR: 0.53, 95% CI: 0.40-0.71). CONCLUSION: For patients with NSCLC tumors > 5 cm, SBRT trends towards fewer toxicities and improved survival compared to other forms of radiotherapy. Our findings support SBRT as an appropriate treatment strategy for older patients with larger inoperable NSCLC tumors.

A randomized study for dosimetric assessment and clinical impact of bone marrow sparing intensity-modulated radiation therapy versus 3-dimensional conformal radiation therapy on hematological and gastrointestinal toxicities in cervical cancer.

Background: Cervical cancer requires multimodality therapy, resulting in acute toxicities. Intensity-modulated radiation therapy (IMRT) is postulated to spare bone marrow (BM) and bowel to reduce acute hematological and gastrointestinal (GI) toxicities of chemoradiotherapy. Patients and Methods: This is a prospective randomized phase III study enrolling patients with Stage IB to IVA cervical carcinoma in two arms receiving either three-dimensional conformal radiotherapy (3DCRT) or IMRT from December 2017 to December 2019. The primary objective was to compare the hematologic toxicities (Grade 2 or more neutropenia as the primary factor) and the secondary objectives were to compare GI toxicities, and dosimetric analysis for volumes of BM, and bowel irradiated. SPSS version 20 was used for all statistical calculations. Results: Eighty patients with histopathologically confirmed cervical cancer were randomized to receive IMRT or 3DCRT (40 in each arm). The median age of the patients was 56.5 (36-67) and 59.5 (37-68) years, respectively, in IMRT and 3DCRT arms. The median dose of external radiation was 50 Gy in 25 fractions, and of brachytherapy was 24 Gy in 3 fractions in both the arms. The incidence of grade ≥2 neutropenia was 42.5% and 15% in the 3DCRT and IMRT arms, respectively (P < 0.001). All patients received concurrent chemotherapy with cisplatin, with the median number of cycles being 5 (range 3-5) in both the arms. All five cycles of concurrent chemotherapy could be completed in 25 (62.5%) patients in the IMRT arm and 24 (60%) patients in the 3DCRT arm. Conclusions: IMRT significantly reduces acute hematologic and GI toxicities compared with 3DCRT with a better dosimetry profile.

Risk of Cardiovascular Toxicity According to Tumor Laterality Among Older Patients With Early Stage Non-small Cell Lung Cancer Treated With Radiation Therapy.

BACKGROUND: The long-term risk of cardiovascular outcomes from either stereotactic body radiation therapy (SBRT) or three-dimensional conformal radiation therapy (3DCRT) plus intensity-modulated radiation therapy (IMRT) to treat early stage non-small cell lung cancer (NSCLC) is largely unknown. As continued adoption of SBRT accelerates, it is important to delineate unforeseen cardiovascular risks associated with treatment. RESEARCH QUESTION: Does the long-term risk of cardiovascular outcomes for patients with early stage NSCLC treated with either SBRT or 3DCRT plus IMRT differ by tumor laterality? STUDY DESIGN AND METHODS: Data from the Surveillance, Epidemiology, and End Results registry linked to Medicare was analyzed to identify a sample of 3,256 patients (1,506 treated with SBRT and 1,750 treated with 3DCRT plus IMRT) with node-negative stage I or IIA NSCLC. Cardiovascular events were identified using diagnosis codes, and outcomes were compared between left- and right-sided tumors. We assumed that tumor laterality was random and that the radiation field for left-sided tumors likely would result in greater dose to cardiac tissues. Cox regression models were fit to quantify the association of laterality on outcomes. RESULTS: Patients were followed up for a median of 2 years. Those treated with SBRT showed no difference in hazard of any cardiovascular outcomes by tumor laterality, including the cardiovascular composite (hazard ratio [HR] comparing left- vs right-sided tumors, 0.98; 95% CI, 0.84-1.15). In contrast, patients treated with 3DCRT plus IMRT showed a greater risk of congestive heart failure (HR, 1.23; 95% CI, 1.01-1.48) and percutaneous coronary artery intervention (HR, 2.24; 95% CI, 1.12-4.47). INTERPRETATION: Patients with left- vs right-sided early stage NSCLC showed similar rates of cardiovascular events when treated with SBRT. However, these patients also showed higher rates of select cardiac events when they were treated with 3DCRT plus IMRT. This study provides evidence that SBRT may provide a safer option over 3DCRT plus IMRT for patients with left-sided early stage NSCLC and underscores the need for long-term follow-up for patients treated with radiation therapy.

Monte Carlo study of organ doses and related risk for cancer in Algeria from scattered neutrons in prostate treatment involving 3D-CRT.

The present study aimed to evaluate organ doses and related risk for cancer from scattered neutrons involving 3D Conformational Radiotherapy (3D-CRT) for patients with prostate cancer in Algeria based on Monte Carlo technique and to estimate the secondary cancer risks. To this purpose, a detailed geometric Monte Carlo (MC) modeling of the LINAC Varian 2100C combined with a computational whole-body phantom was carried out. The neutron equivalent doses were calculated in-field and out-of field of patient's organs using the phase-space method. The obtained neutron equivalent doses were used to estimate the Lifetime Attributable Risks (LARs) for cancer incidence in out of field organs. LARs was evaluated assuming Biological Effects of Ionizing Radiation VII (BEIR VII) risk model for exposure age in the range 35-70 years, according to the interval's age of treated patients in Algeria. The baselines cancer risks and survival data were associated with the statistical data for the Algerian population. The results showed that the neutrons equivalent doses per prescribed dose (Photon Dose) mostly depend on the distance of organs from the treated volume. The highest and lowest equivalent doses of 1.18 mSv/Gy and 0.25 mSv/Gy were recorded in the bladder and heart, respectively. The highest estimated lifetime attributable risk per 100,000 population was found for 35 yrs' exposure age in colon 49.94, lung 16.63 and stomach 11.17. The lowest risks were found for 70 yrs' age, in spine 0.06 and thyroid 0.14. The results showed that LARs values decrease with the increase of the exposure age and cancer incidence risk is lower than the baseline cancer risk incidence for all organs. The present study may help in providing a database on the impact of radiotherapy-induced secondary cancer incidence during 3D-CRT for prostate cancer in Algeria.

The Cost of Locally Advanced Cervical Cancer in Thailand: an Empirical Study for Economic Analysis.

OBJECTIVE: To evaluate cost of illness of locally advanced cervical cancer patients from societal perspective in three scenarios including completely cured without severe late side effects (S1), completely cured with late grade 3-4 gastrointestinal side effects (S2.1) or genitourinary side effects (S2.2), and disease recurrence and death (S3). METHODS:  The incidence-based approach was conducted. The cost was calculated for 5-year time horizon starting for the treatment initiation. Direct medical costs were extracted from hospital database. Cost of using two-dimensional technique and three-dimensional conformal radiation therapy were calculated separately. Direct non-medical costs and indirect costs in terms of productivity loss were based on actual expenses from the interview of 194 locally advanced cervical cancer patients from two tertiary hospitals in Bangkok, during June to December 2019. All costs were converted to US dollar in 2019 values. RESULTS: For 5 years, cost of illness per patient for using two-dimensional technique and three-dimensional conformal radiation therapy were US $8,391 and US $10,418 for S1, US $18,018 and US $20,045 for S2.1, US $17,908 and US $19,936 for S2.2, and US $61,076 and US $63,103 for S3, respectively. The economic burden for newly diagnosed locally advanced cervical cancer patients in Thailand in 2018 was approximately US $129 million and US $131 million for using two-dimensional technique and three-dimensional conformal radiation therapy, respectively. Cost from S3 accounted for 70% of all total cost. Premature death was the most important cost driver of cost of illness accounted for 64 % of the total cost estimates. CONCLUSIONS: Cost of illness of locally advanced cervical cancer patients produced significant economic burden from societal perspective. Disease recurrence and early death from cancer was the most influential cause of this burden.

Post-operative radiation therapy for non-small cell lung cancer: A comparison of radiation therapy techniques.

OBJECTIVES: Post-operative radiation therapy (PORT) in locally advanced non-small cell lung cancer (LA-NSCLC) has historically been associated with toxicity. Conformal techniques like intensity modulated radiation therapy (IMRT) have the potential to reduce acute and long-term toxicity from radiation therapy. Among patients receiving PORT for LA-NSCLC, we identified factors associated with receipt of IMRT and evaluated the association between IMRT and toxicity. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER)-Medicare database between January 1, 2006 to December 31, 2014 to identify patients diagnosed with Stage II or III NSCLC and who received upfront surgery and subsequent PORT. Baseline differences between patients receiving 3-dimentional conformal radiation therapy (3D-CRT) and IMRT were assessed using the chi-squared test for proportions and the t-test for means. Multivariable logistic regression was used to identify predictors of receipt of IMRT and pulmonary, esophageal, and cardiac toxicity. Propensity-score matching was employed to reduce the effect of known confounders. RESULTS: A total of 620 patients met the inclusion criteria, among whom 441 (71.2%) received 3D-CRT and 179 (28.8%) received IMRT. The mean age of the cohort was 73.9 years and 54.7% were male. The proportion of patients receiving IMRT increased from 6.2% in 2006 to 41.4% in 2014 (P < 0.001). IMRT was not associated with decreased pulmonary (OR 0.89; 95% CI, 0.62-1.29), esophageal (OR 1.09; 95% CI, 0.0.75-1.58), or cardiac toxicity (OR 1.02; 95% CI, 0.69-1.51). These findings held on propensity-score matching. Clinical risk factors including comorbidity and prior treatment history were associated with treatment toxicity. CONCLUSION: In a cohort of elderly patients, the use of IMRT in the setting of PORT for LA-NSCLC was not associated with a difference in toxicity compared to 3D-CRT. This finding suggests that outcomes from PORT may be independent of radiotherapy treatment technique.

Analysis of a novel X-ray lens for converging beam radiotherapy.

We describe the development and analysis of a new teletherapy modality that, through a novel approach to targeted radiation delivery, has the potential to provide greater conformality than conventional photon-based treatments. The proposed system uses an X-ray lens to reflect photons from a conventional X-ray tube toward a focal spot. The resulting dose distributions have a highly localized peak dose, with lower doses in the converging radiation cone. Physical principles governing the design of this system are presented, along with a series of measurements analyzing various characteristics of the converging beam. The beam was designed to be nearly monoenergetic (~ 59 keV), with an energy bandwidth of approximately 10 keV allowing for treatment energies lower than conventional therapies. The focal spot was measured to be approximately 2.5 cm long and 4 mm wide. Mounting the proposed X-ray delivery system on a robotic arm would allow sub-millimeter accuracy in focal spot positioning, resulting in highly conformal dose distribution via the optimal placement of individual focal spots within the target volume. Aspects of this novel radiation beam are discussed considering their possible clinical application as a treatment approach that takes maximum advantage of the unique properties afforded by converging X-ray beam therapy.

Cost-effectiveness analysis comparing intensity-modulated radiotherapy with conformational radiotherapy (3D-RT) for prostate cancer in the brazilian health system.

OBJECTIVE: The intensity-modulated radiotherapy (IMRT) has been established as the standard external-beam radiation technique to treat prostate cancer in several countries. In Brazil, the public health system and the National Health Agency do not reimburse its utilization. This study compared the cost-effectiveness of IMRT and tridimensional radiotherapy (3D-RT) from a payer's perspective. METHODS: We built a Markov model to delineate the health states after treatment with IMRT and 3D-RT. The treatment-related toxicity data were extracted from the literature. The sensitivity analyses were performed over potential parameters. RESULTS: The incremental cost of IMRT was R$ 5,553.78. At a time horizon of 5 years, the quality-adjusted life expectancy after IMRT was higher than 3D-RT. The incremental cost-effectiveness ratio (ICER) of IMRT over 3D-RT was R$-296,74/quality-adjusted life year (QALY). Therefore, IMRT was the dominant strategy, which depended on the value of interventional procedures for severe toxicity and the difference between IMRT and 3D-RT reimbursement. The IMRT was still most likely to be cost-effective at a willingness-to-pay R$ 100,000/QALY, with a net monetary benefit (NMB) superior to 3D-RT after R$ 50,000.00, resulting in a difference of R$220.000,00 after 5 years. CONCLUSIONS: IMRT generated more values than 3D-RT for external-beam treatment. Given its potential to reduce late toxicity with hypofractionation, these data reinforce its incorporation to treat prostate cancer in the Brazilian health system from a payer's perspective.

Outcomes between intensity-modulated radiation therapy versus 3D-conformal in early stage glottic cancer.

BACKGROUND: The purpose of this study is to evaluate practice patterns and outcomes between intensity-modulated radiation therapy (IMRT) and 3D-conformal radiation (3D-CRT) in early stage glottic cancer. METHODS: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify and compare patient and disease profiles, mortality, and toxicity in patients with T1-2 larynx cancer undergoing definitive radiation (RT). RESULTS: A total of 1520 patients underwent definitive radiation with 3D-CRT (n = 1309) or IMRT (n = 211). Non-white race, those with a Charlson Comorbidity Index ≥2, T2 disease, and those treated at community practices were more likely to undergo IMRT. Rates of IMRT increased from 2006 to 2015, while relative rates of 3D-CRT decreased. Two-year CSS was superior with 3D-CRT (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.22-0.65; p < 0.001). There was no difference in OS between 3D-CRT and IMRT (p = 0.119). CONCLUSIONS: Patients receiving 3D-CRT had improved CSS compared to IMRT with no difference in OS.

National variation in the delivery of radiation oncology procedures in the non-facility-based setting.

PURPOSE: Though utilization of medical procedures has been shown to vary considerably across the United States, similar efforts to characterize variation in the delivery of radiation therapy (RT) procedures have not been forthcoming. Our aim was to characterize variation in the delivery of common RT procedures in the Medicare population. We hypothesized that delivery would vary significantly based on provider characteristics. METHODS: The Centers for Medicare and Medicaid Services (CMS) Physician and Other Supplier Public Use File was linked to the CMS Physician Compare (PC) database by physician NPI to identify and sum all treatment delivery charges submitted by individual radiation oncologists in the non-facility-based (NFB) setting in 2016. Multivariable logistic regression analysis was carried out to determine provider characteristics (gender, practice rurality, practice region, and years since graduation) that predicted for the delivery of 3D conformal RT (3DCRT), intensity modulated RT (IMRT), stereotactic body RT (SBRT), stereotactic radiosurgery (SRS), low dose rate (LDR) brachytherapy, and high dose rate (HDR) brachytherapy delivery in the Medicare patient population. The overall significance of categorical variables in the multivariable logistic regression model was assessed by the likelihood ratio test (LRT). RESULTS: In total, 1,802 physicians from the NFB practice setting were analyzed. Male gender predicted for greater LDR brachytherapy delivery (OR 8.19, 95% CI 2.58-26.05, p < 0.001), but not greater delivery of other technologies. Metropolitan practice was the only predictor for greater HDR brachytherapy utilization (OR 12.95, 95% CI 1.81-92.60, p = 0.01). Practice region was predictive of the delivery of 3DCRT, SRS and SBRT (p < 0.01, p < 0.001, and p < 0.001, respectively). With the Northeast as the reference region, 3DCRT was more likely to be delivered by providers in the South (OR 1.33, 95% CI 1.09-1.62, p < 0.01) and the West (OR 1.38, 95% CI 1.11-1.71, p < 0.01). At the same time, SRS use was less likely in the Midwest (OR 0.71, 95% CI 0.55-0.91, p < 0.01), South (OR 0.49, 95% CI 0.40-0.61, p < 0.001), and West (OR 0.43, 95% CI 0.34-0.55, p < 0.001). SBRT, on the other hand, was more commonly utilized in the Midwest (OR 2.63, 95% CI 1.13-6.13, p = 0.03), South (OR 3.44, 95% CI 1.58-7.49, p < 0.01), and West (OR 4.87, 95% CI 2.21-10.72, p < 0.001). HDR brachytherapy use was also more likely in the Midwest (OR 1.97, 95% CI 1.11-3.49, p = 0.02) and West (OR 1.87, 95% CI 1.08-3.24, p = 0.03). While the degree held by the billing physician did not predict for delivery of a given procedure, greater years since graduation was related to decreased likelihood of SBRT use (OR 0.98, 95% CI 0.96-0.99, p < 0.001) and increased likelihood of LDR brachytherapy use (OR 1.02, 95% CI 1.00-1.04, p = 0.02). CONCLUSIONS: Substantial geographic variation in the use of specific RT technologies was identified. The degree to which this variation reflects effective care, preference-sensitive care, or supply-sensitive care warrants further investigation.

Provider-Level Variation in Treatment Planning of Radiation Oncology Procedures in the United States.

PURPOSE: Variation in the use of radiation oncology procedures and technologies is poorly characterized. We sought to identify associations between the treatment planning codes used to bill for radiotherapy procedures and the demographic characteristics of the radiation oncologists submitting them. METHODS: The Physician and Other Supplier Public Use File was linked to the Physician Compare database by using the physician National Provider Identifier for the year 2016. Analysis was stratified by practice setting, considering both the freestanding non-facility-based (NFB) setting and the facility-based (FB) setting. Multivariable logistic regression was used to determine provider characteristics (gender, practice rurality, and years since graduation) that predicted for the use of 3D-conformal RT (3DCRT) planning, intensity-modulated RT (IMRT) planning, and brachytherapy planning in the Medicare population. RESULTS: Three thousand twenty-nine physicians were linked for analysis. In both the FB and NFB settings together, male gender predicted for decreased likelihood of 3DCRT planning (OR, 0.70, 95% CI, 0.62 to 0.80, P < .001) and increased likelihood of IMRT planning (OR, 1.35, 95% CI, 1.19 to 1.54, P < .001). Brachytherapy planning was also more likely with increasing years since medical school graduation (OR, 1.03, 95% CI, 1.01 to 1.04, P < .001) in the combined FB and NFB settings. These significant associations persisted when examining the NFB and FB settings individually. In both settings overall, brachytherapy planning was more likely in male providers (OR, 1.75, 95% CI, 1.10 to 2.76, P = .02) and also more likely for providers practicing in metropolitan regions compared with those practicing in rural areas (OR, 3.01, 95% CI, 1.23 to 7.39, P = .02). CONCLUSION: Male gender predicts for utilization of IMRT planning, whereas female gender predicts for utilization of 3DCRT planning. Future research is warranted to better understand the role that provider gender and rurality play in the selection of radiation planning techniques for Medicare patients.

Comparing second cancer risk for multiple radiotherapy modalities in survivors of hodgkin lymphoma.

OBJECTIVES: To assess if excess absolute risk (EAR) of radiation-induced solid cancer can be used to rank radiotherapy plans for treatment of Hodgkin lymphoma (HL) in a statistically significant way. METHODS: EAR models, calibrated with data from the Life Span Study and HL survivors, have been incorporated into a voxelised risk-calculation software, which is used to compare four treatment modalities planned for five virtual HL patients. Organ-specific parameters are generated repeatedly in a Monte Carlo fashion to model their uncertainties. This in turn enables a quantitative estimation of the EAR uncertainties. RESULTS: Parameter-driven uncertainties on total EAR are around 13%, decreasing to around 2-5% for relative EAR comparisons. Total EAR estimations indicate that intensity modulated proton therapy decreases the average risk by 40% compared to the intensity modulated radiation therapy plan, 28% compared to the volumetric modulated arc therapy plan whereas the three-dimensional conformal radiation therapy plan is equivalent within the uncertainty. CONCLUSION: Relative EAR is a useful metric for distinguishing between radiotherapy plans in terms of second cancer risk. ADVANCES IN KNOWLEDGE: Relative EAR is not dominated by model or parameter uncertainties and can be used to guide the choice of radiotherapy for HL patients.

COVID-19 and radiotherapy: potential new strategies for patients management with hypofractionation and telemedicine.

COVID-19 disease is one of the biggest public health challenges in Italy and global healthcare facilities, including radiotherapy departments, faced an unprecedented emergency. Cancer patients are at higher risk of COVID-19 infection because of their immunosuppressive state caused by both tumor itself and anticancer therapy adopted. In this setting, the radiation therapy clinical decision-making process has been partly reconsidered; thus, to reduce treatment duration and minimize infection risk during a pandemic, hypofractionated regimens have been revised. Moreover, telemedicine shows its helpfulness in the radiotherapy field, and patients get the supportive care they need minimizing their access to hospitals. This review aims to point out the importance of hypofractionated RT and telemedicine in cancer patient management in the COVID-19 era.