3-dimensional Conformal Radiotherapy Research Articles

Critical Appraisal of the Risk of Secondary Cancer Induction From Breast Radiation Therapy With Volumetric Modulated Arc Therapy Relative to 3D Conformal Therapy

To evaluate the excess absolute risk (EAR) comparing volumetric modulated arc therapy (VMAT) and 3-dimensional (3D) conformal radiation therapy (CRT) in breast cancer radiation therapy treatment. Two VMAT arrangements (VMAT_tang and VMAT_full, i.e. partial arcs with and without a sector of 0 Monitor Unit, respectively) and a 3D CRT (field-in-field [FinF]) plan were calculated with an accurate dose calculation algorithm, Acuros, in 20 patients presenting with early-stage breast cancer. The dose prescription was 40.05Gy in 15 fractions. The planning aim was to maximize the dose reduction in the lungs, contralateral breast, heart, and coronary artery. EAR was estimated using different models: linear, linear-exponential, plateau, and full model, which better uses a carcinogenesis model and epidemiologic data for carcinoma induction and which accounts for cell repopulation or repair during the radiation therapy dose fractionation. EAR was computed for contralateral structures-breast and lung-as well as the ipsilateral lung. Normal tissue complication probability (NTCP) was computed to estimate the ipsilateral lung, heart, and skin toxicity, to balance with respect to second cancer induction. The planning objectives were fulfilled with all the planning techniques. EAR for contralateral breast carcinoma induction, estimated with the most accurate model, was 1.7, 2.4, and 8.5 (per 10,000 patients per year) with FinF, VMAT_tang, and VMAT_full, respectively. For the contralateral lung, these figures were 1.5, 1.6, and 7.3 (per 10,000 patients per year), respectively. NTCP for all the analyzed endpoints was significantly higher with FinF relative to both VMAT settings, with VMAT_full presenting the lowest toxicity risk. VMAT, in particular with the VMAT_tang setting, could have the same risk of second cancer induction as 3D CRT delivered with the FinF setting for the contralateral organs while reducing acute and late NTCP for the ipsilateral organs. VMAT might be considered a safe technique for breast cancer treatment for those aspects.

Trends in intensity modulated radiation therapy use for locally advanced rectal cancer at National Comprehensive Cancer Network centers

PurposeIntensity modulated radiation therapy (IMRT) has been rapidly incorporated into clinical practice because of its technological advantages over 3-dimensional conformal radiation therapy (CRT). We characterized trends in IMRT utilization in trimodality treatment of locally advanced rectal cancer at National Comprehensive Cancer Network cancer centers between 2005 and 2011. Methods and materialsUsing the prospective National Comprehensive Cancer Network Colorectal Cancer Database, we determined treatment patterns for 976 patients with stage II-III rectal cancer who received pelvic radiation therapy at contributing centers between 2005 and 2011. Multivariable logistic regression was used to identify factors associated with IMRT versus 3-dimensional CRT. Radiation therapy compliance and time to completion were used to compare acute toxicity. ResultsA total of 947 patients (97%) received 3-dimensional CRT (80%) or IMRT (17%). Ninety-eight percent of these patients received radiation therapy preoperatively, and 81% underwent definitive resection. IMRT use increased from <13% pre-2009 to >30% in 2010 and thereafter, with significant variability among institutions (range, 0%-43%). Other factors associated with IMRT use included age ≥65 years, dose >50.4 Gy, African-American race, and no transabdominal surgery. Rates of and time to radiation therapy completion were similar between the groups. ConclusionsAlthough most patients with stage II-III rectal cancer at queried National Cancer Institute–designated cancer centers between 2005 and 2011 received 3-dimensional CRT, significant and increasing numbers received IMRT. IMRT utilization is highly variable among institutions and not uniform among sociodemographic groups but may be more consistently embraced in specific clinical settings. Given this trend, comparative-effectiveness research is needed to evaluate the benefits of IMRT for rectal cancer.

Dosimetric comparison of 3-dimensional conformal and intensity-modulated radiotherapy techniques for whole breast irradiation in the prone and supine positions

Dosimetric comparison of 3-dimensional conformal and intensity-modulated radiotherapy techniques for whole breast irradiation in the prone and supine positions

Vertebral Bone Marrow Irradiation Contributes to Hematologic Toxicity During Chemoradiation Therapy for Esophageal Cancer

Hematological toxicity (HT) commonly occurs during chemoradiation therapy (CRT) for esophageal cancer, with both modalities contributing to the decline in blood counts. Since leukopenia commonly precludes chemotherapy delivery, we sought to determine the dose volume histogram (DVH) constraints that correlate with decline in leukocyte counts due to comprehensive vertebra (CV) irradiation during CRT. 32 esophageal cancer patients treated with weekly neoadjuvant CRT were selected to be in the study. The typical chemotherapy regimen consisted of weekly intravenous carboplatin (area under the curve = 2) and paclitaxel (50 mg/m2). Radiation therapy (RT) was delivered using 3-dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT). Patients who missed CRT for reasons other than neutropenia or received colony-stimulating factors were excluded. HT was scored using the Common Terminology Criteria for Adverse Events version 4.0. CV were contoured from C2 to L2 vertebra on 4DCT simulation scans. DVH data in both percentages and cubic centimeters was collected for CV V10-V60 (CVV) in increments of 10s. CVV5 and mean vertebral dose (MVD) were included as well. A DVH parameter of Vx was defined as either the percentage or volume in cubic centimeters of organ receiving at least x Gy of radiation. Univariate linear regression was performed to identify associations between leukopenia nadirs and DVH parameters. β represents the change in blood counts in k/μL for every 1 unit increase in DVH parameter. Receiver operator curves demonstrate cutoffs to avoid grade ≥ 3 leukopenia. Of the 32 esophageal patients, 6 patients developed grade 1 leukopenia, 12 developed grade 2 leukopenia, 8 developed grade 3 leukopenia, and 3 developed grade 4 leukopenia. CVV30, CVV20, CVV10, and MVD were significantly associated with decreasing WBC when calculated either as a percentage or by volume of the organ on univariate analysis. CVV5 was significantly associated with decreasing WBC counts only when calculated as a percentage of the volume and not as volume by cubic centimers. Associations with leukopenia were not seen with higher DVH values. CVV60, CVV50, and CVV40 did not significantly influence WBC levels during CRT. Cutoffs to avoid grade ≥ 3 leukopenia were CVV20 < 44.3%, CVV10 < 54.2%, CVV20 < 225 cc, CVV10 < 260 cc, and MVD < 18.8 Gy.< table class=”abstracttable>< tbody>< tr> CVV30 CVV20 CVV10 CVV5 MVD WBC (DVH by %) β p-value . -0.00528 0.0154 . -0.00767 0.0016 . -0.00826 0.0005 . -0.00828 0.0005 . -0.00014 0.0125 WBC (DVH by cc) . . . . . β p-value -0.00111 0.022 -0.00109 0.0269 -0.00107 0.0268 -0.000804 0.0577 -0.00014 0.0125 Leukopenia is associated with higher RT doses to the CVV30, CVV20, CVV10, CVV5, and MVD during CRT for esophageal cancer patients. Improved low dose radiation sparing of the CV may decrease HT.

Seven-Year Outcomes Following Accelerated Partial Breast Irradiation Stratified by ASTRO Consensus Groupings.

Limited long-term data exist regarding outcomes for patients treated with accelerated partial breast irradiation (APBI), particularly, when stratified by American Society for Radiation Oncology (ASTRO) Consensus Statement (CS) risk groups. The purpose of this analysis is to present 5- and 7-year outcomes following APBI based on CS groupings. A total of 690 patients with early-stage breast cancer underwent APBI from 1993 to 2012, receiving interstitial brachytherapy (n=195), balloon-based brachytherapy (n=290), or 3-dimensional conformal radiotherapy (n=205) at a single institution. Patients were stratified into suitable, cautionary, and unsuitable groups with 5-year outcomes analyzed. Seven-year outcomes were analyzed for a subset with follow-up of ≥2 years (n=625). Median follow-up was 6.7 years (range, 0.1 to 20.1 y). Patients assigned to cautionary and unsuitable categories were more likely to have high-grade tumors (21% to 25% vs. 9%, P=0.001), receive chemotherapy (15% to 38% vs. 6%, P<0.001), and have close/positive margins (9% to 11% vs. 0%, P<0.001). There was no difference in ipsilateral breast tumor recurrence at 5 or 7 years: 2.2%, 1.2%, 2.8% at 5 years (P=0.57), and 2.2%, 1.9%, 4.6% at 7 years (P=0.58) in the suitable, cautionary, and unsuitable groups, respectively. As compared with the suitable group, increased rates of distant metastases were noted for the unsuitable and cautionary groups at 5 years (P=0.04). No differences in rates of ipsilateral breast tumor recurrence were seen at 5 or 7 years when stratified by ASTRO CS groupings. Modest increases in distant recurrence were noted in the cautionary and unsuitable groups. These findings suggest that the ASTRO CS groupings stratify more for systemic recurrence and may not appropriately select patients for whole versus partial breast irradiation.

Scintigraphic Evaluation of Salivary Function after Intensity Modulated Radiotherapy for Head and Neck Cancer

Xerostomia is a common complication in patients treated for head and neck cancers (HNC). Highly conformal radiotherapy (RT) techniques, such as intensity modulated radiotherapy (IMRT), result in better normal tissue sparing in comparison to 3-dimensional conformal radiotherapy. We investigated salivary function using quantitative scintigraphy and aimed to identify associations between dosimetric parameters of the parotid glands and quality of life (QoL) for HNC patients receiving IMRT. Thirty patients treated for HNC were prospectively recruited. Salivary excretion function (SEF) was measured by 99mTc pertechnetate scintigraphy prior to RT and then 1 and 12 months after its completion. The recovery of parotid gland excretion function was expressed as the ratio of post- and pre-treatment SEF. Patient-reported QoL was evaluated by the EORTC QLQ-C30 and H&N35 questionnaires. The mean SEF before RT was 49.2±14.8%. In the univariate analysis we found that older age (r=-0.29, p=0.049) and localization of tumour in oral cavity or oropharynx (comparing to larynx/hypopharynx, p=0.030) affected recovery of salivary flow 12 months after RT. Mean parotid dose was significantly correlated with recovery of salivary flow 12 months after RT (r=-0.46, p=0.001). In the multivariate analysis all aforementioned factors were found to be significantly associated with salivary flow 12 months after RT - age (β=-0.39, p=0.002), tumour localized in oral cavity or oropharynx (β =-0.36, p=0.004), mean parotid dose (β=-0.44, p<0.001). Self-reported grade ≥3 xerostomia was more often in patients with tumour localized in oral cavity or oropharynx (p=0.027). It was also more common in patients who received higher mean dose for both parotids and in patients with worse recovery of salivary flow 12 months after RT. However these results were not statistically significant (p=0.104 and p=0.089, respectively). The results of scintigraphic evaluation of salivary function are strongly correlated with the mean parotid dose. However, this objective method is only partially associated with patients’ self-reported outcomes. The possible reason for that phenomenon is the fact that xerostomia is highly subjective and several factors, not just simply salivary flow, may be involved in its perception. This may be particularly important in older patients who were found to have the worst recovery of salivary flow.

Simultaneous integrated boost intensity-modulated radiotherapy versus 3-dimensional conformal radiotherapy in preoperative concurrent chemoradiotherapy for locally advanced rectal cancer.

PurposeTo evaluate the feasibility of simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for preoperative concurrent chemoradiotherapy (PCRT) in locally advanced rectal cancer (LARC), by comparing with 3-dimensional conformal radiotherapy (3D-CRT).Materials and MethodsPatients who were treated with PCRT for LARC from 2015 January to 2016 December were retrospectively enrolled. Total doses of 45 Gy to 50.4 Gy with 3D-CRT or SIB-IMRT were administered concomitantly with 5-fluorouracil plus leucovorin or capecitabine. Surgery was performed 8 weeks after PCRT. Between PCRT and surgery, one cycle of additional chemotherapy was administered. Pathologic tumor responses were compared between SIB-IMRT and 3D-CRT groups. Acute gastrointestinal, genitourinary, hematologic, and skin toxicities were compared between the two groups based on the RTOG toxicity criteria.ResultsSIB-IMRT was used in 53 patients, and 3D-CRT in 41 patients. After PCRT, no significant differences were noted in tumor responses, pathologic complete response (9% vs. 7%; p = 1.000), pathologic tumor regression Grade 3 or higher (85% vs. 71%; p = 0.096), and R0 resection (87% vs. 85%; p = 0.843). Grade 2 genitourinary toxicities were significantly lesser in the SIB-IMRT group (8% vs. 24%; p = 0.023), but gastrointestinal toxicities were not different across the two groups.ConclusionSIB-IMRT showed lower GU toxicity and similar tumor responses when compared with 3D-CRT in PCRT for LARC.

Dosimetric evaluation of MLC-based dynamic tumor tracking radiotherapy using digital phantom: Desired setup margin for tracking radiotherapy

The purpose of this study is to evaluate the dosimetric impact of the margin on the multileaf collimator-based dynamic tumor tracking plan. Furthermore, an equivalent setup margin (EM) of the tracking plan was determined according to the gated plan. A 4-dimensional extended cardiac-torso was used to create 9 digital phantom datasets of different tumor diameters (TDs) of 1, 3, and 5 cm and motion ranges (MRs) of 1, 2, and 3 cm. For each dataset, respiratory gating (30% to 70% phase) and tumor tracking treatment plans were prepared using 8-field 3-dimensional conformal radiation therapy by 4-dimensional dose calculation. The total lung V20 was calculated to evaluate the dosimetric impact for each case and to estimate the EM with the same impact on lung V20 obtained with the gating plan with a setup margin of 5 mm. The EMs for {TD = 1 cm, MR = 1 cm}, {TD = 1 cm, MR = 2 cm}, and {TD = 1 cm, MR = 3 cm} were estimated as 5.00, 4.16, and 4.24 mm, respectively. The EMs for {TD = 5 cm, MR = 1 cm}, {TD = 5 cm, MR = 2 cm}, and {TD = 5 cm, MR = 3 cm} were estimated as 4.24 mm, 6.35 mm, and 7.49 mm, respectively. This result showed that with a larger MR, the EM was found to be increased. In addition, with a larger TD, the EM became smaller. Our result showing the EMs provided the desired accuracy for multileaf collimator-based dynamic tumor tracking radiotherapy.

Predicted Cardiac and Second Cancer Risks in Hodgkin Lymphoma Patients Treated With Advanced Proton Beam Therapy Compared to Photon Radiation Therapy

To estimate cardiovascular and second cancer risks for Hodgkin Lymphoma (HL) patients treated with deep inspiration breath hold (DIBH) proton pencil beam scanning (PBS). To compare those risks with optimized DIBH photon radiotherapy (RT) delivered using both partial arc volumetric photon RT (PartArc) and field in field 3 dimensional conformal RT (3D-CRT). Sixteen HL patients were treated with DIBH-PBS involved site RT at 30 Cobalt-Gray equivalent (CGE) in 15 fractions. The average age was 30.8 yrs (range: 18-48) and the average PTV volume was 1385 cc (range: 766-2134). For every patient, clinically deliverable PartArc and 3D-CRT plans were produced by a different institution. PTV coverage was evaluated and dosimetric parameters such as body integral dose (BDI), Dmean, Dmax, D2%, and V(5, 10, 20, and 30) Gy were compared for organs at risk including 12 cardiac substructures. Cardiovascular and second cancer risks were estimated using published dose-response relationships. Wilcoxon signed-rank test was used to assess statistical significance of the differences. There were no significant differences in PTV coverage among the 3 techniques, except from an increased V107% for 3D-CRT (419 cc) compared to PartArc (7 cc) and PBS (4 cc). The BDI for PBS (2.1 Gy) was 57.0% and 65.0% lower compared to PartArc (4.9 Gy) and 3D-CRT (5.9 Gy) respectively (P = 0.007). PBS reduced the mean dose to the heart, lungs, breast, esophagus and larynx compared to 3D-CRT and PartArc by between 1.0 and 5 Gy (P<0.05). PBS increased the V30 Gy and D2% to the lungs, heart and esophagus compared to PartArc by 5.0%, 6.0%, 20.0% and 1.1 Gy, 2.0 Gy and 1.0 Gy respectively (P < 0.05). There were no significant differences to the thyroid. The highest differences were observed in the spinal cord where PBS reduced the D2% and Dmax by almost 85.0% (25.0 Gy) compared to both photon techniques (P < 0.05). Cardiac and second cancer risks are presented on Table 1. PBS reduced predicted cardiac and second cancer risks for HL patients compared to 3D-CRT and PartArc RT.Abstract 1026; Table 1Cardiac and second cancer risks predicted for HL patientsCardiac Risk3D-CRT95% CIPartArc95% CIPBS95% CIAER 30-year Cardiac Mortality (%)2.000.88-3.111.590.67-2.511.260.67-1.86RR CHF (based on MHD)1.090.97-1.221.041.00-1.091.021.01-1.03RR CHF (Based on LVD)1.210.99-1.421.121.00-1.241.041.01-1.08RR VHD1.761.41-2.111.471.21-1.721.271.08-1.47RR CHD1.841.56-2.121.671.43-1.911.571.40-1.75Second Cancer RiskRR Breast1.411.21-1.621.401.21-1.591.231.13-1.34RR Lung2.552.32-2.782.322.13-2.511.791.68-1.91RR Esophagus8.257.51-8.997.627.02-8.216.616.07-7.15AER: Absolute Excess Risk, RR: relative risk, CHF: Cardiac Heart Failure, MHD: Mean Heart Dose, LVD: Left Ventricle Dose, VHD: Valvular Heart Disease, CHD: Coronary Heart Disease. Open table in a new tab

Postoperative radiotherapy for prostate cancer: the sooner the better and potential to reduce toxicity even further

To evaluate biochemical relapse-free survival (bRFS), overall survival (OS), late rectal and bladder toxicities in a retrospective single institution series, also applying an in-house software for biological dose calculation. 258 patients submitted to radiotherapy after prostatectomy were considered. Differences between groups were calculated using the log-rank test and the relevant clinical and therapeutic variables were considered for multivariate analysis. PRODVH is an in-house system able to calculate mean dose-volume histograms (DVHs) of a series of patients, to convert them in biologically effective DVHs (BEDVHs) and allowing to compare them with ANOVA and t Student test. Adjuvant radiotherapy (ART) and salvage radiotherapy (SRT) were performed in 131 (50.8%) and 127 patients (49.2%). At multivariate analysis advanced T stage, androgen deprivation total (ADT) and SRT resulted as independent variables related to a worst bRFS (p=0.019, 0.001 and 0.02), while GS>7 and SRT affected negatively OS (p 0.047 and 0.039). High grade toxicity events occurred mainly in patients treated with 3-dimensional conformal radiotherapy (3DCRT) (proctitis p=0.006; cystitis: p=0.041). A significantly more favorable mean rectum BEDVH for patients with G0 or G1 rectal toxicity was shown (p<0.001). Mean BEDVH for both bladder (p<0.01) and rectum (p<0.05) were also significantly better for volumetric modulated arc therapy-image guided radiotherapy (VMAT-IGRT) plans than for 3DCRT plans. ART is better than SRT in terms of bRFS and OS, particularly for more aggressive cases, advanced T stage and higher Gleason Score. Postoperative prostate cancer radiotherapy should be applied as soon as possible after surgery. The use of modern techniques such as VMAT-IGRT significantly reduces toxicity.

Evaluation of Delivery Costs for External Beam Radiation Therapy and Brachytherapy for Locally Advanced Cervical Cancer Using Time-Driven Activity-Based Costing

To evaluate the delivery costs, using time-driven activity-based costing, and reimbursement for definitive radiation therapy for locally advanced cervical cancer. Process maps were created to represent each step of the radiation treatment process and included personnel, equipment, and consumable supplies used to deliver care. Personnel were interviewed to estimate time involved to deliver care. Salary data, equipment purchasing information, and facilities costs were also obtained. We defined the capacity cost rate (CCR) for each resource and then calculated the total cost of patient care according to CCR and time for each resource. Costs were compared with 2016 Medicare reimbursement and relative value units (RVUs). The total cost of radiation therapy for cervical cancer was $12,861.68, with personnel costs constituting 49.8%. Brachytherapy cost $8610.68 (66.9% of total) and consumed 423minutes of attending radiation oncologist time (80.0% of total). External beam radiation therapy cost $4055.01 (31.5% of total). Personnel costs were higher for brachytherapy than for the sum of simulation and external beam radiation therapy delivery ($4798.73 vs $1404.72). A full radiation therapy course provides radiation oncologists 149.77 RVUs with intensity modulated radiation therapy or 135.90 RVUs with 3-dimensional conformal radiation therapy, with total reimbursement of $23,321.71 and $16,071.90, respectively. Attending time per RVU is approximately 4-fold higher for brachytherapy (5.68minutes) than 3-dimensional conformal radiation therapy (1.63minutes) or intensity modulated radiation therapy (1.32 minutes). Time-driven activity-based costing was used to calculate the total cost of definitive radiation therapy for cervical cancer, revealing that brachytherapy delivery and personnel resources constituted the majority of costs. However, current reimbursement policy does not reflect the increased attending physician effort and delivery costs of brachytherapy. We hypothesize that the significant discrepancy between treatment costs and physician effort versus reimbursement may be a potential driver of reported national trends toward poor compliance with brachytherapy, and we suggest re-evaluation of payment policies to incentivize quality care.

National Population-Based Study Comparing Treatment-Related Toxicity in Men Who Received Intensity Modulated Versus 3-Dimensional Conformal Radical Radiation Therapy for Prostate Cancer

To compare, in a national population-based study, severe genitourinary (GU) and gastrointestinal (GI) toxicity in patients with prostate cancer who were treated with radical intensity modulated radiation therapy (IMRT) or 3-dimensional conformal radiation therapy (3D-CRT). Patients treated with IMRT (n=6933) or 3D-CRT (n=16,289) between January 1, 2010 and December 31, 2013 in the English National Health Service were identified using cancer registry data, the National Radiotherapy Dataset, and Hospital Episodes Statistics, the administrative database of care episodes in National Health Service hospitals. We developed a coding system that identifies severe toxicity (at least grade 3 according to the National Cancer Institute Common Terminology Criteria for Adverse Events scoring system) according to the presence of a procedure and a corresponding diagnostic code in patients' Hospital Episodes Statistics records after radiation therapy. A competing risks regression analysis was used to estimate hazard ratios (HRs), comparing the incidence of severe GI and GU complications after IMRT and 3D-CRT, adjusting for patient, disease, and treatment characteristics. The use of IMRT, as opposed to 3D-CRT, increased from 3.1% in 2010 to 64.7% in 2013. Patients who received IMRT were less likely than those receiving 3D-CRT to experience severe GI toxicity (4.9 vs 6.5 per 100 person-years; adjusted HR 0.66; 95% confidence interval 0.61-0.72) but had similar levels of GU toxicity (2.3 vs 2.4 per 100 person-years; adjusted HR 0.94; 95% confidence interval 0.84-1.06). Prostate cancer patients who received radical radiation therapy using IMRT were less likely to experience severe GI toxicity, and they had similar GU toxicity compared with those who received 3D-CRT. These findings in an unselected "real-world" population support the use of IMRT, but further cost-effectiveness studies are urgently required.

Intensity-modulated versus 3-dimensional conformal radiotherapy in the definitive treatment of esophageal cancer: comparison of outcomes and acute toxicity

BackgroundThough the vast majority of seminal trials for locally advanced esophageal cancer (EC) utilized three-dimensional conformal radiotherapy (3DCRT), the advanced and highly conformal technology known as intensity-modulated radiotherapy (IMRT) can decrease doses to critical cardiopulmonary organs. To date, there have been no studies comparing both modalities as part of definitive chemoradiation (dCRT) for EC. Herein, we investigated local control and survival and evaluated clinical factors associated with these endpoints between cohorts.MethodsWe retrospectively analyzed 93 patients (3DCRT n = 49, IMRT n = 44) who received dCRT at our institution between 2000 and 2012 with the histologic diagnosis of nonmetastatic EC, a Karnofsky performance status of ≥70, curative treatment intent, and receipt of concomitant CRT. Patients were excluded if receiving <50 Gy. Kaplan-Meier analysis was used to evaluate the endpoints of local relapse rate (LR), progression-free survival (PFS), and overall survival (OS). Cox proportional hazards modeling addressed factors associated with outcomes with univariate and multivariate approaches. Rates of acute toxicities and basic dosimetric parameters were compared between 3DCRT and IMRT patients.ResultsMean follow-up was 34.7 months. The 3-year LR was 28.6% in the 3DCRT group and 22.7% in the IMRT group (p = 0.620). Median PFS were 13.8 and 16.6 months, respectively (p = 0.448). Median OS were 18.4 and 42.0 months, respectively (p = 0.198). On univariate analysis, only cumulative radiation dose was associated with superior LR (hazard ratio (HR) 0.736; 95% confidence interval (CI) 0.635 – 0.916, p = 0.004). Factors clearly affecting survival were not observed.ConclusionsWhen comparing 3DCRT- versus IMRT-based dCRT, no survival benefits were observed. However, we found a lower local recurrence rate in the IMRT group potentially owing to dose-escalation. Prospective data are needed to verify the presented results herein.

Photon and Proton Radiation Therapy Utilization in a Population of More Than 100 Million Commercially Insured Patients

To characterize the changes in the use of radiation therapy (RT), specifically proton beam radiation therapy (PBRT), among adult and pediatric patients over a 11-yearperiod in a verylarge population of insured patients. We conducted a retrospective analysis of the OptumLabs Data Warehouse claims database of more than 100 million insured US enrollees. Descriptive analyses were undertaken to evaluate the characteristics of patients receiving RT from 2002 to2012. There were 474,533 patients treated with RT from 2002 to 2012. The percentage of patients treated with 3-dimensional conformal radiation therapy, 2-dimensional RT/brachytherapy, intensity modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT), and PBRT was 34.5%, 63.4%, 2.1%, 0.0%, and 0.1% and 40.4%, 36.0%, 21.9%, 1.1%, and 0.6% in 2002 and 2012, respectively. The greatest increase in utilization was of IMRT for prostate cancer, growing from 3.5% to 64.0%. For non-prostate cancer adults, IMRT use grew from 1.7% to 16.4%. For children, PBRT utilization increased from 0.3% to 9.7%. For prostate cancer patients, PBRT increased from 0.0% to 2.6%. For all patients, advanced technology (SBRT and PBRT) use was very low at <2%, versus 22% for IMRT. This is the largest and most geographically diverse description of RT utilization. Proton beam RT utilization remains very low and has had little impact on overall RT utilization compared with IMRT. The largest shift has occurred in IMRT for prostate cancer. Our findings indicate that overall utilization of proton therapy has been low and that its use has likely had little impact on national expenditures on cancer care in the current environment.

Outcome and toxicity of radical radiotherapy or concurrent Chemoradiotherapy for elderly cervical cancer women

BackgroundConcurrent chemoradiotherapy (CCRT) is the standard treatment for local advanced cervical cancer. However, for elderly patients, studies are limited and the outcomes are controversial. We retrospectively analyzed the efficacy and tolerance of radical radiotherapy (RT) or CCRT in elderly cervical cancer patients and performed comparisons between them.MethodsWe retrospectively analyzed the elderly cervical cancer patients (≥70 years old) treated with radical RT or CCRT between January 2006 and December 2014. For external beam radiotherapy, 50Gy in 25 fractions or 50.4Gy in 28 fractions were delivered via 3-dimensional conformal radiation therapy or intensity modulated radiation therapy. High-dose-rate intracavitary brachytherapy was performed with a dose of 30-36Gy in 5–7 fractions to point A. Concurrent chemotherapy regimens included weekly cisplatin and paclitaxel.ResultsSeventy-three patients were eligible for this study. Twenty-one(28.8%) and 52(71.2%) patients suffered with FIGO stage IB-IIA and IIB-IVA disease, respectively. Twenty-four (32.9%) patients received CCRT. The median duration of follow-up was 32.4 months (4.8–118.8 months). The 3-year overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) were 64.9%, 67.8% and 66.5%, respectively. By multivariate analysis, CCRT was a significant predictive factor of OS(p = 0.023, 95% confidence interval [CI]: 1.172–8.860), CSS(p = 0.031, 95% CI: 1.131–13.908)and DFS(p = 0.045, 95% CI: 1.023 ~ 6.430). The 3-year OS of patients received RT and CCRT were 54.3% and 83.1%, CSS were 56.8% and 87.1%, DFS were 57.6% and 83.3%. There was no treatment related death. Grade 3–4 acute hematological, gastrointestinal and urinary toxicity incidences were 31.5%, 19.1% and 12.3%, respectively. For grade 3–4 chronic gastrointestinal and genitourinary toxicities, the incidences were 4.1% and 2.7%, respectively. Compared with RT, CCRT was related with high grade 3–4 hematological toxicity (16.3% and 62.5% respectively, p < 0.001), respectively. However, acute nonhematological toxicity and chronic toxicity were not significantly different.ConclusionElderly cervical cancer patients could tolerate radical RT and CCRT very well and get a favored survival. Compared with RT, CCRT could improve the survival of elder cervical cancer patients with similar nonhematological toxicity. CCRT should be considered in elderly cervical cancer patients.

Primary Management of Squamous Cell Carcinoma of the Anal Canal: A 30-year Community Hospital Experience

ABSTRACTWe reviewed outcomes of 41 patients treated with curative-intent radiotherapy for anal canal carcinoma at a community hospital between 1985 and 2015. Twenty-six (63%) presented with stage I or II disease while 15 (37%) had stage III. Thirty-seven received definitive chemoradiation and 4 radiotherapy alone. Thirteen (31.7%) received ≤59.4Gy. Thirty-two (78%) were treated with 3-dimensional conformal radiotherapy while 9 (22%) received intensity-modulated radiotherapy. At 5 years, local control, regional control, freedom from distant metastasis, cause-specific survival, and overall survival were 80%, 98%, 88%, 77%, and 51%. Of those who received >59.4Gy, local control and overall survival were not improved.

Recent Time Trends and Predictors of Heart Dose From Breast Radiation Therapy in a Large Quality Consortium of Radiation Oncology Practices

Limited data exist regarding the range of heart doses received in routine practice with radiation therapy (RT) for breast cancer in the United States today and the potential effect of the continual assessment of the cardiac dose on practice patterns. From 2012 to 2015, 4688 patients with breast cancer treated with whole breast RT at 20 sites participating in a state-wide consortium were enrolled into a registry. The importance of limiting the cardiac dose has been emphasized in the consortium since 2012, and the mean heart dose (MHD) has been reported by each institution since 2014. The effects on the MHD were estimated for both conventional and accelerated fractionation using regression models, with technique (intensity modulated RT [IMRT] vs 3-dimensional conformal RT), deep inspiration breath hold use, patient position (supine vs prone), nodal RT (if delivered), and boost (yes vs no) as covariates. For left-sided breast cancer treated with conventional fractionation, the median MHD in 2012 was 2.19Gy versus 1.65Gy in 2015 (P<.001). The factors that significantly increased the MHD for conventional fractionation were increased separation relative to 22cm (1.5%/1cm), supraclavicular or infraclavicular nodal RT (17.1%), internal mammary nodal RT (40.7%), use of a boost (20.9%), treatment year before 2015 (7.7%), and use of IMRT (20.8%). For left-sided BC treated with accelerated fractionation, the median MHD in 2012 was 1.70Gy versus 1.22Gy in 2015 (P<.001). The factors that significantly increased the MHD for accelerated fractionation were separation (1.7%/1cm), use of a boost (20.0%), year before 2015 (8.5%), and use of IMRT (19.2%). The factors for both conventional fractionation and accelerated fractionation that significantly reduced the MHD were the use of deep inspiration breath hold and prone positioning. The MHD for left-sided breast cancer decreased during a recent 4-year period, coincident with an increased focus on cardiac sparing in the radiation oncology community in general and a state-wide consortium specifically. These data suggest a positive effect of systematically monitoring the heart dose delivered.

Intensity-modulated radiotherapy for hepatocellular carcinoma: dosimetric and clinical results.

Since the introduction of 3-dimensional conformal radiotherapy (3DCRT), new radiotherapy techniques have expanded the indication of radiotherapy for the treatment of hepatocellular carcinoma (HCC), from the hitherto palliative to a now curative-intent purpose. Intensity-modulated radiotherapy (IMRT), currently the most advanced radiotherapy technique, is considered an attractive option for the treatment of HCC, and is more widely applied because it can deliver a higher dose to the tumor than 3DCRT while sparing surrounding normal organs. However, the advantages and potential disadvantages of IMRT for treating HCC have not been fully established. This article deals with three different IMRT techniques, including static IMRT and volumetric modulated arc therapy using conventional multileaf collimator (MLC) mounted linear accelerators, and helical IMRT using binary MLC mounted helical tomotherapy machine. We review dosimetric and clinical studies for these IMRT techniques for the treatment of HCC.

Hepatectomy after down-staging of hepatocellular carcinoma with portal vein tumor thrombus using chemoradiotherapy: A retrospective cohort study

BackgroundThis study evaluates the survival benefit and safety of hepatectomy after down-staging by 3-dimensional conformal radiation therapy (3D-CRT) for major portal vein tumor thrombus (PVTT) combined with hepatic arterial infusion chemotherapy (HAIC) for advanced hepatocellular carcinoma (HCC). MethodsFifty-two patients with unresectable advanced HCC treated with HAIC combined with 3D-CRT for PVTT, from January 2002 to March 2015, were analyzed in this retrospective study. Hepatectomy was offered to patients if, based on radiologic findings, all gross lesions were considered resectable. The safety of hepatectomy was investigated and overall survival (OS) was compared between the resection group (n = 7) and non-resection group (n = 43). ResultsOS was significantly higher in the resection group than in the non-resection group. Results of multivariate analysis identified conversion to surgery (hazard ratio, 0.35; 95% confidence interval, 0.10–0.99; P = 0.048) as an independent factor influencing OS. There were no serious postoperative complications and no case of mortality in patients who underwent hepatectomy. ConclusionsOur findings suggest that hepatectomy after down-staging by 3D-CRT for PVTT combined with HAIC for advanced HCC is safe and results in good long term outcome.

Ischemic Cardiac Events Following Treatment of the Internal Mammary Nodal Region Using Contemporary Radiation Planning Techniques

Regional nodal irradiation, including radiation therapy (RT) to the internal mammary node (IMN) region, improves oncologic outcomes in patients with node-positive breast cancer. Concern remains, however, given the proximity of the IMNs to the heart and the association between cardiac RT exposure and toxicity. The objective of the study was to evaluate rates of ischemic cardiac events (ICEs) and associated risk with treatment of the IMN region. The cardiac outcomes of 2126 patients treated with adjuvant breast RT or breast and nodal RT from 1984 to 2007 at a single institution were reviewed. The primary endpoint was an ICE following RT initiation. The association between IMN RT and ICEs was assessed using Cox proportional hazards models. Treatment with both IMN RT and 3-dimensional (3D) conformal radiation therapy (CRT) began in 1997; therefore, subset analyses of patients with only 3D CRT were performed to minimize bias associated with improved treatment technique. The median follow-up period was 9.3years. An ICE occurred in 87 patients (4.1%). No increased 10-year rate of ICEs was observed with IMN RT compared with no IMN RT in the total cohort (3.2% [95% confidence interval (CI), 2.4%-4.3%] vs 3.4% [95% CI, 1.5%-7.5%]; hazard ratio [HR], 0.88; P=.73). Similarly, no statistically significant difference was noted in the 3D CRT-planned, left-sided disease subset (5.1% [95% CI, 1.8%-14.1%] vs 4.0% [95% CI, 2.0%-8.0%]; HR, 1.18, P=.76). On multivariate analysis, adjusting for cardiac risk factor imbalances, no significantly increased hazard was noted with IMN RT (HR, 1.84; P=.28) in the 3D CRT-planned, left-sided disease subset. No statistically significant association between IMN RT and ICEs was demonstrated in a review of patients treated at a single institution from 1984 to 2007. Given the long natural history and low overall rate of ICEs, continued follow-up of this study, as well as additional studies in the 3D CRT era, is warranted to confirm these results. Minimizing cardiac exposure, when treating a limited IMN field, is critical to limit excess risk of ICEs.