3-dimensional Conformal Radiotherapy Research Articles

A Comparison of Radiation Techniques in Patients Treated With Concurrent Chemoradiation for Stage III Non-Small Cell Lung Cancer

The standard of care in management of patients with good performance status and unresectable stage III non-small cell lung cancer (NSCLC) therapy is concurrent chemoradiation. Newer techniques such as intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) are replacing 3-dimensional conformal radiation (3DCRT) despite low-quality evidence of improved outcomes. We used population-based data to examine survival outcomes by radiation technique. A population-based retrospective cohort of patients with stage III NSCLC treated with concurrent chemoradiation from 2009 to 2017 in Ontario were identified. The primary outcome was a comparison of overall survival among 3DCRT, IMRT, and VMAT, calculated using the Kaplan-Meier method and compared using log-rank test. Cox regression was used to investigate effect of radiation type on overall survival adjusted for other covariates. A total of 3872 patients were treated with 3DCRT (n = 1178), IMRT (n = 1847), or VMAT (n = 847). A decline in 3DCRT and increase in VMAT use were observed over time. Median survival in months was 21.2 (95% confidence interval [CI], 20.0-22.8) for 3DCRT, 23.9 (95% CI, 22.3-25.6) for IMRT, and 24.9 (95% CI, 22.5-27.4) for VMAT, but these differences were not statistically significant (P = .06). Our study demonstrates that survival is not compromised in patients receiving IMRT or VMAT (compared with 3DCRT). Thus, given the potential dosimetric advantages associated with these techniques, VMAT and IMRT are recommended for the management of patients with stage III NSCLC.

Locoregional Control, Overall Survival, and Disease-Free Survival in Stage IIIA (N2) Non–Small-Cell Lung Cancer: Analysis of Resected and Unresected Patients

IntroductionThe standard of care for stage IIIA (N2) non–small-cell lung cancer (NSCLC) includes concurrent definitive chemoradiation (dCRT) followed by durvalumab, thus challenging the role of surgery in resectable patients. We assessed locoregional disease control and survival in patients with surgically resected and unresected stage IIIA (N2) NSCLC disease. Patients and MethodsWe conducted a retrospective analysis from prospectively collected databases at MD Anderson Cancer Center. Patients undergoing neoadjuvant chemotherapy and surgery or dCRT for clinical stage IIIA (N2) disease (2004-2014) were evaluated. Primary outcomes included locoregional disease control, disease-free survival (DFS), and overall survival (OS). Kaplan-Meier outcome analyses were performed. ResultsOf the 159 resected patients, the majority had lobectomy (82.4%), followed by pneumonectomy (11.9%) and sublobar resection (5.7%). The 30- and 90-day mortality rates were 0.6% and 1.3%, respectively. At median follow-up of 52.8 months, recurrence was 55.3%, with 44.0% having distant and 15.1% locoregional recurrence. At 5 years, OS was 50.8% and DFS was 33.1% Median OS was 61.2 months. A total of 366 patients underwent dCRT, with intensity-modulated radiation in 64.5%, proton therapy in 26.0%, and 3-dimensional conformal radiotherapy in 9.6%. The mean dose was 68.1 Gy. At median follow-up of 20.8 months, recurrence was 53.6%, with distant and locoregional recurrence of 40.7% and 30.3%, respectively. At 5 years, OS was 29.2% and DFS was 20.5%. Median OS was 27.5 months. ConclusionStage IIIA (N2) NSCLC continues to be a heterogeneous disease, and patients with surgically resected and unresected disease represent different risk populations. Ongoing immunotherapy trials may further redefine treatment algorithms in this complex patient population.

Ten-Year Outcomes of Moderately Hypofractionated Salvage Postprostatectomy Radiation Therapy and External Validation of a Contemporary Multivariable Nomogram for Biochemical Failure

Although high-level evidence supports moderately hypofractionated radiation therapy for definitive prostate treatment, there is less evidence for its use in the postprostatectomy setting. We externally validated a contemporary nomogram predicting biochemical failure (BF) after salvage radiation therapy (SRT) and report long-term disease control outcomes for hypofractionated SRT to the prostate bed. A retrospective review was performed for 112 patients treated with hypofractionated SRT (52.5 Gy in 20 fractions using 3-dimensional conformal radiation therapy) for pT2-4R0-1N0/XM0 prostate adenocarcinoma, with postoperative prostate-specific antigen (PSA) greater than 0.1 ng/mL or rising. Freedom from BF (FFBF), distant metastasis, cancer-specific mortality, and overall survival were analyzed from commencement of radiation therapy. Cox regression was performed on FFBF to account for covariates. BF was defined as a PSA ≥0.4 ng/mL and rising after SRT. Early SRT was defined as SRT commencing at a pre-SRT PSA of ≤0.2 ng/mL. Median follow-up was 10.0 years (interquartile range, 9.3-10.7 years), median pre-SRT PSA was 0.4 ng/mL, and androgen deprivation therapy was used in 14% of patients. The 5/10-year FFBF, distant metastasis, cancer-specific mortality, and overall survival were 68%/51%, 7%/16%, 5%/11%, and 90%/75%, respectively. FFBF for early SRT compared with late SRT was 81% versus 66% at 5 years and 68% versus 49% at 10 years. On multivariable analysis, pre-SRT PSA, International Society of Urologic Pathology grade group, seminal vesicle invasion, and androgen deprivation therapy use were associated with FFBF. The nomogram c-index was 0.67, and it overestimated FFBF by 10% and 15% at 5 and 10 years, respectively, with confidence intervals overlapping the line of unity. Hypofractionated SRT provides long-term disease control outcomes comparable to conventionally fractionated radiation therapy. Early SRT provides improved disease control, with two-thirds of patients with pre-SRT PSA of ≤0.2 ng/mL free of BF at 10 years. We performed the first external validation of the Tendulkar salvage nomogram, which showed a robust model performance.

Positron emission tomography-computed tomography guided radiotheraphy planning in lung cancer

Aims and backgroundIn three dimensional conformal radiotherapy (3D-CRT), treatment planning is based on computerized tomography (CT) images. However, the data obtained from CT may not be sufficient in target delination. The purpose of this study is to show the differences between the radiotherapy (RT) plans which were done with positron emission tomography (PET) fusion or not.MethodsPatients with lung cancer between February 2009 and January 2012 at our institution were assessed retrospectively. Sixty patients who were treated with 3DCRT, CT simulation images were registrated with PET images. For each patient target volumes were determined and normal tissues were revised. Wilcoxon Signed Rank Test was used to compare the two groups.ResultsFor gross tumor volume (GTV), clinical target volume (CTV) and planning target volume (PTV); median volume values, median mean dose values and median maximum dose values were significantly different according to use of PET. About normal tissue doses; mean lung dose (MLD), lung V20, mean and maximum esophagus dose, V50 and V60, mean heart dose and maximum medulla spinalis dose were analyzed.ConclusionWithin these parameters there were statistically significant difference except in maximum dose of esophagus and V60. In our study, we observed decreased target volumes and higher dose distrubutions for target volumes in PET registrated RT plans. According to these data, it is possible to say that optimal RT plans can be formed for lung cancer by using PET registration.

Confidence and proficiency levels of medical dosimetry graduates

The purpose of this study was to examine the confidence and proficiency levels of medical dosimetry graduates as they transition from student to professional during their first employment as medical dosimetrists. In addition, this study explored the support provided by employers to assist those medical dosimetry graduates during this transitional period. With assistance from the Medical Dosimetrist Certification Board (MDCB), individuals who graduated from a Joint Review Committee on Education in Radiologic Technology accredited medical dosimetry program between 2011 and 2018 and earned MDCB certification between 2012 and 2018 were invited to complete an original survey detailing their experiences during their first employment as medical dosimetrists. Data were collected using Qualtrics and analyzed with IBM's SPSS. Most (93, 56.7%) participants indicated a moderate confidence level in their abilities to function as medical dosimetrists and suggested it took approximately 6 months (56, 34.1%) to feel confident in their role as medical dosimetrists in the professional clinical setting. Regarding treatment planning techniques, participants indicated low proficiency levels in proton beam and brachytherapy plans and high proficiency levels in 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, and electron beam plans. These findings suggest that educators should consider strengthening curricula and offering additional clinical rotations specific to those areas that lacked proficiency. Most (128, 78.0%) did not complete a dosimetry-specific new employee training program, but believed such support would have been somewhat helpful (44, 34.4%) during their transition from student to professional. Hiring managers and dosimetry supervisors may find it beneficial to implement support measures to assist medical dosimetry graduates as they transition from student to professional.

A retrospective evaluation of mixed energy volumetric modulated arc therapy for anal cancers with lymph node involvement

Applying dual, or mixed photon energies during radiation therapy is a common practice in 3-dimensional conformal radiation therapy (3D-CRT). Mixed photon energies are used to provide uniform dose coverage to a planning target volume (PTV) that ranges in depth from the skin surface. Though the application of mixed photon energies in 3D-CRT was once the convention for treating anal cancers with lymph node involvement (AC-LNI), the advantages offered by volumetric modulated arc therapy (VMAT) prove to be the optimal form of therapy for AC-LNI. Recently, multiple researchers have uncovered benefits in employing multiple photon energies in VMAT planning for prostate cancer. A retrospective study was completed to assess the impact of implementing mixed energy VMAT planning in comparison to conventional single energy VMAT planning for AC-LNI. Data from 20 patients with AC-LNI was collected to analyze the dosimetric effects of mixed energy VMAT treatments in terms of PTV conformity index, PTV homogeneity index, monitor unit usage, and organs at risk sparing. For each patient 3 treatment plans were created: a single energy 6 MV plan, a single energy 10 MV plan, and a mixed 6 MV and 10 MV energy plan. Analysis of the resulting dosimetric outcomes showed statistical significance. The current study concluded that mixed energy VMAT plans have some effect on treating AC-LNI when compared to single energy VMAT plans.

The Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin A

Background: Head and neck cancer (HNC) mean a heterogeneous group of tumors in multiple anatomical sites in the head and neck structures. Radiation therapy(RT) is one of the fundamental treatment options for tumors. Saliva is a clear, mucoserous fluid produced in the mouth which determines the environment of the oral structures. Immunoglobulin A (IgA) can considered to be the major specific protection mechanism in the mouth. Aims of study: To monitor the effects of two techniques of head and neck radiotherapy on salivary flow rate (SFR) and salivary IgA. Materials and method: study included thirty healthy individuals as control group and two patients groups with HNC: the first group consist of 30 patients treated by three dimensional conformal radiation therapy (3DCRT) and the second group also consist of the same patient's number but treated by intensity-modulated radiation therapy (IMRT) ) at middle Euphrates oncology center/ Najaf-Iraq. Saliva samples were collected before the first session and after the last session of RT. Results: study shows highly significant decrease in SFR in both patients groups after finishing RT. SFR in patients treated by IMRT is significantly higher than SFR in other group treated by 3DCRT. Salivary IgA is significantly reduced after RT, without difference statically in the level of IgA between the two patients group. Conclusion: present study shows that head and neck RT decrease both SFR and salivary IgA, at the same time IMRT technique is better than 3DCRT in maintaining saliva secretion. How to Cite this Article Pubmed Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin SRP. 2020; 11(1): 286-291. doi:10.5530/srp.2020.1.37 Web Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin http://www.sysrevpharm.org/?mno=83794 [Access: March 29, 2021]. doi:10.5530/srp.2020.1.37 AMA (American Medical Association) Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin SRP. 2020; 11(1): 286-291. doi:10.5530/srp.2020.1.37 Vancouver/ICMJE Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin SRP. (2020), [cited March 29, 2021]; 11(1): 286-291. doi:10.5530/srp.2020.1.37 Harvard Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA (2020) Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin SRP, 11 (1), 286-291. doi:10.5530/srp.2020.1.37 Turabian Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. 2020. Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin Systematic Reviews in Pharmacy, 11 (1), 286-291. doi:10.5530/srp.2020.1.37 Chicago Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. The Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin A. Systematic Reviews in Pharmacy 11 (2020), 286-291. doi:10.5530/srp.2020.1.37 MLA (The Modern Language Association) Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA. The Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin A. Systematic Reviews in Pharmacy 11.1 (2020), 286-291. Print. doi:10.5530/srp.2020.1.37 APA (American Psychological Association) Style MOHAMMED H. ALBURGAIBA, FAWAZ D. AL-ASWAD, AMMAR R. MOHAMMAD RUTHA (2020) Effect of Two Different Techniques of Head and Neck Radiotherapy on Saliva Secretion and Salivary Immunoglobulin Systematic Reviews in Pharmacy, 11 (1), 286-291. doi:10.5530/srp.2020.1.37

Dose Volume Relationship in Estimating Cardiac Doses in Breast Cancer Radiotherapy

Introduction: Radiation therapy is an integral part of adjuvant treatment for breast cancer which reduces local recurrence and significantly increases survival. But, radiation therapy also has the propensity to increase cardiac morbidity and mortality due to dose received by the heart which is more in left-sided breast cancer. Mean Heart dose and Maximum Heart Distance (MHD) are two parameters to study dose received by the heart. Aim: The purpose of this study was to determine individual doses received by the heart and to correlate MHD with the mean heart dose received by heart in carcinoma breast patients receiving radiotherapy. Materials and Methods: Ninety patients of histologically proven carcinoma breast who attended the Department of Radiotherapy, Acharya Harihar Regional Cancer, Cuttack from January 2017 to January 2019 were selected for a prospective observational study. All patients were treated with 3D Conformal Radiotherapy technique using free breathing multi slice Computed Tomography (CT) scans to contour target and vital organs. Parallel opposed tangential treatment plans were generated for each patient. Individual dose received by the heart and MHD was assessed for each case. SPSS version 21 used for statistical analysis. The Spearman’s Rho test was used for correlation of MHD with Mean heart dose. The Mann-Whitney U test was used for comparing mean of MHD in left-sided and right-sided breast cancer. The Independent t-test was used for comparing means of Mean heart dose in left-sided and right-sided breast cancer. A p-value <0.05 was considered as statistically significant. Results: The Mean Heart Dose was 4.63 Gy for left-sided breast carcinoma patients and 0.846 Gy for right-sided breast cancer and there was a significant difference (p<0.001). Mean MHD for left-sided breast cancer was 2.974 cm while for right-sided it was 0.017 cm, the difference was statistically significant (p-value <0.001). MHD also correlated positively with Mean Heart Dose with correlation coefficient of 0.849 and p-value <0.001. Conclusion: MHD and Mean Heart dose were significantly higher in left-sided breast cancer receiving radiotherapy. MHD was also found to be positively related to Mean Heart dose and therefore found to be an important predictor of cardiac dose. For right-sided breast carcinoma receiving radiotherapy, free breathing technique using 3-Dimensional Conformal Radiotherapy (3DCRT) will suffice in terms of cardiac dose.

Transarterial Chemoembolization Followed by Radiotherapy Versus Sandwich Treatment for Unresectable or Ablative Hepatocellular Carcinoma.

Objective:Our objective is to assess whether the outcome of intrahepatic unresectable or ablative hepatocellular carcinoma (HCC) could be improved by supplemental transarterial chemoembolization (TACE) following initial treatment of TACE with 3-dimensional conformal radiotherapy (3DCRT), compared to TACE followed by 3DCRT alone.Methods:We retrospectively analyzed intrahepatic unresectable or ablative HCC patients who underwent TACE, followed by 3DCRT with or without additional TACE, from June 2010 to December 2016 at our institution. Survival was assessed using the Kaplan-Meier method and compared with the log-rank test. Cox regression analyses were used to identify factors that influenced prognosis. Toxicity profiles were evaluated using CTCAE 4.0.Results:27 patients received TACE with 3DCRT (TR group) and 11 received additional TACE following TACE and 3DCRT (sandwich group), respectively. The median intrahepatic progression-free survival (IPFS), progression-free survival (PFS), and overall survival (OS) in the TR group and sandwich group were 5.4 months vs. 17 months (P = 0.018), 5.4 months vs. 17 months (P = 0.008), and 13.5 months vs. 29.2 months (P = 0.011), respectively. Multivariate Cox regression demonstrated that TACE followed by radiotherapy alone had a shorter IPFS (HR: 2.516, 95% CI (1.136-5.570), P = 0.023) and PFS (HR: 2.637, 95% CI (1.182-5.880), P = 0.018) compared with the sandwich treatment. Hepatitis B virus reactivation occurred in 1 patient in the sandwich group. Myleosuppresion was considered a grade 3/4 adverse event.Conclusion:Unresectable or ablative HCC patients possibly benefit from the combination of TACE and 3DCRT followed by additional TACE therapy, compared with TACE followed by 3DCRT alone.

Challenges of radical chemoradiation planning in Stage III non-small-cell lung cancer: Can volumetric modulated arc radiotherapy overcome an unfavourable location?

Radiotherapy treatment planning of radical doses for concurrent chemoradiation in Stage III non-small-cell lung cancer (NSCLC) presents many challenges. This dosimetric study aimed to analyse the impact of spatial location of tumour and nodal burden in limiting the achievement of normal organ constraints and the use of appropriate radiotherapy technique to address it. Fifteen Stage III NSCLC patients underwent 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) based treatment planning. VMAT (Volumetric Modulated Arc Radiotherapy) plans were made for all patients treated by 3D-CRT (3-Dimensional Conformal Radiotherapy). A binomial logistic regression was performed to ascertain the tumour and nodal characteristics that decreased the likelihood of being planned to 60Gy. Inability to achieve normal tissue constraints, particularly spinal cord dose to less than 50Gy, during initial planning by the assigned treatment technique was the primary dose limiting factor in four patients (p=0.02). Alternate VMAT plans could achieve the dose constraints where 3D-CRT was unsuccessful in patients with bulky central disease in two patients. This technique fell short when there was gross vertebral body erosion. For tumours with bulky central disease, VMAT should be preferred. With gross vertebral body erosion, even VMAT falls short if the planning target volume includes the spinal cord. In a subset of Stage III NSCLC upfront chemoradiation to radical doses may not be feasible.

Preliminary Simulation Study of Carotid Artery and Pharyngeal Constrictor Muscle Sparing-Radiotherapy in Glottic Carcinoma.

Background:This preliminary simulation study aimed to compare the dosimetric outcomes of carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) in patients with T1N0M0 glottic carcinoma undergoing helical tomotherapy-intensity modulated radiotherapy (HT-IMRT) and 3-dimensional conformal radiotherapy (3D-CRT) plans.Methods:In addition to the clinical target volume (CTV) which was defined as the entire larynx, the CAs and PCM of 11 glottic carcinoma patients were delineated. The CTV was uniformly expanded 5 mm to create a planning target volume (PTV) relative to the PCM and at a distance of 2 mm from the CA. The dosimetric characteristics in HT-IMRT and lateral opposed fields-based 3D-CRT plans were analyzed.Results:Median D95%and V100% of PTV were significantly higher in HT-IMRT (p < 0.001) compared to 3D-CRT. The right/left CA dosimetric outcomes, including the mean doses (20.7/21.5 Gy versus 48.7/50.5 Gy), Dmax (53.6/52.0 Gy versus 67.4/67.7 Gy), V30 (25.0/27.1% versus 77.6/80.3%), V40 (8.0/7.9% versus 74.6/71.9%), and V50 (2.0/1.2% versus 70.0/71.6%) were also significantly lower in HT-IMRT (p < 0.05), similar to the mean PCM doses (49.6 Gy versus 62.6 Gy for 3D-CRT;p < 0.001), respectively.Conclusions:Our present results demonstrated the feasibility of simultaneous sparing of the CAs and PCM in HT-IMRT- compared to 3D-CRT plans in glottic carcinoma patients undergoing definitive radiotherapy.

The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques

Introduction: In medulloblastoma patients craniospinal irradiation is an important element the treatment. Our study aimed to evaluate the effect of absorbed dose to organs at risk using the hybrid intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) for craniospinal irradiation (CSI) in average risk medulloblastoma patients. Materials and Methods: In this study, thirteen medulloblastoma patients were included. The prescribed total dose to the planning target volume (PTV) was 23, 40 Gy in 13 fractions. Two radiotherapy techniques, three dimensional conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (IMRT) were used to treat these patients. The coverage of the Target was evaluated using the D mean, D95%, D2%, D98% and V95%. Other parameters were also compared such as Integral dose (ID), Homogeneity index (HI) and doses to the organs at risk (OARs). Results: There was no significant difference in the mean dose received by the PTV-Brain or the dose received by 95% and 98% of PTV volume using the two techniques. For PTV-Spine, the percentage volume receiving 95% of the total dose increased significantly in the hybrid IMRT technique compared to the conformal technique. So, hybrid IMRT plan achieved the best coverage for PTV spine. Lower dose for OAR was delivered by 3DCRT, except the heart and thyroid, hybrid IMRT achieved better sparing. All plans resulted in the same dose homogeneity index (DHI) for PTV-Brain. For PTV-Spine, hybrid IMRT technique achieved better dose homogeneity compared to 3DCRT technique (1.09 vs. 1.12; p > 0.05). Conclusions: hybrid IMRT technique can be realized on conformal technique because it achieved better dose coverage for the (PTV) and organ at risk (OAR). 3DCRT reduced mean dose to most OARS, except the heart and thyroid. Therefore, the hybrid IMRT technique may be a CSI treatment alternative to 3DCRT.

EBRT Modality-Specific Treatment Outcome of Cervical Cancer Patients for Real-World Practice

Purpose: To compare the clinical outcome while treating cervical cancer patients with intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3DCRT). Methods: Analyzed a very large dataset from real-world practice using the National Cancer Database (NCDB) for FIGO IB-IIIB inoperable cervical cancer patients treated with chemoradiation from 2004 to 2014. Patients who received initial treatment with external beam radiation therapy (EBRT), either IMRT or 3DCRT, of 40-60Gy dose were included. Patients who received EBRT boost were stratified based on treatment modality (IMRT or 3DCRT for initial and boost). Also considered another group where EBRT is followed by brachytherapy, i.e. the standard of care. IBM-SPSS was used for statistical analysis; p-value &lt;0.05 was considered statistically significant. Results: Median age of the eligible patient population was 53 years and the median follow-up was 24.4 months. Analysis revealed that the median OS was 36.1 months for IMRT versus 51.2 months for 3DCRT (p &lt;0.05); 2- and 5-year OS were 7% and 9%, higher for 3DCRT (p &lt;0.007). Conclusion: This study demonstrates 3DCRT was better than IMRT for OS when no brachytherapy boost was considered. However, 3DCRT and IMRT did not make any difference in OS when brachytherapy boost was used. Therefore, it is important to use brachytherapy boost whenever possible for treatment of inoperable cervical cancer patients with curative intent.

Do Higher Radiation Doses with Concurrent Chemotherapy in the Definitive Treatment of Esophageal Cancer Improve Outcomes? A Meta-Analysis and Systematic Review.

Background: To investigate the effects and safety profile of radiation dose escalation utilizing computerized tomography (CT) based radiotherapy techniques (including 3-Dimensional conformal radiotherapy, intensity-modulated radiotherapy and proton therapy) in the definitive treatment of patients with esophageal carcinoma (EC) with definitive concurrent chemoradiotherapy (dCCRT).Methods: All relevant studies utilizing CT-based radiation planning, comparing high-dose (≥ 60 Gy) versus standard-dose (50.4 Gy) radiation for patients with EC were analyzed for this meta-analysis.Results: Eleven studies including 4946 patients met the inclusion criteria, with 96.5% of patients diagnosed with esophageal squamous cell carcinoma (ESCC). The high-dose group demonstrated a significant improvement in local-regional failure (LRF) (OR 2.199, 95% CI 1.487-3.253; P<0.001), two-year local-regional control (LRC) (OR 0.478, 95% CI 0.309-0.740; P=0.001), two-year overall survival (OS) (HR 0.744, 95% CI 0.657-0.843; P<0.001) and five-year OS (HR 0.683, 95% CI 0.561-0.831; P<0.001) rates relative to the standard-dose group. In addition, there was no difference in grade ≥ 3 radiation-related toxicities and treatment-related deaths between the groups.Conclusion: Under the premise of controlling the rate of toxicities, doses of ≥ 60 Gy in CT-based dCCRT of ESCC patients might improve locoregional control and ultimate survival compared to the standard-dose dCCRT. While our review supports a dose-escalation approach in these patients, multiple ongoing randomized trial initial and final reports are awaited to evaluate the effectiveness of this strategy.

A Validation Study on IDO Immune Biomarkers for Survival Prediction in Non-Small Cell Lung Cancer: Radiation Dose Fractionation Effect in Early-Stage Disease.

We recently reported that indoleamine 2, 3-dioxygenase (IDO) activity is significantly correlated with more distant metastasis and worse survival. The present study examined whether radiotherapy (RT) dose fractionation correlates with IDO-mediated immune activity in patients with early-stage NSCLC.Methods: Patients with newly diagnosed stage I-II NSCLC treated with either conventionally fractionated 3-dimensional conformal radiotherapy (3DCRT) or stereotactic body radiotherapy (SBRT) were analyzed. Levels of two key molecules associated with the IDO immune checkpoint, serum kynurenine and the kynurenine:tryptophan ratio (K:T ratio), were measured at pre-RT, during-RT, and 3-month post-RT. The relationship between disease control outcomes [overall survival (OS), progression free survival, and local/regional/distant failure rates] and absolute levels of these markers, as well as dynamic changes in their levels during RT, was studied. Fifty-six patients (SBRT = 28, 3DCRT = 28) with early-stage NSCLC were studied. In all patients, higher kynurenine post-RT was significantly associated with worse OS ([HR, 1.25; 95% confidence interval (CI), 1.01-1.55; P = 0.044). No statistically significant differences in absolute kynurenine levels or the K:T ratio were observed in patients treated with 3DCRT or SBRT at any of the three time points. However, the absolute kynurenine levels rose significantly more post-RT in the 3DCRT patients with a median increase 0.721 ng/mL, compared to that of SBRT patients (0.115 ng/mL); P = 0.022. This study validated that elevated IDO activity correlated with worse survival outcomes in patients with early-stage NSCLC treated with definitive RT. Hypofractionated SBRT may have less immunosuppressive effect than 3DCRT, as measured by IDO.

Dosimetric parameters of heart and left ventricle – comparison of 3D CRT and IMRT in left cancer breast

Background: Conformal Radiotherapy techniques adapting to the ballistics of delineated volumes allowed significant reduction in excess radiation induced mortality however the increasing number of long-term survivors and expanding use of cardiotoxic drug highlight the persistent need for maximal cardiac possible sparing. The low dose volume of left ventricle are better predictor of acute coronary events than mean heart dose. Materials and Methods: 38 post-MRM patients were randomized to treatment by 3Dimensional Conformal Radiotherapy (3D CRT) and Intensity Modulated Radiotherapy (IMRT) technique. Two tangential beams were used in 3D CRT technique while five to seven (mostly tangential beams) were used in inversely planned IMRT technique. The dose volume parameters of planning target volume, heart and left ventricle were compared. Results: The dosimetry of Planning target volume showed significantly better coverage in IMRT technique (D90, D95) however the D50 was comparable in both the techniques. In dosimetry of heart, the high dose volumes (V30, V40) were nearly comparable in both the techniques. The other dose volume parameters (V5, V10, V20, V25, D33, D67, D100) and the mean dose were significantly lesser in 3D CRT technique along with significantly better sparing of left ventricle (Dmean and V5). Conclusion: The dosimetry of target volume was better with IMRT technique, but this was accompanied by a huge increase in dose to whole heart and specifically the left ventricle which has strong potential to translate into an increased cardiotoxicity. A better distribution of the target region may be obtained by multiple segmentation of the two tangential fields in 3D CRT plans with further reduction in dose to heart and left ventricle.

IMRT and brachytherapy comparison in gynaecological cancer treatment: thinking over dosimetry and radiobiology.

BackgroundThe role of radiotherapy and brachytherapy in the management of locally advanced cervical and endometrial cancer is well established. However, in some cases, intracavitary brachytherapy (ICBRT) is not recommended or cannot be carried out. We aimed to investigate whether external-beam irradiation delivered by means of intensity-modulated radiation therapy (IMRT) might replace ICBRT in gynaecological cancer when the standard ICBRT boost delivering cannot be administered for technical or clinical reasons.Materials and methodsFifteen already delivered treatments for gynaecological cancer patients were analysed. The treatments were performed through 3-dimensional conformal radiotherapy (3D-CRT) to the whole-pelvis up to the dose of 45–50.4 Gy followed by a boost dose administered with ICBRT in high-dose-rate or pulsed-dose-rate modality. For each patient, IMRT plans were elaborated to mimic the ICBRT. We analysed the ICBRT boost versus IMRT boost in terms of dosimetric and radiobiological aspects.ResultsMean conformity index value calculated on boost volume was 0.73 for ICBRT and 0.97 for IMRT. Mean conformation number was 0.24 for ICBRT boost and 0.78 for IMRT boost. Mean normal tissue complication probability (NTCP) values for 3D-CRT plus ICBRT and for IMRT (pelvis plus boost) were, respectively, 28% and 5% for rectum; 1.5% and 0.1% for urinary bladder and 8.9% and 6.1% for bowel.ConclusionsOur findings suggest that IMRT may represent a viable alternative in delivering the boost in patients diagnosed with gynaecological cancer not amenable to ICBRT.

Patterns of Failure Observed in the 2-Step Institution Credentialing Process for NRG Oncology/Radiation Therapy Oncology Group 1005 (NCT01349322) and Lessons Learned

PurposeTo investigate patterns of failure in institutional credentialing submissions to NRG/RTOG 1005 with the aim of improving the quality and consistency for future breast cancer protocols. Methods and MaterialsNRG/RTOG 1005 allowed the submission of 3-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), and simultaneous integrated boost (SIB) breast plans. Credentialing required institutions to pass a 2-step quality assurance (QA) process: (1) benchmark, requiring institutions to create a plan with no unacceptable deviations and ≤1 acceptable variation among the dose volume (DV) criteria, and (2) rapid review, requiring each institution’s first protocol submission to have no unacceptable deviations among the DV criteria or contours. Overall rates, number of resubmissions, and reasons for resubmission were analyzed for each QA step. ResultsIn total, 352 institutions participated in benchmark QA and 280 patients enrolled had rapid review QA. Benchmark initial failure rates were similar for 3DCRT (18%), IMRT (17%), and SIB (18%) plans. For 3DCRT and IMRT benchmark plans, ipsilateral lung most frequently failed the DV criteria, and SIB DV failures were seen most frequently for the heart. Rapid review contour initial failures (35%) were due to target rather than organs at risk. For 29% of the rapid review initial failures, the planning target volume boost eval volume was deemed an unacceptable deviation. ConclusionsThe review of the benchmark and rapid review QA submissions indicates that acceptable variations or unacceptable deviations for the ipsilateral lung and heart dose constraints were the most commonly observed cause of benchmark QA failure, and unacceptable deviations in target contouring, rather than normal structure contouring, were the most common cause of rapid review QA failure. These findings suggest that a rigorous QA process is necessary for high quality and homogeneity in radiation therapy in multi-institutional trials of breast cancer to ensure that the benefits of radiation therapy far outweigh the risks.

IMRT Reduces Acute Toxicity in Patients Treated With Preoperative Chemoradiation for Gastric Cancer

PurposePreoperative chemoradiation is being currently evaluated in 2 randomized international trials. However, chemoradiation for gastric cancer can be associated with relatively high rates of acute toxicity. We compared rates of toxicity, toxicity-related events, and oncologic outcomes in patients treated with intensity modulated radiation therapy (IMRT) and those treated with 3-dimensional conformal radiation therapy (3DCRT). Methods and MaterialsWe retrospectively reviewed records of 202 patients with consecutive gastric cancer treated with preoperative intent radiation therapy at our institution from 1998 to 2018. Patients with gastroesophageal junction involvement and those with metastatic disease were excluded. Eighty-two patients received 3DCRT, and 120 patients received IMRT. The median radiation dose was 45 Gy, and 99% received concurrent chemotherapy. ResultsThere were no significant differences between the 3DCRT and IMRT groups regarding sex, race, histology, tumor location, histology, or nodal stage. The rate of grade 3 to 4 acute toxicity was significantly lower in patients treated with IMRT compared with 3DCRT (49% vs 70%, P = .004). The composite rate of toxicity-related events (hospitalization, feeding tube use, intravenous rehydration, or radiation therapy breaks) was also significantly lower in patients treated with IMRT compared with 3DCRT (56% vs 85%, P <.001). In addition, 68% of patients who received IMRT and 73% of patients who received 3DCRT underwent subsequent surgical resection (P = .245). Among patients who underwent surgery, the 3-year overall survival rates were not significantly different between those treated with IMRT and 3DCRT (71% vs 69%, P = .786). Patients receiving IMRT had a significantly higher absolute nadir lymphocyte count compared with patients receiving 3DCRT (median, 0.21 vs 0.16 K/UL; P = .047). ConclusionsOur study suggests that IMRT might significantly reduce rates of grade 3 to 4 acute toxicity and toxicity-related events compared with 3DCRT, with no significant difference in oncologic outcomes. IMRT is an appropriate and possibly preferable radiation modality in patients treated with preoperative chemoradiation for gastric cancer.

Optimal Target Delineation and Treatment Techniques in the Era of Conformal Photon and Proton Breast and Regional Nodal Irradiation

PurposeRegional nodal irradiation improves disease-free and distant disease–free survival in patients with high-risk breast cancer (BC). Trials demonstrating this used 2- or 3-dimensional conformal radiation therapy (2-dimensional or 3-dimensional [3D] conformal radiotherapy [CRT]) fields based on bony anatomy. Modern volumetric-modulated arc therapy (VMAT) and pencil beam scanning proton therapy (PBSPT) may underdose regional nodes (RNs) not contoured but covered by 3D CRT. Multiple atlases guide modern treatment planning. This study addresses the risk of underdosing when relying on published atlases and treating with 3D CRT, VMAT, and PBSPT. Methods and MaterialsTargets per the Radiation Therapy Oncology Group (RTOG), European Society for Radiotherapy and Oncology (ESTRO), and Radiotherapy Comparative Effectiveness Consortium (RADCOMP) atlases were contoured on a representative patient CT scan. 3D CRT plans based on anatomic borders and VMAT and PBSPT plans for each set of target volumes were generated. Positron emission tomography/computed tomography (PET/CT) scans were reviewed. CT-positive and 18F-fluorodeoxyglucose (18F-FDG)–avid RNs (n = 389) were mapped from 102 patients with locally advanced (n = 51; median 2; range, 1-8 nodes) and metastatic (n = 51; median 4; range, 1-19 nodes) BC: axillary (AX; n = 284), supraclavicular (SCV; n = 60), and internal mammary nodal (IMN; n = 45). 18F-FDG-avid RNs falling within the 95% isodose line were considered adequately covered. Results3D CRT plans provided excellent RN coverage. Low AX nodes were covered (≥99%) in all plans. Underdosing of 18F-FDG–avid RNs falling in the high AX (78%-92%), SCV (52%-75%), and IMN (84%-89%) volumes was observed following the RTOG and ESTRO atlases for VMAT and PBSPT plans. Use of the RADCOMP atlas provided coverage of these areas (89%-100%) with slightly increased heart and lung doses. Atlas guided VMAT/PBSPT plans provided cumulative nodal coverage as follows: ESTRO (89%/88%), RTOG (93%/91%), and RADCOMP (98%/96%). ConclusionsVMAT and PBSPT for regional nodal irradiation in patients with high-risk BC risks underdosage in the high AX, SCV, and IMN nodal regions unless comprehensive target delineation is performed.