3D-CRT Group Research Articles

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

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

Intra-arterial chemoradiotherapy for oral cancer: Superiority of intensity-modulated radiation therapy over three-dimensional conformal radiation therapy

PurposeTo determine the superiority of intensity-modulated radiation therapy (IMRT) over three-dimensional conformal radiation therapy (3DCRT) in patients who underwent intra-arterial chemoradiotherapy for oral cancer. MethodsWe retrospectively analyzed patients with locally advanced oral cancer curatively treated with intra-arterial chemoradiotherapy at a single institution between 2010 and 2021. All patients treated after May 2015 underwent IMRT. Docetaxel (12 mg/m2/week) and nedaplatin (5 mg/m2/day) were administered through a shallow temporal artery using a catheter. ResultsIn total, 143 patients (IMRT: 71; 3DCRT: 72) were included in this study. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 75.7 % and 59.8 %, respectively, with no significant differences between the irradiation methods. In multivariate analysis, cervical lymph node metastasis (LNM) was the only significant poor prognostic factor contributing to OS, PFS, locoregional control (LRC), and local control (LC). In multivariate subgroup analysis of LNM cases (n = 90), IMRT contributed to favorable LRC (hazard ratio [HR]=0.4, P = 0.01) and LC (HR=0.4, P = 0.006). There was no difference in the incidence of grade ≥2 osteonecrosis of the jaw (4.2 % vs. 12.5 %, P = 0.13), xerostomia (75 % vs. 82 %, P = 0.316), or dysgeusia (80 % vs. 82 %, P = 0.834) between the IMRT and 3DCRT groups. However, the rates of xerostomia at 6 months and dysgeusia at 3 months were lower in the IMRT group (both P < 0.001). ConclusionIMRT neither improved patient survival nor significantly reduced the incidence of osteonecrosis of the jaw. However, it demonstrated favorable LRC and LC in patients with LNM, suggesting an advantage in early recovery from xerostomia and dysgeusia.

Impact of Radiation on Dysphagia-Related Structures: A Dosimetric and Clinical Comparative Analysis of Three-Dimensional Conformal Radiotherapy (3D-CRT) and Intensity-Modulated Radiation Therapy (IMRT) Techniques in Patients With Head and Neck Cancer.

Introduction Head and neck squamous cell carcinoma (HNSCC)is a significant health concern in India, with around one million new cases annually. The prevalence of HNSCC is notably high in Asia, especially in India, due to habitslike tobacco chewing, betel nut usage, and alcohol consumption. Treatment typically involves a combination of surgery, radiation, chemotherapy, and biological therapy, aiming for tumor control while preserving function and quality of life. However, survivors often face long-term side effectslike difficulty swallowing, leading to complicationssuch as aspiration pneumonia. Intensity-modulated radiotherapy (IMRT) has shown promise in improving outcomes by sparing critical swallowing structures. Efforts to minimize radiation-related dysphagia are crucial for enhancing patients' quality of life post-treatment. Our study focuses on examining dosimetric parameters associated with dysphagia aspiration, alongside evaluating dysphagia grades in both treatment groups using the RTOGscale. Material and methods Patients with histologically confirmed non-metastatic head and neck carcinomas were included in our study in November 2018-April 2020. A total of 56 patients were taken into our study with 28 in each arm. They underwent radical radiotherapy (RT) with a total dose of 66-70 Gy, with or without concurrent chemotherapy, meeting specific inclusion criteria and excluding those receiving reirradiation or with distant metastasis. Patients were divided into two groups: Group I received three-dimensional conformal radiotherapy (3D-CRT), and Group II received IMRT. Treatment planning involved immobilization, CT imaging, delineation of target volumes and organs at risk, and contouring of swallowing structures. Dose-volume histogram parameters (mean dose, maximum dose, V30, V70, V80, D50, and D80) were used to assess mean dose to swallowing structures outside the planning target volume (PTV), with a mean dose constraint of 50 Gy. Dysphagia was evaluated using the RTOGcriteria at baseline, during treatment, and six months post-treatment. Statistical analysis was performed using SPSS, with significance set at p < 0.05. Results In our study, the mean age at presentation differed slightly between the IMRT and 3D-CRT arms: 58 years versus 55 years, respectively. A higher proportion of patients in both arms experienced symptoms for three to six months, with 53.6% in 3D-CRT and 42.9% in IMRT. Stage distribution varied, with IV being most common in 3D-CRT and stage II in IMRT. Approximately 56% of patients in both groups had a history of smoking. Significant differences were observed in spinal cord dose between 3DCRT and IMRT techniques (p < 0.001). Similarly, a significant difference was found in the mean dose received by dysphagia aspiration-related structures (DARSs) between the 3D-CRT and IMRT arms (p = 0.04). Patients in the IMRT arm exhibited superior dysphagia grades compared to those in the 3D-CRT arm, with statistical significance observed in the third month (p = 0.008) and sixth month (p = 0.048). Conclusion Our study found a notable decrease in the mean DARS dose and reduced dysphagia severity at three and six months in the IMRT group compared to the 3D-CRT group. However, due to the diverse study population, establishing a definitive correlation between the DARS dose and dysphagia severity was challenging. Future large-scale studies are needed to validate these findings for improved preservation of DARS structures.

Does Breast Surgery Type Alter Incidental Axillary Irradiation? A Dosimetric Analysis of the "Sentinel Envahi et Randomisation du Curage" SERC Trial.

An incidental axillary dose of adjuvant radiotherapy using tangential beams is usually given after breast-conserving surgery for breast cancer. The goal of this sub-study was to evaluate this incidental dose in the setting of post-mastectomy radiotherapy (PMRT) according to two different radiotherapy techniques. Patients participating in a randomized SERC trial who received PMRT in a single center were included. We collected the incidental axillary dose delivered to the Berg level 1 using different dosimetric parameters and compared two techniques using Student's t-test: three-dimensional conformal radiotherapy (3D-CRT) and volumetric arc therapy (VMAT). We analyzed radiotherapy plans from 52 patients who received PMRT from 2012 to 2021. The mean dose delivered to the Berg level 1 was 37.2 Gy. It was significantly higher with VMAT than with 3D-CRT-43.6 Gy (SD = 3.1 Gy) versus 34.8 Gy (SD = 8.6 Gy) p < 0.001. Eighty-four percent of the Berg level 1 was covered by 40 Gy isodose in the VMAT group versus 55.5% in the 3D-CRT group p < 0.001. On the Berg level 1, PMRT gives a dose at least equivalent to the one given by post-breast-conserving surgery radiotherapy, making it possible to limit completion axillary lymph node dissections in select pN1a patients treated with a mastectomy. Modern radiotherapy techniques like VMAT tend to increase this incidental dose.

Comparison of Thyroid Toxicity Profiles in Head and Neck Cancer Patients Irradiated by 3D-Conformal Radiation Therapy and Intensity-Modulated Radiation Therapy

ABSTRACT Background: In spite of recent technical advances in the radiation field, exposure to non-target organs such as the thyroid gland remains unavoidable in locally advanced head and neck cancer (LAHNC) planning, which is associated with late toxicities, and this may affect the lifestyle of cancer survivors. Aim: The purpose of this study was to estimate the incidence of thyroid toxicity in LAHNC patients treated with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). To establish its correlation, we have analyzed thyroid profile levels, DVH, and the doses of radiation received by the thyroid volume in both radiotherapy planning methods. Material and Method: Sixty patients with LAHNC enrolled and were divided into two groups treated with 3D-CRT (group A) and IMRT (group B). The patient’s thyroid function test, which consisted of serumT3, T4, and TSH, was done before starting radiotherapy and at 6 months and 12 months follow-up. Absolute thyroid volume, maximum dose, minimum dose, mean dose to the thyroid gland, and percentage of thyroid volume receiving as V10, V20, V30, V40, and V50 were studied. Results: After 6-month post-RT, 6.7% of patients in group A showed biochemical hypothyroidism, whereas biochemical hypothyroidism, sub-clinical hypothyroidism, and hyperthyroidism were observed in 10%, 3.3%, and 10% patients of group B, respectively. After 12 months post-RT, 23.3% of patients in group A showed hypothyroidism. In the 3DCRT group, mean T3 was significantly higher for patients with no hypothyroidism (P &lt; 0.05). Mean T4 was observed to be significantly lower in both the groups in hypothyroid patients (P &lt; 0.05). Mean TSH was significantly higher for hypothyroid patients in the IMRT group (P &gt; 0.01). The difference in thyroid volume and thyroid dose was observed to be statistically significant (P &lt; 0.05). Conclusion: The incidence of thyroid toxicity may be decreased by sparing the volume of the thyroid gland and the thyroid dose kept to a minimum. As per dosimetric parameters, &gt;V40 may predict the risk of developing hypothyroidism after irradiation in LAHNC patients. We recommend regular thyroid function tests on follow-up visits of irradiated patients of LAHNC.

Comparison of radiotherapy techniques in patients with thymic epithelial tumor who underwent postoperative radiotherapy.

This retrospective study aimed to compare clinical outcomes and dosimetric parameters between radiation therapy (RT) techniques in patients with thymic epithelial tumor (TET). From January 2016 to December 2020, 101 patients with TET received adjuvant RT (median, 52.8 Gy; range, 48.4 to 66.0). Three different RT techniques were compared: three-dimensional conformal RT (3D-CRT; n = 59, 58.4%), intensity-modulated RT (IMRT; n = 23, 22.8%), and proton beam therapy (PBT; n = 19, 18.8%). The median age of the patients and the follow-up period were 55 years (range, 28 to 79) and 43.4 months (range, 7.7 to 77.2). Patients in the PBT group were of the youngest age (mean age, 45.4 years), while those in IMRT group had the largest clinical target volume (mean volume, 149.6 mL). Patients in the PBT group had a lower mean lung dose (4.4 Gy vs. 7.6 Gy vs. 10.9 Gy, respectively; p < 0.001), lower mean heart dose (5.4 Gy vs. 10.0 Gy vs. 13.1 Gy, respectively; p = 0.003), and lower mean esophageal dose than patients in the 3D-CRT and IMRT groups (6.3 Gy vs. 9.8 Gy vs. 13.5 Gy, respectively; p = 0.011). Twenty patients (19.8%) showed disease recurrence, and seven patients (6.9%) died. The differences in the survival rates between RT groups were not statistically significant. In patients with TET who underwent adjuvant RT, PBT resulted in a lower dose of exposure to adjacent organs at risk. Survival outcomes for patients in PBT group were not significantly different from those in other groups.

A comparison of the incidence of ≥ grade 2 radiation pneumonitis between intensity-modulated radiotherapy and three-dimensional conformal radiotherapy in patients with unresectable non-small cell lung cancer treated with durvalumab after concurrent chemoradiotherapy.

Intensity-modulated radiation therapy (IMRT) has been increasingly used as a new radiation modality for unresectable non-small cell lung cancer (NSCLC). The risk factors for radiation pneumonitis (RP) during consolidation durvalumab following concurrent chemoradiotherapy (CCRT) using IMRT have not been thoroughly investigated. This retrospective study analyzed medical record data from consecutive patients diagnosed with NSCLC who underwent CCRT and consolidation durvalumab at our institution between April 2018 and September 2022. Since we adopted IMRT for the treatment of NSCLC in April 2020, these patients were categorized into two groups: those treated with IMRT after April 2020 and those treated with three-dimensional conformal radiotherapy (3D-CRT) before April 2020. A total of 31 patients underwent IMRT (the IMRT group), while 25 patients underwent 3D-CRT (the 3D-CRT group). In both groups, the total dose was 60Gy in 30 fractions. The cumulative incidence of ≥ grade 2 RP at 12months was significantly lower in the IMRT group than in the 3D-CRT group (27.0% vs. 64.0%, hazard ratio [HR]: 0.338, 95% confidence interval [CI]: 0.144-0.793, p=0.013). In the multivariable analysis, V20 (≥ 25.6%, HR: 2.706, 95% CI: 1.168-6.269, p=0.020) and radiotherapy technique (IMRT, HR: 0.414, 95% CI: 0.172-0.994, p=0.048) were identified as significant risk factors for ≥ grade 2 RP. IMRT is associated with a lower rate of ≥ grade 2 RP in patients with NSCLC who received CCRT followed by durvalumab.

Clinical Efficacy and Complications of Intensity-modulated Radiation Therapy in Patients With Oropharyngeal Carcinoma: Especially Focus On Osteoradionecrosis

We explored the relative clinical efficacy of intensity-modulated radiation therapy (IMRT) in patients with oropharyngeal cancer (OPC) compared with three-dimensional conformal radiation therapy (3D-CRT). Seventy-four OPC patients treated with definitive IMRT or 3D-CRT between May 2010 and December 2018 were analyzed. Of these, 42 patients were treated with IMRT and 32 with 3D-CRT. We compared clinical benefits and complications. Particular attention was focused on osteoradionecrosis (ORN), which is the most problematic radiation late adverse event, and evaluated the irradiated mandibular volumes. There was no significant difference in the 3-year overall survival (OS), progression free survival (PFS) and locoregional control (LRC) rates between the two groups. However, late Grade 2 xerostomia was lower in the IMRT groups. Four patients (19.0%) developed Grade 3, while no patients developed ORN in the IMRT group (P = 0.003). A comparison of the mandible volumes between the two groups showed that the IMRT group had lower mandibular volumes than the 3D-CRT group in the high-dose range of V40, V50, V60 and V70. In addition, a comparison of the mandibular volumes between ORN and non-ORN showed a significant difference in the V60 and V70. ORN incidence was higher in V60 ≥ 25% and V70 ≥ 15%. A comparison of IMRT and 3D-CRT showed no significant difference in outcomes, however, IMRT led to a significant reduction in late xerostomia and ORN in OPC patients. Reducing of the mandibular V60 and V70 by IMRT seemed to reduce the risk of ORN.

The Outcomes of Intensity Modulated Radiotherapy versus Conventional 2D Radiotherapy in Patients with Oropharyngeal or Hypopharyngeal Squamous Cell Carcinoma. A Case-Control Study

"Introduction: Head and neck cancers’ radiotherapy (RT) is challenging due to the irregular target volumes and the proximity of multiple organs at risk. The purpose of this study is to compare the toxicity, loco-regional control and the pattern of tumour recurrence after intensity modulated radiotherapy (IMRT) or conventional 2D radiotherapy (2D CRT) in patients with squamous cell carcinoma (SCC) oropharyngeal or hypopharyngeal cancers. Material and method: We retrospectively compared the outcomes of SCC oropharyngeal or hypopharyngeal cases treated by IMRT or 2D CRT from 1998 to 2010 in a Canadian Academic Hospital. We matched the patients in the two groups according to primary tumour location and clinical stage. The information on treatment, toxicity and outcomes was retrieved from patients’ medical records. For the patients having a recurrence after IMRT, the CT scan at relapse was fused with the planning CT. For the patients recurring after 2D CRT, we matched the CT images with the relative position of the radiotherapy fields. Statistical analysis was made using GraphPad Prism software. Results: We included a total of 50 patients in the IMRT group and 50 in the 2D CRT group. The median age was 62 and 58 years, respectively, and the median follow-up was 18 and 22.6 months, respectively. Some of the side effects were less frequent on the IMRT group compared to the 2D CRT: xerostomia (16% vs 64%, P=0.0036), mucositis (70% vs 74% P=0.5451), weight loss (18% vs 46% P= 0.0027), radionecrosis/mandibular fracture (0 % vs 2%), fibrosis (0% vs 10%), and telangiectasia (0% vs 4%). However, acute dermatitis and late dysphagia were more frequent in the IMRT group (44% vs 28% P=0.0042; and 14% vs 2% P=0.028; respectively). The overall survival at 2 years was for 74.03% for IMRT and 60% for 2D CRT (P&lt; 0.001) and the 5 years actuarial locoregional control was 89.54 % for IMRT group, and 62.48% for the 2DCRT group (P&lt; 0.001). Three patients from the IMRT group had a local recurrence (2 in-field and 1 marginal), while in the 2D-CRT group, there were 10 patients with a local recurrence (6 in-field and 4 marginal). Conclusion: SCC oropharyngeal and hypopharyngeal patients treated with IMRT and concurrent cisplatin had better outcomes and fewer side effects, when compared to similar cases treated with 2D CRT. The local recurrence had a similar pattern for both techniques."

Comparative evaluation of oral mucositis in oral cancer patients undergoing 3-dimensional conformal radiation therapy and intensity modulated radiation therapy with or without chemotherapy.

Oral cancer is a significant cause of death across the world. A combined multimodal approach integrating surgery and radiation therapy (RT) with or without chemotherapy (CT) is commonly employed in advanced oral cancer to prevent recurrences and locoregional spread. Oral mucositis is a common acute toxicity reported in patients undergoing RT and CT. The delivery of optimal cancer therapy protocols is compromised due to morbidity caused by oral mucositis. To compare the severity of oral mucositis in oral cancer patients undergoing 3-Dimensional Conformal Radiation Therapy (3DCRT) and Intensity Modulated Radiation Therapy (IMRT) with or without concomitant CT. This was a prospective, unicentric and longitudinal study conducted in a cancer centre. One hundred four patients with locally advanced oral cancer were enrolled in this study. Fifty-two patients were treated with IMRT and 52 patients with 3DCRT to a dose of >60 Gy, along with concurrent cisplatin weekly CT. Mucositis was recorded before the start, in the end, 1 month, and 3 months post-chemoradiotherapy treatment. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) software (v. 21.0, Chicago. 2012). Descriptive and frequency statistics were performed for different parameters assessed in 3DCRT and IMRT group. Grade 3 mucositis was the most predominant grade observed in both groups at the end of treatment. Thirty-six patients (69.3%) versus 24 patients (46.1%) developed grade 3 mucositis in 3DCRT and IMRT group, respectively (P = 0.013). Healing was better with IMRT group when compared to 3DCRT group 1 month and 3 months post-RT. Mucositis was severe in patients undergoing concomitant CT. IMRT reduced the incidence of severe mucositis and also improved the treatment-compliance compared to 3DCRT in locally advanced head neck cancer patients treated by chemoradiotherapy.

Locally advanced cervical cancer: how the improvement in techniques in external beam radiotherapy and brachytherapy impacts on survival outcomes and long-term toxicities.

Platinum-based chemoradiotherapy and brachytherapy are the standard treatment for locally advanced cervical cancer. Reported long-term outcomes for treated with both IMRT and 3D-Image-guided-adaptive brachytherapy are lacking. This retrospective study included 165 patients with FIGO Stage IB-IVB cervical cancer, treated with chemoradiotherapy in combination with brachytherapy. External beam radiotherapy was delivered as IMRT/VMAT/TOMO helical or 3DCRT. The intracavitary brachytherapy treatment (ICBT) was performed using two different planning system (with or without optimization). Among the patient subgroups, comprising those who received IMRT/VMAT/Tomo helical and 3DCRT, as well as those who underwent ICBT planning optimization and those who did not, homogeneity was observed in terms of age, performance status, T stage, N status, TNM stage, and histology. With a median follow-up time of 60.5months, the 5-year overall survival (OS) in the 3DCRT and IMRT groups was 74.9% and 92.8%, respectively (p = 0.033). The 5-year OS in the ICBT planning optimization group was 93.7%, compared to 75% in the non-optimization group (p = 0.014). Regarding late radiation toxicities, patients in the IMRT group had a lower incidence of chronic rectal toxicity compared to those in the 3DCRT group (6.5% vs. 34.1%, p = 0.001). The group with ICBT planning optimization had a lower incidence of late urinary toxicities (10.4%) compared to the non-optimized ICBT planning group (18.2%, p = 0.012). Similarly, the ICBT planning optimization group had a lower incidence of late rectal toxicity (6.5% with 80% grade 1 and 20% grade 2) compared to the non-optimized ICBT planning group (34.1%, p = 0.001). In this series, the group of patients receiving optimized ICBT had an advantage in terms of OS and CSS suggesting that the use of new Treatment Planning Systems associated with 3D imaging, improves the long-term survival. Additionally, a significant reduction in late rectal and urinary toxicity has been observed.

Retrospective comparison of side effects and outcomes of three-dimensional conformal vs. intensity-modulated radiation therapy in the palliative-intent treatment (4 Gy × 5 daily fractions) of canine intranasal tumors (2010-2017).

To compare the occurrence of radiation side effects and treatment outcomes in dogs with intranasal tumors treated with a total dose of 20 Gy delivered in 5 daily 4 Gy fractions using computer-based 3D conformal (3DCRT) or intensity-modulated (IMRT) radiation therapy plans. Retrospective case series. Medical records for dogs with intranasal tumors treated with 4 Gy × 5 fractions between 2010 and 2017 were reviewed. Radiation side effects, time to local progression (TTLP), progression-free survival (PFS) and survival time (OS) were evaluated. Thirty-six dogs (24 carcinomas, 10 sarcomas and 2 others) met the inclusion criteria. Sixteen were treated with 3DCRT and 20 with IMRT. Clinical signs improvement or resolution were reported in 84% of dogs. The median time to clinical signs improvement was 12 days (1-88 days) after the end of treatment. Eight dogs treated with 3DCRT (8/16, 50%) and 5 with IMRT (5/20, 25%) were documented acute radiation side effects. Almost all were classified as grade 1 skin, oral or ocular acute side effects. Only one dog in 3DCRT group was demonstrated grade 2 skin acute effects. The median TTLP for dogs treated with 3DCRT or IMRT was 238 days and 179 days, respectively (p = 0.967). The median PFS for 3DCRT or IMRT was 228 days and 175 days, respectively (p = 0.940). The median OS for 3DCRT or IMRT was 295 days and 312 days, respectively (p = 0.787). No significantly differences were observed in side effects, TTLP, PFS and OS between 3DCRT and IMRT groups. Palliative-intent conformal radiation therapy given in five daily 4 Gy fractions relieved clinical signs with minimal radiation side effects, with no statistical difference in occurrence between 3DCRT and IMRT dogs.

Toxicity Profile of Intensity Modulated Radiotherapy Vs. 3D-Conformal Radiotherapy in Head and neck cancer: A Retrospective study

Background: Most head and neck patients have historically been treated with photon-based radiation techniques such as intensity modulated radiation therapy (IMRT), there is a growing awareness of the potential clinical benefits of proton therapy over IMRT in the definitive, postoperative and reirradiation settings given the unique physical properties of protons. Aim of the work: to assess toxicity profile of IMRT in comparison to 3D conformal radiotherapy (3DCRT) and to assess predictors for progression free survival and overall survival rates. Patients and Methods: This retrospective cohort study included 131 head and neck cancer patients who were recruited from El Hussein University Hospital over 10 years then they were divided into 2 groups according to the type of radiotherapy. Results: Both groups were comparable regarding age, sex and associated medical disorders except for ischemic heart disease and smoking. Sites of primary tumors were comparable except tongue and nasopharynx. Most of 3DCRT group received TPF as induction chemotherapy and most of IMRT group received concurrent chemotherapy. Dose of irradiation was higher significantly among IMRT group. Grades of early and late toxicity were higher among 3DCRT group. There was no statistically significant difference between both groups regarding response to treatment. Mortality cases were higher significantly among 3DCRT group. Cox regression analysis was performed to assess predictors for progression free survival and overall survival in each group. Conclusion: IMRT provide good choice as radiotherapy technique for head and neck cancers with adequate efficacy similar to other techniques and better toxicity profile.

Impact of Lung and Heart Radiation Dose during Preoperative Chemoradiation on Overall Survival (OS) in Esophageal Cancer (EC) – Secondary Analysis of CALGB 80803 (Alliance)

<h3>Purpose/Objective(s)</h3> In CALGB 80803, patients with locally advanced EC received PET-directed neoadjuvant therapy consisting of induction chemotherapy followed by chemoradiation and then surgical resection. Historically, radiotherapy has been delivered using techniques with limited ability to minimize doses to the heart and lungs, potentially leading to increased risk of peri-operative and late cardiopulmonary toxicities with significant morbidity and mortality. We evaluated the relationship between OS and radiation dose to the heart and lungs, and the impact of intensity-modulated radiation therapy (IMRT) and adherence to protocol-specified dose constraints in CALGB 80803. <h3>Materials/Methods</h3> Protocol-specified dose constraints were based on standard of care guidelines: total lung V_{10 Gy} ≤ 40%, V_{20 Gy} ≤ 20%, V_{30 Gy} ≤ 15%, V_{40 Gy} ≤ 10%; heart V_{30 Gy} ≤ 30%. Optimal dose cutpoints for each volumetric constraint were calculated that best differentiated OS. Each cutpoint was dichotomized and the Kaplan-Meier method was used to evaluate its impact on OS. The significance threshold was <i>p</i><0.05 and a Holm multiple comparisons correction was applied. <h3>Results</h3> There were 226 patients (n) included in the analysis, 60.3% were treated with IMRT. Rates of adherence were high for each of the protocol-specified dose constraints: 74.8%, 84.1%, 98.7%, 99.1%, and 73.0% for total lung V_{10 Gy}, V_{20 Gy}, V_{30 Gy}, V_{40 Gy}, and heart V_{30 Gy}, respectively. See the table for calculated dose cutpoints for each dosimetric variable as well as treatment and survival data. For heart V_{30 Gy}, 90.6% and 68.2% with V₃₀ Gy > 21% received three-dimensional conformal radiation therapy (3D-CRT) vs IMRT, respectively, while 9.4% and 31.8% with V_{30 Gy} > 21% received 3D-CRT vs IMRT, respectively (<i>p</i> < 0.001). Mean heart V_{30 Gy} was significantly lower in the IMRT vs 3D-CRT group (24.7% vs 35.5%; <i>p</i> < 0.001). On univariable Cox regression, lung V_{10 Gy} > 41% (hazard ratio [HR]: 1.87; <i>p</i> = 0.002) and heart V_{30 Gy} > 21% (HR: 1.77; <i>p</i> = 0.017) were significant poor prognostic factors for OS. <h3>Conclusion</h3> The majority of patients on CALGB 80803 were treated with IMRT plans that met the protocol-specified dose constraints for total lung and heart_. Minimizing volume of low dose to the lungs (V_{10 Gy}) was associated with a significant survival benefit, as was a lower heart V_{30 Gy}. Total lung V_{10 Gy} ≤ 41% and heart V_{30 Gy} ≤ 21%, and the use of IMRT over 3D-CRT, should be considered when designing radiation plans for EC patients. <b>Support:</b> U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org. <b>ClinicalTrials.gov ID:</b> NCT01333033

The Significance of Increased Dose in the Outcome of Definitive Chemoradiotherapy at Doses above 60Gy for cT3-4 Cervical Esophageal Cancer: A Report of 83 Cases from a Single Institution

<h3>Purpose/Objective(s)</h3> We investigated whether increasing the RT dose from 60 Gy to 67-68 Gy, which is comparable to the dose for squamous cell carcinoma of the head and neck, would improve the treatment outcome in cT3-4NxM0 patients enrolled for definitive chemoradiotherapy (CRT) for locally advanced cervical esophageal cancer based on late adverse events and recurrence patterns. <h3>Materials/Methods</h3> From 2004 to 2020, 83 patients with cT3-4bNxM0 squamous cell carcinoma of the cervical esophagus (including 22 cases of Ce, 8 cases of CePh, and 53 cases of CeUt, but not UtCe) were enrolled in a radical CRT (1.8-2.1 Gy/F, total dose >60 Gy, and concurrent CDDP80mg/m²x1 and 5-fluorouracil 800 mg/m²x5, 2 courses) protocol at our institution. Pretreatment imaging, including MRI and ultrasound tracheal endoscopy, showed that 71% of 59 patients were cT4 (89% tracheal invasion) and the rest were cT3. cN1 or higher was found in 73 patients (88%) and cN0 in 10 patients (12%). Thirty-six patients were in the cohort group for VMAT of 67-68 Gy/33 F/7 wks with D50 indication for PTV, and the rest were in the non-cohort group. In the remaining 47 patients in the non-cohort (3DCRT) group, 30 patients were completed at 60 Gy (or less than 60 Gy for surgery), and only 14 patients underwent 3DCRT of 62 Gy or more, which was presumably added due to poor response. A total of four patients were judged to be candidates for salvage surgery at 50 Gy intermediate assessment: one in the cohort group and three in the non-cohort group. The median observation period for survivors was 87.4 months (95% CI: 65.0-109.7). <h3>Results</h3> OS was 30.3% (SE 5.4%) at 5 years in all cT3-4NxM083 patients. cT3/T4, cN0/N1, age, gender ratio, and tumor occupying subsite CePh/CeUt types in cohort vs. non-cohort were not significantly skewed. There was no significant difference in OS between the cohort group and the non-cohort group in the ITT comparison of all patients, including the 4 patients who were converted to surgery (Breslow, p=0.84). Multivariate analysis showed that the two factors significant for OS were cT3 vs. cT4 (p=0.035, HR=2.12) and tumor occupation site Ce/CePh vs. CeUt (p=0.047, HR=1.91). There was no significant difference in local recurrence and regional recurrence, 41.5% and 12.2% in the cohort group and 39.5% and 7.9% in the non-cohort group, respectively. The main late adverse events Grade 3 or higher were esophageal stenosis in 6 cases and bilateral recurrent nerve palsy in 1 case, but there was no significant difference between the cohort group (3 cases) and the non-cohort group (4 cases), and it could not be said to occur at doses higher than 60 Gy by dose. <h3>Conclusion</h3> It has long been pointed out that cervical esophageal cancer may require higher doses than thoracic esophageal cancer. However, in advanced cancers of cT3 or higher, treatment planning to obtain an appropriate dose distribution of 60 Gy or higher in VMAT did not directly lead to improved OS.

Comparison of acute gastrointestinal toxicities between 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy including prophylactic regions in chemoradiotherapy with S-1 for pancreatic cancer-importance of dose volume histogram parameters in the stomach as the predictive factors.

The purpose of this study was to compare acute gastrointestinal (GI) toxicities in patients who underwent 3-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) in chemoradiotherapy (CRT) with S-1 including prophylactic regions for pancreatic cancer. We also investigated the predictive factor of acute GI toxicities in dose volume histogram (DVH) parameters. Patients who received CRT with S-1 for pancreatic cancer between January 2014 and March 2021 were included. Radiotherapy (RT) with a total dose of 50-54 Gy was delivered. We examined the differences in the frequencies of acute GI toxicity of grade 2 or higher and DVH parameters of the stomach (ST) and duodenum (DU) between the 3DCRT group and the IMRT group. The RT-related predictive factors of acute GI toxicities were investigated by univariate and multivariate analyses. There were 25 patients in the 3DCRT group and 31 patients in the IMRT group. The frequencies of acute GI toxicity of G2 or higher were 36% in the 3DCRT group and 9.7% in the IMRT group (p = 0.035). ST V50 was the most predictive factor (p = 0.001), and the incidences of acute GI toxicity of G2 or higher in ST V50 ≥ 4.1 cc and < 4.1cc were 43.7% and 7.7%, respectively. ST V40 was also a significant predictive factor of acute GI toxicity (p = 0.002). IMRT could reduce acute GI toxicities in CRT with S-1 including prophylactic regions for pancreatic cancer. Acute GI toxicities may be affected by moderate to high doses to the ST.

Research Value of Intensity Modulated Radiation Therapy in Alleviating Parotid Gland Function Injury in Patients with Stage N0 Nasopharyngeal Carcinoma from Physical and Dosimetric Aspects.

Objective To study the feasibility of intensity modulated radiation therapy (IMRT) for stage N0 nasopharyngeal carcinoma (NPC) and its parotid gland (PG) function preservation from physical and dosimetric aspects. Methods All the clinical data of 77 patients with pathologically confirmed T1-4N0M0 NPC who received radiotherapy between July 2017 and October 2019 in the Radiotherapy Center of Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University were analyzed retrospectively. Three-dimensional conformal radiotherapy (3D-CRT) and IMRT were used in 35 and 42 cases, respectively. The treatment efficiency and the dosimetry differences of the PG in the intensity modulation plan were compared between groups. Quantitative monitoring of 99mTc radionuclide imaging of PG was performed before, at the end of, and 3, 6, and 12 months after radiotherapy. The degree of PG function injury and xerostomia was compared between groups at the end of radiotherapy and 12 months later. Results Higher minimal, maximal, and average irradiation doses of PG were determined in 3D-CRT-treated patients compared with IMRT-treated cases (P < 0.05). Compared with before radiotherapy, the PG uptake index (UI) and excretion index (EI) of both cohorts of patients decreased to varying degrees at the end of radiotherapy, with PG function injury and xerostomia symptoms observed in all cases but with no obvious difference between groups (P > 0.05). To a certain extent, the PG function recovered and the xerostomia symptoms relieved in both groups 12 months after radiotherapy, with better improvements in IMRT group versus 3D-CRT group. Conclusion IMRT has similar short-term efficacy to 3D-CRT in treating patients with stage N0 NPC, but it can effectively reduce the dose of PG radiotherapy and protect the PG function on the premise of ensuring sufficient tumor coverage and dose, showing certain dosimetry advantages.

Association of 3D-CRT and IMRT accelerated hyperfractionated radiotherapy with local control rate and 5-year survival in esophageal squamous cell carcinoma patients.

This retrospective study examined the relevance and prognostic factors of whole-course conformal radiotherapy (CRT) and late-course accelerated hyperfractionation radiotherapy (LCAFRT) for esophageal squamous cell carcinoma (ESCC). A total of 110 patients with ESCC received whole-course CRT and LCAFRT between May 2004 and January 2015. All patients received conventional CRT of 2 Gy per day, up to 30-40 Gy, followed by LCAFRT using reduced fields at 1.5 Gy/fraction twice a day, up to 24-39 Gy, for a total dose of 60-69 Gy. The median follow-up was 85 months. The whole groups 1-, 3-, and 5-year survival rates were 81.8%, 46.4%, and 41.8%, respectively. The local control rates for the whole group at 1, 3, and 5 years were 82.7%, 70.0%, and 68.2%, respectively. There were no significant differences among survival rates and local control rates between the 3D-CRT and intensity-modulated radiotherapy (IMRT) groups. The main reactions to acute radiotherapy were acute radiation tracheitis, esophagitis, and pneumonia. The tumor location and TNM stage were independent prognostic factors for overall survival. The results showed that whole-course CRT and LCAFRT for ESCC can improve survival and local control with a tolerable acute reaction compared to previous studies. Local recurrence and distant metastasis are the main failure modes of treatment. Whole-course CRT and LCAFRT for ESCC can improve the survival and local control rate compared with previous studies from the 2DRT era. It might provide another treatment for patients with inoperable ESCC or refusing surgery.

Independent Dose Calculation when External Radiotherapy Cancer Patient Planning

Purpose: Independent dose calculation (IDC) and quantitative processing of the calculating the 3D&#x0D; CRT, IMRT, RapidArc results of patients irradiation plans was conducted. Criteria for passing the exposure plans for the implementation of radiation therapy was developed.&#x0D; Materials and methods: An independent manual dose calculation of patient exposure plans was performed using 3D CRT, IMRT and RapidArc techniques. Discrepancies were obtained for three groups of&#x0D; patients: 3D CRT group contained 1584 patients, the group of patients who received IMRT included&#x0D; 647 patients. The patient group, in which rotary mode RapidArc was performed, included 364 patients.&#x0D; Results: As the analysis result of the IDC for 3D CRT, IMRT, RapidArc technologies, the quantitative indicators were ranked. The allowable discrepancies between the dose IDC and the dose calculated by the&#x0D; TPS were proposed for consideration: for 3D CRT technology from –5 to +10 %, for IMRT from 1.5 to 6&#x0D; times, for RapidArc from 1, 5 to 2.5 times. Outside the specified intervals, it is necessary to check and&#x0D; reschedule plans or conduct verification.

Ultra-hypofractionated whole breast adjuvant radiotherapy in the real-world setting: single experience with 271 elderly/frail patients treated with 3D and IMRT technique.

PurposeThe purpose of the study was to evaluate the toxicity, local control, overall and disease-free survival of elderly breast cancer (BC) patients treated with adjuvant once-weekly ultra-hypofractionated radiotherapy (RT) either with intensity-modulated RT (IMRT) or 3D conformal RT (3DCRT).MethodsFrom July 2011 to July 2018, BC patients receiving 5.7 Gy once a week for 5 weeks to the whole breast after breast-conserving surgery were considered for the study. Inclusion criteria were: T1–T3 invasive BC, no or limited axillary involvement, age ≥ 65 years or women with commuting difficulties or disabling diseases.ResultsA total of 271 patients were included in the study. Median age was 76 (46–86) years. Most of BC were T1 (77%), while the remaining were T2 (22.2%) and T3 (0.4%). Axillary status was negative in 68.3% of the patients. The only severe acute toxicity (G3) at the end of RT was erythema (0.4%), registered in the 3DCRT group; no G3 edema or epitheliolysis was recorded. With 18 months of median follow-up, severe early–late toxicity (G3) was reported in terms of fibrosis and breast retraction, both with an incidence of 1.4%, mostly in the 3DCRT group. Oncological outcomes at a median follow-up of 2.9 years reported 249/271 (91.9%) patients alive and free from any event and 5 (1.8%) isolated locoregional recurrences. At 3 years, disease-free survival and overall survival were 94.9% and 97.8%, respectively. Breast volume > 500 cm3 was reported as predictive for moderate–severe (≥ G2) acute toxicity.ConclusionsWeekly ultra-hypofractionated whole breast RT seems feasible and effective. Toxicity was mild, local control was acceptable, and overall survival was 97.8% at 3 years. Rates of severe toxicity were reduced with the IMRT technique.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00432-021-03907-w.