3-dimensional Conformal Radiotherapy Research Articles

Treatment Related Acute Toxicities Between Treatment with 3D-CRT and IMRT in Localised Prostate Cancer.

To compare the acute toxicities of two radiation treatment techniques, intensity modulated radiation therapy (IMRT), and 3-dimensional conformal radiation therapy (3D-CRT) in localised prostate adenocarcinoma. Descriptive study. Place and Duration of the Study:Department of Oncology, Dr. Ziauddin Hospital, Karachi, Pakistan, from July 2016 to June 2022. Patients with localised prostate adenocarcinoma who underwent treatment using two different advanced radiotherapy techniques i.e., IMRT and 3D-CRT were recruited during the study period. They were followed up for six months for acute gastrointestinal (GI) and genitourinary (GU) adverse events (acute toxicities) related to both treatment modalities according to Modified radiation therapy oncology group (RTOG) criteria. The acute toxicities were assessed at the 2nd, 4th, and 6th week during treatment and at the 3rd and 6th month after treatment. There were 78 patients, with 39 patients in each group. The mean age was 68 ± 10 years in the 3D-CRT and 68 ± 07 years in the IMRT group. Patients in the IMRT group exhibited markedly lower treatment-related acute GI and GU effects at the end of 4th and 6th weeks for anorectal pain (p = 0.04) and (p = 0.01) and burning micturition (p = 0.003) and (p = 0.01), respectively. Furthermore, at 3 months anorectal pain (p = 0.02), loose stools (p = 0.005), and burning micturition (p = 0.01) were present and at 6 months anorectal pain was (p = 0.01) still present. Radiation therapy modalities 3D-CRT and IMRT both showed acceptable toxicity profile in the management of localised prostate cancer, while IMRT group exhibited significantly lower treatment-related acute GI and GU effects. 3D-CRT (3-Dimensional Conformal Radiation Therapy), IMRT (Intensity-Modulated Radiation Therapy), Radiation toxicity.

Teknik Terapi Radiasi 3DCRT Pada Kasus Kanker Serviks Dengan Studi Literatur

Research with literature studies is still rarely carried out, therefore in this article we want to know about the External Radiation Radiotherapy Technique in Cervical Cancer Cases with 3D-CRT (3-Dimensional Conformal Radiation Therapy): This literature discusses the application of the 3D-CRT external radiation radiotherapy technique in treatment cervical cancer. 3D-CRT is a method that allows external radiation exposure from more than one side,possiblemore appropriate radiation dose according to the shape and location of the tumor. This study also lists other techniques such as Brachytherapy, IMRT, and 2D in the treatment of cervical cancer. Photon Dose Distribution Using 3D-CRT and IMRT Techniques in Cervical Cancer Therapy: This research discusses photon dose distribution in the Treatment Planning System (TPS) using 3DCRT and IMRT techniques for cervical cancer therapy. This provides insight into the comparison between the two techniques in delivering appropriate radiation doses to the tumor target. 6 MV Energy Linac Radiotherapy Against Cervical Cancer: This journal discusses the use of radiotherapy on a Linac aircraft with a 6 MV energy photon beam using the 3DCRT technique in the treatment of cervical cancer. This technique helps deliver the right dose of radiation according to the target area. The literature above provides information about external radiotherapy techniques, including 3D-CRT, in the treatment of cervical cancer. They help understand the role and application of this technique in cervical cancer treatment.

Preliminary results of hypofractionated radiotherapy in breast cancer in Chandigarh, India: single-centre, non-inferiority, open-label, randomised, phase 3 trial

Globally, most of the randomised trials with hypofractionation in patients with breast cancer have used 3-dimensional conformal radiotherapy technique (3D-CRT). As facilities for 3D-CRT technique may not be available in low-resource settings, there is a need to see if hypofractionation is feasible and safe with 2-dimensional (2-D) technique. In this study, we compared a 3-week radiation schedule with a 2-week schedule of hypofractionated radiotherapy in patients with breast cancer with 2-D technique. The current study was an open-label, randomised, phase 3 trial. Patients with breast cancer, stage I-III, post mastectomy or after breast conservative surgery who needed adjuvant locoregional radiotherapy were randomised in the Department of Radiotherapy & Oncology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh, India; to 34Gy in 10 fractions over 2 weeks (2-week arm) or 35Gy in 15 fractions over 3 weeks to the chest wall and 40Gy/15#/3wks to breast and supraclavicular fossa (3-week arm). Boost dose when indicated was 8-10Gy/2-4#/2-4 days in both the arms. Patients were planned on a 2-dimensional (2D) simulator with 2 tangential fields to breast/chest wall and incident supraclavicular fossa field. Acute toxicity was assessed using the Radiation Therapy Oncology Group (RTOG) grading scale. Assessments were carried out weekly during radiotherapy and at 4 weeks after treatment by the physician. Cosmetic outcome was assessed using the Harvard/National Surgical Adjuvant Breast and Bowel Project (NSABP)/RTOG scale. The toxicity rates between the two arms were compared using Fisher's exact tests. The trial was approved by institutional ethics committee and registered with ClinicalTrials.gov, number NCT04075058. This study included 1121 eligible patients from June 2015 to December 2020. Median follow-up was 35 months (6-84 months). Mean age was 48 years (24-75 years). The patient characteristics were comparable between the two arms except for more mastectomies in the 3-week arm and more node-positive patients in the 2-week arm. There were more oestrogen receptor-positive tumors in the 3-week arm. Acute skin toxicities were comparable between the two arms. Grade 2 and 3 skin toxicity was 100 (18%) and 82 (15%); and 16 (3%) and 12 (2%) in the 3-week and 2-week arm (p=0.21), respectively. Cosmetic outcome was assessed as Excellent or Good for 89% of patients in the 3-week arm as compared to 94% in the 2-week arm (p=0.004). The two radiation schedules were comparable in terms of acute skin toxicity. The cosmetic outcome was better with the 2-week schedule. The preliminary findings indicate 2-week radiotherapy schedule with 2-D technique was better than the 3-week schedule in patients with breast cancer. However, disease outcomes and late-term toxicities need to be further checked. This study was funded by Science and Engineering Research Board (SERB), India.

Comparative Study of 3D Conformal Radiation Therapy by 3 Fields v/s 5 Fields Treatment Planning Techniques for Head and Neck Cancer

Purpose: The purpose of this study was to compare conventional 3 field versus 5 field treatment planning techniques during 3-dimensional conformal radiotherapy(3D-CRT) in respect of OAR, PTV coverage, treatment response & toxicities in head and neck Cancer. Materials and methods: This study included 50 biopsy proven and registered patients of head and neck cancer. Twenty five patients randomized to each arm. Arm A- 3D- conformal radiotherapy by 3 field delivery technique. Arm B--3D- conformal radiotherapy by 5 field delivery technique. All patients were irradiated on linear accelerator with concurrent chemotherapy in form of 3 weekly Cisplatin. Target volumes and normal structures were manually contoured on the axial slices of the planning CT scan. Patients were evaluated at end of treatment, 1st, 3rd & 6th months follow up visits. Results: At the end of treatment 22 (88%) patient in 3 field and 23 (92%) patients in 5 field had complete response. At 6 months complete response was 76% and 80 % in Arm A and B respectively (p value=0.6836). Grade 3rd xerostomia was seen 12% Vs 4% in Arm A and B respectively ( p value= 0.92 ) Mean V95 was 90.93 for conventional 3 field technique and 93.28 with 5 field technique ( p value=0.08).Conclusion: 5 field 3D-CRT technique can be used to spare parotid and other OAR and better PTV coverage specially in larynx carcinoma , patient with N2 or less nodal involvement and not involving higher neck node level.

A phantom study investigating effective strategies for reducing fetal dose in pregnant patients with head and neck cancer

PurposeTo measure the out-of-field doses for various treatment planning techniques and assess the impact on fetal dose with and without the use of custom shielding. Materials and methodsA total of six treatment plans were generated with different treatment techniques such as 3-dimensional conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), utilizing both 6 MV flattened beams and flattening filter-free (FFF) beams. The measurements were carried out both out-of-field at the surface and at depth to assess the dose reduction achieved by removing the flattening filter and incorporating shielding. ResultsThe custom-made frame shielding can effectively reduce the surface dose with a maximum reduction of 15.2% observed in VMAT plans and achieve a maximum reduction of 100% for cone beam computed tomography (CBCT) imaging. Out-of-field dose measurements conducted at depth, positioned 58 cm inferior to the target isocenter, reveal that the shielding effectiveness consistently remains the greatest for 3DCRT technique. A maximum reduction of 21% is observed when utilizing a flattening filter-free beam. ConclusionThe results of this study indicate that the 3DCRT technique exhibits the least amount of scatter radiation both near and far from the treatment isocenter, which is the most suitable approach for radiation therapy of pregnant patients. In cases where meeting dose constraints for critical organs becomes challenging, VMAT technique emerges as the most suitable treatment technique for reducing out-of-field doses. Additionally, a flattening filter-free beam significantly reduces out-of-field doses due to lower contributions from head scatter.

Are We Missing Acute Toxicities Associated With Hypofractionated Breast Irradiation? A Report From a Large Multicenter Cohort Study

The efficacy and long-term safety of hypofractionated whole breast irradiation (HF-WBI) have been established through multiple randomized trials, yet data about acute toxicities remain more limited. Since 2013, our group has prospectively collected acute toxicity data from weekly treatment evaluations and additional assessment after completion. In 2016, we intentionally shifted the posttreatment assessment follow-up visit from 1 month to 2 weeks to evaluate for missed acute toxicity occurring in that immediate posttreatment window. Here, we report whether 2-week follow-up has resulted in increased detection of acute toxicities compared with 4-week follow-up. We prospectively compared acute toxicity for patients treated with HF-WBI between January 1, 2013, and August 31, 2015 (4 week follow-up cohort) to patients treated between January 1, 2016, and August 31, 2018 (2 week follow-up cohort). Analyses included a multivariable model that adjusted for other factors known to correlate with toxicity. We prospectively defined acute toxicity as maximum breast pain (moderate or severe rating) and/or occurrence of moist desquamation reported 7 days before the completion of radiation therapy (RT) until 42 days after completion. A total of 2689 patients who received postlumpectomy radiation and boost were analyzed; 1862 patients in the 2-week follow-up cohort and 827 in the 4-week follow-up cohort. All acute toxicity measures assessed were statistically similar between follow-up cohorts when compared in an unadjusted fashion. Overall acute composite toxicity was 26.4% and 27.7% for patients in the 4-week follow-up and 2-week follow-up cohorts, respectively. Overall acute composite toxicity remained similar between follow-up cohorts in a multivariable, adjusted model and was significantly related to patient's age, body mass index, smoking status, and treatment technique (intensity-modulated RT vs 3-dimensional conformal radiation therapy) but not follow-up cohort. An earlier posttreatment follow-up for HF-WBI patients did not reveal a significant increased incidence of acute toxicities at 2 weeks compared with 4 weeks. This study provides physicians and patients with additional data on the safety and tolerability of HF-WBI for early stage breast cancer.

Unraveling the efficacy network: A network meta-analysis of adjuvant external beam radiation therapy methods after hepatectomy.

Primary liver cancer is a malignant tumor with a high recurrence rate that significantly affects patient prognosis. Postoperative adjuvant external radiation therapy (RT) has been shown to effectively prevent recurrence after liver cancer resection. However, there are multiple RT techniques available, and the differential effects of these techniques in preventing postoperative liver cancer recurrence require further investigation. To assess the advantages and disadvantages of various adjuvant external RT methods after liver resection based on overall survival (OS) and disease-free survival (DFS) and to determine the optimal strategy. This study involved network meta-analyses and followed the PRISMA guidelines. The data of qualified studies published before July 10, 2023, were collected from PubMed, Embase, the Web of Science, and the Cochrane Library. We included relevant studies on postoperative external beam RT after liver resection that had OS and DFS as the primary endpoints. The magnitudes of the effects were determined using risk ratios with 95% confidential intervals. The results were analyzed using R software and STATA software. A total of 12 studies, including 1265 patients with hepatocellular carcinoma (HCC) after liver resection, were included in this study. There was no significant heterogeneity in the direct paired comparisons, and there were no significant differences in the inclusion or exclusion criteria, intervention measures, or outcome indicators, meeting the assumptions of heterogeneity and transitivity. OS analysis revealed that patients who underwent stereotactic body radiotherapy (SBRT) after resection had longer OS than those who underwent intensity modulated radiotherapy (IMRT) or 3-dimensional conformal RT (3D-CRT). DFS analysis revealed that patients who underwent 3D-CRT after resection had the longest DFS. Patients who underwent IMRT after resection had longer OS than those who underwent 3D-CRT and longer DFS than those who underwent SBRT. HCC patients who undergo liver cancer resection must consider distinct advantages and disadvantages when choosing between SBRT and 3D-CRT. IMRT, a RT technique that is associated with longer OS than 3D-CRT and longer DFS than SBRT, may be a preferred option.

Comparative evaluation of quality of life in oral cancer patients undergoing 3-dimensional conformal radiation therapy with or without concomitant chemotherapy - A longitudinal study.

To assess and compare the quality of life (QOL) in Oral Cancer patients undergoing 3-DCRT with or without concomitant Chemotherapy at three different time intervals. This unicentric longitudinal study included 50 patients of oral cancer undergoing 3-DCRT with or without concomitant chemotherapy. QOL was recorded using the EORTC H and N 35 Questionnaire at baseline, end of treatment (EOT), and 3 months after treatment. Maximum deterioration of most QOL domains were noted at End of treatment (EOT) in all the patients. A highly statistically significant difference was noted between different time intervals with the highest scores noted at the EOT (P < 0.01). There was a statistically significant difference in patients undergoing 3DCRT with chemotherapy when compared to those with 3DCRT without chemotherapy (P < 0.05). There is substantial deterioration in QOL at the EOT after head-neck irradiation by 3-DCRT with or without concomitant Chemotherapy although it gradually improves over time. However, 3DCRT results in clinically meaningful and statistically better QOL scores at 3 months after treatment compared to baseline and EOT.

Treatment outcomes of radiotherapy with concurrent weekly cisplatin in older patients with locally advanced head and neck squamous cell carcinoma

BackgroundTri-weekly cisplatin and radiotherapy (CDDP + RT) is a standard of care for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) but is sometimes challenging to complete in older patients. Weekly CDDP + RT has shown mild toxicity compared to tri-weekly CDDP + RT for LA-HNSCC and is a promising option for older adults. We aimed to report the treatment outcomes and prognostic factors in patients with LA-HNSCC treated with weekly CDDP + RT.MethodsWe analyzed patients aged ≥ 70 years who started weekly CDDP + RT for LA-HNSCC between July 2006 and October 2022. LA-HNSCC includes cancer in the oropharynx, hypopharynx, or larynx with a clinical stage of 3 or 4 without distant metastases based on the Union for International Cancer Control staging system 8th edition. The radiation dose of 70 Gy was delivered in 35 fractions by 3-dimensional conformal radiotherapy, intensity-modulated radiotherapy, or proton beam therapy. The primary endpoint was the 3-year overall survival (OS), and the secondary endpoints were the 3-year progression-free survival (PFS) and 3-year cause-specific survival (CSS). The Kaplan–Meier method was used to calculate survival rates, and the log-rank test was used to evaluate statistical significance. A Cox proportional hazards model was used for the multivariate analysis of prognostic factors.ResultsThe median age of the 49 patients was 72 (range: 70–78) years. The median CDDP dose was 200 (40–280) mg/ m2, and 47 patients completed scheduled radiotherapy. Forty-eight patients (98.0%) had a performance status of ≥ 1 at the initial visit. The 3-year OS, PFS, and CSS were 80.9% (95% confidence interval [CI]: 64.8–90.7), 58.9% (95%CI: 42.7–73.3), and 85.0% (95%CI: 68.7–93.4), respectively. In the multivariate analysis, the cumulative CDDP dose (< 200 or ≥ 200 mg/m2) was a significant factor for OS (hazard ratio: 0.29 [95% CI 0.08–0.97], p = 0.044). There was one case of early mortality. Grade 3 or higher late adverse events were observed in four patients (8.2%).ConclusionsWeekly CDDP + RT in older patients led to good survival outcomes with an acceptable rate of adverse events. CDDP should be administered at a dose of at least 200 mg/m2 in older patients.Trial registration Retrospectively registered

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

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

Dosimetric comparison of five different radiotherapy treatment planning approaches for locally advanced non-small cell lung cancer with sequential plan changes.

The purpose of this study was to compare the dosimetric characteristics of five different treatment planning techniques for locally advanced non-small cell lung cancer (LA-NSCLC) with sequential plan changes. A total of 13 stage III NSCLC patients were enrolled in this study. These patients had both computed tomography (CT) images for initial and boost treatment plans. The latter CT images were taken if tumor shrinkage was observed after 2 weeks of treatment. The prescription dose was 60 Gy/30 Fr (initial: 40 Gy/20 Fr, and boost: 20 Gy/10 Fr). Five techniques (forward-planed 3-dimensional conformal radiotherapy [F-3DCRT] on both CT images, inverse-planned 3DCRT [I-3DCRT] on both CT images, volumetric modulated arc therapy [VMAT] on both CT images, F-3DCRT on initial CT plus VMAT on boost CT [bVMAT], and hybrid of fixed intensity-modulated radiotherapy [IMRT] beams and VMAT beams on both CT images [hybrid]) were recalculated for all patients. The accumulated doses between initial and boost plans were compared among all treatment techniques. The conformity indexes (CI) of the planning target volume (PTV) of the five planning techniques were 0.34 ± 0.10, 0.57 ± 0.10, 0.86 ± 0.08, 0.61 ± 0.12, and 0.83 ± 0.11 for F-3DCRT, I-3DCRT, VMAT, bVMAT, and hybrid, respectively. In the same manner, lung volumes receiving >20 Gy (V20Gy ) were 21.05 ± 10.56%, 20.86 ± 6.45, 19.50 ± 7.38%, 19.98 ± 10.04%, and 17.74 ± 7.86%. There was significant improvement about CI and V20Gy for hybrid compared with F-3DCRT (p < 0.05). The IMRT/VMAT hybrid technique for LA-NSCLC patients improved target CI and reduced lung doses. Furthermore, if IMRT was not available initially, starting with 3DCRT might be beneficial as demonstrated in the bVMAT procedure of this study.

Safety of Radiation Therapy for Treatment of Malignancy in Patients with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) has been considered a relative contraindication to radiation therapy (RT) due to the potential greater risk of RT-induced toxicities, however, there is limited toxicity data using modern RT techniques. This study aims to assess toxicity outcomes in patients with IBD treated with abdominal or pelvic RT. After institutional review board approval, patients with IBD who received RT to the abdomen or pelvis were filtered from an institutional research repository and their electronic medical records were reviewed. Acute toxicity was defined as that occurring within 3 months of RT. Toxicities were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. Univariable Cox proportional hazards regression was used to assess rates of grade ≥2 toxicity-free survival. We identified 62 patients with median age of 69 years (interquartile range [IQR] 62-77) who received RT from 2006-2022. Median follow up was 15 months (IQR 4-33). Most patients were male (42; 68%) and had a diagnosis of ulcerative colitis (44; 71%). The most common primary malignancy was colorectal/anal (26; 42%). Intensity-modulated RT (IMRT) was most frequently used (38; 61%) followed by 3-dimensional conformal RT (3D-CRT) (12; 19%) and stereotactic body RT (SBRT)/brachytherapy (12; 19%). For IMRT/3D-CRT, median dose delivered was 50 Gy (IQR 49-59) in 25 fractions (IQR 25-30), and median maximum dose (Dmax) to bowel was 48 Gy (IQR 43-52); whereas for SBRT/brachytherapy, the median dose was 32 Gy (IQR 27-40) in 3 fractions (IQR 2-5) and median bowel Dmax was 32 Gy (IQR 20-37). The median biologically effective dose delivered with an assumed alpha/beta ratio of 10 (BED10) across all RT modalities was 63 Gy (IQR 60-72). After initiation of RT, 31 patients (50%) and 14 patients (23%) experienced grade ≥2 acute and late toxicity, respectively. Thirteen patients (21%) and 7 patients (11%) experienced grade 3 acute and late toxicity, respectively. No patients experienced grade >3 toxicity. Acute toxicity resulted in interruption to RT for 5 patients (8%), 2 of which did not resume RT. Four patients (6%) required adjustment to chemotherapy or IBD medication dosage as a result of their acute toxicity. Median time from RT start to acute toxicity onset was 41 days (IQR 32-46), whereas median time to onset of late toxicity was 9 months (IQR 5-15). The most common acute and late toxicities were diarrhea (21; 34%) and bowel obstruction/perforation/fistula (4; 6%), respectively. Rates of grade ≥2 toxicity-free survival overtime were not significantly associated with IBD status (active vs quiescent), delivered BED10, or bowel Dmax BED3. In patients with IBD treated with abdominal or pelvic RT for malignancy, RT was feasible with acceptable rates of toxicity and active versus quiescent IBD status did not impact toxicity outcomes. Future research is needed to elucidate specific dose constraints when treating patients with IBD.

Radiation Therapy in the Management of Cutaneous Squamous Cell Carcinoma Metastatic to the Parotid: A 50-Year Single Institution Experience

Cutaneous squamous cell carcinoma (cSCC) represents 20% of skin cancers of the head and neck, and metastatic spread to the parotid area lymph nodes (PALN) are found in 1-3% of cases. Herein, we present the updated results of the largest single institution experience using radiation therapy (RT) in the management of patients (pts) with PALN metastases from cSCC in North America. Our hypothesis is the addition of pts treated with modern RT would maintain acceptable efficacy with a favorable toxicity profile. With IRB approval, we retrospectively reviewed all pts diagnosed with cSCC metastatic to PALN treated at our institution with >6 months follow up. All pts were staged by the O'Brien staging system. Fifteen pts (10%) were treated preoperatively, 111 (72%) post operatively, and 28 (18%) with RT alone. Most pts were treated with three dimensional conformal RT (3DCRT) or a combination of 3DCRT and electron therapy (n = 112), while 31 pts were treated with intensity modulated RT (IMRT). There were 115 pts treated once daily fractionation and 39 pts being treated twice per day. We estimated disease control and survival, including local (parotid) control (LC), neck control (NC), local-regional control (LRC), distant metastasis free survival (DMFS), cause specific survival (CSS), and overall survival (OS) using the cumulative incidence method. Treatment toxicities were documented per CTCAEv3. From November 1969 to December 2019, 154 pts were included. Median age at RT initiation was 66 years (range, 28-89). Fifty-two pts (33.8%) had an unknown location of a primary, while the most common identifiable locations of a primary were the temple, helix, and forehead. Forty-eight percent of pts had P2 or P3 disease with 26 of these pts being N1 or N2. Forty-six percent of pts were current or former smokers. Median follow up for this cohort was 4.9 years (range, <0.1 - 34.0) with 8 pts being lost to follow up. The overall 10-year Kaplan-Meier estimates for LC, NC, LRC, DMFS, CSS, and OS were 82%, 93%, 77%, 92%, 76%, and 31%, respectively. Eighty-one percent of treatment failures occurred within 2 years of treatment. LC was improved with IMRT (100%) compared to non-IMRT (78%) treatment (p = 0.005), with no other outcomes differing between the cohorts. There were 31 treatment complications were reported with 13 being ³ grade 3. Our results represent the 10-year outcomes for the largest reported single institution experience of RT for cSCC metastatic to PALN showing favorable clinical outcomes with an acceptable toxicity profile. There was improved LC for pts treated with IMRT compared to 3DCRT/electrons; yet these did not translate to significant changes in other clinical outcomes.

Long-Term Outcomes and Toxicity in Esophageal Cancer Patients after Neoadjuvant or Definitive Concurrent Chemotherapy with Proton Beam Therapy

Proton-beam therapy (PT) is increasingly utilized over three dimensional-conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) photon irradiation for the treatment of various malignancies due to better toxicity reduction. We investigated the long-term outcomes and toxicity in esophageal cancer (EC) patients treated with PT as part of their neoadjuvant concurrent chemoradiation followed by surgery (nCRT) or definitive concurrent chemoradiation (dCRT) treatment regimen. All consecutively treated, American Joint Committee on Cancer 7th edition clinical stage I-IV EC patients from 2006 to 2022 were retrospectively analyzed. Standard RT dose for most patients was 50.4 Gy/28 fractions. nCRT patients had surgery within 4 months post-RT. Kaplan-Meier method was used to determine overall survival (OS), locoregional recurrence-free survival (LRRFS) and distant metastatic-free survival (DMFS). Acute and chronic RT-related toxicities were graded with Common Terminology Criteria for Adverse Events version 4.0. There were 510 EC PT patients: 204 (40%) had nCRT and 306 (60%) had dCRT. Most lesions were located in the lower esophagus, of adenocarcinoma histology and treated with passive scatter PT. Overall median follow-up was 72 months. Median, 3- and 5-year OS for all patients were 43 months, 54.1% and 44.9%, respectively. Median LRRFS and DMFS were not reached. Esophagitis was the most common grade ≥3 (G3+) toxicity (59 patients; 28.9%, including a G4 and a G5 toxicity), followed by nausea (29 patients; 14.2%) and esophageal stricture (26 patients, 12.7%). With nCRT, median, 3- and 5-year OS were 80 months, 64.7% and 56.1%, respectively, while the median LRRFS and DMFS were not reached again. Their most common G3+ toxicity was esophagitis in 14 patients (6.9%) followed by nausea (8 patients; 3.9%). An nCRT patient developed G4 RT pneumonitis. Pathological complete response (pCR) was observed in 58 patients (28.4%). Surgery-related pulmonary, cardiac and gastrointestinal complications were reported in 38 (18.6%), 40 (19.6%) and 43 (21.1%) patients, respectively. dCRT patients had a median follow-up of 65 months, and median, 3- and 5-year OS of 32 months, 46.7% and 37.0%, respectively. Although the median LRRFS was not reached, the median DMFS was 74 months. The most observed dCRT G3+ toxicity was esophagitis (45 patients, 22.1%: including both G4 and G5 patients) and then esophageal stricture (23 patients, 11.3%). A dCRT patient developed G4 fistula. To our knowledge, this is the largest single-institutional study on EC long-term outcomes and toxicity using PT. Our cohort reveals good outcomes and mostly mild CRT-related toxicities. Trimodality nCRT with protons demonstrates excellent outcomes relative to the CROSS trial (49.4 months) with identical pCR rate (29% in CROSS) and similar toxicity profile. nCRT with protons should be studied rigorously in the current randomized phase III trial NRG GI006.

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

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

Analysis of Radiation Therapy Quality Assurance in NRG Oncology RTOG 0848

NRG/Radiation Therapy Oncology Group 0848 is a 2-step randomized trial to evaluate the benefit of the addition of concurrent fluoropyrimidine and radiation therapy (RT) after adjuvant chemotherapy (second step) for patients with resected pancreatic head adenocarcinoma. Real-time quality assurance (QA) was performed on each patient who underwent RT. This analysis aims to evaluate adherence to protocol-specified contouring and treatment planning and to report the types and frequencies of deviations requiring revisions. In addition to a web-based contouring atlas, the protocol outlined step-by-step instructions for generating the clinical treatment volume through the creation of specific regions of interest. The planning target volume was a uniform 0.5 cm clinical treatment volume expansion. One of 2 radiation oncology study chairs independently reviewed each plan. Plans with unacceptable deviations were returned for revision and resubmitted until approved. Treatment started after final approval of the RT plan. From 2014 to 2018, 354 patients were enrolled in the second randomization. Of these, 160 patients received RT and were included in the QA analysis. Resubmissions were more common for patients planned with 3-dimensional conformal RT (43%) than with intensity modulated RT (31%). In total, at least 1 resubmission of the treatment plan was required for 33% of patients. Among patients requiring resubmission, most only needed 1 resubmission (87%). The most common reasons for resubmission were unacceptable deviations with respect to the preoperative gross target volume (60.7%) and the pancreaticojejunostomy (47.5%). One-third of patients required resubmission to meet protocol compliance criteria, demonstrating the continued need for expending resources on real-time, pretreatment QA in trials evaluating the use of RT, particularly for pancreas cancer. Rigorous QA is critically important for clinical trials involving RT to ensure that the true effect of RT is assessed. Moreover, RT QA serves as an educational process through providing feedback from specialists to practicing radiation oncologists on best practices.

Dosimetric comparison of rectal carcinoma radiation therapy using three dimensional conformal radiation therapy and intensity modulated radiation therapy: an analytical observational study

Rectal cancer is the second most common cancer in large intestine. Recently, preoperative chemoradiotherapy has been generally used in the management of locally advanced rectal cancer on the basis of several benefits proven by clinical studies, in the aspect of better locoregional tumor control, reduced toxicity of normal organs, and an increased chance of preserving the anal sphincter, when compared with postoperative chemoradiotherapy. In this observational study, conducted between January 2017 and December 2021, pursuant to the recommendations of the radiation therapy oncology group (RTOG), all patients underwent CT simulation, a bladder protocol and target contouring. 10 patients were treated with intensity modulated radiotherapy (IMRT) and 10 with three-dimensional conformal radiation therapy (3DCRT). Planned target volume (PTV) coverage, homogeneity index (HI), conformity index (CI), and doses to organs at risk (OAR) were compared. Our findings showed that 3DCRT and IMRT have statistically significant differences in PTV coverage and dosages to OAR (p&lt;0.001), proving that IMRT achieves improved target dose coverage and superior normal tissue avoidance (bladder and intestine) compared to 3DCRT.

Bladder only versus bladder plus pelvic lymph node chemoradiation for muscle-invasive bladder cancer.

Bladder-sparing chemoradiation therapy (CRT) is a definitive first-line treatment for muscle-invasive bladder cancer. The optimal radiotherapy target volume, either bladder-only (BO) or bladder plus pelvic lymph nodes (BPN), remains unclear. We identified 2,104 patients in the National Cancer Database with cT2-4N0M0 urothelial cell carcinoma of the bladder treated with CRT following maximal transurethral resection of bladder tumor from 2004 to 2016. The exposure of interest was BO vs. BPN treatment volume. The primary outcome was overall survival (OS), compared between groups using Kaplan-Meier and multivariable Cox proportional hazards. Sensitivity analysis tested an interaction term for clinical T stage (T2 vs. T3-4) and radiation modality (3-dimensional conformal radiotherapy vs. intensity modulated radiotherapy or proton therapy). Annual use of BO vs. BPN from 2004 to 2016 was compared using Cochran-Armitage test. A total of 578 patients were treated with BO and 1,526 patients treated with BPN CRT. There was a significant increase in BPN use from 2004 to 2016 (66.9%-76.8%, P < 0.0001). With a median follow-up of 6.2 years, there was no survival difference between groups: 5- and 10-year OS 27.4% (95% CI 23.4%-31.4%) in the BO group vs. 31.9% (95% CI 29.3%-34.6%) in the BPN group, and 13.1% (95% CI 9.7%-17.1%) in the BO group vs. 13.2% (95% CI 10.6%-16.0%) in the BPN group, respectively (log-rank P = 0.10). On multivariable analysis, there was no significant association between BPN and OS (adjusted HR 0.90, 95% CI 0.81-1.02, P = 0.09). On sensitivity analysis, we found no differential effect by T stage or radiation modality. Use of pelvic lymph node radiation has risen in the US but may not impact long-term survival outcomes for patients with node-negative muscle-invasive bladder cancer (MIBC). Optimizing radiation treatment volumes for CRT for MIBC will be important to study under prospective trials, such as the SWOG/NRG 1806.

Early effect of contemporary radiotherapy protocol on myocardium in patients with breast cancer assessed with cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Medical Centre Ljubljana Research Grant. Introduction Early cardiotoxicity of modern radiotherapy (RT) is not known. Purpose To study the early cardiotoxic effect of contemporary RT on myocardium with cardiac magnetic resonance (CMR) in patients with breast cancer (BC). Methods Patients with in-situ ductal carcinoma of the breast, scheduled for RT were included. All patients had undergone surgical tumorectomy. Exclusion criteria were prior systemic chemotherapy, prior RT or known cardiac disease. Patients were treated with 3-dimensional conformal RT or intensity-modulated RT, left-sided BC patients were also scheduled for deep inspiration breath hold protocol, if feasible. Patients underwent CMR imaging prior to RT and within 2 weeks after RT. Left and right ventricular volumes and ejection fraction, global native and postcontrast T1 values and T2 values, prior to and after completion of RT were analyzed. All patients provided written informed consent. Results A total of 40 female patients (mean age 55 ± 7 years) were included, 22 with left-sided BC. The mean radiation dose was 42 Gy. CMR results are presented in Table 1. Left-sided BC patients had statistically significant increase in global T2 values. There were no significant differences in other studied parameters. No patient developed pericardial effusion and no patient had presence of late gadolinium enhancement at both exams. Conclusion Modern RT of left-sided BC is associated with increased T2 values, most likely representing myocardial edema, early after completion of RT.

Survival for patients of stage III non-small cell lung cancer after radiotherapy in different periods.

e20611 Background: Concurrent chemoradiotherapy (CCRT) is the main treatment for patients of unresectable stage Ⅲ non-small cell lung cancer (NSCLC).To retrospectively analyze prognosis and its related factors for patients of unresectable stage III NSCLC after radiotherapy in different periods. Methods: From 2000 to 2010 and from 2015 to 2019, patients of stage III NSCLC which received radiotherapy in the Fourth Hospital of Hebei Medical University were enrolled. Statistical analysis was used with the SPSS 21.0 software.The Kaplan-Meier method, log-rank test and Cox model were used for survival analysis, univariate analysis, and multivariate analysis, respectively. Results: A total of 808 patients of stage III NSCLC were enrolled. There were 674 males and 134 females. The median age was 63 years old( 29-86 years old ) . Radiotherapy (RT) were performed in 474 patients between 2000 to 2010 and in 334 patients between 2015 to 2019. There were 240 cases received with RT alone, 449 cases with sequential chemoradiotherapy (Seq-CRT) and 119 cases with CCRT. 55 were treated with 3-dimensional radiotherapy (2DRT) plus 3-dimensional conformal radiotherapy (3DCRT)，386 with 3DCRT，and 367 with intensity-modulated radiotherapy（IMRT)， respectively. The median doses was 60 Gy (range 36-77Gy). The median overall survival (OS) was 21.0 months (19.4-22.6 months), and the 1-, 3- and 5-year OS rates were 69.8%, 30.7% and 21.3%, respectively. Under univariate analysis, gender, age, radiotherapy technology，period of treatment and whether combined chemotherapy were significantly associated with OS ( P&lt; 0.05). The median OS was 18.0 months in group of 2000-2010 and 26.1 months in group of 2015-2019, respectively. The median OS for groups of2DRT+3DCRT, 3DCRT and IMRT were 10.0, 21.0, 23.4 months, respectively. The median OS for RT alone, Seq-CRT and CCRT was 17.0, 21.0, 30.3 months, respectively. Under multivariate analysis, sex, age, times of RT and combined chemotherapy were independent prognostic factors for OS ( P&lt; 0.05). Conclusions: From 2DRT to 3DCRT or IMRT, the OS in patients of stage Ⅲ NSCLC was gradually increased; the OS was more higher in patients treated between 2015-2019 also. In addition, the OS was significantly longer in patients with CCRT than with Seq-CRT or RT alone.