3-dimensional Conformal Radiotherapy Research Articles

Radiographic predictors of IMRT for treating regional lymph nodes in breast cancer

Regional nodal irradiation (RNI) is an essential part of the treatment of high risk early stage (Stage IIb) and locally advanced (Stage III) breast cancer. Acceptable radiation plans can usually be achieved using 3-dimensional conformal radiation therapy with deep-inspiration breath hold to limit dose to the heart, although in some cases intensity-modulated radiation therapy produces superior results. The goal of this study is to identify radiographic parameters that predict the need for IMRT when delivering RNI. We retrospectively examined breast cancer patients treated with comprehensive RNI including internal mammary lymph nodes, supraclavicular lymph nodes, and undissected axillary lymph nodes at our institution from January 2016 to February 2018. Radiographic parameters including lung volume, internal mammary lymph nodes depth, modified central lung distance (mCLD), tangent length, and target height were recorded. Univariate and multivariate logistic regression was performed using IMRT as a binary endpoint (yes/no). A total of 46 patients were evaluated, of which 9 (20%) required IMRT. Five of the 9 (56%) IMRT patients were postmastectomy with a tissue expander in place. There was an increased likelihood of IMRT per 0.5 cm increase in mCLD (odds ratios [OR]: 3.27; 95% confidence interval [CI]: 1.39 to 9.63; p = 0.01) and per 1 cm increase in target height (OR: 1.77; 95% CI: 1.08 to 3.40; p = 0.04). A threshold value of 3.38 cm was identified for mCLD (OR 10.3; 95% CI: 2.14 to 61.4; p value = 0.005), and 25.2 cm for target height (OR 10.9; 95% CI: 2.19 to 82.7; p value = 0.007). When delivering RNI, larger values of mCLD and target height corresponded to the use of IMRT. Further investigations are warranted to confirm these findings, which may improve the efficiency of the treatment planning process and in turn patient care.

262P - Is bone marrow sparing intensity modulated radiotherapy better than 3-dimensional conformal radiotherapy in reducing haematological toxicities during pelvic irradiation in locally advanced carcinoma cervix?: A prospective study

262P - Is bone marrow sparing intensity modulated radiotherapy better than 3-dimensional conformal radiotherapy in reducing haematological toxicities during pelvic irradiation in locally advanced carcinoma cervix?: A prospective study

Association between Acute Hematological Toxicities and Bone Marrow Dosimetric Parameters in Cervical Cancer Patients Undergoing Concurrent Chemoradiation – A Comparison between Three Dimensional Conformal Radiotherapy and Intensity Modulated Radiotherapy

Association between Acute Hematological Toxicities and Bone Marrow Dosimetric Parameters in Cervical Cancer Patients Undergoing Concurrent Chemoradiation – A Comparison between Three Dimensional Conformal Radiotherapy and Intensity Modulated Radiotherapy

387P - Radiation dose to contralateral parotid during treatment of carcinoma buccal mucosa

Background: To compare the contralateral parotid gland dose during radiation treatment of carcinoma buccal mucosa with 3 Dimensional Conformal Radiotherapy (3D-CRT) vs. Parotid sparing Intensity Modulated Radiotherapy (IMRT). Methods: Ten consecutive lateralized carcinoma of the oral cavity patients treated with a prospective management using ipsilateral irradiation were studied. This included 4 radical and 6 postoperative oral cavity carcinomas, with Stage T1-T2, N0-N2b disease. Five patients were treated with 3D-CRT and five with IMRT. The dose received by contralateral parotid gland was assessed by volumetric analysis. Results: Dose-volume histograms (DVH) showed the mean dose to contralateral parotid was 896.6 cGy (range: 0.5-10 Gy) with 3D-CRT and 503.8cGy (range: 0.4-4 Gy) with IMRT. With IMRT 97%-105% of the prescribed dose was received by 95% of the target volumes. Mean dose to the PTV Primary site was 67.8 Gy (range, 65-71 Gy) for primary RT and 60.5 Gy (range: 55-66 Gy) for post-operative RT. The mean dose to the PTV Node (ipsilateral lymph nodes) was 50.8 Gy (range: 49-53 Gy). Conclusions: There is a considerable increase in the mean dose of contralateral parotid in 3DCRT compared to IMRT. Parotid sparing IMRT helps reducing the radiation dose received by salivary glands. Legal entity responsible for the study: CBCC-Chennai, Saveetha University, Chennai. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.

32P - Dosimetric plan evaluation of hypofractionated 3-dimensional conformal radiotherapy (3DCRT) and 2-dimensional (2D) simulator planning in whole breast irradiation after breast conserving surgery

32P - Dosimetric plan evaluation of hypofractionated 3-dimensional conformal radiotherapy (3DCRT) and 2-dimensional (2D) simulator planning in whole breast irradiation after breast conserving surgery

Greater reduction in mid-treatment FDG-PET volume may be associated with worse survival in non-small cell lung cancer

Background and purposeThis study tested the hypotheses that 1) changes in mid-treatment fluorodeoxyglucose (FDG)-positron emission tomography (PET) parameters are predictive of overall survival (OS) and 2) mid-treatment FDG-PET–adapted treatment has the potential to improve survival in patients with non-small cell lung cancer (NSCLC). Material and methodsPatients with stage I-III NSCLC requiring daily fractionated radiation were eligible. FDG-PET-CT scans were obtained prior to and mid-treatment with radiotherapy at 40–50 Gy. The normalized maximum standardized uptake value (NSUVmax), normalized mean SUV (NSUVmean), PET-metabolic tumor volume (MTV), total lesion glycolysis (TLG), and computed tomography-based gross tumor volume (CT-GTV) were consistently measured for all patients. The primary study endpoint was OS. ResultsThe study is comprised of 102 patients who received 3-dimensional conformal radiotherapy, among whom 30 patients who received mid-treatment PET-adapted dose escalation radiotherapy. All PET-CT parameters decreased significantly (P < 0.001) mid-treatment, with greater reductions in FDG-volumetric parameters compared to FDG-activity factors. Mid-treatment changes in MTV (P = 0.053) and TLG (P = 0.021) were associated with OS, while changes in NSUVmax, NSUVmean, and CT-GTV were not (all Ps>0.1). Patients receiving conventional radiation (60-70 Gy) with MTV reductions greater than the mean had a median survival of 14 months, compared to those with MTV reductions less than the mean who had a median survival of 22 months. By contrast, patients receiving mid-treatment PET-adapted radiation with MTV reductions greater than the mean had a median survival of 33 months, compared to those with MTV reductions less than the mean who had a median survival of 19 months. Overall, PET-adapted treatment resulted in a 19% better 5-year survival than conventional radiation. ConclusionChanges in mid-treatment PET-volumetric parameters were significantly associated with survival in NSCLC. A greater reduction in the mid-treatment MTV was associated with worse survival in patients treated with standard radiation, but with better survival in patients who received mid-treatment PET-adapted treatment.

A Multi-institutional Analysis of Dosimetric Predictors of Toxicity Following Trimodality Therapy for Esophageal Cancer

Abstract Purpose This multi-institutional review explored associations between radiation dose-volume histogram (DVH) parameters and cardiopulmonary toxicities with trimodality therapy for esophageal cancer. Methods and Materials We reviewed 465 consecutive patients with esophageal cancer treated with chemoradiation therapy followed by surgery at 2 tertiary-care institutions between 2007 and 2013. Using logistic regression, we assessed associations between lung and heart DVH parameters and cardiopulmonary toxicities and survival. Statistically significant variables were subsequently included in multivariable models, which incorporated age, smoking history, previous history of heart disease, and type of chemotherapy. Results The median age of the patients was 61 years (interquartile range, 54-68 years), and 86% were men. At baseline, 60% of the patients had known cardiac risk factors, 64% were current or former smokers, and 10% had other pulmonary comorbidities. Most patients had stage II to III (96%) adenocarcinoma (94%) of the distal esophagus. The radiation therapy (RT) modalities used were 3-dimensional conformal RT (38%), intensity modulated RT (41%), and proton therapy (20%). An increased heart dose was associated with increased risk of cardiac toxicity on univariable analysis (V20 Gy: odds ratio [OR], 1.20; 95% CI, 1.08-1.33; P = .001) (V30 Gy: OR, 1.24; 95% CI, 1.11-1.38; P Conclusions We observed an association between heart dose and cardiac toxicity for esophageal cancer. The risk of cardiac toxicity was 5%, 10%, and 15% when the heart V30 Gy dose was 14%, 20%, and 30%, respectively. For every 10% increase in V30 Gy, there was a corresponding 24% increase in the relative risk of cardiac toxicity.

A Prospective Study of IMRT Versus 3D-CRT for Post-Operative Cervical Cancer Patients.

The use of intensity-modulated radiation therapy (IMRT) in postoperative cervical cancer is on the rise, yet there is still some controversy to adopt adjuvant IMRT as standard practice. The purpose of this study is to compare the difference between IMRT and three dimensional conformal radiation therapy (3D-CRT) especially in quality of life for pelvic radiation of postoperative treatment with cervical cancer. A total of 398 patients were enrolled from Oct 2015 to Oct 2017. They were selected randomly into two groups: IMRT group (n=190) and 3D-CRT group (n=208). Each patient received a prescribed dose of 45Gy/25F. Radiation dosimetry, the grade 2-4 in GI and GU; the score from functional assessment of cancer therapy scale-cervix (FACT-CX) scale and expanded prostate cancer index composite for clinical practice (EPIC-CP) scale were compared. (1) There was no significant difference on age, culture level, family economic condition and ratio of radiochemotherapy in two groups (P>0.05). (2) Dosimetric comparison: IMRT plans had a significant better conformity index (CI) of PTV compared with 3D-CRT (P<0.05). Compared with 3D-CRT plans , V40 of the small bowel, rectum, bladder, V20 and V10 of bone marrow were all significantly reduced (P<0.05). (3) The incidence of acute grade 2-3 gastriontestinal reaction was significantly high for 3D-CRT group versus the IMRT group(24.0%,15.8%; P=0.04). The incidence of acute grade 2-3 urinary toxicity was high for 3D-CRT group versus the IMRT group(25.5%,17.9%),but has no statistically difference P=0.07). (4) Quality of life scale: FACT-Cx score were 84.8±16.3 and 71.2±17.9 before and after radiation therapy in 3D-CRT group, 81.8±15.5 and 76.4±14.4 in IMRT group. FACT-Cx score was decreased significantly from beginning of radiation in 3D-CRT group ,it was reached 12.3±4.5,but it was only 5.1±2.3 in IMRT group(t=15.530, P=0.000). EPIC-CP scale score: EPIC-CP score were 15.4 ± 6.2 and 21.7±7.1 before and after radiation therapy in 3D-CRT group, 15.6 ± 6.9 and 18.4±7.2 in IMRT group. EPIC-CP score was increased significantly from beginning of radiation in 3D-CRT group ,it was reached 6.6±4.1,but it was only 3.1±4.2 in IMRT group(t=5.500, P=0.000). IMRT has shown a dosimetric advantage and also provided good quality of life for the postoperative patients with cervical cancer compared to 3D-CRT. Long term follow up will be needed to determine late toxicity and DFS/OS.

Effect of Gastric Filling on Radiation Therapy in Patients with Gastrointesinal Cancer

In the treatment of gastrointestinal (GI) cancers, radiotherapy (RT) is frequently delivered with 3-dimensional conformal RT (3DCRT) or intensity modulated RT (IMRT) techniques. These tumors are highly sensitive to neighboring organs’ movement. Differences in gastric or bowel filling may alter the position of target volumes and cause the risk of missing the target volumes and increase the organs at risk (OAR) doses. Thus, it is very important to ensure the same conditions of the patient during simulation and in all RT fractions. In this study, we tried to determine the optimal RT technique (3DCRT or IMRT) in patients with upper GI cancers and investigated the effect of gastric filling (empty-ES vs. full-FS) on target coverage and OARs doses. Ten patients with either gastric (n=5) or pancreatic cancer (n=5), who were treated with adjuvant RT following surgery were included. Two computed tomography (CT) images were taken with ES and FS. The first scan was taken after at least 2 hours fasting. Then the patients drank 1.5 L (50.7 fl oz) of water in 30 minutes and second CT images were taken. Following delineation of target volumes and OARs, 3DCRT [2 different 3 fields (3-field and 3-field 1) and 4-field] and IMRT (5- and 7-fields) plans were generated in each CT images. Firstly, it was evaluated whether there was a difference between planning techniques in terms of ES or FS. Secondly, CT images of each patient including ES and FS were fused and dose volume parameters were analyzed. We also obtained dosimetric measurements with thermoluminescence dosimetry (TLD) and Gafochromic EBT3 films using Alderson rando phantom. Calculations of treatment planning system (TPS) did not indicate a marked difference in target coverage in relation to gastric filling (ES vs. FS) for each planning technique (3DCRT vs. IMRT). As for ES plans best target coverage is achieved with 7-field IMRT for pancreatic cancer and 4-field 3DCRT for gastric cancer. IMRT plans yielded better results concerning OAR doses, especially liver and bowel doses. If patients were treated with FS instead of ES, target volume doses were significantly decreased for both cancers (p=0.043). For 7-field IMRT plans, the differences between TPS calculations and measurements by TLDs and Gafchromic EBT3 films were higher in plans for ES than plans for FS (1.15% - 8.08% and 1.20% - 3.99% for ES whereas 1.49% - 5.49% and 0.65% - 3.34% for FS, respectively) IMRT technique produced better dose distributions than 3DCRT regarding target volumes and OARs. The most important point for the accuracy and reproducibility of the treatment is that the ensuring same gastric filling during the treatment. For this purpose, each center should prepare a suitable treatment protocol, instruct the patient in detail and monitor its implementation. Funded by The Scientific and Technological Research Council of Turkey’s #S115S913 grant.

A Chinese Multi-Institutional Analysis of Three Dimensional Conformal Radiation or Intensity-Modulated Radiation Therapy for Non-Operated Localized Esophageal Squamous Cell Carcinoma in Definitive (Chemo)Radiation

A Chinese Multi-Institutional Analysis of Three Dimensional Conformal Radiation or Intensity-Modulated Radiation Therapy for Non-Operated Localized Esophageal Squamous Cell Carcinoma in Definitive (Chemo)Radiation

Dosimetric Comparison of Volumetric Modulated Arc Therapy Versus 3-Dimensional Conformal Radiation Therapy in Post-Operative Patients of High Grade Glioma

Dosimetric Comparison of Volumetric Modulated Arc Therapy Versus 3-Dimensional Conformal Radiation Therapy in Post-Operative Patients of High Grade Glioma

A Novel Three Dimensional Conformal Radiation Therapy Technique to Decrease the Mean Parotid Gland Dose in Whole Brain Radiation Therapy

A Novel Three Dimensional Conformal Radiation Therapy Technique to Decrease the Mean Parotid Gland Dose in Whole Brain Radiation Therapy

Assessment of Cardiac Dosimetry and Additional Cardiac Risk Factors in Patients Undergoing Modern Breast Cancer Radiation Therapy

Previous data have demonstrated an association with left breast cancer radiotherapy (RT) and cardiac events; as such, greater focus has been placed on cardiac dosimetry and cardiac sparing techniques. Additionally, the need for long–term cardiac surveillance following breast cancer radiotherapy remains unclear and may be impacted by factors beyond receipt of radiotherapy. As such, an analysis was performed to assess cardiac dosimetry with modern breast cancer RT and to evaluate the presence of additional cardiac risk factors. Breast cancer patients treated between 2014 and 2017 at a single institution were included in the analysis; all patients received 3-dimensional conformal RT. Patient information included demographic data, cardiac risk factors, RT technique, and dosimetry. Non-treatment cardiac risk factors included hypertension, diabetes, hyperlipidemia, history of coronary artery disease, body mass index > 30, tobacco use, and family history of cardiac disease. Treatment related risk factors included mean heart dose > 4 Gy, and anthracycline/HER2-targeted systemic therapy. A total of 218 patients were included with a median age of 60 years old. 80 cases (36.7%) were post-mastectomy. The mean heart dose (MHD) for the population (right, left, and bilateral cases) was 1.71 Gy, with increased MHD for left vs right sided radiotherapy (1.68 Gy vs. 0.83 Gy, p=0.03); MHD for bilateral cases (n=10) was 3.15 Gy. For left sided cases, treatment of the internal mammary nodes (IM, n=34) increased MHD from 1.37 to 3.23Gy (p <0.001). Overall, 15 cases (6.9% of all patients) had MHD exceeding 4 Gy. Of these cases, 13 included IM node treatment, representing 86.7% of cases exceeding 4 Gy and 32.5% of all cases where IM nodes were treated. The only factor associated with MHD > 4 Gy was coverage of IM nodes (p<0.001). For those plans with IM coverage, mean heart dose was 2.60Gy with partially wide tangents as compared to 4.63Gy with matched electron fields (p= 0.001). With respect to additional non-treatment cardiac risk factors, 20 patients (9.2%) had no additional risk factors, 40 (18.3%) had 1 additional factor, 46 (21.1%) 2 additional factors, 42 (19.3%) 3 additional factors, 38 (17.4%) 4 additional factors, and 28 (12.8%) 5 or more. When including treatment factors, only 6 patients had no cardiac risk factors, 38 (17.4%) had 1 additional factor, 38 (17.4%) had 2 additional factors, 50 (22.9%) had 3 additional factors, 47 (21.6%) had 4 additional factors, and 39 (17.9%) had 5 or more. During or following treatment, 129 of 218 patients (59.2%) had either an echocardiogram or follow up with a cardiologist. Mean heart dose with modern radiotherapy techniques was less than 2 Gy using 3D-CRT. Mean heart doses exceeding 4 Gy were primarily seen in cases requiring internal mammary node treatment. Patients undergoing treatment for breast cancer commonly have additional cardiac risk factors, which together may warrant additional post-treatment cardiac follow up.

Optimal Target Delineation for Highly Conformal Photon and Proton Radiation Therapy Techniques in Breast Cancer with Regional Nodal Irradiation

Regional nodal irradiation (RNI) improves disease-free and distant disease-free survival in select women with breast cancer. For the most part, trials demonstrating this utilized 3-dimensional conformal radiotherapy (3D-CRT). Multiple atlases guide targeting using conformal techniques. We hypothesize that nodal failure patterns adequately covered by 3D-CRT may be under-covered with more conformal techniques. The Radiotherapy Comparative Effectiveness Consortium (RADCOMP), Radiation Therapy Oncology Group (RTOG), and the European Society for Radiotherapy and Oncology (ESTRO) breast cancer nodal atlases were utilized for contouring on a representative patient CT scan. 5mm PTV margins were applied. 3D-CRT, volumetric modulated arc therapy (VMAT), and pencil beam scanning proton (PBSPT) plans were prepared for each set of target volumes by two blinded dosimetrists. PET-positive lymph nodes of patients treated for breast cancer (2009-2017) were mapped (5 mm diameter brush at the center of the node) onto the representative patient utilizing anatomical landmarks. Lymph nodes were designated as adequately covered if they fell within the 95% isodose line. FDG-avid lymph nodes (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) breast cancer: Axilla (AX) n=284, supraclavicular (SCV) n=60, internal mammary (IMN) n=45. With 3D-CRT (partially wide tangents, AP/PA SCV), coverage was excellent across all nodal levels (Table 1). With VMAT/PBSPT, overall coverage by 95% isodose was encouraging regardless of atlas: ESTRO (89%/88%), RTOG (93%/91%), and RADCOMP (98%/96%). At least 99% of level I and 94% level II lymph nodes were covered in all plans. Areas of under-coverage in level III, SCV, and IMN-SCV junction were identified in the ESTRO and RTOG atlases (Table 1). A greater than expected number of IMN nodes (n=45) were identified. The RADCOMP atlas improved coverage at the expense of slightly increased heart and lung doses (Table 1). Comprehensive target delineation, as detailed in the RADCOMP atlas is strongly recommended when utilizing conformal techniques for RNI to prevent under-coverage of areas of potential nodal failure.Abstract 111; Table 1Locoregional nodal coverage (%) by the 95% isodose line, lung V20 and heart dose.PlanTechniqueAll nodes (%)Level I Ax n (%)Level II Ax n (%)Level III Ax n (%)SCV n (%)IMN n (%)Left lung V20 (%)Heart Mean (cGy)3DPWT, AP/PA SCV379 (97%)161 (99%)86 (100%)36 (100%)56 (93%)40 (89%)44%987ESTROVMAT347 (89%)162 (100%)86 (100%)28 (78%)31 (52%)40 (89%)15.4%831ESTROPBSPT344 (88%)162 (100%)81 (94%)28 (78%)33 (55%)40 (89%)10.5%206RTOGVMAT362 (93%)160 (99%)86 (100%)33 (92%)45 (75%)38 (84%)16.7%853RTOGPBSPT354 (91%)160 (99%)81 (94%)31 (86%)43 (72%)39 (87%)10%204RADCOMPVMAT381 (98%)162 (100%)86 (100%)36 (100%)57 (95%)40 (89%)16.6%950RADCOMPPBSPT381 (98%)162 (100%)86 (100%)36 (100%)57 (95%)40 (89%)12.1%259 Open table in a new tab

Patterns of Failure and Clinical Outcomes of Post-operative Buccal Mucosa Cancers Treated with Ipsilateral Radiation Therapy

Loco-regional failure in carcinoma buccal mucosa (BM) after radical resection and adjuvant radiotherapy (RT) generally entails a bad prognosis. Usually, adjuvant RT (if indicated), is delivered to tumor bed and bilateral neck nodes. However, selected patients could be treated with ipsilateral RT to tumor bed and neck nodes (IL-RT). Literature on patterns of failure in this group of patients is sparse. We aimed to analyse the failure patterns and survival outcome in these cohort of patients treated at our institute. Eighty patients of post-operative BM cancers treated with IL-RT from June 2013 to May 2017 were included in this retrospective analysis. RT dose was 60-66 Gray in 30-33 fractions over 6-6.5 weeks delivered by linear accelerator using 3-dimensional conformal radiotherapy techniques. All outcomes were evaluated from the time of registration. Local, regional and loco-regional control was defined as time from registration to failure in tumor bed, regional nodes or both, respectively. Disease free survival (DFS) and overall survival (OS) were defined as time from registration to failure at any site (local, regional or distant) and death from any cause, respectively. Kaplan Meier method was used for all outcome analysis. The median age was 45.5 years (range 30-80). Patient characteristics are described in table 1. Median RT completion time and the overall treatment time were 6.2 weeks (range 5.9-7.1) and 11.6 weeks (range 8.5-19), respectively. 62 patients received 60 Gy, one patient 64 Gy and the rest received 66 Gy. The median follow-up time was 24.4 months (range 5-54.2).The 2-year local, regional and loco-regional control rates were 91.9%, 87.6% and 80.5%, respectively. The 2-year DFS and 2-year OS rates were 76.4% and 82.8%, respectively. The crude rates of failures at primary site, ipsilateral and contralateral neck were 12.5%, 12.5% and 3.7%, respectively. All patients with contralateral neck recurrence had N2 disease. Five patients (6.25%) had distant failures. Sixteen patients (20%) died of cancer and 2 patients died of non-malignant causes. The incidence of contralateral recurrence in BM cancer patients treated with primary surgery and adjuvant IL-RT is low. BM cancer with 1-3 risk factors may be treated with IL-RT, except, patients with N2 nodal status, who are at higher risk of contralateral regional recurrence.Abstract MO_23_2678; Table 1Patient CharacteristicsDistributionGender (Male: Female)75: 5T stage (T1: T2: T3: T4)10%: 43%: 26%: 21%N stage (N0: N1: N2)63%: 19%: 18%Overall TNM stage (I: II: III: IV) (As per AJCC 7th edition)5%: 30%: 23%: 42%Risk factors for post-operative RT (>pT3: pN+: PNI: LVI: Close margins: Tumor thickness)*52: 40: 18: 24: 13: 55Number of risk factors for post-op RT (1: 2: 3: >4)10%: 60%: 17.5%: 12.5%Grade (1: 2: 3)42: 34: 4*The total may not add up to 100% because of presence of multiple factors. Abbreviations: RT=Radiotherapy; PNI=Peri-neural invasion; LVI=Lympho-vascular invasion Open table in a new tab

Comparative treatment planning study for mediastinal Hodgkin’s lymphoma: impact on normal tissue dose using deep inspiration breath hold proton and photon therapy

Background: Late effects induced by radiotherapy (RT) are of great concern for mediastinal Hodgkin’s lymphoma (HL) patients and it is therefore important to reduce normal tissue dose. The aim of this study was to investigate the impact on the normal tissue dose and target coverage, using various combinations of intensity modulated proton therapy (IMPT), volumetric modulated arc therapy (VMAT) and 3-dimensional conformal RT (3D-CRT), planned in both deep inspiration breath hold (DIBH) and free breathing (FB).Material and methods: Eighteen patients were enrolled in this study and planned with involved site RT. Two computed tomography images were acquired for each patient, one during DIBH and one during FB. Six treatment plans were created for each patient; 3D-CRT in FB, 3D-CRT in DIBH, VMAT in FB, VMAT in DIBH, IMPT in FB and IMPT in DIBH. Dosimetric impact on the heart, left anterior descending (LAD) coronary artery, lungs, female breasts, target coverage, and also conformity index and integral dose (ID), was compared between the different treatment techniques.Results: The use of DIBH significantly reduced the lung dose for all three treatment techniques, however, no significant difference in the dose to the female breasts was observed. Regarding the heart and LAD doses, large individual variations were observed. For VMAT, the mean heart and LAD doses were significantly reduced using DIBH, but no significant difference was observed for 3D-CRT and IMPT. Both IMPT and VMAT resulted in improved target coverage and more conform dose distributions compared to 3D-CRT. IMPT generally showed the lowest organs at risk (OAR) doses and significantly reduced the ID compared to both 3D-CRT and VMAT.Conclusions: The majority of patients benefited from treatment in DIBH, however, the impact on the normal tissue dose was highly individual and therefore comparative treatment planning is encouraged. The lowest OAR doses were generally observed for IMPT in combination with DIBH.

Curative-intent radiotherapy in patients with oligometastatic lesions from colorectal cancer: A single-center study.

The purpose of the present study was to investigate the efficacy and safety of radiotherapy for patients with oligometastases from colorectal cancer (CRC).This was a retrospective cross-sectional study. Patients with liver and/or lung oligometastatic lesions from CRC treated with curative-intent radiotherapy in West China Hospital, Sichuan University, between 2009 and 2013 were included. Radiotherapy modality included 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and stereotactic body radiation therapy (SBRT); simultaneous chemotherapies along with radiotherapy of metastasis were allowed. Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan–Meier method. Local control (LC) rates, toxicities, and factors of prognostic significance were also assessed.A total of 40 CRC patients with 57 liver and/or lung oligometastatic lesions were included. Most of the patients (95%) had received at least 1 line of previous systemic chemotherapy. Among them, 19 patients with 26 lesions received 3D-CRT with a median dose of 51.5 Gy in 16.1 fractions, 7 patients with 11 lesions received IMRT with a median dose of 49.3 Gy in 10.4 fractions, and 14 patients with 20 lesions received SBRT with a median dose of 56.4 Gy in 6.7 fractions, respectively. The median follow-up time was 34 months (range, 9–86 months). Median OS and PFS for patients were 30.0 months [95% confidence interval (95% CI), 21.3–38.7] and 11.0 months (95% CI, 9–13), respectively. One, 3, and 5 years’ LC rates for metastasis were 63.2%, 24.6%, and 16.9%, respectively. In subgroup analysis, patients with metachronous metastases had longer OS (median, 41.0 months; 95% CI, 33.3–48.7) than patients with synchronous lesions (median, 17.0 months; 95% CI, 7.4–26.6, P = .001). All patients tolerated the radiation treatment well, and there was no treatment-related death. Multivariate analysis showed that number of metastasis lesions and simultaneous liver and lung metastases were potential survival predictors.The study demonstrated that curative radiotherapy might be a tolerable and potential alternative for the treatment of patients with liver and/or lung oligometastases from CRC, and patients with metachronous lesions might have better survival than those with synchronous lesions when treated with curative-intent radiotherapy.

Results of a multicentre randomised controlled trial of cochlear-sparing intensity-modulated radiotherapy versus conventional radiotherapy in patients with parotid cancer (COSTAR; CRUK/08/004)

PurposeAbout 40–60% of patients treated with post-operative radiotherapy for parotid cancer experience ipsilateral sensorineural hearing loss. Intensity-modulated radiotherapy (IMRT) can reduce radiation dose to the cochlea. COSTAR, a phase III trial, investigated the role of cochlear-sparing IMRT (CS-IMRT) in reducing hearing loss. MethodsPatients (pT1-4 N0-3 M0) were randomly assigned (1:1) to 3-dimensional conformal radiotherapy (3DCRT) or CS-IMRT by minimisation, balancing for centre and radiation dose of 60Gy or 65Gy in 30 daily fractions. The primary end-point was proportion of patients with sensorineural hearing loss in the ipsilateral cochlea of ≥10 dB bone conduction at 4000 Hz 12 months after radiotherapy compared using Fisher's exact test. Secondary end-points included hearing loss at 6 and 24 months, balance assessment, acute and late toxicity, patient-reported quality of life, time to recurrence and survival. ResultsFrom Aug 2008 to Feb 2013, 110 patients (54 3DCRT; 56 CS-IMRT) were enrolled from 22 UK centres. Median doses to the ipsilateral cochlea were 3DCRT: 56.2Gy and CS-IMRT: 35.7Gy (p < 0.0001). 67/110 (61%) patients were evaluable for the primary end-point; main reasons for non-evaluability were non-attendance at follow-up or incomplete audiology assessment. At 12 months, 14/36 (39%) 3DCRT and 11/31 (36%) CS-IMRT patients had ≥10 dB loss (p = 0.81). No statistically significant differences were observed in hearing loss at 6 or 24 months or in other secondary end-points including patient-reported hearing outcomes. ConclusionCS-IMRT reduced the radiation dose below the accepted tolerance of the cochlea, but this did not lead to a reduction in the proportion of patients with clinically relevant hearing loss.

Efficacy and safety of 3D-conformal half body irradiation in patients with multiple bone metastases.

Half-body irradiation (HBI) represented a standard treatment for multiple painful bone metastases (BMs). However, its use has progressively reduced due to the associated toxicity rates. The aim of this paper was to evaluate HBI delivered by conformal radiotherapy (RT) technique in a large patients population with widespread BMs. HBI was delivered in 3Gy fractions, bid, ≥ 6h apart, on 2 consecutive days (total dose: 12Gy) using 3-dimensional conformal RT (3D-CRT) box technique. The target included pelvic bones, lumbar-sacral vertebrae and upper third of femurs. Acute and late toxicity was scored based on RTOG and EORTC-RTOG scales, respectively. Pain was evaluated using the Pain-Drug scores and the Visual Analog Scale (VAS). One hundred and eighty patients were eligible for inclusion in this retrospective analysis. Grade 3 and 4 acute toxicity rates were 1.1% and 0.0%, respectively. Mean VAS before and after HBI was 5.3 versus 2.7, respectively (p: 0.0001). Based on VAS, 37.5% of patients showed complete pain relief (VAS: 0) while 38.1% had partial response (≥ 2-point VAS reduction). Overall, Pain and Drug Score reduction was observed in 76.3% and 50.4% of patients, respectively. 1-, 2-, and 3-year pain progression free survival was 77.0%, 63.4%, and 52.7%, respectively. Thirty patients (16.7%) underwent RT retreatment on the same site with median 15.9months interval (range 2-126months). HBI delivered with 3D-CRT technique is safe and effective. It provides long lasting pain control in patients with multiple BMs with negligible rates of relevant toxicity.

Comparing simultaneous vs sequential boost strategies during concurrent chemo-radiation for anal cancer: Results of a retrospective observational study

To evaluate clinical outcomes of a simultaneous integrated boost- intensity modulated radiotherapy (SIB-IMRT) approach in patients with non metastatic anal cancer compared to those of a set of patients treated with 3-dimensional conformal radiation and sequential boost (CRT).