Three-dimensional Conformal Technique Research Articles

Dosimetric analysis and acute toxicity comparison of bone marrow sparing intensity-modulated radiation therapy versus three-dimensional conformal therapy with concurrent chemotherapy for the treatment of cervical carcinoma: A prospective single institutional study

Background: The aim of the study was to compare the dosimetry and acute toxicities of bone marrow sparing intensity-modulated radiation therapy (BMS-IMRT) and three-dimensional conformal radiation techniques (3DCRT) in locally advanced cervical cancer. Materials and Methods: This is a hospital-based prospective randomized study and histologically proven locally advanced cervical carcinoma patients were selected for the analysis. A total of thirty patients were equally allocated in the two treatment arms: BMS-IMRT and 3DCRT. External beam radiation therapy was delivered to a dose of 50 Gy/25# followed by high dose rate brachytherapy along with concurrent chemotherapy. The target volumes and the organs at risks were delineated. The BM comprised pelvic BM (PBM); lumbosacral BM (LSBM); ilium BM (IBM) and Ischium, Pubis and Pelvic femora together constituting lower PBM (LPBM). Results: BMS-IMRT was superior to the 3DCRT arm in reducing the dose to the PBM, small bowel, rectum, and bladder. On comparison of the BM dose volume histogram, the P value was significant (BMS IMRT vs. 3DCRT) in the higher dose range (30 and 40 Gy) for the IBM, LPBM, and whole pelvis BM. However, the difference in the low-dose irradiation (10 and 20 Gy) region was not significant. Furthermore, in the LSBM region, BMS IMRT was superior at all dose levels with no significant P value. Acute toxicities were higher in the 3DCRT arm. Conclusion: Thus, BMS-IMRT resulted in significant reduction of dose to the PBM. This can help in reducing the hematologic toxicities associated with pelvic radiation.

Real world clinical outcomes of adjuvant sequential chemoradiation in patients with gallbladder carcinomas with poor performance status.

The purpose of the study is to analyze the overall survival, relapse-free survival, and relapse patterns of adjuvant sequential chemoradiation for gallbladder cancers after curative resection in patients with poor performance status. We retrospectively reviewed clinical records of gallbladder patients with pathologic stage T2-4 or node positivity treated with sequential chemoradiation at our institute between January 2015 and January 2019. Sequential chemoradiotherapy protocol consisted of six cycles of gemcitabine 1,000 mg/m2 and oxaliplatin 100 mg/m2 administered every 2 weekly and postoperative radiation therapy (45 Gy in 25 fractions over 5 weeks) by three-dimensional conformal technique. A total of 36 patients were included. The median overall survival and relapse-free survival was 26 months (95% confidence interval [CI], 21.4-30.5) and 21 months (95% CI, 11.8-30.1), respectively. The 2-year overall and relapse-free survival rates were 55.1% (95% CI, 37.9%-72.3%) and 44.7% (95% CI, 27.5%-61.9%), respectively. Locoregional, systemic, and combined recurrence were noted in 2 (5.5%), 14 (38.8%), and 3 (8.3%) patients, respectively. On univariate analysis, tumour grading significantly influenced relapse free survival; nodal stage and overall stage demonstrated a statistically significant influence on overall survival (p < 0.05) with a trend towards significance for lymphovascular invasion. On multivariate analysis, no significant factors were found. Grade 3 and 4 haematological adverse events were observed only in 2 (5.5%) with chemotherapy. No grade 3 and 4 adverse events were observed due to radiation therapy. Sequential chemoradiation is feasible and tolerable with acceptable efficacy in the adjuvant setting in patients unfit for concurrent chemoradiotherapy.

The Risk of Second Primary Cancers in Prostate Cancer Survivors Treated in the Modern Radiotherapy Era.

PurposeConcerns have been raised that modern intensity modulated radiotherapy (IMRT) may be associated with increased second primary cancer risks (SPC) compared to previous three-dimensional conformal radiation techniques (3DCRT), due to increased low dose volumes and more out-of-field ionizing dose to peripheral tissue further away from the target. We assessed the impact of treatment technique on SPC risks in a cohort of prostate cancer (PCa) survivors.Material and MethodsThe study cohort comprised 1,561 PCa survivors aged 50–79 years at time of radiotherapy, treated between 2006–2013 (N=707 IMRT, N=854 3DCRT). Treatment details were extracted from radiotherapy systems and merged with longitudinal data of the Netherlands Cancer Registry to identify SPCs. Primary endpoint was the development of a solid SPC (excluding skin cancer) in peripheral anatomical regions, i.e. non-pelvic. Applied latency period was 12 months. SPC rates in the IMRT cohort (total cohort and age subgroups) were compared to 1) the 3DCRT cohort by calculating Sub-Hazard Ratios (sHR) using a competing risk model, and 2) to the general male population by calculating Standardized Incidence Ratios (SIR). Models were adjusted for calendar period and age.ResultsMedian follow-up was 8.0 years (accumulated 11,664 person-years at-risk) with 159 cases developing ≥1 non-pelvic SPC. For IMRT vs 3DCRT we observed a significantly (p=0.03) increased risk (sHR=1.56, 95% Confidence Interval (CI) 1.03–2.36, corresponding estimated excess absolute risk (EAR) of +7 cases per 10,000 person-years). At explorative analysis, IMRT was in particular associated with increased risks within the subgroup of active smokers (sHR 2.94, p=0.01). Within the age subgroups 50–69 and 70–79 years, the sHR for non-pelvic SPC was 3.27 (p=0.001) and 0.96 (p=0.9), respectively. For pelvic SPC no increase was observed (sHR=0.8, p=0.4). Compared to the general population, IMRT was associated with significantly increased risks for non-pelvic SPC in the 50–69 year age group (SIR=1.90, p<0.05) but not in the 70–79 years group (SIR=1.08).ConclusionIMRT is associated with increased SPC risks for subjects who are relatively young at time of treatment. Additional research on aspects of IMRT that may cause this effect is essential to minimize risks for future patients receiving modern radiotherapy.

Efficacy and Safety of Large-field Postoperative Radiotherapy Using Three-dimensional Radiation Technique for Local Advanced Thoracic Esophageal Squamous Cell Carcinoma: A Phase II Clinical Trial

This trial aimed to explore the feasibility and safety of large-field postoperative radiotherapy for locally advanced (T3-4 or N+, M0) esophageal cancer using three-dimensional radiation technique. This trial is a single-center single-arm, phase II clinical trial initiated in 2014. Patients who underwent a radical transthoracic resection with negative margins within 3 months and histologically confirmed as esophageal squamous cell carcinoma (pT3-4 or N+, M0 according to AJCC 7th) were eligible for this study. Radiotherapy was delivered with total dose of 40Gy in 20 fractions using three-dimensional conformal radiation technique including conformal and intensity modulated radiotherapy. TV included tumor bed, anastomosis site, bilateral supraclavicular region, all mediastinal lymph node site, left gastric and celiac trunk lymph node site. The primary endpoint was 2-year local control rate. The secondary endpoint was overall survival (OS) and adverse events. 70 patients were enrolled in this phase II study from 2014 to 2016. The majority of patients were Ilia (40%), IIIA (27.1%) and IIIB (27.1%). 17 patients died. The 2 year-local control rate is 67.29%. Median OS was 57months. The 1, 2, 3 and 4-year OS rate were 92.75%, 69.57%, 60.87%, 53.47%. Locoregional recurrence was found in 28 patients (40%), most of which in mediastinal lymph node region (16 patients) and supraclavicular lymph node region (10 patients), followed by anastomosis (5 patients), celiac lymph node region (3 patients). 18 patients (25.7%) was found hematogenous recurrence. Nearly all patients complete the whole course postoperative radiotherapy with the completion rate of 97.1%, except for two patients. Although the tumor volume is relatively high with the median PTV volume of 1273.22cm3, despite the average dose of the heart is slightly higher, the dose volume histogram parameters of the other normal tissue and organ dose-volume are relatively ideal. Incidences of acute grade 3 hematological toxicity including 4(5.7%) leukopenia and 1(1.4%) neutropenia. In term of acute grade 3 nonhematological toxicity, nausea and vomiting (7.1%) were the most frequent AE followed by fatigue (2.8%) and radiation induced pneumonitis (1.4%). Nobody suffered grade 4 hematological or nonhematological AE. A No late AE occurred. This study is the first phase II study of postoperative radiotherapy in three-dimensional era, which proves that the dose distribution of large-field radiation is feasible and the toxicity is acceptable. It provides a basis for further exploration of higher dose large-field radiation and combined chemotherapy.

Investigation of 3D-Conformal and Intensity-Modulated Therapy Techniques to Determine the Absorbed Fetal Dose in Patients With Nasopharyngeal Cancer During Pregnancy

The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for nasopharyngeal cancers at various times during pregnancy. In this work, the head and neck cancer treatment of a pregnant patient was experimentally simulated. Two treatment plans were calculated using a female RANDO anthropomorphic phantom. This phantom was irradiated using the Clinac DHX linear accelerator, according to the Standard treatment plans of both three-dimensional conformal radiation therapy (3-DCRT) and IMRT techniques. During pregnancy, the height of the fundus at different weeks was determined and a sign was placed on the phantom. OSLD (optically stimulated luminescence dosimeter) and MOSFET (Metal oxide semiconductor field effect transistor) dosimeters were used to measure the dose of virtually designated uterus area at various times during pregnancy. The data carried out by TPS were compared with measured data. PBC calculation method in the treatment planning system (TPS) was unable to estimate the peripheral doses in uterus area. TPS showed a dose of 0 cGy at many points. On the contrary, OSLD measurement results revealed that the uterus (fetus) doses were ranging from 14.46–43.05 cGy (mean 27.9 ± 10.1 cGy) for 7-field IMRT treatment plan and 6,12–27,3 cGy (mean 14,7 ± 7,97 cGy) for 3-DCRT in Alderson anthropomorphic female RANDO phantom. MOSFET measurements showed that the uterus (fetus) doses were ranging from 15–50.1 cGy (mean 36.25 ± 11.7 cGy) for 7-field IMRT treatment plan and 10–36.3 cGy (mean 21.3 ± 9.54 cGy) for 3-DCRT treatment plan. All the observed fetal dose for the measurements and TPS data for two techniques are given in the Table below. In summary, comparing two techniques, it is clear that IMRT causes higher fetal radiation dose than 3-D CRT due to its higher MU value. Considering that fetal radiogenic effects are seen at 5-10 cGy (American Association of Physicists in Medicine Radiation Therapy Committee Task Group 36), 3-D CRT is a more reliable method. The TPS is unable to estimate peripheral doses accurately. Since the TPS underestimates the fetal dose, relying on the dose calculated by TPS does not seem possible under the current circumstances. The fetal dose from radiotherapy may vary depending on the gestational age at the time of treatment. The use of special shielding devices can considerably reduce the fetal dose from radiation therapy.Tabled 1Abstract 2597; TableIMRT3DMOSFETOSLDTPSMOSFETOSLDTPS12weeks15 cGy14.46cGy0.0cGy12weeks10cGy6.12cGy0.0cGy16 weeks32.2cGy22cGy0.0cGy16 weeks12.3cGy8.68cGy0.0cGy20-22 weeks32.55cGy23.1 cGy0.7cGy20-22 weeks15.6cGy10.5cGy0.0cGy24-26 weeks36.5 cGy25.69 cGy0.7cGy24-26 weeks21.5cGy12.25cGy0.0cGy28 weeks39.6 cGy27.09 cGy11cGy28 weeks23.4cGy14.03cGy0.0cGy36 weeks50.1 cGy43.05 cGy15cGy36 weeks36.3cGy27.3cGy9.7cGy40 weeks47.8 cGy40.01cGy11.6cGy40 weeks30cGy24.1cGy9.7cGy Open table in a new tab

Linear accelerator-based stereotactic body radiation therapy in the treatment of oligometastatic disease.

The present study reports the clinical outcomes of hypofractionated stereotactic body radiation therapy (SBRT) for oligometastasis (OM) originating from various tumors. Between February 2012 and April 2017, 40 patients with unresectable OM were treated with SBRT. Of these patients, 92% showed a solitary nodal metastasis and the rest had up to three metastases. The dose prescription was 50 Gy in 10 fractions with three-dimensional conformal techniques or volumetric intensity-modulated arc therapy. Median follow-up was 14 months. Of the 40 patients, none showed local progression at the site of SBRT, but 20 patients showed tumor growth at distant sites during follow-up. The 2- and 3-year overall survival rates were 45.1 and 36.1%, respectively. The 2- and 3-year progression-free survival rates were 35.4 and 26.5%, respectively. The interval between diagnosis and detection of OM (<2 vs. >2 years) and primary tumor site (esophagus vs. others) emerged as significant variables affecting survival. Grade 3 subacute and grade 4 chronic toxicities were observed in 1 and 2 patients, respectively. SBRT of 50 Gy in 10 fractions for OM from various primary tumors was shown to lead to good clinical outcomes from the viewpoints of local control and toxicity frequency. However, additional studies are required to identify the patient groups likely to receive maximal benefits from such treatment.

Impact of 6 MV photons and mixed beam (6 MV and 15 MV) photons on the dose distribution in high-grade gliomas using three-dimensional conformal radiotherapy technique - A Retrospective Analysis

Background and Aim: The present study focused on the impact of 6 MV photons and mixed beam (6 MV and 15 MV) photons on dose distribution in high-grade gliomas using three-dimensional conformal radiotherapy (3DCRT) technique. The suitability of using different photon beam energies was evaluated with respect to dose distribution. Materials and Methods: A total of 24 patients of high-grade glioma treated on linear accelerator were enrolled and evaluated in this retrospective study. All patients had undergone total/subtotal resection of tumor. These patients were treated with postoperative adjuvant external beam radiotherapy on a linear accelerator using 3DCRT technique. Treatment plans were generated using 6 MV and a combination of both 6 MV and 15 MV photon beams. All plans were generated using suitable planning objectives, and dose constraints which were identical across the plans, except the beam energy. The plans were analyzed in terms of their target coverage, conformity, and normalized dose range. Results: In 16 patients out of 24, the treatment plans were generated using 6 MV photons, the normalization dose was well within 5%–7% of the dose prescribed. In the remaining 8 patients, the normalized dose was >107%, and in these cases, the use of mixed beam plans yielded a better dose distribution with normalized dose between 101% and 105%. Conformity index (CI) values were between 1.2 and 1.98. CI mean was 1.59. Conclusions: The use of mixed beams in 3DCRT technique may be considered as an alternative, especially in a scenario where pure 6 MV photons do not yield homogeneous dose distribution within the normalized range, and in centers where intensity-modulated radiation therapy and field-in-field technique are not available.

Trends in combined radio-chemotherapy for locally advanced rectal cancer: a survey among radiation oncology centers of Sicily region on behalf of AIRO.

To conduct a survey among Sicilian centers of radiation oncology belonging to Associazione Italiana di Radioterapia ed Oncologia Clinica (AIRO), to record the different methods of integration of radio-chemotherapy both in neoadjuvant and adjuvant settings, to evaluate surgical procedures in relation to the sphincter preservation and to report the different toxicity profiles of the treatment strategies. A questionnaire was sent at the end of 2017 to all the radiation oncology centers of Sicily region in order to collect the data from individual centers and the treatment characteristics retrospectively over the previous 5years, from 2012 to 2016. The required data were collected from 13 centers out of 17 which, in relation to the single catchment areas, correspond to approximately 85% of the Sicilian population. The requested data concerned the type of integrated treatment (neoadjuvant vs adjuvant vs radical), combination with chemotherapy (induction, concomitant, adjuvant), type of surgical intervention (sphincter-saving vs abdomino-perineal resection), disease stage, schedule and radiotherapy technique adopted, as well as toxicity detected over the treatment period. A total of 784 pts (M/F: 509/275) were treated between 2012 and 2016, with a median age of 67years (range 25-92). The majority of patients was treated in the neoadjuvant phase (62% of the total) compared to the adjuvant phase (31%) and to those treated radically (7%). Twenty-five percent of patients did not receive combination chemotherapy mainly for cardiovascular problems. Chemotherapy used concomitantly to radiotherapy was single-agent capecitabine (73% of patients) or 5-fluorouracil (27%). The use of chemotherapy alone before concomitant treatment is more common for patients treated in the adjuvant phase (64% of this subgroup), while 14% of patients treated in the neoadjuvant phase received induction chemotherapy before the concomitant phase; in both cases of chemotherapy alone, the majority of patients (91%) received oxaliplatin-based protocols (FOLFOX/XELOX/CAPOX). Few patients (3%) received chemotherapy alone after the concomitant phase. Information on the surgical treatment received is available for 88% of the sample. Of these, 93% received a surgical treatment. The overall rate of sphincter-saving surgery (anterior resection) was 72%, but the contribution of neoadjuvant treatment allowed to reach a rate of 83% in this subgroup (against 65% found in the subgroup of patients treated in adjuvant phase). Traditional radiotherapy schedule (45-50Gy in 25-28 fractions) was used in 90% of patients, of which an intensified treatment in neoadjuvant phase (45Gy + boost of 9-10Gy) was used in 11% of patients. A short-course regimen (25Gy in 5 fraction) in neoadjuvant setting was opted rarely (7%). Three-dimensional conformal technique was preferred over intensity-modulated ones (73% vs 27%). Toxicity was mainly of grade I-II CTCAE (skin 23%, gastrointestinal 39%, genitourinary 14%) compared to grade III (gastrointestinal 4%, genitourinary and hematological < 1%). Interestingly, the toxicity rates were significantly higher in the adjuvant group compared to the neoadjuvant (GI: 58% vs 31%, GU: 21% vs 10%). The present survey shows that in the Sicily region integrated therapies for rectal cancer have allowed a neoadjuvant approach in the majority of patients, thus resulting in a greater use of sphincter conservative surgery. The toxicity has also been reported to be significantly less in this treatment setting.

Comparison of conformal radiotherapy, intensity-modulated radiotherapy and tomotherapy irradiation techniques in prostate cancers

AbstractAimThe aim of this study is to compare three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and tomotherapy techniques used in the treatment of prostate cancer with target and critical organ doses to be included.Materials and MethodsThe target dose was studied with 4-and 6-field 3D-CRT, 7-field IMRT and tomotherapy techniques used to treat ten patients for prostate cancer and the dose volume histograms of critical organs were analyzed. The same target volumes, critical organs doses prescribed and treatment times for the three techniques were compared. Total dose of 76 Gy was given using 6 MV and 18 MV for 3D-CRT, 6 MV for IMRT and tomotherapy techniques.ResultsWhen we compare the three techniques, for rectum V35(p:0·001), V65(p:0·001), D50(p:0·020) and D25(p:0·002), for bladder V50(p:0·027), V65(p:0·006), V100(p:0·006) and for femoral head, the V50(p:0·001) dose was found to be significantly different and more favourable in the tomotherapy technique. Significant differences were found with IMRT planning in 50% of bladder volume (p:0·002). There is no significant difference between the three techniques for doses of 100% volume of rectum and 25% of volume of bladder. The minimum dose that healthy tissue received which was outside the tumour volume was investigated.FindingsDoses to critical organs were lower using the tomotherapy technique. However, the minimum doses that healthy tissue received were higher for the tomotherapy technique. When the beam on times were compared for all three techniques, a significant difference was found in favor of tomotherapy.

Hypofractionated whole-breast radiotherapy using a three-dimensional conformal technique: Toxicity comparison in different breast sizes

Hypofractionated whole-breast radiotherapy using a three-dimensional conformal technique: Toxicity comparison in different breast sizes

Breast size impact on adjuvant radiotherapy adverse effects and dose parameters in treatment planning.

BackgroundBreast radiotherapy is an established adjuvant treatment after breast conserving surgery. One of the important individual factors affecting the final cosmetic outcome after radiation is breast size. The purpose of this review is to summarise the clinical toxicity profile of adjuvant radiotherapy in women with breasts of various sizes, and to evaluate the treatment planning studies comparing target coverage and dose to thoracic organs at risk in relation to breast size.ConclusionsInhomogeneity and excessive radiation dose (hot spots) in the planning of target volume as well as large volume of the breast per se, all contribute to a higher rate of acute adverse events and suboptimal final cosmetic outcome in adjuvant breast cancer radiotherapy, regardless of the fractionation schedule. Improved homogeneity leads to a lower rate of ≥ grade 2 toxicity and can be achieved with three-dimensional conformal or modulated radiotherapy techniques. There may be an association between body habitus (higher body mass index, bigger breast size, pendulous breast, and large chest wall separation) and a higher mean dose to the ipsilateral lung and whole heart. A combination of the technical innovations (i.e. the breath-hold technique, prone position with or without holding breath, lateral decubitus position, and thermoplastic bra), dose prescription (i.e. moderate hypofractionation), and irradiated volume (i.e. partial breast irradiation) should be tailored to every single patient in clinical practice to mitigate the risk of radiation adverse effects.

The impact of the definition of biochemical recurrence following salvage radiotherapy on outcomes and prognostication in patients with recurrent prostate cancer after radical prostatectomy: a comparative study of three definitions.

PurposeThe clinical management and follow-up of patients with recurrent prostate cancer after salvage radiotherapy (SRT) has not yet been established, and no standardized definition of biochemical recurrence (BCR) after SRT exists. We compared the impact of applying three different definitions of BCR following SRT on patient outcomes and prognostication.SubjectsPatients who received salvage androgen-deprivation therapy before the completion of SRT were excluded. The data of 118 men who had undergone salvage radiation as monotherapy for BCR after radical prostatectomy were reviewed. In all patients, SRT comprised irradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcomes, including BCR-free survival and prognostic factors, were analyzed and compared among three definitions: The Nara, Radiation Therapy Oncology Group (RTOG) 9601, and GETUG-AFU 16 definitions.ResultsThe BCR rate differed significantly among the applied definitions. Multivariate analyses identified the same four independent prognostic factors, including primary Gleason pattern 4 or 5, negative resection margin, prostate-specific antigen (PSA) level before SRT 0.5 or more, and PSA doubling time before SRT <6 months, using the RTOG 9601 and GETUG-AFU 16 definitions, whereas only two of the four factors were identified using the Nara definition. Although the results obtained using the RTOG 9601 and GETUG-AFU 16 definitions were similar, the prognostic value of the four factors differed. According to the RTOG 9601 definition of BCR, a negative resection margin on prostatectomy specimens and short PSA doubling time before SRT were associated with no subsequent response in PSA level.ConclusionsThe applied definition of BCR after SRT can influence the reported BCR-free rate and the potential prognostic factors. Establishment of the standardized definition is needed for the optimal management of patients with recurrent prostate cancer undergoing SRT.

Cancer Trials Ireland (ICORG) 06-34: A multi-centre clinical trial using three-dimensional conformal radiation therapy to reduce the toxicity of palliative radiation for lung cancer

TitleCancer Trials Ireland (ICORG) 06-34: A multi-centre clinical trial using three-dimensional conformal radiation therapy to reduce the toxicity of palliative radiation for lung cancer. NCT01176487. Background & purposeTrials of radiation therapy for the palliation of intra-thoracic symptoms from locally advanced non-small cell lung cancer (NSCLC) have concentrated on optimising fractionation and dose schedules. In these trials, the rates of oesophagitis induced by this “palliative” therapy have been unacceptably high. In contrast, this non-randomised, single-arm trial was designed to assess if more technically advanced treatment techniques would result in equivalent symptom relief and reduce the side-effect of symptomatic oesophagitis. Materials & methodsThirty-five evaluable patients with symptomatic locally advanced or metastatic NSCLC were treated using a three-dimensional conformal technique (3-DCRT) and standardised dose regimens of 39 Gy in 13 fractions, 20 Gy in 5 fractions or 17 Gy in 2 fractions. Treatment plans sought to minimise oesophageal dose. Oesophagitis was recorded during treatment, at two weeks, one month and three months following radiation therapy and 3–6 monthly thereafter. Mean dose to the irradiated oesophagus was calculated for all treatment plans. ResultsFive patients (14%) had experienced grade 2 oesophagitis or dysphagia or both during treatment and 2 other patients had these side effects at the 2-week follow-up. At follow-up of one month after therapy, there was no grade two or higher oesophagitis or dysphagia reported. 22 patients were eligible for assessment of late toxicity. Five of these patients reported oesophagitis or dysphagia (one had grade 3 dysphagia, two had grade 2 oesophagitis, one of whom also had grade 2 dysphagia). Quality of Life (QoL) data at baseline and at 1-month follow up were available for 20 patients. At 1-month post radiation therapy, these patients had slightly less trouble taking a short walk, less shortness of breath, did not feel as weak, had better appetite and generally had a better overall quality of life than they did at baseline. They did report being slightly more tired. ConclusionsThis trial is the first of its kind showing that 3-DCRT provides patients with lower rates of oesophageal toxicity whilst yielding acceptable rates of symptom control. (Sponsored by Cancer Trials Ireland (ICORG) Study number 06-34, the Friends of St. Luke’s and the St. Luke’s Institute of Cancer Research.)

Assessment of quality of life in resectable gastric cancer patients undergoing chemoradiotherapy as adjuvant treatment.

Introduction:Quality of life (QOL) is increasingly recognized as an important endpoint in cancer therapies. However, few data are available on QOL in patients who have received radiotherapy as adjuvant treatment for cancer stomach.Methods:Thirty patients who underwent curative resection were enrolled and received chemoradiotherapy (45 Gy in 25 fractions using three-dimensional conformal radiotherapy technique), together with 5-fluorouracil and leucovorin. The European Organization for Research and Treatment of Cancer QOL questionnaire C30 and STO Q22 was assessed at four time points: pre- and postchemoradiotherapy and at 1-month and 6-month follow-up.Results:Mean age of the patients was 54 years. Male:female ratio was 4:1. Stage II and Stage III disease was present in 60% and 30% of patients, respectively. All patients were able to complete the chemoradiotherapy protocol. Our study found out significant impairment in QOL for emotional functioning, fatigue, nausea and vomiting and dyspnea. Results showed that QOL levels decrease postchemoradiotherapy; however, QOL levels returned to baseline at 1-month and 6-month follow-up period.Conclusion:Chemoradiotherapy as adjuvant treatment for cancer stomach patients who have undergone resection with curative intent is a safe and well-tolerated regimen with respect to QOL.

Comparison of Stereotactic Body Radiotherapy Delivery Techniques for Early-Stage Lung Cancer Using Lung Toxicity Modeling

Purpose: Lung toxicity is a primary side effect in stereotactic radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC). We aimed to use a set of radiobiological models to evaluate and compare modern IMRT delivery techniques with three-dimensional conformal techniques for SBRT treatment of NSCLC in terms of lung toxicity, and aimed to compare the results from different radiobiologcal models. Methods: Ten early-stage NSCLC patients treated with SBRT were retrospectively selected. Five treatment plans were generated to deliver 50 Gy in five fractions to the planning target volume for each case: a helical tomotherapy (HT) plan, two three-dimensional cofnromal radiotherapy (3D-CRT) plans using 6-MV and 10-MV photon beams respectively, and two volumetric modulated arc therapy (VMAT) plans using one and two arc fields respectively. The lung RDV was calculated with three parallel functional sub-unit (FSU) models and two normal tissue complication probability (NTCP) models. Results: Both the HT and VMAT plans showed significantly higher contralateral mean lung dose and lower ipsilateral mean lung dose compared to the 3D-CRT plans. There was no statistically significant difference in terms of lung toxicities between the IMRT and 3D-CRT techniques using either the FSU models or the NTCP models. Based on both the FSU and the NTCP models, there was strong correlation between lung toxicity and the mean lung dose in SBRT treatment plans. Conclusions: Based on both the NTCP and parallel FSU models, both IMRT and traditional 3D-CRT delivery techniques could achieve comparable lung sparing inn SBRT treatment of early-stage lung cancer. However, the validity of the radiobiological model results should be checked by clinical data.

667P - Definitive concurrent chemoradiotherapy using S-1 in the treatment of elderly patients with esophageal cancer

Definitive concurrent chemoradiotherapy (CCRT) with 5-florouracil (5-FU) and cisplatin (CDDP) are often associated with signifiant incidence of toxicities in elderly patients with esophageal cancer. This reteospective study was aimed at investigating the efficiency and safety of using S-1 as mono and maintenance therapy combined with concurrent radiotherapy (RT) for elderly patients with esophageal cancer. From January 2009 to December 2010, 68 (aged over 70 years) elderly patients were included. RT was delivered with a daily fraction of 1.8-2.0Gy to a total radiation dose of 54.0-60.0Gy using the three-dimensional conformal technique (3D-CRT). Preplanned concurrent S-1 (80mg/m2/day) was given on Days 1-14, every 3 weeks. After concurrent chemoradiotherapy (CCRT), maintenance S-1 was repeated up to four cycles. The median age was 76 years (range: 70-88 years), and the clinical stages were stage I (two patients), stage II (24 patients), stage III (28 patients), and stage IV (14 patients). 51 (75.0%) patients finished treatment on schedule and the median cycles of S-1 was five, of which 35 (51.5%) patients achieved complete response. The median follow-up time was 42.7 months, and the median overall survival (OS) and progression-free survival (PFS) time were 25.7 and 21.5 months, respectively. The 1- and 3-year OS and PFS rates were 70.6%, 41.8% and 68.1%, 32.9%, respectively. Grade ≥3 neutropenia and leukopenia were found in 14 and 13 patients, respectively. The most common non-hematologic toxicity was esophagitis including six and one patients with grade 3 and 4. For elderly patients with esophageal cancer, S-1 as mono and maintenance chemotherapy in combination with RT could improve survival outcomes with tolerable toxicities. More clinical trials (like NCT02716688) are highly warranted to further clarify this issue.

Conformal orbit sparing radiation therapy: a treatment option for advanced skin cancer of the parotid and ear region

IntroductionNew surgical methods have enabled resection of previously in‐operable tumours in the region of the parotid gland and ear. This has translated to deeper target volumes being treated with adjuvant radiotherapy. Due to the limitations of existing conformal techniques, alternative planning approaches are required to cover the target volume with appropriate sparing of adjacent critical structures. Although intensity modulated radiation therapy (IMRT) may be able to achieve these goals compared with the existing conformal method, a new orbital sparing radiation therapy (OSRaT) technique was evaluated as an alternative conformal planning process. The study objective was to evaluate the dosimetry of three planning methods: pre‐existing conformal, IMRT and OSRaT techniques.MethodsTen patients were planned retrospectively using the existing three‐dimensional conformal radiotherapy (3DCRT), IMRT and OSRaT techniques. Dosimetry was analysed using the homogeneity index (HI), conformity index (CI), the volume of planning target volumes (PTV) under and over treated by the 95% isodose and dose to critical structures.Results OSRaT achieved superior 95% coverage of the high‐dose PTV while delivering HI similar to IMRT for intermediate and high‐dose PTVs. The CI for the high‐dose PTV was comparable between the three techniques, however IMRT was statistically better for the low‐ and intermediate dose PTVs. All three techniques showed adequate orbital sparing, however OSRaT and IMRT achieved this with less under dosing of the PTVs.ConclusionFor the treatment of patients with advanced skin cancer of the parotid and ear, both IMRT and the OSRaT techniques are viable options.

Investigation of conformal and intensity-modulated radiation therapy techniques to determine the absorbed fetal dose in pregnant patients with breast cancer

The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for breast cancers. An Alderson Rando phantom was chosen to simulate a pregnant patient with breast cancer who is receiving radiation therapy. This phantom was irradiated using the Varian Clinac DBX 600 system (Varian Medical System, Palo Alto, CA) linear accelerator, according to the standard treatment plans of both three-dimensional conformal radiation therapy (3-D CRT) and IMRT techniques. Thermoluminescent dosimeters were used to measure the irradiated phantom׳s virtually designated uterus area. Thermoluminescent dosimeter measurements (in the phantom) revealed that the mean cumulative fetal dose for 3-D CRT is 1.39cGy and for IMRT it is 8.48cGy, for a pregnant breast cancer woman who received radiation treatment of 50Gy. The fetal dose was confirmed to increase by 70% for 3-D CRT and 40% for IMRT, if it is closer to the irradiated field by 5cm. The mean fetal dose from 3-D CRT is 1.39cGy and IMRT is 8.48cGy, consistent with theoretic calculations. The IMRT technique causes the fetal dose to be 5 times more than that of 3-D CRT. Theoretic knowledge concerning the increase in the peripheral doses as the measurements approached the beam was also practically proven.

Rôle de la radiothérapie postopératoire des cancers bronchiques non à petites cellules : revue de la littérature actualisée sur de nouvelles données

Most non-small-cell lung cancer long-term survivors are patients having had a completely resected tumor. Even in this highly selected group of patients, there is still a high risk of both local and distant failure. In patients with stage II and III, administration of adjuvant platinum-based chemotherapy is now considered the standard of care, based on level 1 evidence. The role of postoperative radiation therapy (PORT) remains controversial, especially in stage III. In the PORT meta-analysis published in 1998, the conclusions were that if PORT was detrimental to completely resected patients with no mediastinal involvement (pN0 and pN1 patients), the role of PORT in the treatment of tumors with N2 involvement was unclear and further research was warranted. Thus at present, after complete resection, adjuvant radiotherapy should not be administered in patients with early lung cancer (pN0 or pN1). Recent retrospective and non-randomized studies as well as subgroup analyses of randomized trials evaluating adjuvant chemotherapy, provide evidence of the possible benefit of PORT in patients with mediastinal nodal involvement. The role of PORT needs to be evaluated also for patients with proven N2 disease who undergo neo-adjuvant chemotherapy followed by surgery. Based on currently available data, PORT should be discussed for fit patients with completely resected non-small-cell lung cancer with N2 nodal involvement, preferably after completion of adjuvant chemotherapy or after surgery if patients have had pre-operative chemotherapy. There is need for new randomized evidence to reassess PORT using modern three-dimensional conformal radiation technique. A new large multi-institutional randomized trial (Lung ART IFCT 0503) evaluating PORT in this patient population is needed and now underway. In patients with R1 or R2 resection, postoperative radiotherapy should be proposed when re-resection cannot be achieved, based on a strong consensus, and despite the absence of randomized trial.

Dosimetric study of 3-dimensional conformal radiotherapy, electronic compensator technique, intensity modulated radiation therapy, and volumetric arc therapy in whole-breast irradiation.

44 Background: Whole breast irradiation is an essential treatment after breast conserving surgery (BCS). Adverse effects are from inhomogeneity of PTV and excessive dose to normal tissues. Aim of this study is to compare dosimetry among standard technique, three-dimensional Conformal Radiotherapy (3D-CRT) and advanced techniques, Electronic Compensator (ECOMP), Intensity Modulated Radiation Therapy (IMRT) and Volumetric Arc Therapy (VMAT). Methods: Images from CT simulation of patients who underwent BCS were replanned. Clinical Target Volume (CTV) was contoured followed RTOG atlas as breast only and breast with chest wall respectively. Planning Target Volume (PTV) was expanded 0.7 cm from CTV. Each patient was replanned with all four techniques. Dose prescription was 50 Gy in 25 fractions. Results: Twenty five patients underwent CT simulation from November 2013 to November 2014 were included. Six patients with node positive were planned for breast with chest wall irradiation and 19 patients with node negative were planned for breast only irradiation. Primary outcome, homogeneity index (HI) of 3D-CRT, ECOMP, IMRT and VMAT were 0.865, 0.889, 0.890 and 0.866 respectively which ECOMP and IMRT were significant higher than 3D-CRT (p values &lt; 0.001). Secondary outcome, conformity index (CI), Mean heart dose (MHD), heart V25, heart V30, mean lung dose (MLD), mean ipsilaterallung dose (MILD), mean contralateral lung dose (MCLD) and mean contralateral breast dose (MCBD) of advanced techniques were significant better than 3D-CRT technique. Conclusions: HI of ECOMP and IMRT were statistically significant higher compared with 3D-CRT technique. Advanced techniques showed statistically significant superior in CI dose to heart, lungs and contralateral breast.