Integrated Boost IMRT Research Articles

Simultaneous integrated boost-intensity modulated radiation therapy (SIBIMRT) planning for pelvic tumours: dose coverage to target volume and normal tissue sparing.

To evaluate the better radiotherapy plan for pelvic tumours that may achieve a high target coverage dose and low normal tissue tolerance dose using simultaneous integrated boost-intensity-modulated radiation therapy technique. The analytical, cross-sectional, descriptive study was conducted from October 2020 to March 2021 at Al- Amal National Hospital for Cancer Treatment, Baghdad, Iraq, and comprised male pelvic cancer patients aged 50-80 years. Computed tomography scans were randomly selected. For each patient, 4 treatment plans (phases Ι and Π) were generated using the simultaneous integrated boost-intensity-modulated radiation therapy technique while keeping all parameters constant except the number of beams, which were 5, 7, 9 and 11. The optimal and safe dose was defined as the one to cover 95% planning target volume. Homogeneity and conformity indices were used to assess the uniformity of dose distribution in the target volume, and various treatment plans in the same patient were compared. Data was analysed using SPSS 24. There were 15 males with mean age 67.12±2.84 years. There was a significant variance in the target volume dose and organ at risk in the 4 different plans generated using the simultaneous integrated boost-intensitymodulated radiation therapy technique (p<0.05). The 9-beam treatment plan was the best for coverage of tumours and protection of healthy organs assessed through homogeneity and conformity indices (p<0.05). The 9-beam treatment plan showed significant tumour coverage, homogeneity and conformity values, and sparing dose for organs at risk.

Volumetric Response and Survival of Patients With Bulky IDH-Mutated Grade 3 Glioma Managed With FET-FDG–Guided Integrated Boost IMRT

AimsDespite relatively favourable outcomes associated with IDH-mutant grade 3 gliomas, many patients present with diffuse non-enhancing disease involving multiple brain regions, prompting concern over both durable disease control and the morbidity associated with large volume radiation therapy. This study audits volumetric response, survival and functional outcomes in this ‘large volume’ subgroup that undergoes intensity modulated radiation therapy (IMRT). Materials and methodsFrom a prospective database of 187 patients with IDH-mutant grade 3 gliomas managed with IMRT between 2008 and 2020, recorded PTV was divided into quartiles. The top quartile, termed the ‘large volume cohort’ (LVC), was identified. IMRT involved FET-FDG guided integrated boost (59.4/54Gy in 33 fractions). Manual volumetric segmentation of baseline, four months and 13 months post-IMRT tumour were performed for T1, T2 and T1gd MRI sequences. The primary endpoint was volumetric reduction on the T1 and T2 sequences at 13 months and analysed with relapse-free survival (RFS) and overall survival (OS). Morbidity endpoints were assessed at year four post-IMRT and included performance status (ECOG PS) and employment outcomes. ResultsThe fourth quartile (LVC) identified 44 patients for whom volumetric analysis was available. The LVC had median PTV of 320cm3 compared to 186.2cm3 for the total group. Anaplastic astrocytoma and oligodendroglioma were equally distributed and tumour sites were frontal (54%), temporal (18%) and parietal lobes (16%).Median follow-up for survivors was 71.5 months. Projected 10-year RFS and OS in LVC was 40% and 62%, compared to 53% and 62% respectively in the overall cohort. The RFS (p = 0.06) and OS (p = 0.65) of the LVC was not significantly different to other PTV quartiles; however the impact of PTV volume reached significance when analysed as a continuous variable (RFS p < 0.01; OS p = 0.02).Median T1 volumes were 26.1cm3, 8.0cm3 and 5.3cm3 at months +0, +3 and +12, respectively. The corresponding T2 volumes were 120.8cm3, 29.1cm3 and 26.3cm3. The median T1 and T2 volume reductions were 77% (q1–3: 57–92%) and 78% (q1–3: 60–85%) at 13 months post-IMRT. Initial T2 volume was associated with worse RFS (p = 0.04) but not OS (p = 0.96). There was no association between median T2 volume reduction and RFS (p = 0.77).For patients assessable at year 4 post-IMRT, no late CTCAE Grade 3/4 toxicity events were recognised. 92% of patients were ECOG PS 0–1, 45% were employed at prior capacity and 28% were working with impairment. ConclusionPatients with large volume IDH-mutant Grade 3 glioma demonstrated significant tumour reduction post-IMRT, and good long-term outcomes with respect to survival and functional status. Although larger IMRT volumes were associated with poorer RFS, this was also associated with the initial volume of non-enhancing tumour.

Capecitabine/Mitomycin versus 5-Fluorouracil/Mitomycin in Combination with Simultaneous Integrated Boost Intensity-Modulated Radiation Therapy for Anal Cancer.

Since EXTRA, a non-randomized phase II trial with 31 patients, explored the use of capecitabine, mitomycin and radiation therapy (RT) in the treatment of localized squamous cell carcinoma of the anal canal (SCCAC), this treatment has been considered as an acceptable alternative to infusional 5-FU. However, the differences in efficacy between capecitabine and 5-FU in chemoradiation therapy (CRT) with simultaneous integrated boost (SIB) radiation therapy (SIB-IMRT) for local SCCAC are not well documented. Patients included in this prospective monocentric cohort study were treated with SIB-RapidArc (a unique RT method treatment for all patients: identical technique, volume and constraints for at-risk organs), mitomycin C and 5-FU each day of RT for 7 weeks (group 1) or capecitabine each day of RT (group 2). Patients treated between July 2009 and August 2017 (group 1) and between November 2012 and April 2018 (group 2) for local SCCAC T2-4 classified as N, M0 or T, N1-3, M0 were included. Primary endpoints were progression-free survival (PFS) and acute toxicities. Results: One hundred forty-seven patients were included, 91 in group 1 and 56 in group 2. The two groups were statistically comparable in terms of sex, Eastern Cooperative Oncology Group Performance Status (ECOG PS) and TNM. With a median duration of follow-up of 53.5 months, the PFS rate at 3 years was 80% for group 1 and 75% for group 2 (p = 0.32). The 3-year colostomy-free survival rate was 92% for group 1 and 85% for group 2 (p = 0.11). The rate of patients with at least one grade 3 or higher acute toxicity was 35.5% in group 1 and 21.4% in group 2 (p = 0.10), with a trend of fewer acute toxicities with capecitabine. Conclusion: Capecitabine/mitomycin in combination with SIB RapidArc radiation therapy for anal cancer seems as effective as 5-FU-based chemotherapy and is well tolerated with minimal toxicity.

Analysis of the prognostic factors of simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) in 220 cases of locally advanced squamous esophageal cancer: a retrospective cohort study.

Esophageal cancer is one of the most common malignant tumors in China. Patients with advanced esophageal cancer often cannot be treated by surgery; in these cases, radiation therapy is usually applied. However, there are currently few studies on the clinical efficacy of this treatment method. The present study aimed to investigate and observe the clinical efficacy and related prognostic factors of simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) in esophageal squamous carcinoma, and to provide a reference for clinicians in radiotherapy (RT) departments. The clinical and follow-up data of 220 patients with esophageal squamous carcinoma admitted to the First Affiliated Hospital of Bengbu Medical College from January 2017 to December 2018 were retrospectively analyzed to assess the relevant prognostic factors and analyze their effects on 3-year overall survival (OS) and progression-free survival (PFS). The prognostic influencing factors were analyzed using the log-rank test and Cox multi-factor regression analysis. The median follow-up time was 56.0 months (3.0 to 66.0 months). The 1-, 2-, and 3-year survival rates were 68.6%, 49.1%, and 36.3%, respectively, for the entire cohort, and the 1-, 2-, and 3-year PFS rates were 52.3%, 37.7%, and 25.5%, respectively. The median OS time was 24 months [95% confidence interval (CI): 19.16-28.84 months] and the median PFS time was 15 months (95% CI: 11.04-18.96 months). The multifactorial analysis results showed that gender, RT dose, treatment modality, absolute lymphocyte count (ALC), and gross tumor volume (GTV) were independent prognostic factors affecting 3-year OS (P<0.05); while gender, N-stage, RT dose, and GTV were independent prognostic factors affecting 3-year PFS (P<0.05). In the SIB-IMRT era, the survival of esophageal squamous cell carcinoma (ESCC) patients treated with radical (chemo)radiotherapy is relatively satisfactory. As a single-institution study on radiation therapy for esophageal cancer, this study yielded accurate results that help to provide references for subsequent related studies and clinicians' selection of treatment options.

Comparison of Simultaneous Integrated Boost IMRT for Dose Escalation (54 Gy) and Conventional IMRT (45 Gy) Twice Daily Combined with Concurrent Chemotherapy for Limited-Stage Small-Cell Lung Cancer: Analysis of Two Prospective Trials

<h3>Purpose/Objective(s)</h3> Twice-daily thoracic radiotherapy (TRT) with concurrent chemotherapy is standard for limited-stage small-cell lung cancer (LS-SCLC). However, the importance of twice-daily simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) has not been clearly defined in LS-SCLC. Therefore, we conducted a prospective single arm, multicenter phase II study of SIB-IMRT for dose escalation (54 Gy) to the gross tumor volume for LS-SCLC. Here, we compared SIB-IMRT for dose escalation (54 Gy) to the gross tumor volume versus conventional intensity-modulated radiotherapy (IMRT) of standard-dose (45 Gy) twice-daily combined with concurrent chemotherapy in patients with LS-SCLC. <h3>Materials/Methods</h3> Sixty patients with LS-SCLC were entered from 2015 to 2021 in the phase II study of SIB-IMRT, and all 60 patients were treated with SIB-IMRT to the postchemotherapy tumor volume, as the SIB-IMRT group. In the SIB-IMRT group, the prescribed dose was 54Gy at 1.8 Gy twice daily to PGTV, and 45 Gy at 1.5 Gy twice daily to PCTV. We previously conducted a prospective phase III study on thoracic radiotherapy (TRT) target volumes for LS-SCLC (Cancer, 2020, 126(4), 840-849). In that study, from 2012-2017, 85 patients received thoracic IMRT to the postchemotherapy tumor volume, as the IMRT group. In the IMRT group, the prescribed dose was 45 Gy at 1.5 Gy per twice-daily fraction to both the planning gross tumor volume (PGTV) and the planning clinical tumor volume (PCTV). All of the 145 patients in both groups received concurrent chemoradiotherapy (CCRT) after completion of 2 cycles of induction cisplatin-etoposide chemotherapy, and received chemotherapy for 4 to 6 cycles in total. We compared progression free survival (PFS) and overall survival (OS) between the treatment groups by using the Kaplan-Meier method. <h3>Results</h3> Overall, with a median follow-up of 34.6 months, the median PFS and OS were 11.9 and 23.7 months, respectively. The patients in the SIB-IMRT group showed marginal longer PFS than those in the IMRT group (13.3 months versus 11.5 months; <i>p</i> = 0.08). The median OS of the SIB-IMRT and IMRT groups were 35.0 and 20.3 months, with the 2-year OS rate of 66.1% and 38.8%, respectively (<i>p</i> =0.007). For radiotherapy toxicity, grade 2 acute esophagitis was more common in the SIB-IMRT group, but grade≥3 esophagitis and grade≥2 pneumonitis was no difference in both two groups. <h3>Conclusion</h3> For LS-SCLC patients, SIB-IMRT for dose escalation (54 Gy at 1.8Gy twice daily) to PGTV benefited survival greatly. Our results suggest that SIR-IMRT is safe and effective for patients with LS-SCLC and should be further evaluated in a large prospective clinical trial.

Concurrent Weekly Cisplatin and Simultaneous Integrated Boost-IMRT in Locally Advanced Head and Neck Squamous Cell Carcinoma-An Institutional Experience.

Introduction Concurrent chemoradiation with weekly cisplatin in locally advanced head and neck squamous cell carcinoma (LA-HNSCC) is widely practiced in India. Radiation with simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) has the advantage of executing IMRT in single phase with better dose distribution. Material and Methods 150 patients with LA-HNSCC treated between April 2015 and December 2019 were retrospectively evaluated. All patients received 70Gy in 33 to 35 fractions with SIB-IMRT and concurrent weekly cisplatin at a dose of 40 mg/m 2 . Treatment compliance and toxicities were assessed. Overall survival (OS) was evaluated using Kaplan-Meier estimates; univariate and multivariate analysis of prognostic factors were also evaluated. Results Median age was 58.5 years. Forty-five percent had primary oropharyngeal cancer. Sixty-two percent had T3 disease, 41% had N2 disease, and 51% had stage IV disease. All patients received 70Gy dose of RT. Median chemotherapy cycles were six, 84.7% received 200 mg/m 2 . Acute grade 2 xerostomia was seen in 79%, grade 3 neutropenia, mucositis and pharyngitis were seen in 11, 15, and 21%, respectively. Complete response was seen in 66.6%. At median follow-up of 21.4 months (3-71) OS was 60% and median OS was 33.2 months. Estimated 2 and 3 year OS was 56 and 48%. On univariate analysis, absence of node, N0-N1, stage III, cisplatin use, dose per fraction 2.12Gy ,and complete response showed good OS ( p <0.05). On multivariate analysis dose per fraction 2.12Gy and complete response showed good OS ( p <0.05). Conclusion Definitive chemoradiation with weekly cisplatin and SIB-IMRT in LA-HNSCC is well tolerated with good clinical outcomes.

RADT-21. DUAL FET PET-GUIDED SIB IN RADIOTHERAPY OF NEWLY DIAGNOSED GLIOBLASTOMA - A PILOT STUDY

Abstract BACKGROUND PET using FET is a valuable tool to determine the actual glioblastoma infiltration.The FET-PET examination can be performed using the dual-time point acquisition of FET . Infiltration defined in dual FET PET corresponds to the location and shape of the recurrence. The aim of this study was to evaluate safety and efficacy of simultaneous integrated boost based on dual FET PET combined with temozolomide TMZ for the postoperative treatment of GBM. METHODS AND MATERIALS In a prospective pilot study, 17 patients were enrolled. All patient presented an active tumor in postoperative PET imaging. The radiotherapy was performed as an FET-PET-based integrated-boost IMRT. The prescribed dose was 78 and 60 Gy (single dose 2.6 and 2.0 Gy, respectively). The progression-free survival (PFS) and overall survival (OS), toxicities and radiation necrosis rate were evaluated. RESULTS The median follow up was 37 months.Two patients were found to have uncontrolled seizures during radiation treatment and were not able to received treatment per protocol. Patients treated per protocol presented new or increased neurological deficits in 7/15 cases in a month after irradiation. In 4 patients radiation necrosis was confirmed in pathological report after re-surgery. Three patients were still alive after 26,28 and 38 months of follow up without progression and any signs of treatment related late toxicity. The 2-year survival rate was 43% in all patients treated per protocol. Median overall survival (OS) and disease-free survival (DFS) were 20 and 12 months, respectively. In a subgroup of MGMT methylated and unmethylated the median survival was 25 and 12 months. CONCLUSIONS Our dose escalation concept with a total dose of 78 Gy, based on FET-PET, have lead to promising survival results even within MGMT unmethylated subgroup. However rate of early toxicity and radiation necrosis is high.

Twice-Daily Thoracic Radiotherapy by Intensity-Modulated Radiation Therapy (IMRT) or Simultaneous Integrated Boost (SIB) IMRT With Concurrent Chemotherapy for Limited-Stage Small Cell Lung Cancer Patients? A Propensity-Score Matched Analysis

<h3>Purpose/Objective(s)</h3> Concurrent chemoradiotherapy is the standard treatment for limited-stage small-cell lung cancer patients (SCLC), but the optimal dose and schedule of radiotherapy have not been established. <h3>Materials/Methods</h3> We retrospectively reviewed the clinical records of limited-stage SCLC patients treated with twice-daily thoracic radiotherapy by intensity modulated radiotherapy (IMRT) or Simultaneous integrated boost IMRT (SIB-IMRT) with concurrent chemotherapy between December 2009 to December 2017. The patients were divided into two groups according to the radiotherapy dose. The patients of SIB-IMRT group received 57Gy at 1.9Gy twice-daily to the gross tumor volume (GTV), 51Gy at 1.7Gy twice-daily to the clinical target volume (CTV) and 45Gy at 1.5Gy twice-daily to the planning target volume (PTV), and the patients of IMRT group received 45Gy at 1.5Gy twice-daily to PTV. A 1:1 propensity score matching (PSM) was applied to balance observable potential confounding factors between two groups. Primary endpoint was progression-free survival (PFS). Overall survival (OS), objective tumor response (ORR) and treatment-related toxicities were also evaluated. Statistical analyses were conducted using SPSS version 22.0 and statistical significance was defined as <b>P</b> < 0.05. <h3>Results</h3> A total of 112 patients were enrolled in our study, including 71 patients in IMRT group and 41 patients in SIB-IMRT group. After PSM, the clinical features were well balanced between two groups included 37 patients each. ORR in IMRT group and SIB-IMRT group were 94.6% (35/37) and 97.3% (36/37), respectively. Median PFS was 17.54 months in IMRT group <b>vs</b> 34.92 months in SIB-IMRT group (<b>P</b> = 0.047). Median OS was 38.52 months in IMRT group <b>vs</b> 63.41 months in SIB-IMRT group (<b>P</b> = 0.261). The incidence of grade 3-4 treatment-related toxicities was 43.24% (32/74), and there was no significant difference between two groups (<b>P</b> = 0.639). <h3>Conclusion</h3> Compared with IMRT, the high dose of twice-daily thoracic radiotherapy by SIB-IMRT approach with concurrent chemotherapy for the patients with limited-stage SCLC were well-tolerated and may improve PFS, but PFS improvement didn't result in significant advantage in OS.

P49.02 Simultaneous Integrated Boost IMRT (54 Gy) versus Conventional IMRT (45 Gy) Twice Daily Combined With Chemotherapy for LS-SCLC

P49.02 Simultaneous Integrated Boost IMRT (54 Gy) versus Conventional IMRT (45 Gy) Twice Daily Combined With Chemotherapy for LS-SCLC

P-341 Capecitabine/mitomycin versus 5-fluorouracil/mitomycin in combination with simultaneous integrated boost-intensity modulated radiation therapy for anal cancer

Within the past decade, several studies have tested capecitabin as a substitute for 5-FU in the treatment of localised squamous cell carcinoma of the anal canal (SCCAC) and reported similar clinical response rates, making capecitabin an acceptable and more convenient alternative to infusional 5-FU. However, the differences in efficacy between capecitabine and 5-FU in CRT with simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) for locally SCCAC are not documented. We performed this retrospective study to compare the response of capecitabine and 5-FU in survival and toxicity terms in patients with locally SCCAC treated with concurrent SIB-IMRT.

Simultaneous Integrated Boost IMRT with Three Dose Gradients in Patients with Stage I-II Nasal Cavity and Waldeyer's Ring Natural Killer/T-Cell Lymphoma: A Prospective Phase II Clinical Trial

Simultaneous Integrated Boost IMRT with Three Dose Gradients in Patients with Stage I-II Nasal Cavity and Waldeyer's Ring Natural Killer/T-Cell Lymphoma: A Prospective Phase II Clinical Trial

Dose escalation in radiotherapy for incomplete transarterial chemoembolization of hepatocellular carcinoma.

To investigate the efficacy of radiation dose escalation in patients with hepatocellular carcinoma (HCC) after incomplete transarterial chemoembolization (TACE). This study evaluated retrospective data of 323 HCC patients who received radiotherapy after incomplete TACE from 2001-2016. Radiation dose in biologically effective dose (BED) (α/β = 10) was categorized as <72 Gy (261 patients) and ≥72 Gy (62patients). Simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) was used significantly more frequently in the high-dose group (64.5% vs. 12.9%; P < 0.001). Local failure-free rate (LFFR), progression-free rate (PFR), and toxicities were compared between the two groups. Additionally, propensity score matching was performed. Median follow-up time for patients who were alive at the time of analysis was 47months (range 18-189months). Median overall survival after radiotherapy was 14months. In multivariate analysis, BED ≥72 Gy was an independent predictor of favorable LFFR (hazard ratio [HR] 0.32; 95% confidence interval [CI] 0.14-0.72; P = 0.006) and PFR (HR 0.67; 95% CI 0.45-0.98; P = 0.04). In the propensity score-matched cohort (62pairs), 1‑year LFFR (94% vs. 81%; P = 0.002), and 1‑year PFR (49% vs. 42%; P = 0.01) were significantly higher in the high-dose group. Treatment-related toxicities were comparable between the high-dose and low-dose groups (classic radiation-induced liver disease: 5.3% [3/57] vs. 13.8% [29/210], P = 0.08; grade2-4 gastrointestinal bleeding: 3.2% [2/62] vs. 7.3% [19/261], P = 0.39). Radiation dose with BED ≥72 Gy improved LFFR and PFR without increasing toxicity. In radiotherapy for incomplete TACE of HCC, dose escalation using SIB-IMRT should be actively considered to improve oncologic outcome.

Efficacy of Preoperative Neoadjuvant Simultaneous Integrated Boost IMRT Radiation Therapy Combined with Preoperative Chemotherapy for Locally Advanced Rectal Cancer: A Prospective II Clinical Study

Efficacy of Preoperative Neoadjuvant Simultaneous Integrated Boost IMRT Radiation Therapy Combined with Preoperative Chemotherapy for Locally Advanced Rectal Cancer: A Prospective II Clinical Study

Feasibility and Efficacy of Simultaneous Integrated Boost Intensity-modulated Radiation Therapy based on MRI-CT fusion in Patients with Brain Metastases of Non-small Cell Lung Cancer.

Purpose: To assess the feasibility and therapeutic effects of simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) based on the fusion imaging of magnetic resonance imaging (MRI) and computed tomography (CT) as a dose-intensive technique in patients with brain metastases (BM) of non-small cell lung cancer (NSCLC).Methods and materials: Forty-six NSCLC patients with 1 to 7 brain metastases were enrolled in this retrospective study between November, 2011 and February, 2017. Thirty-one patients (67.4%) had 1-3 metastases (oligometastases), otherwise, more than 3 metastases were seen in only 15 patients (32.6%). GTV (Gross tumor volume) contouring was based on the fusion imaging of MRI-CT, WBRT was prescribed in 37.5 Gy/15 fractions with a simultaneous boost in the metastatic lesions of 52.5 Gy/15 fractions.Results: The median overall survival (OS) and intracranial progression free survival (PFS) for all the patients were 20.0 months and 11.0 months, respectively. The 6-month and 1-year OS were 87.0% and 69.6% respectively, while the 6-month and 1-year PFS were 78.3% and 43.5% respectively. Until the end of the follow-up, 16 patients (34.8%) were alive. No evidence of intracranial progress or recurrence was found in 6 patients (13.0%) during the follow-up.Conclusion: SIB-IMRT with the dose/fractionation based on the fusion imaging of MRI-CT is feasible and safe. It is beneficial to the NSCLC patients with BM and can reduce the overall costs of treatment.

P1.14-012 Hypofractionated Simultaneous Integrated Boost IMRT Concurrent with Chemotherapy Improved Loco-Regional Control in Locally Advanced NSCLC

This study investigated the loco-regional control (LRC) and toxicity of hypofractionated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) for locally advanced non-small-cell lung cancer (LANSCLC) in the setting of concurrent chemotherapy. One hundred and ten LANSCLC patients treated with SIB-IMRT and concurrent chemotherapy were retrospectively analyzed. Radical-intent radiotherapy was delivered at a fraction dose of 2.0∼2.2, 2.4∼2.6, and 2.9∼3.1Gy respectively. Factors potentially predictive of LRC (age, sex, tumor stage, tumor volume, biological effective dose (BED), dose per fraction, overall radiation time (ORT) and concurrent chemotherapy) were assessed in the univariate analysis and Cox multivariate model. Toxicity data was collected and analyzed. With a median follow-up of 24.4 months, the median duration of LRC was 21.4 months. LRC was 71.9% at 1 year, 45.9% at 2 years, and 41.8% at 3 years. In univariate analysis, BED (p=0.007), dose per fraction (p=0.002) and ORT (p=0.029) were associated significantly with LRC. In multivariate analysis, RT dose per fraction was independently prognostic of LRC (HR, 0.597; CI, 0.362∼0.986). Grade ≥3 pneumonitis, pulmonary fibrosis and esophagitis were observed in 6 (5.5%), 2 (1.8%) and 19 (17.3%) of patients, respectively. There was no significant difference in toxicity among different doses per fraction. Our study showed that LRC was improved by the dose per fraction escalation in the setting of concurrent chemotherapy. Hypofractionated SIB-IMRT could be a feasible and effective approach for dose intensification, while maintaining tolerable toxicities.

Treatment Results of Simultaneous Integrated Boost Intensity-Modulated Radiation Therapy in 219 patients with Nasopharyngeal Carcinoma

Treatment Results of Simultaneous Integrated Boost Intensity-Modulated Radiation Therapy in 219 patients with Nasopharyngeal Carcinoma

Image-Guided Radiotherapy Dose Escalation in Intermediate and High Risk Cancer Prostate Patients and Its Effect on Treatment Toxicity

Purpose: To study the effect of escalating radiation dose; in intermediate and high risk prostate cancer patients; via online image-guidance on acute toxicities. Patients and Methods: thirty-eight prostate cancer patients were treated by using simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) with online image guided correction via kilo voltage cone beam computed tomography (KV-CBCT)/electronic portal imaging device (EPID) of trans-rectal ultrasound (TRUS)-inserted intraprostatic gold fiduciary markers. High-risk patients received a median dose of 80.5 Gy to prostate and 56 Gy to pelvic nodes in 35 fractions over 7 weeks. Intermediate-risk patients received a similar prostate dose over the same overall treatment time. Acute toxicity (bladder, rectal and bowel symptoms) was reported once weekly during the radiation course and up to 3 months from the end of the radiation course. Results: The image guided (IG)-IMRT allows escalating the radiation dose delivered to the prostate through minimizing the margin of setup error to less than 0.5 cm with subsequent sparing of nearby organs at risk. Out of thirty-eight patients, no patient developed >grade 1 acute rectal toxicity, 7.9% of patients experienced grade 3 urinary toxicity and there was no reported small intestinal toxicity. Conclusion: Escalating the radiation dose more than 80 Gy in intermediate and high risk prostate cancer patients was safe and not associated with grade 3 - 4 RTOG toxicity when guided by online verification of intra-prostatic fiducial markers.

A phase I dose escalation study using simultaneous integrated-boost IMRT with temozolomide in patients with unifocal glioblastoma

PurposeTo evaluate the maximum tolerated dose of simultaneous integrated-boost intensity-modulated radiotherapy (SIB-IMRT) associated with temozolomide in patients with glioblastoma. Patients and methodsBetween November 2009 and January 2012, nine patients with malignant glioma were enrolled in this phase I clinical trial. Radiotherapy was delivered using fractions of 2.5Gy on the planning target volume b and of 1.9Gy on the planning target volume a. Volumes were defined as follow: gross tumour volume b: tumour taking up contrast on T1 weighted MRI images; clinical target volume b: gross tumour volume b+0.5cm (adapted to the anatomical structures) and lastly planning target volume b: clinical target volume b+0.5cm; gross tumour volume a: tumour (gross tumour volume b)+2cm and including oedema outlined on T2Flair MRI sequences; clinical target volume a gross tumour volume a+0.5cm (adapted to the anatomical structures); planning target volume a: clinical target volume a+0.5cm. Three patients were enrolled at each of the three levels of dose (70, 75 and 80Gy prescribed on the planning target volume b and 56, 60 and 60.8Gy on the planning target volume a). Radiotherapy was delivered with temozolomide according to the standard protocol. Dose-limiting toxicities were defined as any haematological toxicities at least grade 4 or as any radiotherapy-related non-haematological acute toxicities at least grade 3, according to the Common Terminology Criteria for Adverse Events, version 3.0. ResultsUntil the last dose level of 80Gy, no patient showed dose-limiting toxicity. ConclusionsSIB-IMRT, at least until a dose of 80Gy in 32 daily fractions, associated with temozolomide is feasible and well tolerated.

EP-1362: Hypofractionated Simultaneous Integrated Boost IMRT in high risk prostate cancer – A novel approach

EP-1362: Hypofractionated Simultaneous Integrated Boost IMRT in high risk prostate cancer – A novel approach

Prospective study of special stage II (T2b-3N0M0) non-small-cell lung cancer treated with hypofractionated-simultaneous integrated boost-intensity modulated radiation therapy.

To analyze the effects of hypofractionated-simultaneous integrated boost-intensity modulated radiation therapy (Hypo-SIB-IMRT) on medically inoperable patients with special stage II (T2b-3N0M0) non-smallcell lung cancer (NSCLC). Twenty-eight qualified patients were included. Hypo-SIB-IMRT was delivered with internal gross tumor volume (iGTV) 75 Gy, clinical target volume (CTV) 60 Gy, and planning target volume (PTV) 45 Gy on weekdays in 3 weeks. The 1-, 2-, and 3-year overall survivals (OSs) were 93, 85, and 61%, respectively, with a median survival of 46.5 months; while progression-free survivals (PFSs) were 92, 79, and 64%; and distant metastasis-free survivals (DMFSs) were 92, 84, and 77%, respectively. The cancer-specific survivals (CSS) were 93, 88, and 74%, and local control (LC) were 92, 83, and 74%, respectively. 7.1% (2/28) of patients occurred local pain, 28.6% (8/28) were with Grade 1 or 2 radiation pneumonitis (RP), and 7.1% (2/28) with Grade 1 esophagitis. Of the eight patients with RP, 17.9% (5/28) developed Grade 1 radiation pulmonary fibrosis (RPF). Due to the favorable long-term survivals, LC, and minimal toxicities, Hypo-SIB-IMRT presented in this prospective study may be considered an option for patients with special stage II (T2b-3N0M0) NSCLC who were medically inoperable.