PURPOSE: To Study the dosimetric advantage of the Jaw tracking technique in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for Head and Neck Cancers. MATERIALS AND METHODS: We retrospectively selected 10 previously treated head and neck cancer patients stage (T1/T2, N1, M0) in this study. All the patients were planned for IMRT and VMAT with simultaneous integrated boost technique. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for a particular patient. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without JT for all the patients. RESULTS: The conformity index average of all patients followed by standard deviation (x¯±σ(x¯)) of the JT-IMRT, SJ-IMRT, JT-VMAT, and SJ-VMAT were 1.72 ± 0.56, 1.67 ± 0.57, 1.83 ± 0.65, and 1.85 ± 0.64, and homogeneity index were 0.059 ± 0.05, 0.064 ± 0.05, 0.064 ± 0.04, and 0.064 ± 0.05. JT-IMRT shows significant mean reduction in right parotid and left parotid shows of 7.64% (p < 0.001) and 7.45% (p < 0.001) compare to SJ-IMRT. JT-IMRT plans also shows considerable dose reduction to thyroid, inferior constrictors, spinal cord and brainstem compared to the SJ-IMRT plans. CONCLUSION: Significant dose reductions were observed for critical structure in the JT-IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the SJ-IMRT due to relatively lesser monitor units.
Brain Stem ; Head and Neck Neoplasms ; Head* ; Humans ; Jaw* ; Neck* ; Radiotherapy* ; Radiotherapy, Intensity-Modulated ; Retrospective Studies ; Spinal Cord ; Thyroid Gland

PURPOSE: To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. MATERIALS AND METHODS: Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. RESULTS: The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. CONCLUSION: HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.
Brachytherapy* ; Humans ; Mouth Neoplasms ; Mouth* ; Radiotherapy ; Recurrence ; Retrospective Studies

PURPOSE: To evaluate the predictive value of the early response of 18F-flurodeoxyglucose positron emission tomography (FDG PET) during concurrent chemoradiotherapy (CCRT) for locally advanced non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: FDG PET was performed before and during CCRT for 13 NSCLC patients. Maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured and the changes were calculated. These early metabolic changes were compared with the standard tumor response by computed tomograms (CT) one month after CCRT. RESULTS: One month after the completion of CCRT, 9 patients had partial response (PR) of tumor and 4 patients had stable disease. The percent changes of SUVmax (%DeltaSUVmax) were larger in responder group than in non-responder group (55.7% +/- 15.6% vs. 23.1% +/- 19.0%, p = 0.01). The percent changes of SUVmean (%DeltaSUVmean) were also larger in responder group than in non-responder group (54.4% +/- 15.9% vs. 22.3% +/- 23.0%, p = 0.01). The percent changes of MTV (%DeltaMTV) or TLG (%DeltaTLG) had no correlation with the tumor response after treatment. All the 7 patients (100%) with %DeltaSUVmax > or = 50% had PR, but only 2 out of 6 patients (33%) with %DeltaSUVmax < 50% had PR after CCRT (p = 0.009). Likewise, all the 6 patients (100%) with %DeltaSUVmean > or = 50% had PR, but only 3 out of 7 patients (43%) with %DeltaSUVmean < 50% had PR after CCRT (p = 0.026). CONCLUSION: The degree of metabolic changes measured by PET-CT during CCRT was predictive for NSCLC tumor response after CCRT.
Carcinoma, Non-Small-Cell Lung* ; Chemoradiotherapy* ; Glycolysis ; Humans ; Lung Neoplasms ; Positron-Emission Tomography ; Tumor Burden

PURPOSE: To evaluate the risk of vertebral compression fracture (VCF) after conventional radiotherapy (RT) for colorectal cancer (CRC) with spine metastasis and to identify risk factors for VCF in metastatic and non-metastatic irradiated spines. MATERIALS AND METHODS: We retrospectively reviewed 68 spinal segments in 16 patients who received conventional RT between 2009 and 2012. Fracture was defined as a newly developed VCF or progression of an existing fracture. The target volume included all metastatic spinal segments and one additional non-metastatic vertebra adjacent to the tumor-involved spines. RESULTS: The median follow-up was 7.8 months. Among all 68 spinal segments, there were six fracture events (8.8%) including three new VCFs and three fracture progressions. Observed VCF rates in vertebral segments with prior irradiation or pre-existing compression fracture were 30.0% and 75.0% respectively, compared with 5.2% and 4.7% for segments without prior irradiation or pre-existing compression fracture, respectively (both p < 0.05). The 1-year fracture-free probability was 87.8% (95% CI, 78.2-97.4). On multivariate analysis, prior irradiation (HR, 7.30; 95% CI, 1.31-40.86) and pre-existing compression fracture (HR, 18.45; 95% CI, 3.42-99.52) were independent risk factors for VCF. CONCLUSION: The incidence of VCF following conventional RT to the spine is not particularly high, regardless of metastatic tumor involvement. Spines that received irradiation and/or have pre-existing compression fracture before RT have an increased risk of VCF and require close observation.
Colorectal Neoplasms* ; Follow-Up Studies ; Fractures, Compression* ; Humans ; Incidence ; Multivariate Analysis ; Neoplasm Metastasis ; Radiotherapy ; Retrospective Studies ; Risk Factors ; Spinal Fractures ; Spinal Neoplasms ; Spine*

Insufficiency fracture occurs when normal or physiological stress applied to weakened bone with demineralization and decreased elastic resistance. Recently, many studies reported the development of IF after radiation therapy (RT) in gynecological cancer, prostate cancer, anal cancer and rectal cancer. The RT-induced insufficiency fracture is a common complication during the follow-up using modern imaging studies. The clinical suspicion and knowledge the characteristic imaging patterns of insufficiency fracture is essential to differentiate it from metastatic bone lesions, because it sometimes cause severe pain, and it may be confused with bone metastasis.
Anus Neoplasms ; Follow-Up Studies ; Fractures, Stress* ; Neoplasm Metastasis ; Prostatic Neoplasms ; Rectal Neoplasms ; Stress, Physiological

PURPOSE: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. MATERIALS AND METHODS: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intraclass correlation coefficient (ICC). RESULTS: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. CONCLUSION: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.
Carcinoma, Non-Small-Cell Lung ; Evaluation Studies as Topic* ; Fibrosis* ; Follow-Up Studies ; Humans ; Lung* ; Observer Variation* ; Radiotherapy ; Thorax ; Tomography, X-Ray Computed

PURPOSE: To evaluate the usefulness of positron emission tomography/computed tomography (PET/CT) for field modification during radiotherapy in esophageal cancer. MATERIALS AND METHODS: We conducted a retrospective study on 33 patients that underwent chemoradiotherapy (CRT). Pathologic findings were squamous cell carcinoma in 32 patients and adenocarcinoma in 1 patient. All patients underwent PET/CT scans before and during CRT (after receiving 40 Gy and before a 20 Gy boost dose). Response evaluation was determined by PET/CT using metabolic tumor volume (MTV), total glycolytic activity (TGA), MTV ratio (rMTV) and TGA ratio (rTGA), or determined by CT. rMTV and rTGA were reduction ratio of MTV and TGA between before and during CRT, respectively. RESULTS: Significant decreases in MTV (MTV2.5: mean 70.09%, p < 0.001) and TGA (TGA2.5: mean 79.08%, p<0.001) were found between before and during CRT. Median rMTV2.5 was 0.299 (range, 0 to 0.98) and median rTGA2.5 was 0.209 (range, 0 to 0.92). During CRT, PET/CT detected newly developed distant metastasis in 1 patient, and this resulted in a treatment strategy change. At a median 4 months (range, 0 to 12 months) after completion of CRT, 8 patients (24.2%) achieved clinically complete response, 11 (33.3%) partial response, 5 (15.2%) stable disease, and 9 (27.3%) disease progression. SUVmax (p = 0.029), rMTV50% (p = 0.016), rMTV75% (p = 0.023) on intra-treatment PET were found to correlate with complete clinical response. CONCLUSION: PET/CT during CRT can provide additional information useful for radiotherapy planning and offer the potential for tumor response evaluation during CRT. rMTV50% during CRT was found to be a useful predictor of clinical response.
Adenocarcinoma ; Carcinoma, Squamous Cell ; Chemoradiotherapy* ; Disease Progression ; Electrons ; Esophageal Neoplasms* ; Humans ; Neoplasm Metastasis ; Positron-Emission Tomography and Computed Tomography* ; Radiotherapy ; Retrospective Studies ; Tumor Burden

PURPOSE: The goal of this study is to determine whether the magnitude of overlap between planning target volume (PTV) and rectum (Rectumoverlap) or PTV and bladder (Bladderoverlap) in prostate cancer volumetric-modulated arc therapy (VMAT) is predictive of the dose-volume relationships achieved after optimization, and to identify predictive equations and cutoff values using these overlap volumes beyond which the Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) dose-volume constraints are unlikely to be met. MATERIALS AND METHODS: Fifty-seven patients with prostate cancer underwent VMAT planning using identical optimization conditions and normalization. The PTV (for the 50.4 Gy primary plan and 30.6 Gy boost plan) included 5 to 10 mm margins around the prostate and seminal vesicles. Pearson correlations, linear regression analyses, and receiver operating characteristic (ROC) curves were used to correlate the percentage overlap with dose-volume parameters. RESULTS: The percentage Rectumoverlap and Bladderoverlap correlated with sparing of that organ but minimally impacted other dose-volume parameters, predicted the primary plan rectum V45 and bladder V50 with R(2) = 0.78 and R(2) = 0.83, respectively, and predicted the boost plan rectum V30 and bladder V30 with R(2) = 0.53 and R(2) = 0.81, respectively. The optimal cutoff value of boost Rectumoverlap to predict rectum V75 >15% was 3.5% (sensitivity 100%, specificity 94%, p < 0.01), and the optimal cutoff value of boost Bladderoverlap to predict bladder V80 >10% was 5.0% (sensitivity 83%, specificity 100%, p < 0.01). CONCLUSION: The degree of overlap between PTV and bladder or rectum can be used to accurately guide physicians on the use of interventions to limit the extent of the overlap region prior to optimization.
Humans ; Linear Models ; Organs at Risk* ; Prostate* ; Prostatic Neoplasms* ; Radiation Injuries ; Radiotherapy Planning, Computer-Assisted ; Radiotherapy, Intensity-Modulated* ; Rectum ; ROC Curve ; Seminal Vesicles ; Sensitivity and Specificity ; Urinary Bladder

PURPOSE: To evaluate the safety and efficacy of transcatheter arterial chemoembolization (TACE) followed by radiotherapy (RT) in treatment-naive patients with locally advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Eligibility criteria were as follows: newly diagnosed with HCC, the Barcelona Clinic Liver Cancer stage C, Child-Pugh class A or B, and no prior treatment for HCC. Patients with extrahepatic spread were excluded. A total of 59 patients were retrospectively enrolled. All patients were treated with TACE followed by RT. The time interval between TACE and RT was 2 weeks as per protocol. A median RT dose was 47.25 Gy10 as the biologically effective dose using the alpha/beta = 10 (range, 39 to 65.25 Gy10). RESULTS: At 1 month, complete response was obtained in 3 patients (5%), partial response in 27 patients (46%), stable disease in 13 patients (22%), and progressive disease in 16 patients (27%). The actuarial one- and two-year OS rates were 60.1% and 47.2%, respectively. The median OS was 17 months (95% confidence interval, 5.6 to 28.4 months). The median time to progression was 4 months (range, 1 to 35 months). Grade 3 or greater liver enzyme elevation occurred in only two patients (3%) after RT. Grade 3 gastroduodenal toxicity developed in two patients (3%). CONCLUSION: The combination treatment of TACE followed by RT with two-week interval was safe and it showed favorable outcomes in treatment-naive patients with locally advanced HCC. A prospective randomized trial is needed to validate these results.
Carcinoma, Hepatocellular* ; Humans ; Liver ; Liver Neoplasms ; Radiotherapy ; Retrospective Studies

PURPOSE: To evaluate the results of postoperative radiotherapy in patients with extra-hepatic bile duct cancer (EHBDC) and identify the prognostic factors for local control and survival. MATERIALS AND METHODS: Between January 2001 and December 2010, we retrospectively reviewed the cases of 70 patients with EHBDC who had undergone curative resection and received postoperative radiotherapy. The median radiation dose was 50.4 Gy (range, 41.4 to 54 Gy). The resection margin status was R0 in 30 patients (42.9%), R1 in 25 patients (35.7%), and R2 in 15 patients (21.4%). RESULTS: The 5-year rates of overall survival (OS), event-free survival (EFS), and locoregional control (LRC) for all patients were 42.9%, 38.3%, and 61.2%, respectively. The major pattern of failure was distant relapses (33 patients, 47.1%). A multivariate analysis showed that the postradiotherapy CA19-9 level, radiation dose (> or =50 Gy), R2 resection margins, perineural invasion, and T stage were the significant prognostic factors for OS, EFS, and LRC. OS was not significantly different between the patients receiving R0 and R1 resections, but was significantly lower among those receiving R2 resection (54.6%, 56.1%, and 7.1% for R0, R1, and R2 resections, respectively). CONCLUSION: In patients with EHBDC who had undergone curative resection, a postoperative radiotherapy dose less than 50 Gy was suboptimal for OS and LRC. Higher radiation doses may be needed to obtain better LRC. Further investigation of novel therapy or palliative treatment should be considered for patients receiving R2 resection.
Bile Duct Neoplasms* ; Bile Ducts* ; Bile* ; Disease-Free Survival ; Humans ; Multivariate Analysis ; Palliative Care ; Radiotherapy Dosage ; Radiotherapy* ; Radiotherapy, Adjuvant ; Recurrence ; Retrospective Studies