A Japanese multi-institutional phase II study of moderate hypofractionated intensity-modulated radiotherapy with image-guided technique for prostate cancer.

BACKGROUND: The aim of this multi-institutional phase II study was to confirm the safety and the potential efficacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients. METHODS: Patients with low- or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included. Hypofractionated IMRT using daily image-guided technique with prostate matching was performed with a total dose of 70 Gy in 28 fractions. Neoadjuvant hormonal therapy for 4-8 months was mandatory for patients with intermediate or high-risk prostate cancer. RESULTS: From 20 institutions, 134 patients enrolled. The median follow-up was 5.16 years (range, 1.43-6.47 years). The number of patients with low, intermediate, and high-risk prostate cancer was 20, 80, and 34, respectively. The 5-year overall, biochemical failure-free, and clinical failure-free survival was 94.5%, 96.0%, and 99.2%, respectively. The 5-year biochemical failure-free survival for patients with low-, intermediate-, and high-risk disease was 94.1%, 97.4%, and 93.9%, respectively. The incidences of grade 2 gastrointestinal (GI) and genitourinary (GU) late toxicities at 5 years were 5.3% and 5.3%, respectively. There are no acute or late toxicities ≥ grade 3. Of 124 patients who were followed for up to 5 years, the grade 2 late GU or GI toxicities were 10.5% (90% confidence intervals, 6.3-16.2%, p = 0.0958). CONCLUSION: The safety and efficacy of moderately hypofractionated IMRT with prostate-based image-guidance was confirmed among Japanese patients with prostate cancer.

Observer uncertainties of soft tissue-based patient positioning in IGRT.

PURPOSE: There remain uncertainties due to inter- and intraobserver variability in soft-tissue-based patient positioning even with the use of image-guided radiation therapy (IGRT). This study aimed to reveal observer uncertainties of soft-tissue-based patient positioning on cone-beam computed tomography (CBCT) images for prostate cancer IGRT. METHODS: Twenty-six patients (7-8 fractions/patient, total number of 204 fractions) who underwent IGRT for prostate cancer were selected. Six radiation therapists retrospectively measured prostate cancer location errors (PCLEs) of soft-tissue-based patient positioning between planning CT (pCT) and pretreatment CBCT (pre-CBCT) images after automatic bone-based registration. Observer uncertainties were evaluated based on residual errors, which denoted the differences between soft-tissue and reference positioning errors. Reference positioning errors were obtained as PCLEs of contour-based patient positioning between pCT and pre-CBCT images. Intraobserver variations were obtained from the difference between the first and second soft-tissue-based patient positioning repeated by the same observer for each fraction. Systematic and random errors of inter- and intraobserver variations were calculated in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) directions. Finally, clinical target volume (CTV)-to-planning target volume (PTV) margins were obtained from systematic and random errors of inter- and intraobserver variations in AP, SI, and LR directions. RESULTS: Interobserver variations in AP, SI, and LR directions were 0.9, 0.9, and 0.5 mm, respectively, for the systematic error, and 1.8, 2.2, and 1.1 mm, respectively, for random error. Intraobserver variations were <0.2 mm in all directions. CTV-to-PTV margins in AP, SI, and LR directions were 3.5, 3.8, and 2.1 mm, respectively. CONCLUSION: Intraobserver variability was sufficiently small and would be negligible. However, uncertainties due to interobserver variability for soft-tissue-based patient positioning using CBCT images should be considered in CTV-to-PTV margins.

Survival and ocular preservation in a long-term cohort of Japanese patients with retinoblastoma.

BACKGROUND: Retinoblastoma is an ocular tumor in infants with cancer predisposition. Treatment of the rare tumor needs to be optimized for ocular preserved survival without second primary malignancy (SPM). METHODS: We studied the outcomes of all patients with retinoblastoma at a tertiary center in 1984-2016, when preservation method changed from radiotherapy (1984-2001) to systemic chemotherapy (2002-2016). RESULTS: One-hundred sixteen infants developed unilateral- (n = 77), bilateral- (n = 38), or trilateral-onset (n = 1) tumor. Ten (8.6%) had a positive family history, despite a few studies on RB1 gene. Contralateral disease occurred in one unilateral-onset case. One-hundred eight of 155 eyes (70%) were enucleated. Nine binocular survivors were from 5 bilateral- and 4 unilateral-onset cases. Two survivors received bilateral enucleation. Six deaths occurred; brain involvement (including 3 trilateral diseases) in 4 bilateral-onset, systemic invasion in a unilateral-onset, and SPM (osteosarcoma) in a bilateral-onset case(s). Two others survived SPM of osteosarcoma or lymphoma. The 10-year overall survival (OS: 98.5% vs. 91.3%, p = 0.068) and binocular survivors (13.2% vs. 5.2%, p = 0.154) between bilateral- and unilateral-onsets did not differ statistically. The 10-year OS and cancer (retinoblastoma/SPM)-free survival (CFS) rates of all patients were 94.9 and 88.5%, respectively. The proportion of preserved eyes did not differ between radiotherapy and chemotherapy eras. The CFS rate of bilateral-onset cases in systemic chemotherapy era was higher than that in radiotherapy era (p = 0.042). The CFS rates of bilateral-onset patients with neoadjuvant chemotherapy (upfront systemic therapy for preservation) was higher than those without it (p = 0.030). CONCLUSIONS: Systemic chemotherapy and local therapy raised OS and binocular survival rates of bilateral-onset patients similarly to those of unilateral-onset patients. All but one death was associated with a probable germline defect of the RB1 gene. Neoadjuvant stratified chemotherapy may support the long-term binocular life with minimized risk of SPM.

Comparison of volumetric-modulated arc therapy and intensity-modulated radiation therapy prostate cancer plans accounting for cold spots.

This study compared dosimetric indices of volumetric-modulated arc therapy (VMAT) with intensity-modulated radiation therapy (IMRT) accounting for cold spots in prostate cancer plans. IMRT plans were retrospectively generated from 30 prostate cancer patients with ten cases for each risk group, who received VMAT plans. The mean, maximum, and minimum doses, and conformity and homogeneity indexes were evaluated for planning target volume (PTV) and the mean dose and V20-V70 for organs at risk (OAR) including the rectum, bladder, right and left femoral heads, and rectum overlapped with PTV (ROP) regions. The numbers and volume percentages of cold spots within PTVs and ROP regions were measured using in-house software. Three-dimensional probabilistic distributions of the probability and distributions of cold spots were generated using a centroid matching technique for visualization and analysis. There was a statistically better dose conformity in the PTV, rectum, and bladder dose-sparing in VMAT compared to that in the IMRT plans, whereas VMAT had statistically worse target dose homogeneity, and right and left femoral head dose-sparing than those of the IMRT plans. The average volume percentage of cold spots per PTV for the VMAT was 4.37 ± 2.68%, which was smaller than the 5.72 ± 1.84% observed for IMRT plans (P = 0.007). The volume percentage of cold spots per ROP for the VMAT did not significantly differ from those for the IMRT plans. Compared with IMRT, the VMAT plans achieved better PTV dose conformity, OAR dose-sparing, and smaller cold spots in the treatment of prostate cancer.

Institutional patient accrual volume and the treatment quality of I­125 prostate seed implantation in a Japanese nationwide prospective cohort study.

PURPOSE: It is unclear whether experience at high-volume institute improves the treatment quality of prostate seed implantation. The aim of this study was to evaluate the effect of institutional experience on postimplant dosimetric parameters in a nationwide prospective cohort study. METHODS: From July 2005 to June 2007, 2354 patients were registered in the Japanese Prostate Cancer Outcome Study of Permanent I­125 Seed Implantation (J-POPS), and 1126 patients treated with seed implantation alone were evaluated. As a surrogate for institutional experience, we classified the J­POPS institutions as high-volume (patient accrual volume was ≥120 patients per institution) or low-volume institutions (patient accrual volume was <120 patients per institution). To compare treatment quality between institutions, we evaluated the postimplant dosimetric parameters including D90, V100/150 (prostatic dose parameters), UD5/90, U200 (urethral dose parameters), and rectum R100/150 (rectal dose parameters). RESULTS: In the 5 high-volume institutions (n = 601 patients), most of the patients were treated with >144 Gy of D90, whereas in the 20 low-volume institutions (n = 525) some of the patients were treated with <144 Gy. The V100 of most of the high-volume institution patients were >90%, whereas in the low-volume institutions a considerable percentage of patients showed lower V100. Although there was no correlation between D90 and rectal dose parameters, UD90 had a moderate positive correlation with D90 in both the high- and low-volume institutions. U200 varied more widely in the low-volume institutions. CONCLUSIONS: Our findings indicate that the institutional patient accrual volume is associated with the treatment quality of I­125 prostate seed implantation.

Effect of accounting for interfractional CTV shape variations in PTV margins on prostate cancer radiation treatment plans.

PURPOSE: The aim of this study was to account for interfractional clinical target volume (CTV) shape variation and apply this to the planning target volume (PTV) margin for prostate cancer radiation treatment plans. METHODS: Interfractional CTV shape variations were estimated from weekly cone-beam computed tomography (CBCT) images using statistical point distribution models. The interfractional CTV shape variation was taken into account in the van Herk's margin formula. The PTV margins without and with the CTV shape variation, i.e., standard (PTVori) and new (PTVshape) margins, were applied to 10 clinical cases that had weekly CBCT images acquired during their treatment sessions. Each patient was replanned for low-, intermediate-, and high-risk CTVs, using both margins. The dose indices (D98 and V70) of treatment plans with the two margins were compared on weekly pseudo-planning computed tomography (PCT) images, which were defined as PCT images registered using a deformable image registration technique with weekly CBCT images, including contours of the CTV, rectum, and bladder. RESULTS: The percentage of treatment fractions of patients who received CTV D98 greater than 95% of a prescribed dose increased from 80.3 (PTVori) to 81.8% (PTVshape) for low-risk CTVs, 78.8 (PTVori) to 87.9% (PTVshape) for intermediate-risk CTVs, and 80.3 (PTVori) to 87.9% (PTVshape) for high-risk CTVs. In most cases, the dose indices of the rectum and bladder were acceptable in clinical practice. CONCLUSION: The results of this study suggest that interfractional CTV shape variations should be taken into account when determining PTV margins to increase CTV coverages.

Feasibility of anatomical feature points for the estimation of prostate locations in the Bayesian delineation frameworks for prostate cancer radiotherapy.

This study aimed to investigate the feasibility of anatomical feature points for the estimation of prostate locations in the Bayesian delineation frameworks for prostate cancer radiotherapy. The relationships between the reference centroids of prostate regions (CPRs) (prostate locations) and anatomical feature points were explored, and the most feasible anatomical feature points were selected based on the smallest location estimation errors of CPRs and the largest Dice's similarity coefficient (DSC) between the reference and extracted prostates. The reference CPRs were calculated according to reference prostate contours determined by radiation oncologists. Five anatomical feature points were manually determined on a prostate, bladder, and rectum in a sagittal plane of a planning computed tomography image for each case. The CPRs were estimated using three machine learning architectures [artificial neural network, random forest, and support vector machine (SVM)], which learned the relationships between the reference CPRs and anatomical feature points. The CPRs were applied for placing a prostate probabilistic atlas at the coordinates and extracting prostate regions using a Bayesian delineation framework. The average estimation errors without and with SVM using three feature points, which indicated the best performance, were 5.6 ± 3.7 mm and 1.8 ± 1.0 mm, respectively (the smallest error) (p < 0.001). The average DSCs without and with SVM using the three feature points were 0.69 ± 0.13 and 0.82 ± 0.055, respectively (the highest DSC) (p < 0.001). The anatomical feature points may be feasible for the estimation of prostate locations, which can be applied to the general Bayesian delineation frameworks for prostate cancer radiotherapy.

Radiotherapy for Langerhans cell histiocytosis with paraplegia: A rare oncologic emergency case report in infancy and literature review.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a clonal disease with focal or disseminated lesions that may compress the surrounding tissues, including the spinal cord. Because few reports have described the spinal symptoms as the first manifestation of pediatric LCH, the long-term neurological outcomes remain unclear. CASE REPORT AND LITERATURE REVIEW: We report a 21-month-old boy who presented with sudden-onset paraplegia. Imaging analyses revealed that osteolytic lesions and epidural tumors compressing the spinal cord at the T7-9 vertebrae. Twelve days after he developed leg weakness, emergency radiotherapy was started after a tumor biopsy. During the course of radiotherapy, paralysis steadily ameliorated. After we excluded infections and determined the pathological diagnosis of LCH, multi-drug chemotherapy was started. Apparent improvement in his complete paraplegia was observed after a total 15 Gy of radiotherapy and subsequent chemotherapy, leaving no neurological sequelae at 4 years of age. Through a literature search of studies published from 1980 to 2017, we found that children with LCH showed a generally favorable recovery from neurological dysfunction after the acute phase of spinal symptoms. CONCLUSION: This report underscores the utility of emergency radiotherapy for the neurological recovery of spinal LCH in infants. Our long-term observation further denotes the value of this treatment in terms of the intact survival with preserved motor functions and physical growth.

Computational analysis of interfractional anisotropic shape variations of the rectum in prostate cancer radiation therapy.

PURPOSE: To analyze the uncertainties of the rectum due to anisotropic shape variations by using a statistical point distribution model (PDM). MATERIALS AND METHODS: The PDM was applied to the rectum contours that were delineated on planning computed tomography (CT) and cone-beam CT (CBCT) at 80 fractions of 11 patients. The standard deviations (SDs) of systematic and random errors of the shape variations of the whole rectum and the region in which the rectum overlapped with the PTV (ROP regions) were derived from the PDMs at all fractions of each patient. The systematic error was derived by using the PDMs of planning and average rectum surface determined from rectum surfaces at all fractions, while the random error was derived by using a PDM-based covariance matrix at all fractions of each patient. RESULTS: Regarding whole rectum, the population SDs were larger than 1.0 mm along all directions for random error, and along the anterior, superior, and inferior directions for systematic error. The deviation is largest along the superior and inferior directions for systematic and random errors, respectively. For ROP regions, the population SDs of systematic error were larger than 1.0 mm along the superior and inferior directions. The population SDs of random error for the ROP regions were larger than 1.0 mm except along the right and posterior directions. CONCLUSIONS: The anisotropic shape variations of the rectum, especially in the ROP regions, should be considered when determining a planning risk volume (PRV) margins for the rectum associated with the acute toxicities.

Exploration of temporal stability and prognostic power of radiomic features based on electronic portal imaging device images.

PURPOSE: We aimed to explore the temporal stability of radiomic features in the presence of tumor motion and the prognostic powers of temporally stable features. METHODS: We selected single fraction dynamic electronic portal imaging device (EPID) (n = 275 frames) and static digitally reconstructed radiographs (DRRs) of 11 lung cancer patients, who received stereotactic body radiation therapy (SBRT) under free breathing. Forty-seven statistical radiomic features, which consisted of 14 histogram-based features and 33 texture features derived from the graylevel co-occurrence and graylevel run-length matrices, were computed. The temporal stability was assessed by using a multiplication of the intra-class correlation coefficients (ICCs) between features derived from the EPID and DRR images at three quantization levels. The prognostic powers of the features were investigated using a different database of lung cancer patients (n = 221) based on a Kaplan-Meier survival analysis. RESULTS: Fifteen radiomic features were found to be temporally stable for various quantization levels. Among these features, seven features have shown potentials for prognostic prediction in lung cancer patients. CONCLUSIONS: This study suggests a novel approach to select temporally stable radiomic features, which could hold prognostic powers in lung cancer patients.

Additional radiotherapy following endoscopic submucosal dissection for T1a-MM/T1b-SM esophageal squamous cell carcinoma improves locoregional control.

BACKGROUND: Endoscopic submucosal dissection (ESD) can be used as a less invasive treatment option for superficial esophageal cancer involving the muscularis mucosae (T1a-MM) or upper third of the submucosa (T1b-SM1). Additional treatment after ESD is needed to prevent lymph node metastasis. However, the efficacy of radiotherapy following ESD has not been well evaluated. Moreover, the clinical outcomes of patients with large mucosal defects of the esophagus who received radiotherapy after ESD have not been reported. This study aimed to clarify the efficacy of additional radiotherapy following ESD for esophageal squamous cell cancer involving T1a-MM or T1b-SM1. METHODS: We analyzed twenty-seven patients with pathologically confirmed T1a-MM or T1b-SM1 esophageal squamous cell cancer treated by ESD. Thirteen patients received additional radiotherapy (RT group), and the remaining patients did not (non-RT group). Locoregional control (LRC), overall survival, cause-specific survival, and adverse events including treatment-related esophageal strictures were evaluated. RESULTS: The three-year LRC was significantly better for the RT than the non-RT group (100% vs. 57.8%, respectively; p = 0.022). Chemotherapy following ESD did not improve LRC. Multivariate analysis showed that radiotherapy was an independent prognostic factor for better LRC (p = 0.0022). Contrary to the results in LRC, overall and cause-specific survival were not significantly different between the RT and non-RT groups. A subgroup analysis of patients with mucosal defects involving ≥ 3/4 of the esophageal circumference after ESD showed that LRC of the RT group was better than that of the non-RT group (p = 0.049). Treatment-related esophageal strictures were observed in 2 of 6 patients in the RT group with large mucosal defects after ESD. No patients with mucosal defects involving less than 3/4 of the circumference after ESD developed treatment-related strictures. CONCLUSIONS: Radiotherapy after ESD contributed to better LRC in esophageal squamous cell cancer involving pT1a-MM and pT1b-SM1. Esophageal strictures were observed in some patients with large mucosal defects after ESD. Despite leading to better LRC, radiotherapy after ESD should be undertaken after careful consideration for patients with large mucosal defects after ESD.

Variability of treatment planning of seed implantation: A Japanese multicenter simulation study.

PURPOSE: This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials. METHODS AND MATERIALS: Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations. RESULTS: A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians. CONCLUSION: Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

Investigation of interfractional shape variations based on statistical point distribution model for prostate cancer radiation therapy.

PURPOSE: The setup errors and organ motion errors pertaining to clinical target volume (CTV) have been considered as two major causes of uncertainties in the determination of the CTV-to-planning target volume (PTV) margins for prostate cancer radiation treatment planning. We based our study on the assumption that interfractional target shape variations are not negligible as another source of uncertainty for the determination of precise CTV-to-PTV margins. Thus, we investigated the interfractional shape variations of CTVs based on a point distribution model (PDM) for prostate cancer radiation therapy. MATERIALS AND METHODS: To quantitate the shape variations of CTVs, the PDM was applied for the contours of 4 types of CTV regions (low-risk, intermediate- risk, high-risk CTVs, and prostate plus entire seminal vesicles), which were delineated by considering prostate cancer risk groups on planning computed tomography (CT) and cone beam CT (CBCT) images of 73 fractions of 10 patients. The standard deviations (SDs) of the interfractional random errors for shape variations were obtained from covariance matrices based on the PDMs, which were generated from vertices of triangulated CTV surfaces. The correspondences between CTV surface vertices were determined based on a thin-plate spline robust point matching algorithm. The systematic error for shape variations was defined as the average deviation between surfaces of an average CTV and planning CTVs, and the random error as the average deviation of CTV surface vertices for fractions from an average CTV surface. RESULTS: The means of the SDs of the systematic errors for the four types of CTVs ranged from 1.0 to 2.0 mm along the anterior direction, 1.2 to 2.6 mm along the posterior direction, 1.0 to 2.5 mm along the superior direction, 0.9 to 1.9 mm along the inferior direction, 0.9 to 2.6 mm along the right direction, and 1.0 to 3.0 mm along the left direction. Concerning the random errors, the means of the SDs ranged from 0.9 to 1.2 mm along the anterior direction, 1.0 to 1.4 mm along the posterior direction, 0.9 to 1.3 mm along the superior direction, 0.8 to 1.0 mm along the inferior direction, 0.8 to 0.9 mm along the right direction, and 0.8 to 1.0 mm along the left direction. CONCLUSIONS: Since the shape variations were not negligible for intermediate and high-risk CTVs, they should be taken into account for the determination of the CTV-to-PTV margins in radiation treatment planning of prostate cancer.

Cataracts after Low-Dose Radiotherapy for Lymphoproliferative Disease of the Ocular Adnexa.

PURPOSE: To investigate the interval between low-dose radiotherapy and radiation-induced cataracts, and the factors affecting this interval, in patients with lymphoproliferative disease of the ocular adnexa. METHODS: A retrospective case series of 73 eyes of 59 patients who underwent radiotherapy from 1996 to 2005 with total doses ranging from 24 to 30 Gy was conducted. We investigated the relationships between the radiation-associated cataract formation intervals and age, gender, diabetes, and the use of corticosteroids. RESULTS: The mean interval was 36 months. None of the patients with lens shield developed cataracts. Age was inversely and significantly and gender was not significantly associated with the interval from first radiotherapy to cataract occurrence. The intervals did not differ significantly according to the presence of diabetes and corticosteroid therapy. CONCLUSIONS: The mean interval from the start of radiation therapy to radiation-related cataract formation was 36 months and age was a significant factor affecting this interval.

Smoking effect on secondary bladder cancer after external beam radiotherapy for prostate cancer.

OBJECTIVE: Although it is well known that radiotherapy for prostate cancer increases comorbid rate of secondary bladder cancer, the effect of aging and smoking with radiotherapy on incidence rate of secondary bladder cancer remains unknown. Then, this study investigated the combinational effect of external beam radiotherapy for prostate cancer and aging or smoking on comorbid rate of secondary bladder cancer. METHODS: This study included 754 Japanese patients with prostate cancer treated with radiotherapy (n = 319) and radical prostatectomy (n = 435) from 2000 through 2013. The relationship between therapeutic modality for prostate cancer as well as age or smoking status and comorbid rate of secondary bladder cancer was examined. RESULTS: During the median follow-up period of 4.3 and 3.1 years, secondary bladder cancer occurred in 11 (3.4%) and 5 (1.1%) of patients with prostate cancer treated with external beam radiotherapy and radical prostatectomy, respectively. The 5-year bladder cancer-free survival rate was 97.3% in the external beam radiotherapy group and 99.4% in the radical prostatectomy group. Age (hazard ratio = 1.15, P = 0.027) and ever smoking (hazard ratio = 5.65, P = 0.011) were significant predictive factors of secondary bladder cancer incidence in the external beam radiotherapy cohort, but not in the radical prostatectomy cohort. Inversely, among men with ever smoking, but not among older men, external beam radiotherapy (hazard ratio = 9.64, P = 0.0052) was a significant risk factor of secondary bladder cancer. CONCLUSIONS: Taken together, these findings suggest that smoking history might be one of criteria to choose radical prostatectomy than external beam radiotherapy for prostate cancer, and that age would not be a criterion for therapeutic selection in terms of secondary bladder cancer.

Prognostic Significance of a Minute Amount of Ascites During Chemoradiotherapy for Locally Advanced Pancreatic Cancer.

AIM: The aim of this study was to investigate the clinical factors for predicting overall survival (OS) and the significance of a minute amount of ascites on computed tomography (CT) in patients with locally advanced pancreatic cancer (LAPC) treated with chemoradiotherapy (CRT). PATIENTS AND METHODS: Between 2003 and 2011, 48 consecutive patients with LAPC were treated with CRT. Various clinical factors, including ascites, were evaluated for correlation with OS. A subset analysis of 16 patients with a minute amount of ascites was also performed. RESULTS: The median survival duration and the 1-year OS rates were 11.5 months and 50%, respectively. A minute amount of ascites on CT and elevated carbohydrate antigen 19-9 (CA19-9) level were significantly associated with poorer OS. In 16 patients with ascites, the amount of ascites increased in the course of the disease, and these were considered to be cancerous clinically, regardless of the amount. CONCLUSION: A minute amount of ascites and CA19-9 were important prognostic factors in CRT. Any amount of ascites was considered an early indicator of peritoneal carcinomatosis in LAPC.

Risk Factors and Preventive Effects of Laser Panretinal Photocoagulation for Neovascular Glaucoma after Ophthalmic Stereotactic Radiotherapy.

Purpose: To evaluate the risk factors and the preventive effects of laser panretinal photocoagulation (PRP) for neovascular glaucoma (NVG) after ophthalmic stereotactic radiotherapy. Methods: Twenty-four patients with ocular malignant tumor (such as uveal malignant melanoma, lacrimal gland cancer) who received stereotactic radiotherapy (such as gamma knife, cyber knife) were retrospectively analyzed. Patients were divided into group A without preventive PRP (n=9), and group B with preventive PRP (n=15). Survival curves were plotted using the Kaplan-Meier method and compared between the two groups with the log-rank test. Results: In group A, NVG occurred in 3 patients. In contrast, in group B, no patient encountered NVG. The significant risk factor for NVG was dose-volumes that irradiated the optic disk (p=0.045). The incidence of NVG was significantly reduced in group B compared with group A (p=0.019). Conclusions: Dose-volumes that irradiated the optic disk were risk factors for NVG. PRP is effective in the prevention of NVG.

Impact of Interstitial Changes on Radiation Pneumonitis After Stereotactic Body Radiation Therapy for Lung Cancer.

AIM: The aim of the present study was to evaluate the impact of interstitial changes (IC) on radiation pneumonitis (RP) after stereotactic body radiation therapy (SBRT) for lung cancer. PATIENTS AND METHODS: We analyzed 260 consecutive patients with primary lung cancer treated with SBRT. According to the presence or absence of IC on the pre-treatment computed tomography, patients were divided into two groups: an IC group (n=18) and a non-IC group (n=242). RESULTS: RP of grade 2 or more was observed in 9 (50.0%) and 14 (6.7%) patients in the IC and non-IC group, respectively. All three patients with grade 5 RP were in the IC group. As indicated by multivariate analysis, the presence of IC was the only significant predictive factor of RP of grade 2 or more. CONCLUSION: The presence of IC was a significant indicator of grade 2 or more RP after SBRT for patients with lung cancer.

Treatment Planning Comparison for Carbon Ion Radiotherapy, Proton Therapy and Intensity-modulated Radiotherapy for Spinal Sarcoma.

BACKGROUND/AIM: Carbon ion radiotherapy (CIRT), proton therapy (PT) and intensity-modulated radiotherapy (IMRT) are new radiation modalities suitable for treatment of spinal sarcomas. The objective of the study was to compare the treatment planning of these modalities. PATIENTS AND METHODS: We conducted a treatment planning comparison of the three modalities using a phantom imitating a spinal sarcoma and then six actual cases with spinal tumors. A uniform biological effective dose (BED) of 90 Gy10 was prescribed in previously reported fractionation schedules for each modality. The surface/center spinal cord dose constraints were set to BED of 96/77 Gy(E)3, respectively. RESULTS: CIRT achieved better homogeneity of dose distribution and coverage of target than PT independently of tumor extent around the spinal cord. In IMRT plans, the spinal cord dose was higher than that under CIRT and PT and coverage of the target deteriorated depending on the tumor extension. CONCLUSION: CIRT was most appropriate for the treatment of advanced spinal sarcomas.

Retrospective Analysis of Concurrent Chemoradiation with Triweekly Cisplatin plus 5-Fluorouracil Versus Weekly Cisplatin in Cervical Cancer.

BACKGROUND/AIM: Concurrent chemoradiation (CCRT) is the standard treatment for locally advanced cervical cancer. The purpose of the study was to compare the outcomes of triweekly cisplatin plus 5-fluorouracil and weekly cisplatin regimens. PATIENTS AND METHODS: We retrospectively reviewed data from 91 patients with stage IB1-IVA cervical cancer. RESULTS: Out of 91 patients, 48 received triweekly CCRT and 43 received weekly CCRT. For triweekly CCRT, patients received a median of two chemotherapy cycles and median total doses of cisplatin and 5-fluorouracil were 210 mg/body and 8,525 mg/body, respectively. For weekly CCRT, patients received a median of five chemotherapy cycles and the median total dose of cisplatin was 252 mg/body. No statistically significant differences in overall survival or progression-free survival were noted between the two groups. CONCLUSION: Both triweekly CCRT and weekly CCRT appear to have similar efficacy for cervical cancer patients, but the toxicities were better tolerable in weekly CCRT.