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Background and Purpose: The aim of this retrospective study was to compare volumetric-modulated arc therapy using simultaneous integrated boosts (SIB-VMAT) of 45 Gy/55 Gy in 25 fractions with three-dimensional conformal radiotherapy (3D-CRT) in preoperative chemoradiation for rectal cancers.Methods and Materials: In the propensity score-matching analysis of 1:2, we selected 60 patients from the SIB-VMAT group and 120patients from the 3D-CRT group matched pairings out of 145 patients between 2005 and 2015. The regimen of concurrent combined chemotherapy was oral uracil/tegafur plus leucovorin with/without irinotecan.Results: There were no significant differences between the two groups, in pathological complete response rates (pCR) (11% in the 3D-CRT group vs. 17% in the SIB-VMAT group, P = 0.39), pathological response rates (44% vs. 60%, P = 0.77), disease-free survival (P = 0.32), or local control (P = 0.52). The SIB-VMAT method marginally improved the rate of pathological grade 2-3 effects and the OS was significantly better in patients with grade 2-3 effects. Recurrence was seen in 36 patients (30%) in the 3D-CRT group and 19 patients (32%) in the SIB-VMAT group. The first distant recurrence site in the SIB-VMAT group was liver in 6 patients and lung in 8 patients. The obvious radiation-induced late toxicity in the SIB-VMAT group was recto-vesical fistula in two patients.Conclusions: The SIB-VMAT may be a promising method for preoperative CRT of rectal cancer. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to introduce the new concept of a four-dimensional (4D) cone-beam computed tomography (CBCT) reconstruction approach for non-periodic organ motion in cooperation with the time-ordered chain graph model (TCGM) and to compare it with previously developed methods such as total variation-based compressed sensing (TVCS) and prior-image constrained compressed sensing (PICCS).Materials and Methods: Our proposed reconstruction is based on a model including the constraint originating from the images of neighboring time phases. Namely, the reconstructed time-series images depend on each other in this TCGM scheme, and the time-ordered images are concurrently reconstructed in the iterative reconstruction approach. In this study, iterative reconstruction with the TCGM was carried out with 90° projection ranges. The images reconstructed by the TCGM were compared with the images reconstructed by TVCS (200° projection ranges) and PICCS (90° projection ranges). Two kinds of projection data sets-an elliptic-cylindrical digital phantom and two clinical patients' data-were used. For the digital phantom, an air sphere was contained and virtually moved along the longitudinal axis by 3 cm/30 s and 3 cm/60 s; the temporal resolution was evaluated by measuring the penumbral width of the air sphere. The clinical feasibility of the non-periodic time-ordered 4D CBCT image reconstruction was examined with the patient data in the pelvic region.Results: In the evaluation of the digital-phantom reconstruction, the penumbral widths of the TCGM yielded the narrowest result; the results obtained by PICCS and TCGM using 90° projection ranges were 2.8% and 18.2% for 3 cm/30 s, and 5.0% and 23.1% for 3 cm/60 s narrower than that of TVCS using 200° projection ranges. This suggests that the TCGM has a better temporal resolution, whereas PICCS seems similar to TVCS. These reconstruction methods were also compared using patients' projection data sets. Although all three reconstruction results showed motion related to rectal gas or stool, the result obtained by the TCGM was visibly clearer with less blurring.Conclusion: The TCGM is a feasible approach to visualize non-periodic organ motion. The digital-phantom results demonstrated that the proposed method provides 4D image series with a better temporal resolution compared to TVCS and PICCS. The clinical patients' results also showed that the present method enables us to visualize motion related to rectal gas and flatus in the rectum. [ABSTRACT FROM AUTHOR]

Background: The optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial. In particular, the prognostic significance of salvage radiotherapy delivered before a current definition of biochemical recurrence, i.e. ultra-early salvage radiotherapy, is unclear.Methods: We reviewed 76 patients with pT2-3N0M0 prostate cancer who underwent salvage radiotherapy for post-prostatectomy biochemical recurrence at the following three timings: ultra-early salvage radiotherapy (n = 20) delivered before meeting a current definition of biochemical recurrence (two consecutive prostate-specific antigen [PSA] values ≥0.2 ng/mL); early salvage radiotherapy (n = 40) delivered after meeting the definition but before PSA reached 0.5 ng/mL; and delayed salvage radiotherapy (n = 16) delivered after PSA reached 0.5 ng/mL. The primary endpoint was failure of salvage radiotherapy, defined as a PSA value ≥0.2 ng/mL. The log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively.Results: During the follow-up period (median: 70 months), four of 20 (20 %), nine of 40 (23 %) and seven of 16 (44 %) patients failed biochemically in the ultra-early, early and delayed salvage radiotherapy groups, respectively. On univariate analyses, the outcome of delayed salvage radiotherapy was worse than the others, while there was no significant difference between ultra-early and early groups. Multivariate analysis demonstrated the presence of Gleason pattern 5, perineural invasion and delayed salvage radiotherapy as independent predictors of poorer survival.Conclusions: No survival benefit of ultra-early salvage radiotherapy was demonstrated, whereas delayed salvage radiotherapy was associated with worse outcome as reported in previous studies. Our results may support the current recommendations that salvage radiotherapy should be undertaken after two consecutive PSA values ≥0.2 ng/mL and before reaching 0.5 ng/mL. [ABSTRACT FROM AUTHOR]

Background: Standard chemoradiotherapy (CRT) using cisplatin (CDDP) and 5-fluorouracil (5-FU) is an optional treatment for patients with stage II-III esophageal cancer. However, there are some demerits in this regimen because CDDP administration requires a large transfusion volume and 5-FU must be continuously infused over 24 h. Therefore, hospitalization is unavoidable. We collected retrospectively the data of definitive CRT with nedaplatin and S-1 as carried out in our institution.Methods: Patients with early and advanced esophageal cancer and relapsed esophageal cancer after radical surgery were included. Nedaplatin 80 mg/m(2) was given on days 1 and 29, and S-1 80 mg/m(2) on days 1-14 and 29-42. No prophylactic treatment with granulocyte colony stimulating factor was administered. Patients received two courses of concurrent radiotherapy of more than 50 Gy with or without two additional courses as adjuvant therapy every 4 weeks.Results: Between August 2011 and June 2015, 89 patients (age range, 44-86 years; K-PS 90-100, 81 %; squamous cell carcinoma histology, 97 %; definitive/salvage CRT, 75/25 %) were collected. Twenty-one (24 %) patients completed four cycles, and 94 % received two or more cycles. Grade 4 leukopenia, thrombocytopenia, and anemia occurred in 12, 7, and 10 % of the patients, respectively. Five patients developed febrile neutropenia. Grade 3 non-hematological toxicity included infection in 12 %, mucositis/esophagitis in 3 %, kidney in 3 %, and fatigue in 3 %. Sixty-four patients (72 %) received the prescribed full dose and full cycles of chemotherapy. A complete response was achieved in 76 patients (85 %). The 3-year overall survival rate was 54.4 % in definitive CRT and 39.8 % in salvage CRT, respectively. Sixty-two subjects (70 %) received treatment as outpatients.Conclusions: Nedaplatin and S-1 in combination with radiotherapy is feasible, and toxicity is tolerable. This treatment method has the potential to shorten hospitalization without impairing the efficacy of CRT. [ABSTRACT FROM AUTHOR]

Purpose The purpose of the present study was to quantify the inter-fractional motion of the rectum and the rectal and bladder volumes using CBCT scans taken during chemoradiation therapy (CRT) for rectal cancer. Also, assessment was made for a better margin for simultaneous integrated boost - intensity modulated radiation therapy (SIB-IMRT) for rectal cancer. Methods and materials There were 32 patients in this study undergoing preoperative CRT for rectal cancer. Each rectum and bladder was contoured on all planning CTs and CBCTs (day 1, 7, 13, 19, 25). The target volume was configured by adding margins (0, 3, 5, 7, 10, and 15 mm) to the rectum on planning CT. The respective percentage of rectal volume that exceeds the target volume was calculated for each of these margins. The percentage of bladder volume that exceeds the bladder volume in the planning CT and motion of the center of gravity of rectum were also analyzed. Results Planning CTs and series of each 5 CBCTs for 32 patients were analyzed in this study. The rectal volume tended to shrink week after week. The mean values (± SD) in the 32 series per patient of the percentage of rectum on the CBCTs exceeding target volume in which the margins of 0, 3, 5, 7, 10, and 15 mm were added to the rectum on planning CT were 20.7 ± 12.5%, 7.2 ± 8.3%, 3.9 ± 5.9%, 2.1 ± 3.9%, 0.7 ± 1.8%, and 0.1 ± 0.3%, respectively. No association was seen between the percentage of changes of bladder volume and motion of rectal centroid. Conclusions In this study, we estimated the motion of the rectum using planning CT and CBCT. Ten to fifteen mm is a sufficient margin for the rectum during SIB-IMRT for rectal cancer in the supine position. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the respiratory motion of metal clips or surgical staples placed in the gastric wall for planning of radiation therapy in gastric cancer patients. Methods: This study examined 15 metal markers in the gastric walls of 12 patients with gastric cancer treated with external-beam photon RT. Motion assessment was analyzed in 41 respiratory phases covering 20 s acquired with computed tomography (CT) in the RT position using 320-multislice CT. The intra-fraction displacement was assessed in the cranio-caudal (CC), antero-posterior (AP), and right-left (RL) directions.Results: Motion in the CC direction showed a very strong correlation (R2 > 0.7) with the respiratory curve in all 15 markers. The mean (+/- SD) intra-fractional gastric motion (maximum range of displacement) was 12.5 (+/- 3.4)mm in the CC, 8.3 (+/- 2.2) mm in the AP, and 5.5 (+/- 3.0) mm in the RL direction. No significant differences in magnitude of motion were detected in the following: a) among the upper (n = 6), middle (n = 4), and lower (n = 5) stomach regions; b) between metal clips (n = 5) and surgical staples (n = 10); and c) between full (n = 9) and empty (n = 6) stomachs. Conclusions: Motion in primary gastric tumor was evaluated with 320-multislice CT. According to this study, the 95th percentile values from the cumulative distributions of the RL, AP, and CC direction were 6.3 mm, 9.0 mm, and 13.6 mm, respectively. [ABSTRACT FROM AUTHOR]

Introduction: The abscopal effect is the effect of radiation therapy at a site distant to the area of irradiation. This is not a common event and has not been clearly defined, resulting in few reported cases in the literature. We discuss this phenomenon in a patient with hepatocellular carcinoma.Case Presentation: A 63-year-old Japanese man underwent extended right hepatic lobectomy for hepatocellular carcinoma. During his follow-up examination, a single lung metastasis and a single mediastinal lymph node metastasis were found. Trans-catheter arterial embolization was initially attempted to treat the mediastinal tumor, however this approach failed to take effect and carried risks of spinal artery embolism. External-beam irradiation, with a dose of 2.25 Gy per fraction, was performed using an antero-posterior parallel-opposed technique (total dose, 60.75 Gy). A computed tomography scan performed one month after starting radiotherapy showed a remarkable reduction of the mediastinal lymph node metastasis. In addition to this, we observed spontaneous shrinking of the lung metastasis, which was located in the right lower lobe and out of the radiation field. No chemotherapy was given during the period. There has been no recurrence of either the lung metastasis or the mediastinal lymph node metastasis during a follow-up 10 years after the radiotherapy.Conclusion: We observed a rare abscopal effect in a site distant from the area of irradiation. Irradiation of the mediastinum resulted in tumor mass regression in the untreated lung tumor. [ABSTRACT FROM AUTHOR]

Purpose: To determine the risk factors of severe radiation pneumonitis (RP) after stereotactic body radiation therapy (SBRT) for primary or secondary lung tumors. Materials and methods: From January 2003 to March 2009, SBRT was performed on 117 patients (32 patients before 2005 and 85 patients after 2006) with lung tumors (primary = 74 patients and metastatic/recurrent = 43 patients) in our institution. In the current study, the results on cases with severe RP (grades 4-5) were evaluated. Serum Krebs von den Lungen-6 (KL-6) and serum Surfactant protein-D (SP-D) were used to predict the incidence of RP. A shadow of interstitial pneumonitis (IP) on the CT image before performing SBRT was also used as an indicator for RP. Since 2006, patients have been prescreened for biological markers (KL-6 & SP-D) as well as checking for an IP-shadow in CT. Results: Grades 4-5 RP was observed in nine patients (7.7%) after SBRT and seven of these cases (6.0%) were grade 5 in our institution. A correlation was found between the incidence of RP and higher serum KL-6 & SP-D levels. IP-shadow in patient's CT was also found to correlate well with the severe RP. Severe RP was reduced from 18.8% before 2005 to 3.5% after 2006 (p = 0.042). There was no correlation between the dose volume histogram parameters and these severe RP patients. Conclusion: Patients presenting with an IP shadow in the CT and a high value of the serum KL-6 & SP-D before SBRT treatment developed severe radiation pneumonitis at a high rate. The reduction of RP incidence in patients treated after 2006 may have been attributed to prescreening of the patients. Therefore, pre-screening before SBRT for an IP shadow in CT and serum KL-6 & SP-D is recommended in the management and treatment of patients with primary or secondary lung tumors. [ABSTRACT FROM AUTHOR]

Background: TomoTherapy (Accuray, USA) has an image-guided radiotherapy system with a megavoltage (MV) X-ray source and an on-board imaging device. This system allows one to acquire the delivery sinogram during the actual treatment, which partly includes information from the irradiated object. In this study, we try to develop image reconstruction during treatment with helical tomotherapy.Findings: Sinogram data were acquired during helical tomotherapy delivery using an arc-shaped detector array that consists of 576 xenon-gas filled detector cells. In preprocessing, these were normalized with full air-scan data. A software program was developed that reconstructs 3D images during treatment with corrections as; (1) the regions outside the field were masked not to be added in the backprojection (a masking correction), and (2) each voxel of the reconstructed image was divided by the number of the beamlets passing through its voxel (a ray-passing correction). The masking correction produced a reconstructed image, however, it contained streak artifacts. The ray-passing correction reduced this artifact. Although the SNR (the ratio of mean to standard deviation in a homogeneous region) and the contrast of the reconstructed image were slightly improved with the ray-passing correction, use of only the masking correction was sufficient for the visualization purpose.Conclusions: The visualization of the treatment area was feasible by using the sinogram in helical tomotherapy. This proposed method would be useful in the treatment verification. [ABSTRACT FROM AUTHOR]

Background: To moving lung tumors, we applied a respiratory-gated strategy to carbon-ion pencil beam scanning with multiple phase-controlled rescanning (PCR). In this simulation study, we quantitatively evaluated dose distributions based on 4-dimensional CT (4DCT) treatment planning.Methods: Volumetric 4DCTs were acquired for 14 patients with lung tumors. Gross tumor volume, clinical target volume (CTV) and organs at risk (OARs) were delineated. Field-specific target volumes (FTVs) were calculated, and 48Gy(RBE) in a single fraction was prescribed to the FTVs delivered from four beam angles. The dose assessment metrics were quantified by changing the number of PCR and the results for the ungated and gated scenarios were then compared.Results: For the ungated strategy, the mean dose delivered to 95% of the volume of the CTV (CTV-D95) was in average 45.3 ± 0.9 Gy(RBE) even with a single rescanning (1 × PCR). Using 4 × PCR or more achieved adequate target coverage (CTV-D95 = 46.6 ± 0.3 Gy(RBE) for ungated 4 × PCR) and excellent dose homogeneity (homogeneity index =1.0 ± 0.2% for ungated 4 × PCR). Applying respiratory gating, percentage of lung receiving at least 20 Gy(RBE) (lung-V20) and heart maximal dose, averaged over all patients, significantly decreased by 12% (p < 0.05) and 13% (p < 0.05), respectively.Conclusions: Four or more PCR during PBS-CIRT improved dose conformation to moving lung tumors without gating. The use of a respiratory-gated strategy in combination with PCR reduced excessive doses to OARs. [ABSTRACT FROM AUTHOR]

Purpose: To report the result of independent absorbed-dose calculations based on a Monte Carlo (MC) algorithm in volumetric modulated arc therapy (VMAT) for various treatment sites.Methods and Materials: All treatment plans were created by the superposition/convolution (SC) algorithm of SmartArc (Pinnacle V9.2, Philips). The beam information was converted into the format of the Monaco V3.3 (Elekta), which uses the X-ray voxel-based MC (XVMC) algorithm. The dose distribution was independently recalculated in the Monaco. The dose for the planning target volume (PTV) and the organ at risk (OAR) were analyzed via comparisons with those of the treatment plan.Before performing an independent absorbed-dose calculation, the validation was conducted via irradiation from 3 different gantry angles with a 10- × 10-cm2 field. For the independent absorbed-dose calculation, 15 patients with cancer (prostate, 5; lung, 5; head and neck, 3; rectal, 1; and esophageal, 1) who were treated with single-arc VMAT were selected. To classify the cause of the dose difference between the Pinnacle and Monaco TPSs, their calculations were also compared with the measurement data.Result: In validation, the dose in Pinnacle agreed with that in Monaco within 1.5%. The agreement in VMAT calculations between Pinnacle and Monaco using phantoms was exceptional; at the isocenter, the difference was less than 1.5% for all the patients. For independent absorbed-dose calculations, the agreement was also extremely good. For the mean dose for the PTV in particular, the agreement was within 2.0% in all the patients; specifically, no large difference was observed for high-dose regions. Conversely, a significant difference was observed in the mean dose for the OAR. For patients with prostate cancer, the mean rectal dose calculated in Monaco was significantly smaller than that calculated in Pinnacle.Conclusions: There was no remarkable difference between the SC and XVMC calculations in the high-dose regions. The difference observed in the low-dose regions may have arisen from various causes such as the intrinsic dose deviation in the MC calculation, modeling accuracy, and CT-to-density table used in each planning system It is useful to perform independent absorbed-dose calculations with the MC algorithm in intensity-modulated radiation therapy commissioning. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate the efficacy and feasibility of carbon ion radiotherapy (CIRT) for oligo-recurrent lung tumors from colorectal cancer (CRC).Methods: From May 1997 to October 2012, 34 consecutive patients with oligo-recurrent pulmonary metastases from CRC were treated with CIRT. The patients were not surgical candidates for medical reasons or patient refusal. Using a respiratory-gated technique, carbon ion therapy was delivered with curative intent using 4 coplanar beam angles. A median dose of 60 GyE (range, 44-64.8 GyE) was delivered to the planning target volume (PTV), with a median daily dose of 15 GyE (range, 3.6-44 GyE). Treatment outcome was analyzed in terms of local control rate (LCR), survival rate, and treatment-related complications.Results: In total, 34 patients with 44 oligo-recurrent pulmonary lesions were treated with CIRT. Median follow-up period was 23.7 months. The 2- and 3-year actuarial LCRs of the treated patients were 85.4% ± 6.2% and 85.4% ± 6.2%, respectively. Overall survival was 65.1% ± 9.5% at 2 years, and 50.1% ± 10.5% at 3 years. Although survival rates were relatively worse in the subsets of patients aged<63 years or with early metastasis (< 36 months after resection of primary site), these factors were not significantly correlated with overall survival (P=0.13 and 0.19, respectively). All treatment-related complications were self-limited, without any grade 3-5 toxicity.Conclusions: CIRT is one of the most effective nonsurgical treatments for colorectal lung metastases, which are relatively resistant to stereotactic body radiotherapy. CIRT is considered to be the least invasive approach even in patients who have undergone repeated prior thoracic metastasectomies. [ABSTRACT FROM AUTHOR]

Background and Aims: Stereotactic body radiotherapy (SBRT) is a relatively new treatment for liver tumor. The outcomes of SBRT for liver tumor unfit for ablation and surgical resection were evaluated.Methods: Liver tumor patients treated with SBRT in seven Japanese institutions were studied retrospectively. Patients given SBRT for liver tumor between 2004 and 2012 were collected. Patients treated with SBRT preceded by trans-arterial chemoembolization (TACE) were eligible. Seventy-nine patients with hepatocellular carcinoma (HCC) and 51 patients with metastatic liver tumor were collected. The median biologically effective dose (BED) (α/β = 10 Gy) was 96.3 Gy for patients with HCC and 105.6 Gy with metastatic liver tumor.Results: The median follow-up time was 475.5 days in patients with HCC and 212.5 days with metastatic liver tumor. The 2-year local control rate (LCR) for HCC and metastatic liver tumor was 74.8% ± 6.3% and 64.2 ± 9.5% (p = 0.44). The LCR was not different between BED10 ≥ 100 Gy and < 100 Gy (p = 0.61). The LCR was significantly different between maximum tumor diameter > 30 mm vs. ≤ 30 mm (64% vs. 85%, p = 0.040) in all 130 patients. No grade 3 laboratory toxicities in the acute, sub-acute and chronic phases were observed.Conclusions: There was no difference in local control after SBRT in the range of median BED10 around 100 Gy for between HCC and metastatic liver tumor. SBRT is safe and might be an alternative method to resection and ablation.Summary: There was no difference in local control after SBRT in the range of median BED10 around 100 Gy for between HCC and metastatic liver tumor and SBRT is safe and might be an alternative method to resection and ablation. [ABSTRACT FROM AUTHOR]

Background and Purpose: The aim of this retrospective study was to compare volumetric-modulated arc therapy using simultaneous integrated boosts (SIB-VMAT) of 45 Gy/55 Gy in 25 fractions with three-dimensional conformal radiotherapy (3D-CRT) in preoperative chemoradiation for rectal cancers., Methods and Materials: In the propensity score-matching analysis of 1:2, we selected 60 patients from the SIB-VMAT group and 120patients from the 3D-CRT group matched pairings out of 145 patients between 2005 and 2015. The regimen of concurrent combined chemotherapy was oral uracil/tegafur plus leucovorin with/without irinotecan., Results: There were no significant differences between the two groups, in pathological complete response rates (pCR) (11% in the 3D-CRT group vs. 17% in the SIB-VMAT group, P = 0.39), pathological response rates (44% vs. 60%, P = 0.77), disease-free survival (P = 0.32), or local control (P = 0.52). The SIB-VMAT method marginally improved the rate of pathological grade 2-3 effects and the OS was significantly better in patients with grade 2-3 effects. Recurrence was seen in 36 patients (30%) in the 3D-CRT group and 19 patients (32%) in the SIB-VMAT group. The first distant recurrence site in the SIB-VMAT group was liver in 6 patients and lung in 8 patients. The obvious radiation-induced late toxicity in the SIB-VMAT group was recto-vesical fistula in two patients., Conclusions: The SIB-VMAT may be a promising method for preoperative CRT of rectal cancer.

Purpose: The purpose of this study is to introduce the new concept of a four-dimensional (4D) cone-beam computed tomography (CBCT) reconstruction approach for non-periodic organ motion in cooperation with the time-ordered chain graph model (TCGM) and to compare it with previously developed methods such as total variation-based compressed sensing (TVCS) and prior-image constrained compressed sensing (PICCS)., Materials and Methods: Our proposed reconstruction is based on a model including the constraint originating from the images of neighboring time phases. Namely, the reconstructed time-series images depend on each other in this TCGM scheme, and the time-ordered images are concurrently reconstructed in the iterative reconstruction approach. In this study, iterative reconstruction with the TCGM was carried out with 90° projection ranges. The images reconstructed by the TCGM were compared with the images reconstructed by TVCS (200° projection ranges) and PICCS (90° projection ranges). Two kinds of projection data sets-an elliptic-cylindrical digital phantom and two clinical patients' data-were used. For the digital phantom, an air sphere was contained and virtually moved along the longitudinal axis by 3 cm/30 s and 3 cm/60 s; the temporal resolution was evaluated by measuring the penumbral width of the air sphere. The clinical feasibility of the non-periodic time-ordered 4D CBCT image reconstruction was examined with the patient data in the pelvic region., Results: In the evaluation of the digital-phantom reconstruction, the penumbral widths of the TCGM yielded the narrowest result; the results obtained by PICCS and TCGM using 90° projection ranges were 2.8% and 18.2% for 3 cm/30 s, and 5.0% and 23.1% for 3 cm/60 s narrower than that of TVCS using 200° projection ranges. This suggests that the TCGM has a better temporal resolution, whereas PICCS seems similar to TVCS. These reconstruction methods were also compared using patients' projection data sets. Although all three reconstruction results showed motion related to rectal gas or stool, the result obtained by the TCGM was visibly clearer with less blurring., Conclusion: The TCGM is a feasible approach to visualize non-periodic organ motion. The digital-phantom results demonstrated that the proposed method provides 4D image series with a better temporal resolution compared to TVCS and PICCS. The clinical patients' results also showed that the present method enables us to visualize motion related to rectal gas and flatus in the rectum.

Background: The optimal timing of salvage radiotherapy for biochemical recurrence after radical prostatectomy is controversial. In particular, the prognostic significance of salvage radiotherapy delivered before a current definition of biochemical recurrence, i.e. ultra-early salvage radiotherapy, is unclear., Methods: We reviewed 76 patients with pT2-3N0M0 prostate cancer who underwent salvage radiotherapy for post-prostatectomy biochemical recurrence at the following three timings: ultra-early salvage radiotherapy (n = 20) delivered before meeting a current definition of biochemical recurrence (two consecutive prostate-specific antigen [PSA] values ≥0.2 ng/mL); early salvage radiotherapy (n = 40) delivered after meeting the definition but before PSA reached 0.5 ng/mL; and delayed salvage radiotherapy (n = 16) delivered after PSA reached 0.5 ng/mL. The primary endpoint was failure of salvage radiotherapy, defined as a PSA value ≥0.2 ng/mL. The log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively., Results: During the follow-up period (median: 70 months), four of 20 (20 %), nine of 40 (23 %) and seven of 16 (44 %) patients failed biochemically in the ultra-early, early and delayed salvage radiotherapy groups, respectively. On univariate analyses, the outcome of delayed salvage radiotherapy was worse than the others, while there was no significant difference between ultra-early and early groups. Multivariate analysis demonstrated the presence of Gleason pattern 5, perineural invasion and delayed salvage radiotherapy as independent predictors of poorer survival., Conclusions: No survival benefit of ultra-early salvage radiotherapy was demonstrated, whereas delayed salvage radiotherapy was associated with worse outcome as reported in previous studies. Our results may support the current recommendations that salvage radiotherapy should be undertaken after two consecutive PSA values ≥0.2 ng/mL and before reaching 0.5 ng/mL.

Background: Standard chemoradiotherapy (CRT) using cisplatin (CDDP) and 5-fluorouracil (5-FU) is an optional treatment for patients with stage II-III esophageal cancer. However, there are some demerits in this regimen because CDDP administration requires a large transfusion volume and 5-FU must be continuously infused over 24 h. Therefore, hospitalization is unavoidable. We collected retrospectively the data of definitive CRT with nedaplatin and S-1 as carried out in our institution., Methods: Patients with early and advanced esophageal cancer and relapsed esophageal cancer after radical surgery were included. Nedaplatin 80 mg/m(2) was given on days 1 and 29, and S-1 80 mg/m(2) on days 1-14 and 29-42. No prophylactic treatment with granulocyte colony stimulating factor was administered. Patients received two courses of concurrent radiotherapy of more than 50 Gy with or without two additional courses as adjuvant therapy every 4 weeks., Results: Between August 2011 and June 2015, 89 patients (age range, 44-86 years; K-PS 90-100, 81 %; squamous cell carcinoma histology, 97 %; definitive/salvage CRT, 75/25 %) were collected. Twenty-one (24 %) patients completed four cycles, and 94 % received two or more cycles. Grade 4 leukopenia, thrombocytopenia, and anemia occurred in 12, 7, and 10 % of the patients, respectively. Five patients developed febrile neutropenia. Grade 3 non-hematological toxicity included infection in 12 %, mucositis/esophagitis in 3 %, kidney in 3 %, and fatigue in 3 %. Sixty-four patients (72 %) received the prescribed full dose and full cycles of chemotherapy. A complete response was achieved in 76 patients (85 %). The 3-year overall survival rate was 54.4 % in definitive CRT and 39.8 % in salvage CRT, respectively. Sixty-two subjects (70 %) received treatment as outpatients., Conclusions: Nedaplatin and S-1 in combination with radiotherapy is feasible, and toxicity is tolerable. This treatment method has the potential to shorten hospitalization without impairing the efficacy of CRT.

Background: This retrospective study on early and locally advanced esophageal cancer was conducted to evaluate locoregional failure and its impact on survival by comparing involved field radiotherapy (IFRT) with elective nodal irradiation (ENI) in combination with concurrent chemotherapy., Methods: We assessed all patients with esophageal cancer of stages I-IV treated with definitive radiotherapy from June 2000 to March 2014. Between 2000 and 2011, ENI was used for all cases excluding high age cases. After Feb 2011, a prospective study about IFRT was started, and therefore IFRT was used since then for all cases. Concurrent chemotherapy regimen was nedaplatin (80 mg/m(2) at D1 and D29) and 5-fluorouracil (800 mg/m(2) at D1-4 and D29-32)., Results: Of the 239 consecutive patients assessed (120 ENI vs. 119 IFRT), 59 patients (24.7%) had stage IV disease and all patients received at least one cycle of chemotherapy. The median follow-up time for survivors was 34.0 months. There were differences in 3-year local control (44.8% vs. 55.5%, p = 0.039), distant control (53.8% vs. 69.9%, p = 0.021) and overall survival (34.8% vs. 51.6%, p = 0.087) rates between ENI vs. IFRT, respectively. Patients treated with IFRT (8 %) demonstrated a significantly lower risk (p = 0.047) of high grade late toxicities than with ENI (16%). IFRT did not increase the risk of initially uninvolved or isolated nodal failures (27.5% in ENI and 13.4% in IFRT)., Conclusions: Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients. Both tendencies of improved loco-regional progression-free survival and a significant increased overall survival rate favored the IFRT arm over the ENI arm in this study.

Introduction: Spontaneous regression of cancer is thought to be a rare event. Here, we report an extremely rare case of repeated episodes of spontaneous regression and progression of recurrent cervical adenocarcinoma., Case Presentation: We report here a case of a 56-year-old Japanese woman who was diagnosed with cervical adenocarcinoma. Her hilar and mediastinal lymph nodes were swollen 6 years after the initial diagnosis and subsequent treatment, and were found to be pathologically malignant by mediastinal biopsy. Then, without any treatment, the hilar and mediastinal lymph nodes spontaneously regressed with decreases in tumor size and serum tumor marker levels, as confirmed by a decrease in uptake of fluorodeoxyglucose during positron emission tomography-computed tomography. Subsequently, although there were repeated episodes of increase and decrease in her serum tumor marker levels and lymph node size, her activities of daily living were and are well preserved., Conclusions: While spontaneous regression of a malignant tumor is a rare event, our case is even rarer in that repeated episodes of spontaneous regression/progression of cervical adenocarcinoma occurred.

Background: The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC) calculations, in actual computed tomography (CT) scans for use in stereotactic radiotherapy (SRT) of small lung cancers., Methods: Slow CT scan of 20 patients was performed and the internal target volume (ITV) was delineated on Pinnacle3. All plans were first calculated with a scatter homogeneous mode (SHM) which is compatible with Clarkson algorithm using Pinnacle3 treatment planning system (TPS). The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs). Collapsed cone convolution (CCC) from Pinnacle3, superposition (SP) from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs) were compared with each other., Results: The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC) doses and the minimal dose received by 95% of the PTV (PTV95) compared to XVMC. The differences in mean doses were 2.96 Gy (6.17%) for IC and 5.02 Gy (11.18%) for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17), and -2.67% (p = 0.0036), respectively., Conclusions: Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.