Assessing alimentary tract radiation in liver cancer treatment with proton beam therapy: a PET/CT imaging study.

BACKGROUND: Proton beams deposit energy along their path, abruptly stopping and generating various radioactive particles, including positrons, along their trajectory. In comparison with traditional proton beam therapy, scanning proton beam therapy is effective in delivering proton beams to irregularly shaped tumors, reducing excessive radiation exposure to the alimentary tract during the treatment of liver cancer. METHODS: In this study, we utilized positron emission tomography/computed tomography (PET/CT) imaging to assess the total amount of radiation to the alimentary tract during liver cancer treatment with proton beam therapy, involving the administration of complex irradiation in 13 patients. RESULTS: This approach resulted in the prevention of excess radiation. The planned radiation restraint doses for the colon exhibited a significant correlation with the PET values of the colon (correlation coefficient 0.8384, P = .0003). Likewise, the scheduled radiation restraint doses for the gastroduodenum were correlated with the PET values of the gastroduodenum (correlation coefficient 0.5397, P = .0569). CONCLUSIONS: PET/CT conducted after proton beam therapy is useful for evaluating excess radiation in the alimentary tract. Proton beam therapy in liver cancer, assessed via PET/CT, effectively reduced alimentary tract radiation, which is vital for optimizing treatments and preventing excess exposure.

Salvage radiation therapy for prostate cancer patients after prostatectomy.

OBJECTIVES: The aim of this study was to identify risk factors to predict a biochemical recurrence (BCR) in patients treated with salvage radiation therapy (SRT) after radical prostatectomy (RP). METHODS: We retrospectively reviewed 122 Japanese patients who received SRT for BCR after RP. Using uni- and multivariate Cox proportional hazard models, we identified the predictive factors of BCR after SRT. RESULTS: With a median follow-up of 61.3 months, 45.9% of the patients showed BCR after SRT, with 61.5 and 41.8% of non-BCR rates at the second and fifth years. Univariate proportional hazards analysis demonstrated that extraprostatic disease (P = 0.029), seminal vesicle invasion (P = 0.005), microvascular invasion (P = 0.001), postoperative Gleason score (P = 0.008) and pre-SRT prostate-specific antigen (PSA) (P = 0.005) were significantly associated with BCR after SRT. However, only the presence of microvascular invasion and a higher pre-SRT PSA were significant predictors in the multivariate analysis. The non-BCR rate in the second year after SRT for 15 patients with microvascular invasion and pre-SRT PSA > 1.2 ng/ml was only 21% compared to 72.5% of 72 patients with negative microvascular invasion and a pre-SRT PSA of <1.2 ng/ml (P = 0.000031). CONCLUSIONS: While SRT is the most important secondary treatment option for patients with BCR after RP, the effectiveness of SRT may not be uniform. The combination of risk factors such as microvascular invasion in RP specimens and pre-SRT PSA may provide a better way to stratify the risk of BCR after SRT.

Prediction of high-stage liver fibrosis using ADC value on diffusion-weighted imaging and quantitative enhancement ratio at the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI at 1.5 T.

Background Recently, diffusion-weighted imaging (DWI) and quantitative enhancement ratio measured at the hepatobiliary phase (HBP) of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) has been established as an effective method for evaluating liver fibrosis. Purpose To evaluate which is a more favorable surrogate marker in predicting high-stage liver fibrosis, apparently diffusion coefficient (ADC) value or quantitative enhancement ratio measured on HBP. Material and Methods Eighty-three patients with 99 surgically resected hepatic lesions were enrolled in this study. DWI was performed with b-values of 100 and 800 s/mm2. Regions of interest were set on ADC map, and the HBP of Gd-EOB-DTPA-enhanced MRI, to calculate ADC value, liver-to-muscle ratio (LMR), liver-to-spleen ratio (LSR), and contrast enhancement index (CEI) of liver. We compared these parameters between low-stage fibrosis (F0, F1, and F2) and high-stage fibrosis (F3 and F4). Receiver operating characteristic analysis was performed to compare the diagnostic performance when distinguishing low-stage fibrosis from high-stage fibrosis. Results LMR and CEI were significantly lower at high-stage fibrosis than at the low stage ( P < 0.01 and P = 0.04, respectively), whereas LSR did not show a significant difference ( P = 0.053). No significant difference was observed in diagnostic performance between LMR and CEI ( P = 0.185). The best sensitivity and specificity, when an LMR of 2.80 or higher was considered to be low-stage fibrosis, were 82.4% and 75.6%, respectively. ADC value showed no significant differences among fibrosis grades ( P = 0.320). Conclusion LMR and CEI were both adequate surrogate parameters to distinguish high-stage fibrosis from low-stage fibrosis.

Salvage Embolization and Histologic Analysis of Gastric Cancer with Hemorrhagic Shock Using Spherical Embolic Material.

BACKGROUND: In a recent study, it was reported that transcatheter arterial embolization with spherical embolic material for life-threatening hemorrhages in various cancer patients was safe and effective. Calibrated microspheres are able to access distal regions of the target arteries, which results in the disappearance of tumor staining. However, there are few reports on the pathological behavior of EmboSpheres in gastric cancer specimens. In this case, we succeeded in salvage embolization for advanced gastric cancer with hemorrhagic shock using spherical embolic material. To our knowledge, this is the first report of a pathological evaluation of spherical embolic microspheres in a gastric cancer specimen. CASE REPORT: A 70-year-old man with scirrhous gastric cancer was admitted to our hospital for staging laparoscopy. Unfortunately, he had a sudden onset of hematemesis and melena leading to hemorrhagic shock due to bleeding from the gastric cancer. While undergoing a rapid blood transfusion, he underwent emergent embolization to achieve hemostasis. The left gastric and right gastroepiploic arteries were embolized with spherical embolic material, and the patient survived. Two days later, the patient was able to undergo gastrectomy. A large number of microspheres were observed in areas of hemorrhage. The range and median diameter of the minor axis were 177-1048 µm and 281 µm, respectively. CONCLUSIONS: Transcatheter arterial embolization using spherical embolic material could become one of safe and effective options, especially when there is no extravasation or pseudoaneurysm but only tumor staining from the clinical and pathological point of view.

Sarcopenia as a Novel Preoperative Prognostic Predictor for Survival in Patients with Bladder Cancer Undergoing Radical Cystectomy.

PURPOSE: To investigate the prognostic significance of sarcopenia on long-term outcomes in patients with bladder cancer after radical cystectomy (RC). METHODS: We retrospectively reviewed 136 patients undergoing RC for urothelial carcinoma at our institution. Prognostic impact of the preoperative clinical, laboratory, and radiologic parameters were evaluated by Cox proportional hazard model analyses, and a nomogram was developed to predict cancer-specific survival (CSS) after RC. RESULTS: The mean follow-up was 46.7 months. Patients with sarcopenia had a significantly shorter CSS than those without sarcopenia. On univariate Cox analysis, clinical T stage, histology of transurethral resection of bladder tumor (TURBT) specimen, pretreatment hemoglobin, pretreatment neutrophil-to-lymphocyte ratio (NLR), pretreatment serum C-reactive protein level, pretreatment serum albumin level, presence of hydronephrosis, and presence of sarcopenia were associated with significantly worse CSS. On multivariate Cox stepwise analysis, sarcopenia (hazard rate [HR] = 2.3, p = 0.015), clinical T stage (cT4: HR = 5.3; p = 0.0096), presence of hydronephrosis (HR = 2.0; p = 0.033), histology of TURBT specimen (HR = 2.2, p = 0.044), and NLR (HR = 1.3; p = 0.0048) were significant independent predictors of an unfavorable prognosis Based on the results of the multivariate analysis, we developed a nomogram to predict 1-, 3-, and 5-year CSS after RC. CONCLUSIONS: Sarcopenia, clinical T stage, presence of hydronephrosis, histology of TURBT specimen, and NLR are novel preoperative prognostic factors even after adjustment for other known preoperative predictors in patients undergoing RC for bladder cancer.

Is scintigraphy necessary to detect migration of 125I seeds after brachytherapy for early prostate cancer?

BACKGROUND: We investigated whether scintigraphy was superior to radiography for detecting migrated seeds after brachytherapy for prostate cancer. METHODS: We studied 57 patients with early prostate cancer who were treated with free (125)I transperineal brachytherapy. Scintigraphy was used to detect seed migration on postoperative day (POD) 1, radiography was used on POD 2, and both tests were used on POD 30. RESULTS: The total number of implanted seeds in this study was 3,753 in 57 patients. Overall, there were 19 seed migrations in 12 patients. On POD 1, there were 4 seed migrations in 4 patients that were detected by scintigraphy. On POD 2, there were 10 seed migrations in 9 patients that were detected by radiography. On POD 30, 17 seed migrations were detected in 10 patients by radiography and 18 seeds migrations were detected by scintigraphy. However, 1 seed migration which was located outside of the detectable range of radiography was detected only by scintigraphy. CONCLUSIONS: Both scintigraphy and radiography have similar abilities to detect migrated seeds 1 month after (125)I brachytherapy for prostate cancer. While both tests have advantages and disadvantages, it is reasonable to only use radiography if scintigraphy is not available.

Significance of CD4+ T-cell count in the management of appendicitis in patients with HIV.

SUMMARY: Identification of complicated appendicitis (CA) is critical to the management of appendicitis. However, previous studies have not investigated indicators of CA among patients with HIV or whether it is safe to use conservative treatment for appendicitis in these patients. Among 322 patients with appendicitis, we identified 14 who had HIV. Six of them were operated and 8 were treated with antibiotics; CA was diagnosed in 4. Patients with HIV and CA had a significantly lower CD4+ T-cell count than those with uncomplicated appendicitis. A white blood cell count lower than 7.4 × 10(9)/L was observed exclusively in patients with CA. No patient with HIV whose appendicitis was treated conservatively died or experienced a recurrence. We discuss our findings, which suggest the possibility of conservative treatment of appendicitis in patients with HIV and identification of CA by low CD4+ T-cell count.

Measuring hepatic functional reserve using low temporal resolution Gd-EOB-DTPA dynamic contrast-enhanced MRI: a preliminary study comparing galactosyl human serum albumin scintigraphy with indocyanine green retention.

OBJECTIVE: To investigate if tracer kinetic modelling of low temporal resolution dynamic contrast-enhanced (DCE) MRI with Gd-EOB-DTPA could replace technetium-99 m galactosyl human serum albumin (GSA) single positron emission computed tomography (SPECT) and indocyanine green (ICG) retention for the measurement of liver functional reserve. METHODS: Twenty eight patients awaiting liver resection for various cancers were included in this retrospective study that was approved by the institutional review board. The Gd-EOB-DTPA MRI sequence acquired five images: unenhanced, double arterial phase, portal phase, and 4 min after injection. Intracellular contrast uptake rate (UR) and extracellular volume (Ve) were calculated from DCE-MRI, along with the ratio of GSA radioactivity of liver to heart-plus-liver and per cent of cumulative uptake from 15-16 min (LHL15 and LU15, respectively) from GSA-scintigraphy. ICG retention at 15 min, Child-Pugh cirrhosis score (CPS) and postoperative Inuyama fibrosis criteria were also recorded. Statistical analysis was with Spearman rank correlation analysis. RESULTS: Comparing MRI parameters with the reference methods, significant correlations were obtained for UR and LHL15, LU15, ICG15 (all 0.4-0.6, P < 0.05); UR and CPS (-0.64, P < 0.001); Ve and Inuyama (0.44, P < 0.05). CONCLUSION: Measures of liver function obtained by routine Gd-EOB-DTPA DCE-MRI with tracer kinetic modelling may provide a suitable method for the evaluation of liver functional reserve. KEY POINTS: • Magnetic resonance imaging (MRI) provides new methods of measuring hepatic functional reserve. • DCE-MRI with Gd-EOB-DTPA offers the possibility of replacing scintigraphy. • The analysis method can be used for preoperative liver function evaluation.

Post-therapeutic needle biopsy in patients with hepatocellular carcinoma is a useful tool to evaluate response to proton irradiation.

AIM: Proton beam therapy is safe and more effective than conventional radiation therapy for the local control of nodular hepatocellular carcinoma (HCC). However, evaluating therapeutic response by imaging is not accurate during the early post-irradiation period. Therefore, we examined whether the histopathological study of biopsy specimens obtained at 3 weeks after irradiation can be used to more accurately assess therapeutic response. METHODS: Fifteen HCC lesions from 13 patients were treated with proton beam irradiation. Tissue biopsy samples were obtained using abdominal ultrasound-guided percutaneous fine-needle aspiration from the center of the tumor before, 3 weeks after and 1 year post-proton therapy. The specimens were examined after staining with hematoxylin-eosin (HE) and a MIB-1 antibody. RESULTS: MIB-1 labeling indices (LI) before treatment were 13.0 ± 8.5% (mean ± SD; range, 0.6-27.0), whereas those 3 weeks after proton therapy were significantly reduced to 3.2 ± 2.4% (range, 0.6-8.9) (P < 0.05). Although the tumor size was reduced, we did not observe a reduction in tumor blood flow by dynamic computed tomography or degenerative changes by HE. All lesions that displayed reduced MIB-1 LI at 3 weeks post-proton treatment were ultimately diagnosed as complete response at 1 year after treatment. In contrast, one case with increased MIB-1 LI at 3 weeks had significant tumor size progression at 1 year post-treatment. CONCLUSION: The percutaneous fine-needle aspiration biopsy of HCC is a safe and useful tool that can be used to evaluate the response to proton irradiation. In particular, MIB-1 LI may provide additional information to assess the therapeutic response of HCC during the early post-irradiated period.

Proton-beam Therapy for Locally Advanced Hepatocellular Carcinoma With Inferior Vena Cava Tumor Thrombus: Case Report.

BACKGROUND/AIM: We report on a case of locally advanced hepatocellular carcinoma (HCC) accompanied by an inferior vena cava tumor thrombus (IVCTT), treated successfully with proton-beam therapy (PBT). CASE REPORT: A 63-year-old male presented with a primary, single HCC with IVCTT, without metastasis to the intrahepatic region, lymph nodes, or distant organs. The clinical staging was identified as T4N0M0 Stage IIIB. The patient's liver function was classified as Child-Pugh class A (score: 6), with a modified albumin-bilirubin (mALBI) grade of 2a. The patient had liver cirrhosis due to non-alcoholic steatohepatitis. Magnetic resonance imaging revealed a nodular tumor measuring 13.2×8.9×9.8 cm across segments 1, 6, 7, and 8, along with IVCTT. The patient received PBT, with a total dose of 72.6 Gy (relative biological effectiveness) delivered in 22 fractions. Throughout the PBT treatment, the patient experienced no acute toxicities and completed the therapy as planned. Twelve months following PBT, the patient was alive without evidence of local recurrence, lymph node involvement, or distant organ metastasis. The only late toxicity observed was a mild worsening of the mALBI grade. CONCLUSION: We observed a favorable local response with manageable toxicities in a patient with locally advanced HCC and IVCTT treated with PBT. While this is a single case report, our findings suggest that PBT could be considered a viable treatment option for HCC with IVCTT.

Assessing liver function using dynamic Gd-EOB-DTPA-enhanced MRI with a standard 5-phase imaging protocol.

PURPOSE: To evaluate liver function obtained by tracer-kinetic modeling of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data acquired with a routine gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced protocol. MATERIALS AND METHODS: Data were acquired from 25 cases of nonchronic liver disease and 94 cases of cirrhosis. DCE-MRI was performed with a dose of 0.025 mmol/kg Gd-EOB-DTPA injected at 2 mL/sec. A 3D breath-hold sequence acquired 5 volumes of 72 slices each: precontrast, double arterial phase, portal phase, and 4-minute postcontrast. Regions of interest (ROIs) were selected semiautomatically in the aorta, portal vein, and whole liver on a middle slice. A constrained dual-inlet two-compartment uptake model was fitted to the ROI curves, producing three parameters: intracellular uptake rate (UR), extracellular volume (Ve), and arterial flow fraction (AFF). RESULTS: Median UR dropped from 4.46 10(-2) min(-1) in the noncirrhosis to 3.20 in Child-Pugh A (P = 0.001), and again to 1.92 in Child-Pugh B (P < 0.0001). Median Ve dropped from 6.64 mL 100 mL(-1) in the noncirrhosis to 5.80 in Child-Pugh A (P = 0.01). Other combinations of Ve and AFF changes were not significant for any group. CONCLUSION: UR obtained from tracer kinetic analysis of a routine DCE-MRI has the potential to become a novel index of liver function.

Comparison of myocardial perfusion imaging between the new high-speed gamma camera and the standard anger camera.

BACKGROUND: Cadmium-zinc-telluride (CZT) solid-state detectors have been recently introduced into the field of myocardial perfusion imaging. The aim of this study was to prospectively compare the diagnostic performance of the CZT high-speed gamma camera (Discovery NM 530c) with that of the standard 3-head gamma camera in the same group of patients. METHODS AND RESULTS: The study group consisted of 150 consecutive patients who underwent a 1-day stress-rest (99m)Tc-sestamibi or tetrofosmin imaging protocol. Image acquisition was performed first on a standard gamma camera with a 15-min scan time each for stress and for rest. All scans were immediately repeated on a CZT camera with a 5-min scan time for stress and a 3-min scan time for rest, using list mode. The correlations between the CZT camera and the standard camera for perfusion and function analyses were strong within narrow Bland-Altman limits of agreement. Using list mode analysis, image quality for stress was rated as good or excellent in 97% of the 3-min scans, and in 100% of the ≥4-min scans. For CZT scans at rest, similarly, image quality was rated as good or excellent in 94% of the 1-min scans, and in 100% of the ≥2-min scans. CONCLUSIONS: The novel CZT camera provides excellent image quality, which is equivalent to standard myocardial single-photon emission computed tomography, despite a short scan time of less than half of the standard time.

Salivary metabolites as novel independent predictors of radiation pneumonitis.

PURPOSE: Radiotherapy is an integral treatment for non-small cell lung cancer (NSCLC); however, radiation-induced toxicities such as radiation pneumonitis (RP) present a considerable challenge. Herein, we aimed to evaluate the potential of salivary metabolomics as an independent risk factor for predicting RP. METHODS: This study included 62 consecutive patients with NSCLC who underwent thoracic radiotherapy at Tokyo Medical University between September 2016 and December 2018. The median age of the patients was 75 years (range: 41-89), comprising 47 (75.8%) males and 15 (24.2%) females. Patients with stage I NSCLC received 75 Gy in 30 fractions, whereas those with stage II and III NSCLC received 66 Gy in 33 fractions. Saliva samples were collected before treatment and at 2 weeks, 1 month, 3 months, and 1 year after initiating radiotherapy. Clinical RP was defined as grade 2 according to the Common Toxicity Criteria for Adverse Events. Salivary metabolomics were analyzed using capillary electrophoresis-mass spectrometry. Salivary metabolites were evaluated as potential predictors of RP. RESULTS: Clinical RP was observed in 11 patients (17.7%); no RP-related deaths were observed. Clinical RP developed at a median of 4 months (range: 2-6 months) after initiating radiotherapy. Three metabolites, butyrate, propionate, and hexanoate, collected before radiotherapy exhibited predictive ability for clinical RP. Multivariate logistic analysis indicated butyrate (P = 0.033) as a predictive factor, along with the previously known factor of lung volume irradiated with > 20 Gy (P = 0.045). CONCLUSION: Salivary metabolite butyrate was an independent risk factor for clinical RP.

Predicting risk factors for hypothyroidism after definitive radiotherapy for early glottic carcinomas.

Hypothyroidism may occur after definitive radiotherapy in rare cases of early glottic carcinoma. However, to the best of our knowledge, no study to date has examined the risk factors for hypothyroidism specifically after definitive radiotherapy in patients with early glottic carcinoma. The present study determined risk factors for hypothyroidism after definitive radiotherapy in patients with early glottic carcinoma. This was a retrospective study that included 73 patients with T1 or T2, N0 glottic squamous cell carcinoma who underwent radiotherapy between June 3, 2009 and December 25, 2020. Demographic and clinical characteristics, including age, sex, tumor stage and pretreatment thyroid volume, were examined to elucidate the clinical risk factors for hypothyroidism. Field size, total prescribed dose and thyroid receiving dose were evaluated as dosimetric risk factors for hypothyroidism. Irradiated underlying thyroid volumes of more than 5, 10, 20, 30, 40, 50, 60 and 65 Gy (V5Gy, V10Gy, V20Gy, V30Gy, V40Gy, V50Gy, V60Gy and V65Gy) and mean thyroid dose were included as thyroid receiving doses. The median follow-up duration was 61 months (range, 7-150 months). Hypothyroidism was present in 15 (21%) of the 73 patients, including 12 and 3 patients with grade 1 and 2 hypothyroidism, respectively. Among the demographic and clinical factors, sex and pretreatment thyroid volume were significantly associated with hypothyroidism (P=0.007 and P<0.001, respectively). Among the dosimetric factors, the presence of hypothyroidism was significantly associated with V5Gy (P=0.012), V10Gy (P=0.015), V20Gy (P=0.020), V30Gy (P=0.024), V40Gy (P=0.028), V50Gy (P=0.028), V60Gy (P=0.027) and mean thyroid dose (P=0.023). In conclusion, sex, pretreatment thyroid volume and thyroid receiving dose were associated with hypothyroidism after definitive radiotherapy in patients with early glottic carcinoma. Particularly, the receiving dose to the thyroid gland should be reduced in female patients and in those with small thyroid volumes who are at higher risk for hypothyroidism following radiotherapy.

Relative Biological Effectiveness Values of Spot-scanning Proton Beam Therapy at Shonan Kamakura General Hospital.

BACKGROUND/AIM: This study aimed to confirm the relative biological effectiveness (RBE) values of the proton beam therapy (PBT) system installed in Shonan Kamakura General Hospital. MATERIALS AND METHODS: Clonogenic cell-survival assays were performed with a human salivary gland (HSG) cell line, a human tongue squamous-cell carcinoma cell line (SAS), and a human osteosarcoma cell line (MG-63). Cells were irradiated with proton beams and X-rays with different doses (1.8, 3.6, 5.5, and 7.3 Gy for proton beams, and 2, 4, 6, and 8 Gy for X-rays). Proton beam irradiation used spot-scanning methods and three different depths (at the proximal, center, and distal sides of the spread-out Bragg peak). RBE values were obtained from a comparison of the dose that resulted in a surviving fraction of 10% (D10). RESULTS: D10 of proton beams at the proximal, center, and distal sides and X-rays in HSG were 4.71, 4.71, 4.51, and 5.25 Gy, respectively; those in SAS were 5.08, 5.04, 5.01, and 5.59 Gy, respectively; and those in MG-63 were 5.36, 5.42, 5.12, and 6.06 Gy, respectively. The RBE10 values at the proximal, center, and distal sides in HSG were 1.11, 1.11, and 1.16 respectively; those in SAS were 1.10, 1.11, and 1.12, respectively; and those in MG-63 were 1.13, 1.12, and 1.18, respectively. CONCLUSION: RBE10 values of 1.10-1.18 were confirmed by in vitro experiments using the PBT system. These results are considered acceptable for clinical use in terms of therapeutic efficacy and safety.

Mathematical evaluation of post-radiotherapy salivary gland function using salivary gland scintigraphy.

OBJECTIVE: Xerostomia is the most common treatment-related toxicity after radiotherapy (RT) for head and neck carcinoma, reducing the quality of life of patients due to a decrease in salivary gland function. METHODS: Salivary gland scintigraphy was performed to quantitatively evaluate the salivary gland functions in patients undergoing RT. It was done chronologically for 62 salivary glands of 31 patients before RT and retested 12 months later. RESULTS: The salivary gland functions of most patients deteriorated post-RT and recovered when the radiation dose to the salivary gland was not high. The mean dose to the salivary gland was found to be the most reliable factor in deteriorating salivary gland function, and the tolerance dose was determined to be 46 Gy. The recovery rate of salivary gland function after 1 year of RT was 72% in the RT alone group (n = 10), 56% in the conformal radiotherapy group (n = 15), and 44% in the bioradiotherapy group (n = 6). CONCLUSION: Scintigraphy revealed that the salivary glands recovered from post-RT hypofunction when decreased doses were administered. The determined tolerance dose of 46 Gy may guide the approach to minimizing associated xerostomia in RT. ADVANCES IN KNOWLEDGE: In this study, the average tolerated dose to the salivary glands was 46 Gy.

Predicting factors for primary cervical cancer recurrence after definitive radiation therapy.

OBJECTIVES: The study aimed to retrospectively investigate the apparent diffusion coefficient (ADC) of primary cervical cancer to examine the recurrence correlations in patients treated with radiotherapy (RT). METHODS: The ADC of 31 patients with cervical cancer treated with RT were analyzed as possible risk factors for recurrence. A receiver operating characteristic (ROC) curve of the mean ADC (ADCmean) for the recurrence was generated to determine the cut-off value that yielded optimal sensitivity and specificity. The patient population was subdivided according to the risk factors for recurrence, and the disease-free survival (DFS) was analyzed. The following were investigated to explore the risk factors for recurrence: age, performance status, stage, pelvic lymph node metastasis, histologic tumor grade, maximal diameter of the primary tumor, chemotherapy, and ADCmean. RESULTS: The median follow-up duration of the patients was 25 months. The recurrence was recognized in 9 (29%) of the 31 cases. The ROC analysis of recurrence showed that the area under the ADCmean curve was 0.889 (95% CI, 0.771-1.000; p = 0.001). The cut-off value of ADC mean was 0.900 × 10- 3 mm2/s, with a sensitivity of 86.4% and a specificity of 88.9%. By univariate analysis, the ADCmean was the only factor significantly associated with recurrence. CONCLUSION: The ADCmean of the primary tumor is a potential predictive factor for the recurrence in of cervical cancer. ADVANCES IN KNOWLEDGE: The ADCmean of the primary tumor is a predictor of recurrence in patients with pre-treatment cervical cancer evaluation.

Clinical results of proton-beam therapy for locoregionally advanced esophageal cancer.

PURPOSE: To evaluate the efficacy and safety of proton-beam therapy for locoregionally advanced esophageal cancer. PATIENTS AND METHODS: The subjects were 51 patients with esophageal cancer who were treated between 1985 and 2005 using proton beams with or without X-rays. All but one had squamous cell carcinoma. Of the 51 patients, 33 received combinations of X-rays (median 46 Gy) and protons (median 36 GyE) as a boost. The median total dose of combined X-rays and proton radiation for these 33 patients was 80 GyE (range 70-90 GyE). The other 18 patients received proton-beam therapy alone (median 79 GyE, range 62-98 GyE). RESULTS: Treatment interruption due to radiation-induced esophagitis or hematologic toxicity was not required for any patient. The overall 5-year actuarial survival rate for the 51 patients was 21.1% and the median survival time was 20.5 months (95% confidence interval 10.9-30.2). Of the 51 patients, 40 (78%) showed a complete response within 4 months after completing treatment and seven (14%) showed a partial response, giving a response rate of 92% (47/51). The 5-year local control rate for all 51 patients was 38.0% and the median local control time was 25.5 months (95% confidence interval 14.6-36.3). CONCLUSION: The results suggest that proton-beam therapy is an effective treatment for patients with locally advanced esophageal cancer. Further studies are required to determine the optimal total dose, fractionation schedules, and best combination of proton therapy with chemotherapy.

Technical considerations for noncoplanar proton-beam therapy of patients with tumors proximal to the optic nerve.

PURPOSE: To investigate technical feasibilities of noncoplanar proton-beam therapy (PBT) on dose reduction to critical organs. MATERIAL AND METHODS: The degree of mechanical precision, rotational limitations of the gantry and the treatment couch were evaluated, and dose-volume histograms were compared for noncoplanar and coplanar PBT. Following these studies, three patients with tumors proximal to the optic nerve underwent noncoplanar PBT. RESULTS: Noncoplanar PBT offered advantage in dose reduction to the optic nerve when compared to coplanar therapy. This advantage was more significant if the tumor reduced in size during treatment. None experienced radiation injury to the optic nerve during a short follow-up time of 7-12 months. CONCLUSION: Noncoplanar PBT appears to reduce doses to organs at risk.

Effect of Gd-EOB-DTPA on T2-weighted and diffusion-weighted images for the diagnosis of hepatocellular carcinoma.

PURPOSE: To evaluate the effect of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) for the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The phantom signal intensity was measured. We also evaluated 72 patients including 30 patients with HCC. T2WI and DWI were obtained before and then 4 and 20 min after injecting the contrast medium. The signal to noise ratio (SNR), contrast to noise ratio (CNR), and apparent diffusion coefficient (ADC) were calculated in the tumor and liver parenchyma. RESULTS: The phantom signal intensity increased on T2WI at a concentration of contrast medium less than 0.2 mmol/L but decreased when the concentration exceeded 0.4 mmol/L. SNR of the liver parenchyma on T2WI was significantly different between before and 4 min after injecting the contrast medium, while there were no significant differences between before and 4 and 20 min after injection. On T2WI, SNR, and CNR of HCC showed no significant differences at any time. SNR, CNR, and ADC of the liver parenchyma and tumor on DWI also showed no significant differences at any time. CONCLUSION: It is acceptable to perform T2WI and DWI after injection of Gd-EOB-DTPA for the diagnosis of HCC.