Shuichi Ono

Tunnel Position and Relationship to Postoperative Knee Laxity After Double-Bundle Anterior Cruciate Ligament Reconstruction With a Transtibial Technique

Background Several laboratory studies have pointed out a potential risk of femoral tunnel misplacement in anterior cruciate ligament reconstruction with a transtibial technique. The tunnel malposition away from the anatomic attachment may result in increased postoperative knee laxity in double-bundle reconstruction. Purpose This study was conducted to evaluate the femoral and tibial tunnel positions in transtibial double-bundle reconstruction, and to determine the relationship between the tunnel positions and the results of the postoperative knee laxity examinations. Study Design Case series; Level of evidence, 4. Methods Fifty-three of 71 patients who underwent transtibial double-bundle reconstruction from 2004 to 2005 were followed more than 24 months. The tunnel positions for the anteromedial and posterolateral grafts were measured using 3-dimensional computed tomography images applying the quadrant method. The postoperative knee laxity was examined with the KT-1000 arthrometer manual maximum test, anterior drawer test, and pivot-shift test. Results The deep-shallow position (parallel to Blumensaats line) and high-low position (perpendicular to Blumensaats line) of the femoral tunnels were 27.7% ± 5.6% from the most posterior condylar contour and 16.3% ± 5.2% from Blumensaats line for the anteromedial graft, and 35.5% ± 6.4% and 48.0% ± 5.4% for the posterolateral graft. The medial-lateral and anterior-posterior positions of the tibial tunnels were 46.1% ± 2.6% from the most medial contour and 36.5% ± 4.9% from the most anterior contour for the anteromedial graft, and 47.5% ± 3.1% and 51.6% ± 5.0% for the posterolateral graft. There was no statistical correlation between any parameters of the femoral or tibial tunnel position and the results of the knee laxity tests. Conclusion The femoral tunnels placed in transtibial double-bundle reconstruction were located appropriately in high-low and deep-shallow orientation, but had larger variability than the previously reported data of the anatomic femoral attachment. However, the variability of the femoral tunnel position was not so large as to result in graft insufficiency with increased postoperative knee laxity.

Incidental prostate 18F-FDG uptake without calcification indicates the possibility of prostate cancer

Incidental 18F-fluorodeoxyglucose (18F-FDG) uptake in the prostate is often experienced in clinical practice; however, it is difficult to determine whether incidental uptake is indicative of a malignancy or benign state based on the maximum standardized uptake value (SUVmax). In the present study, we investigated the clinical significance of incidental prostate uptake by 18F-FDG positron emission tomography (PET)/CT, and examined the differences between malignant and benign uptake from a clinicopathological viewpoint. We reviewed 3,236 male subjects who underwent 18F-FDG PET/CT scans at Hirosaki University Hospital (Japan) from 2008 to 2012 in order to identify cases of incidental prostate FDG uptake. The final diagnosis was made by serum prostate-specific antigen (PSA) levels, biopsy, imaging studies and clinical follow-up with PET findings. Incidental FDG uptake of the prostate was observed in 53 cases (2%). Four cases were excluded due to insufficient clinical data, and 49 cases were included in the present study. Of the 49 cases, 8 (16%) had prostate cancer, while 41 (84%) were benign. All 8 malignant cases had high uptake areas, e.g. in the prostate peripheral zone, where there was no coexistence of calcification or FDG uptake. Of the 41 benign cases, 19 had high uptake in the inner zone, 17 in the peripheral zone, and 5 in both the inner and peripheral zones. Of the 41 cases, 18 (44%) showed FDG uptake coexisting with prostatic calcification. Incidental prostate 18F-FDG uptake infrequently signifies prostate cancer; however, FDG uptake not coexisting with calcification indicates the possibility of prostate cancer and should be included in the differential diagnosis for performing other clinical examinations.

Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54-56 Gy given in 9-7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size

BackgroundRadiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor.MethodsDuring 2003–2008, 41 patients with 42 lung tumors were treated with SBRT to 54–56xa0Gy in 9–7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study.ResultsMedian follow-up time was 68xa0months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16–48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54xa0Gy were 47.7% and 12.9% (pu2009=u20090.0184), and for fraction size of 6, 7 and 8xa0Gy were 19.5%, 31.2% and 55.7% (pu2009=u20090.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10–55, age, sex, and planning target volume were not significantly different.ConclusionsThe doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures.

Incidence of unilateral distal vertebral artery aplasia: evaluation by combining basiparallel anatomic scanning-magnetic resonance imaging (BPAS-MRI) and magnetic resonance angiography

PurposeThe incidence of a unilateral aplastic distal vertebral artery (VA) has been reported as 0.2% of cases on cerebral angiography. During our daily magnetic resonance (MR) examinations, however, we frequently encounter MR angiograms (MRAs) that do not demonstrate unilateral VA. The purpose of this study was to calculate the frequency of aplastic unilateral distal VA by MR images performed for asymptomatic people.Materials and methodsOver a time span of 1 year, 237 asymptomatic people (140 men, 97 women; ages 28–67 years, mean 54.4 years) underwent brain MRI during a “brain check-up examination” in our hospital. To identify an aplastic unilateral distal VA, we retrospectively compared three-dimensional time-of-flight MRA with basiparallel anatomic scanning (BPAS)-MRI which was designed for recognition of the arterial outer contour.ResultsAplasia of the unilateral distal VA was confirmed in 11 persons (4.6%). According to our classification, hypoplastic distal VA in 12 (5.1%) and asymptomatic acquired unilateral distal VA occlusion was also proved in 2 (0.8%).ConclusionWe found that the frequency of aplastic unilateral VA was 4.6% in asymptomatic people using a combination of MRA and BPAS-MRI for assessment of an intracranial VA.

Stereotactic body radiotherapy for lung metastases as oligo-recurrence: a single institutional study.

The purpose of this study was to investigate clinical outcomes following stereotactic body radiotherapy (SBRT) for lung metastases as oligo-recurrence. From May 2003 to June 2014, records for 66 patients with 76 oligo-recurrences in the lungs treated with SBRT were retrospectively reviewed. Oligo-recurrence primary sites and patient numbers were as follows: lungs, 31; colorectal, 13; head and neck, 10; esophagus, 3; uterus, 3; and others, 6. The median SBRT dose was 50 Gy (range, 45–60 Gy) administered in a median of 5 (range, 5–9) fractions. All patients received SBRT, with no acute toxicity. Surviving patients had a median follow-up time of 36.5 months. The 3-year rates of local control, overall survival and disease-free survival were 90.6%, 76.0% and 53.7%, respectively. Longer disease-free interval from initial treatment to SBRT, and non-colorectal cancer were both associated with favorable outcomes. Disease progression after SBRT occurred in 31 patients, most with distant metastases (n = 24) [among whom, 87.5% (n = 21) had new lung metastases]. Among these 21 patients, 12 were judged as having a second oligo-recurrence. Additional SBRT was performed for these 12 patients, and all 12 tumors were controlled without disease progression. Three patients (4.5%) developed Grade 2 radiation pneumonitis. No other late adverse events of Grade ≥2 were identified. Thus, SBRT for oligo-recurrence achieved acceptable tumor control, with additional SBRT also effective for selected patients with a second oligo-recurrence after primary SBRT.

Clinical outcome of stereotactic body radiotherapy for primary and oligometastatic lung tumors: a single institutional study with almost uniform dose with different five treatment schedules

BackgroundTo evaluate clinical outcomes of stereotactic body radiotherapy (SBRT) for localized primary and oligometastatic lung tumors by assessing efficacy and safety of 5 regimens of varying fraction size and number.MethodsOne-hundred patients with primary lung cancer (n = 69) or oligometastatic lung tumors (n = 31), who underwent SBRT between May 2003 and August 2010, were included. The median age was 75 years (range, 45–88). Of them, 98 were judged to have medically inoperable disease, predominantly due to chronic illness or advanced age. SBRT was performed using 3 coplanar and 3 non-coplanar fixed beams with a standard linear accelerator. Fraction sizes were escalated by 1 Gy, and number of fractions given was decreased by 1 for every 20 included patients. Total target doses were between 50 and 56 Gy, administered as 5–9 fractions. The prescribed dose was defined at the isocenter, and median overall treatment duration was 10 days (range, 5–22).ResultsThe median follow-up was 51.1 months for survivors. The 3-year local recurrence rates for primary lung cancer and oligometastasis was 6 % and 3 %, respectively. The 3-year local recurrence rates for tumor sizes ≤3 cm and >3 cm were 3 % and 14 %, respectively (p = 0.124). Additionally, other factors (fraction size, total target dose, and BED10) were not significant predictors of local control. Radiation pneumonia (≥ grade 2) was observed in 2 patients. Radiation-induced rib fractures were observed in 22 patients. Other late adverse events of greater than grade 2 were not observed.ConclusionWithin this dataset, we did not observe a dose response in BED10 values between 86.4 and 102.6 Gy. SBRT with doses between 50 and 56 Gy, administered over 5–9 fractions achieved acceptable tumor control without severe complications.

Correlation between tumor size and blood volume in lung tumors: a prospective study on dual-energy gemstone spectral CT imaging

The purpose of this study was to investigate the relationship between tumor size and blood volume for patients with lung tumors, using dual-energy computed tomography (DECT) and a gemstone spectral imaging (GSI) viewer. During the period from March 2011 to March 2013, 50 patients with 57 medically inoperable lung tumors underwent DECT before stereotactic body radiotherapy (SBRT) of 50–60 Gy in 5–6 fractions. DECT was taken for pretreatment evaluation. The region-of-interest for a given spatial placement of the tumors was set, and averages for CT value, water density and iodine density were compared with tumor size. The average values for iodine density in tumors of ≤2 cm, 2–3 cm, and >3 cm maximum diameter were 24.7, 19.6 and 16.0 (100 µg/cm3), respectively. The average value of the iodine density was significantly lower in larger tumors. No significant correlation was detected between tumor size and average CT value or between tumor size and average water density. Both the average water density and the average CT value were affected by the amount of air in the tumor, but the average iodine density was not affected by air in the tumor. The average water density and the average CT value were significantly correlated, but the average iodine density and the average CT value showed no significant correlation. The blood volume of tumors can be indicated by the average iodine density more accurately than it can by the average CT value. The average iodine density as assessed by DECT might be a non-invasive and quantitative assessment of the radio-resistance ascribable to the hypoxic cell population in a tumor.

Lymphoscintigraphy for sentinel lymph node mapping in Japanese patients with malignant skin neoplasms of the lower extremities: comparison with previously investigated Japanese lymphatic anatomy.

ObjectivesLymph nodes (LN) and lymphatic drainage were identified by lymphoscintigraphy using 99mTc-phytate in order to map the sentinel lymph nodes (SLNs) in patients with malignant skin neoplasms of the lower extremities, and to compare the results with an atlas of Japanese lymphatic anatomy.MethodsSentinel lymphoscintigraphs of 18 patients with malignant skin neoplasms of the lower extremities (9 men, 9 women; age range 45–84xa0years, mean age 66xa0years) were analyzed retrospectively, and the LNs detected were identified as SLNs or secondary nodes.ResultsThe patterns of lymphatic drainage were divided into three different categories: (1) initial drainage into inguinal LN without visualization of popliteal LNs (inguinal type), (2) initial drainage into popliteal LNs and then into intrapelvic LNs (popliteal type), and (3) initial drainage into both popliteal and inguinal LNs (inguinal and popliteal type). More than half of the cases were the inguinal and popliteal type, as both inguinal and popliteal LNs were identified as SLNs. In the cases in which the hallux and its surrounding area were injected, all were the inguinal type and popliteal LNs were not visualized. In one case, only dynamic images detected lymphatic drainage without visualization of popliteal LNs. In contrast to the previously published literature on Japanese lymphatic anatomy, SLN lymphatic drainage from the skin of the lower extremities was wide and overlapping in many areas. However, in agreement with currently accepted anatomy, only the great saphenous lymphatic vessel drained the skin of the hallux and its surrounding area. The present results suggest that it is important to confirm lymphatic drainage in order to identify SLNs in the lower extremities.ConclusionsThe patterns of lymphatic drainage from the skin of the foot were divided into three different categories. In contrast to previously published Japanese lymphatic anatomy, lymphatic drainage from the skin of the lower extremities was wide and overlapping in many areas. However, only the great saphenous lymphatic vessel drained the skin of the hallux and its surrounding area in agreement with currently accepted Japanese lymphatic anatomy. It is important to confirm lymphatic drainage to identify SLNs in the lower extremities.

Prognostic impact of average iodine density assessed by dual-energy spectral imaging for predicting lung tumor recurrence after stereotactic body radiotherapy.

The purpose of this study was to investigate the prognostic significance of average iodine density as assessed by dual-energy computed tomography (DE-CT) for lung tumors treated with stereotactic body radiotherapy (SBRT). From March 2011 to August 2014, 93 medically inoperable patients with 74 primary lung cancers and 19 lung metastases underwent DE-CT prior to SBRT of a total dose of 45–60 Gy in 5–10 fractions. Of these 93 patients, nine patients had two lung tumors. Thus, 102 lung tumors were included in this study. DE-CT was performed for pretreatment evaluation. Regions of interest were set for the entire tumor, and average iodine density was obtained using a dedicated imaging software and evaluated with regard to local control. The median follow-up period was 23.4 months (range, 1.5–54.5 months). The median value of the average iodine density was 1.86 mg/cm3 (range, 0.40–9.27 mg/cm3). Two-year local control rates for the high and low average iodine density groups divided by the median value of the average iodine density were 96.9% and 75.7% (P = 0.006), respectively. Tumors with lower average iodine density showed a worse prognosis, possibly reflecting a hypoxic cell population in the tumor. The average iodine density exhibited a significant impact on local control. Our preliminary results indicate that iodine density evaluated using dual-energy spectral CT may be a useful, noninvasive and quantitative assessment of radio-resistance caused by presumably hypoxic cell populations in tumors.

Temporal variations in stump pressure and assessment of images obtained from cone‐beam computed tomography during balloon‐occluded transarterial chemoembolization

Balloon‐occluded transcatheter arterial chemoembolization (B‐TACE) was used to show the optimized duration of balloon occlusion to start injection of lipiodol in order to maximize lipiodol deposition in the nodule, and to reveal the endpoint of lipiodol injection.