Kengo Kuriyama

A new irradiation unit constructed of self-moving gantry-CT and linac.

PURPOSE To improve reproducibility in stereotactic irradiation (STI) without using noninvasive immobilization devices or body frames, we have developed an integrated computed tomography (CT)-linac irradiation system connecting CT scanner and linac via a common treatment couch. METHODS AND MATERIALS This system consists of a linac, a CT scanner, and a common treatment couch. The linac and the CT gantry are positioned on opposite ends of the couch so that, by rotating the treatment couch, linac radiotherapy or CT scanning can be performed. The rotational axis of the linac gantry is coaxial with that of the CT gantry, and the position of the linac isocenter on the couch matches the origin of the coordinate system for CT scanning when the couch is rotated 180 degrees toward the CT side. Instead of the couch moving into the gantry, as in conventional CT, in this case the table is fixed and scanning is accomplished by moving the gantry. We evaluated the rotational accuracy of the common couch and the scan-position accuracy of the self-moving gantry CT. RESULTS The positional accuracy of the common couch was 0.20, 0.18, and 0.39 mm in the lateral, longitudinal, and vertical directions, respectively. The scan-position accuracy of the CT gantry was less than 0.4 mm in the lateral, longitudinal, and vertical directions. CONCLUSION This irradiation system has a high accuracy and is useful for noninvasive STI and for verification of the position of a target in three-dimensional conformal radiotherapy.

Concurrent two-dimensional radiotherapy and weekly docetaxel in the treatment of stage III non-small cell lung cancer: a good local response but no good survival due to radiation pneumonitis

Docetaxel is a novel, potentially highly beneficial drug for the treatment of lung cancer, and has shown remarkable radio-sensitizing effects in vitro. In the present study, we evaluated whether weekly docetaxel (20 mg/m(2)) and conventionally fractionated radiotherapy with the two-dimensional (2D) technique could be tolerated and effective in the treatment of locally advanced non-small-cell lung cancer (NSCLC). Thirty-two stage III (IIIA:13, IIIB:19) NSCLC patients were treated with weekly administration of docetaxel (20 mg/m(2)) on days 1, 8, 15, 22, 29 and 36 in addition to concurrent radiation therapy. The total tumor dose was 60-66 Gy given with a 2D technique in 6-7 weeks. Complete response was observed in 9/32 (28%) patients and partial response in 20/32 (63%). Three (9%) patients died of chemoradiation-induced pneumonitis after completion of therapy. In total, grade >3 toxicities included pneumonitis (47%) and esophagitis (16%). The median overall survival duration was 12 months. The dimensions of the radiotherapy port were larger in patients who produced severe (grade >3) chemoradiation pneumonitis than in patients who did not (P<0.05). The median survival time was 12.4 months and 2-year overall survival were 35%. The survival was better in patients whose first radiotherapy port dimensions were less than 150 cm(2) compared to patients whose first radiation port dimensions were >==150 cm(2) (P<0.05). In conclusion, concurrent weekly administration of docetaxel (20 mg/m(2)) with 2D radiotherapy for NSCLC, had good local response, but survival rate was not completely satisfactory due to chemoradiation pneumonitis, which was the principal toxicity that adversely affected prognosis in elderly patients whose radiotherapy port was large.

Rib fracture after stereotactic radiotherapy for primary lung cancer: prevalence, degree of clinical symptoms, and risk factors

BackgroundAs stereotactic body radiotherapy (SBRT) is a highly dose-dense radiotherapy, adverse events of neighboring normal tissues are a major concern. This study thus aimed to clarify the frequency and degree of clinical symptoms in patients with rib fractures after SBRT for primary lung cancer and to reveal risk factors for rib fracture. Appropriate α/β ratios for discriminating between fracture and non-fracture groups were also investigated.MethodsBetween November 2001 and April 2009, 177 patients who had undergone SBRT were evaluated for clinical symptoms and underwent follow-up thin-section computed tomography (CT). The time of rib fracture appearance was also assessed. Cox proportional hazard modeling was performed to identify risk factors for rib fracture, using independent variables of age, sex, maximum tumor diameter, radiotherapeutic method and tumor-chest wall distance. Dosimetric details were analyzed for 26 patients with and 22 randomly-sampled patients without rib fracture. Biologically effective dose (BED) was calculated with a range of α/β ratios (1–10 Gy). Receiver operating characteristics analysis was used to define the most appropriate α/β ratio.ResultsRib fracture was found on follow-up thin-section CT in 41 patients. The frequency of chest wall pain in patients with rib fracture was 34.1% (14/41), and was classified as Grade 1 or 2. Significant risk factors for rib fracture were smaller tumor-chest wall distance and female sex. Area under the curve was maximal for BED at an α/β ratio of 8 Gy.ConclusionsRib fracture is frequently seen on CT after SBRT for lung cancer. Small tumor-chest wall distance and female sex are risk factors for rib fracture. However, clinical symptoms are infrequent and generally mild. When using BED analysis, an α/β ratio of 8 Gy appears most effective for discriminating between fracture and non-fracture patients.

Value of dual time point F-18 FDG-PET/CT imaging for the evaluation of prognosis and risk factors for recurrence in patients with stage I non-small cell lung cancer treated with stereotactic body radiation therapy

PURPOSE To investigate prognostic and risk factors for recurrence after stereotactic body radiation therapy (SBRT) in patients with stage I non-small cell lung carcinoma (NSCLC), focusing on dual time point [18]F-fluorodeoxyglucose positron emission tomography (FDG PET). MATERIALS AND METHODS We prospectively evaluated 57 patients with stage I NSCLC (45 T1N0M0 and 12 T2N0M0) who had undergone pretreatment FDG-PET/CT and were subsequently treated with SBRT. All patients received a whole-body PET/CT scan at 60 min and a whole-lung at 120 min after the injection. The maximum standardized uptake value (SUV) and retention index (RI) of the lesions were calculated. Local recurrence, regional lymph node metastasis, distant metastasis, and the recurrence pattern were evaluated. Cox proportional hazard regression analyses were performed to evaluate prognostic factors or risk factors of recurrence. RESULTS During the median follow-up period of 27 months, local recurrence, regional lymph node metastasis, and distant metastasis were seen in 17 (30%), 12 (21%), and 17 (30%) of the 57 patients, respectively. The 3-year overall survival rate was 63.4%. SUVmax did not affect any recurrence, DFS, OS, or CSS. RI significantly predicted higher distant metastasis (HR 47.546, p=0.026). In contrast, RI tended to predict lower local recurrence (HR 0.175, p=0.246) and regional lymph node metastasis (HR 0.109, p=0.115). CONCLUSIONS SUVmax at staging FDG-PET does not predict any recurrence, DFS, OS or CSS. In contrast, higher RI predicts higher distant metastasis and tended to predict lower local or regional lymph node metastasis.

Computed tomography appearances of local recurrence after stereotactic body radiation therapy for stage I non-small-cell lung carcinoma

PurposeThe aim of this study was to characterize computed tomography (CT) manifestations of local recurrence after stereotactic body radiation therapy (SBRT) for stage I non-small-cell lung cancer (NSCLC).Materials and methodsA total of 27 stage I NSCLC patients who were treated with SBRT, including 5 patients with local recurrence, were retrospectively analyzed for serial CT examinations.ResultsA bulging margin appeared in 4 of the 5 cases (80%) with local recurrence and 1 of 22 cases (5%) without local recurrence. Air bronchograms were seen in 3 of 5 cases with local recurrence and 21 of 22 cases without local recurrence, but they subsequently disappeared in all 3 cases (100%) with local recurrence and in 4 of the 21 cases (19%) without local recurrence. Ipsilateral pleural effusion was observed in all 5 cases (100%) with local recurrence and in 5 of 22 cases (22%) without local recurrence. The opacity increased in size even after 12 months from the completion of SBRT in cases with local recurrence, whereas it decreased or did not change in size in cases without recurrence.ConclusionLocal recurrence should be suspected on CT when there was (1) a bulging margin, (2) disappearance of air bronchograms, (3) appearance of pleural effusion, or (4) increase in the abnormal opacity after 12 months.

Rib fracture after stereotactic radiotherapy on follow-up thin-section computed tomography in 177 primary lung cancer patients

BackgroundChest wall injury after stereotactic radiotherapy (SRT) for primary lung cancer has recently been reported. However, its detailed imaging findings are not clarified. So this study aimed to fully characterize the findings on computed tomography (CT), appearance time and frequency of chest wall injury after stereotactic radiotherapy (SRT) for primary lung cancerMaterials and methodsA total of 177 patients who had undergone SRT were prospectively evaluated for periodical follow-up thin-section CT with special attention to chest wall injury. The time at which CT findings of chest wall injury appeared was assessed. Related clinical symptoms were also evaluated.ResultsRib fracture was identified on follow-up CT in 41 patients (23.2%). Rib fractures appeared at a mean of 21.2 months after the completion of SRT (range, 4 -58 months). Chest wall edema, thinning of the cortex and osteosclerosis were findings frequently associated with, and tending to precede rib fractures. No patients with rib fracture showed tumors > 16 mm from the adjacent chest wall. Chest wall pain was seen in 18 of 177 patients (10.2%), of whom 14 patients developed rib fracture. No patients complained of Grade 3 or more symptoms.ConclusionRib fracture is frequently seen after SRT for lung cancer on CT, and is often associated with chest wall edema, thinning of the cortex and osteosclerosis. However, related chest wall pain is less frequent and is generally mild if present.

A Simple Respiratory Indicator for Irradiation during Voluntary Breath Holding: A One-Touch Device without Electronic Materials

PURPOSE To evaluate the use, structural principles, operation, and acquired reproducibility of a respiratory monitoring device to be used for voluntary patient breath holding. MATERIALS AND METHODS Evaluation was performed of a respiratory monitoring device that enables determination of the respiratory level in a patient by measuring the movement of two contacts on the abdomen and chest wall. Neither metallic nor electronic materials are used in the mechanics for this device. The initial study group comprised 21 consecutive patients (15 men, six women; mean age, 75 years; range, 56-92 years) with lung or abdominal tumors who underwent examination with the device and computed tomography (CT) for three-dimensional reproducibility of lung base position during voluntary breath holding with or without use of the device. RESULTS One patient with mild dementia was excluded; in most of the remaining 20 patients, high reproducibility of the breath-holding position was achieved in a short time with the device. In these 20 patients who were able to adapt to use of the device, three-dimensional mean maximum differences in lung base position during three random voluntary breath holds were 2.0 mm along the cranial-caudal axis, 1.5 mm along the anterior-posterior axis, and 1.2 mm along the right-left axis. The differences in all axes were significantly smaller with use of the respiratory monitoring device than without the device. CONCLUSION The device demonstrates satisfactory reproducibility of voluntary patient breath holding easily and inexpensively and may offer a convenient device for easy use during irradiation with voluntary breath-holding conditions that require a small internal margin.

Large prostate motion produced by anal contraction

BACKGROUND AND PURPOSE The aim of this study was to define the effects of voluntary anal contraction on prostate motion in an experimental setting. MATERIALS AND METHODS Thirty-eight patients (median age, 76 years) with prostate cancer underwent thin-slice computed tomography (CT) in the vicinity of the prostate before and after active anal contraction. Three-dimensional displacement of the pelvis and prostate was measured. RESULTS Mean (±standard deviation, SD) overall displacement of the prostate due to anal contraction was 0.3±1.4 mm to the right, 9.3±7.8 mm to the anterior, and 5±4 mm to the cranial direction. Mean displacement of the pelvis was 0.5±1.8 mm to the right, 4.1±7.1 mm to the anterior, and 1±3 mm to the cranial direction. Mean displacement of the prostate relative to the pelvis was 0.1±1.1 mm to the left, 5.2±3.3 mm to the anterior, and 4±4 mm to the cranial direction. CONCLUSIONS Voluntary anal contraction within an experimental setting induces large prostate and bone motion, mainly in the anterior and cranial directions. The frequency and magnitude of actual anal contractions during radiotherapy for prostate cancer need to be determined.

Serious gastric ulcer event after stereotactic body radiotherapy (SBRT) delivered with concomitant vinorelbine in a patient with left adrenal metastasis of lung cancer

Hypofractionated stereotactic body radiation therapy (SBRT) is a form of high-precision radiotherapy delivery characterized by: a) reproducible immobilization to avoid patient movement during treatment sessions; (b) measures to account for tumor motion during imaging, treatment planning, and radiation delivery; c) use of dose distributions tightly covering the tumor, with rapid dose fall-off in surrounding normal tissues, in order to reduce toxicity; and d) use of extremely high doses of radiation, usually delivered in a small number of treatment fractions within a short period. The main aim of SBRT is to acquire better local control of the tumor by providing a higher dose of irradiation to a specifi ed area during a short period. SBRT has been available for more than 10 years and is gaining clinical interest as a means of treating tumors in various organs, particularly for patients with stage I non-small cell lung cancer [1 – 6]. SBRT for oligometastases represents a new trend in radiation oncology [7,8]. It is also commonly accepted that SBRT is safe and frequently effective in such patients, including patients with adrenal gland metastases [9 – 11]. Although late effects in normal tissues after SBRT have been demonstrated [12 – 16], few papers have described the gastrointestinal late effects of SBRT. We describe and discuss herein a serious gastric ulcer event occurring after SBRT was delivered with concomitant vinorelbine in a patient with left adrenal metastasis of lung cancer. Clinical case

Stereotactic Body Radiotherapy for Metachronous Multisite Oligo-Recurrence: A Long-Surviving Case with Sequential Oligo-Recurrence in Four Different Organs Treated Using Locally Radical Radiotherapy and a Review of the Literature

Stereotactic body radiotherapy (SBRT) for oligometastases represents a recent trend in radiation oncology. While abundant data are available regarding the use of SBRT for the treatment of lung or liver oligometastases from various retrospective series and prospective trials, relatively little information has been accumulated for the treatment of oligometastases at sites other than the lungs and liver, particularly for sequential oligometastases in multiple organs. Oligometastases with primary lesions controlled is called “oligo-recurrence.” We describe herein the case of a lung cancer patient who developed repeated oligo-recurrence at multiple sites that were each controlled by radical radiotherapy and achieved long-term survival and discuss the merits of locally aggressive radiotherapy for this type of disease condition with reviewing the literature. Although further investigation should be undertaken to clarify the benefits, objectives, and methods of SBRT for the treatment of oligometastases, we believe utilization of SBRT may be worthwhile for patients with remote metastases who hope for treatment to acquire better local control and possible longer survival.