Toru Harabayashi

THREE-DIMENSIONAL INTRAFRACTIONAL MOVEMENT OF PROSTATE MEASURED DURING REAL-TIME TUMOR-TRACKING RADIOTHERAPY IN SUPINE AND PRONE TREATMENT POSITIONS

PURPOSE To quantify three-dimensional (3D) movement of the prostate gland with the patient in the supine and prone positions and to analyze the movement frequency for each treatment position. METHODS AND MATERIALS The real-time tumor-tracking radiotherapy (RTRT) system was developed to identify the 3D position of a 2-mm gold marker implanted in the prostate 30 times/s using two sets of fluoroscopic images. The linear accelerator was triggered to irradiate the tumor only when the gold marker was located within the region of the planned coordinates relative to the isocenter. Ten patients with prostate cancer treated with RTRT were the subjects of this study. The coordinates of the gold marker were recorded every 0.033 s during RTRT in the supine treatment position for 2 min. The patient was then moved to the prone position, and the marker was tracked for 2 min to acquire data regarding movement in this position. Measurements were taken 5 times for each patient (once a week); a total of 50 sets for the 10 patients was analyzed. The raw data from the RTRT system were filtered to reduce system noise, and the amplitude of movement was then calculated. The discrete Fourier transform of the unfiltered data was performed for the frequency analysis of prostate movement. RESULTS No apparent difference in movement was found among individuals. The amplitude of 3D movement was 0.1-2.7 mm in the supine and 0.4-24 mm in the prone positions. The amplitude in the supine position was statistically smaller in all directions than that in the prone position (p < 0.0001). The amplitude in the craniocaudal and AP directions was larger than in the left-right direction in the prone position (p < 0.0001). No characteristic movement frequency was detected in the supine position. The respiratory frequency was detected for all patients regarding movement in the craniocaudal and AP directions in the prone position. The results of the frequency analysis suggest that prostate movement is affected by the respiratory cycle and is influenced by bowel movement in the prone position. CONCLUSION The results of this study have confirmed that internal organ motion is less frequent in the supine position than in the prone position in the treatment of prostate cancer. RTRT would be useful in reducing uncertainty due to the effects of the respiratory cycle, especially in the prone position.

Registration accuracy and possible migration of internal fiducial gold marker implanted in prostate and liver treated with real-time tumor-tracking radiation therapy (RTRT)

BACKGROUND AND PURPOSE We have developed a linear accelerator synchronized with a fluoroscopic real-time tumor-tracking system to reduce errors due to setup and organ motion. In the real-time tumor-tracking radiation therapy (RTRT) system, the accuracy of tumor tracking depends on the registration of the markers coordinates. The registration accuracy and possible migration of the internal fiducial gold marker implanted into prostate and liver was investigated. MATERIALS AND METHODS Internal fiducial gold markers were implanted in 14 patients with prostate cancer and four patients with liver tumors. Computed tomography (CT) was carried out as a part of treatment planning in the 18 patients. A total of 72 follow-up CT scans were taken. We calculated the relative relationship between the coordinates of the center of mass (CM) of the organs and those of the marker. The discrepancy in the CM coordinates during a follow-up CT compared to those recorded during the planning CT was used to study possible marker migration. RESULTS The standard deviation (SD) of interobserver variations in the CM coordinates was within 2.0 and 0.4 mm for the organ and the marker, respectively, in seven observers. Assuming that organs do not shrink, grow, or rotate, the maximum SD of migration error in each direction was estimated to be less than 2.5 and 2.0 mm for liver and prostate, respectively. There was no correlation between the marker position and the time after implantation. CONCLUSION The degree of possible migration of the internal fiducial marker was within the limits of accuracy of the CT measurement. Most of the marker movement can be attributed to the measurement uncertainty, which also influences registration in actual treatment planning. Thus, even with the gold marker and RTRT system, a planning target volume margin should be used to account for registration uncertainty.

Cytogenetic Abnormalities of Tumor-Associated Endothelial Cells in Human Malignant Tumors

Tumor blood vessels are thought to contain genetically normal and stable endothelial cells (ECs), unlike tumor cells, which typically display genetic instability. Yet, chromosomal aberration in human tumor-associated ECs (hTECs) in carcinoma has not yet been investigated. Here we isolated TECs from 20 human renal cell carcinomas and analyzed their cytogenetic abnormalities. The degree of aneuploidy was analyzed by fluorescence in situ hybridization using chromosome 7 and chromosome 8 DNA probes in isolated hTECs. In human renal cell carcinomas, 22-58% (median, 33%) of uncultured hTECs were aneuploid, whereas normal ECs were diploid. The mechanisms governing TEC aneuploidy were then studied using mouse TECs (mTECs) isolated from xenografts of human epithelial tumors. To investigate the contribution of progenitor cells to aneuploidy in mTECs, CD133(+) and CD133(-) mTECs were compared for aneuploidy. CD133(+) mTECs showed aneuploidy more frequently than CD133(-) mTECs. This is the first report showing cytogenetic abnormality of hTECs in carcinoma, contrary to traditional belief. Cytogenetic alterations in tumor vessels of carcinoma therefore can occur and may play a significant role in modifying tumor- stromal interactions.

Docetaxel Plus Prednisolone for the Treatment of Metastatic Hormone-refractory Prostate Cancer: A Multicenter Phase II Trial in Japan

BACKGROUND Docetaxel-based chemotherapy has been shown to be effective and well tolerated by Western patients with metastatic hormone-refractory prostate cancer (HRPC). This study was undertaken to assess the feasibility of docetaxel in combination with prednisolone in Japanese patients with HRPC. METHODS Patients aged 50-74 years with measurable metastatic HRPC were included in this non-comparative Phase II study. Treatment consisted of docetaxel 70 mg/m(2) once every 3 weeks plus prednisolone 5 mg twice daily, for a maximum of 10 cycles. The primary endpoint was overall tumor response rate, assessed by Response Evaluation Criteria in Solid Tumors; secondary endpoints included prostate-specific antigen (PSA) response and toxicity. RESULTS A total of 43 patients were evaluable for efficacy and toxicity. The response rate was 44.2% (90% CI, 31.2-57.8%), with partial responses in 19/43 patients. The median duration of response was 19.3 weeks. PSA responses were recorded in 44.4% of patients (95% CI, 27.9-61.9%). The most common non-hematological adverse events (of any grade) possibly related to treatment were alopecia (88.4%), anorexia (65.1%) and fatigue (53.5%). Grade 3/4 leukopenia and neutropenia occurred in 81.4 and 93.0% of patients, respectively; however, the grade 3/4 rates of febrile neutropenia (16.3%) and infection without fever (14.0%) were lower. CONCLUSION The combination of docetaxel and prednisolone was feasible and active in Japanese patients with HRPC, with a manageable adverse-event profile similar to that observed in Western patients.

An improved intravesical model using human bladder cancer cell lines to optimize gene and other therapies

Orthotopic implantation of human bladder cancer cells into immunodeficient mice is an important tool for studying the biology and effects of therapy. Nevertheless, the incidence of tumor implantation and growth by transurethral instillation of the human bladder cancer cells into murine bladders has been low or not reproducible. However, using a modified intravesical technique and the human bladder cancer cell lines, KU-7 and UM-UC-2, we have been able to obtain a high and reproducible incidence of superficial bladder tumors. Furthermore, intravesical administration of the LacZ adenovirus vector resulted in significant β-galactosidase expression in these bladder tumors as well as the normal urothelium, which was associated with the removal of the glycosoaminoglycan layer. Because this modified technique produces a high incidence of superficial human tumor growth and allows the efficacy of gene transfer to be evaluated, it should be a useful model for the study of intravesical gene therapy for human bladder cancer. Cancer Gene Therapy (2000) 7, 1575–1580.

Impact of nephron-sparing surgery on quality of life in patients with localized renal cell carcinoma

Objectives: The aim of the study is to evaluate the impact of nephron–sparing surgery on postoperative quality of life (QOL) in patients with localized renal cell carcinoma, compared with radical nephrectomy. Methods: From 1986 to 1996, a total of 66 patients with localized small renal cell carcinoma <4 cm in diameter and a functioning contralateral renal unit underwent radical nephrectomy (n = 51) or nephron–sparing surgery (n = 15). Of these, 50 patients evaluated various dimensions of QOL using standardized self–rating questionnaires, EORTC QLQ–C30. Results: There is no significant difference in 5–year overall survival between the nephron–sparing surgery group and the radical nephrectomy group. With regard to postoperative QOL, patients who underwent nephron–sparing surgery showed a significantly higher score on physical function than patients treated with radical nephrectomy (p<0.05). Nephron–sparing surgery was additionally superior to radical nephrectomy in terms of fatigue, sleep disturbance, pain and constipation. Conclusion: Selected patients with localized, small, unilateral renal cell carcinoma and a normal contralateral kidney will benefit from nephron–sparing surgery.

Reduction in acute morbidity using hypofractionated intensity-modulated radiation therapy assisted with a fluoroscopic real-time tumor-tracking system for prostate cancer: preliminary results of a phase I/II study.

PURPOSEThe positioning of the prostate is improved with the use of the fluoroscopic real-time tumor-tracking radiation therapy system for prostate cancer. The acute radiation reaction and preliminary tumor response of prostate cancer to hypofractionated intensity-modulated radiation therapy assisted with real-time tumortracking radiation therapy were investigated in this study. METHODSPatients were classified into prognostic risk groups on the basis of the presence of the pretreatment prostate-specific antigen, clinical stage, and histologic differentiation. Neoadjuvant hormonal therapy was administered to patients in the high-risk group for 6 months before radiation therapy commenced. The intensity-modulated radiation therapy employed a segmental multileaf collimator, which generated a field made up of two or more shaped subfields using forward planning. Real-time tumor-tracking radiation therapy was used for the precise positioning of the prostate to minimize geometric uncertainties, while the dose was escalated in increments of 5 Gy from 65 Gy using a daily dose of 2.5 Gy (65 Gy/2.5 Gy), following the dose-escalation rules. Acute and late gastrointestinal and genitourinary morbidities due to radiation therapy were scored according to the toxicity criteria of Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer. RESULTSThirty-one patients were enrolled in this study between 1998 and 2001. Eighteen patients were classified as being members of the high-risk group. Total dose was escalated, with 65 Gy/2.5 Gy being administered to 12 patients and 70 Gy/2.5 Gy to 19 patients. The median follow-up period was 37 months (range, 30–43 months), and 19 months (range, 10–27 months), for the 65-Gy and 70-Gy arms, respectively. Patients experienced no acute toxicity and grade 1 late gastrointestinal toxicity (8.3%) in the 65-Gy/2.5-Gy arm. Patients in the 70-Gy/2.5-Gy arm experienced grade 1 acute gastrointestinal toxicity (5.3%) and grade 1 and 2 acute genitourinary toxicities (15.8%). No patients experienced dose-limiting toxicity (defined as a grade 3 or higher acute toxicity) or a grade 2 or higher late complication in this study period. One and two prostate-specific antigen relapses were observed in the 65-Gy and 70-Gy arms, respectively. CONCLUSIONUp to 70 Gy/2.5 Gy, equivalent to 80 Gy with a daily dose of 2.0 Gy, assuming α/β ratio of 1.5, intensity-modulated radiation therapy assisted with real-time tumor-tracking radiation therapy was administered safely with a reasonable biochemical control rate. A further dose-escalation study using this system is justifiable.

Laparoscopic ureteroureterostomy for retrocaval ureter

Abstract Two cases of retrocaval ureter are reported that were successfully treated by a laparoscopic approach. Case 1 was a 20‐year‐old woman who presented with symptoms of a right ureter stone. Case 2 was a 23‐year‐old woman who had suffered from recurrent right flank pain with gross hematuria. A transperitoneal approach was used for case 1, and a retroperitoneal approach was used in case 2. Both were successfully treated with laparoscopic ureteroureterostomy using an intracorporeal suture technique. Laparoscopic surgery should be the first choice for retrocaval ureter not only because of the minimal invasiveness but also because of the cosmetic advantage compared to conventional open surgery. Further technical and instrumental advances are essential for intracorporeal suturing.

Impact of Diagnostic Ureteroscopy on Intravesical Recurrence and Survival in Patients With Urothelial Carcinoma of the Upper Urinary Tract

PURPOSE We determined whether diagnostic ureteroscopy for upper urinary tract cancer affects intravesical recurrence and cancer specific mortality. MATERIALS AND METHODS In a retrospective, multi-institutional study we evaluated 208 patients undergoing nephroureterectomy for upper urinary tract cancer who had no perioperative systemic chemotherapy, history of invasive bladder cancer, distant metastasis or incomplete followup data. Of these 208 patients 55 who composed the study group underwent diagnostic ureteroscopy before nephroureterectomy while 153 serving as controls did not. We analyzed intravesical recurrence and cancer specific survival using the Kaplan-Meier method with the log rank test used to assess significance. RESULTS There was no significant difference between the 2 groups in patient characteristics or upper urinary tract cancer stage and grade while followup, and the proportion of multiple tumors and lymphovascular invasion positive tumors were significantly greater in controls. The 2-year bladder recurrence-free survival rate was 60.0% in the study group and 58.7% in controls. There was no significant difference in the intravesical recurrence rate between the 2 groups (log rank test p = 0.972). Estimated Kaplan-Meier cancer specific survival was 88.3% and 78.1% at 5 years in the study and control groups, respectively (log rank test p = 0.0687). CONCLUSIONS Diagnostic ureteroscopy did not affect intravesical recurrence or cancer specific survival in patients with upper urinary tract cancer undergoing nephroureterectomy.

Role of lymph node dissection in the treatment of urothelial carcinoma of the upper urinary tract: Multi-institutional relapse analysis and immunohistochemical re-evaluation of negative lymph nodes

AIM To determine the role of lymph node dissection (LND) in the treatment of urothelial carcinoma (UC) of the upper urinary tract (UUT). PATIENTS AND METHODS [Study-1] A retrospective multi-institutional study evaluated 293 patients undergoing predominantly nephroureterectomy for UC of the UUT. Of 293 patients, 267 patients had pure UC and 26 demonstrated other histological components. Regarding the pathological node status, 130 patients had pN0 disease, 141 patients had pNx disease and 22 patients had pN+ disease. The sites of initial recurrence and time to first recurrence were reviewed. The sites of recurrence were classified as locoregional or distant recurrence. The relationship between node status and future recurrence was analyzed. [Study-2] Fifty-one patients treated by nephroureterectomy at Hokkaido University Hospital were included. All had LND and all LNs were negative on hematoxylin and eosin staining. We re-evaluated the presence of micrometastasis in LND specimens by anti-cytokeratin immunohistochemistory. RESULTS [Study-1] Of 293 patients, 76 developed disease relapse. Regional lymph node recurrence was the most common site (34 patients). On multivariate analyses that adjusted for the effect of tumor stage and tumor grade, pNx (skipping LND) was an adverse factor not only for locoregional recurrence, but also for distant relapse. [Study-2] Immunohistochemistry identified micrometastases in 7 (14%) of 51 patients. Regarding survival, 5 of these 7 patients with micrometastases were alive at last follow-up. CONCLUSIONS On relapse analysis, skipping LND was an adverse factor not only for locoregional recurrence, but also for distant relapse. Immunohistochemistry detected micrometastases in about 14% of patients previously diagnosed as pN0. These findings further support a potential therapeutic benefit of LND by eliminating micrometastases.