Masashi Yamamoto

Differences in target outline delineation from CT scans of brain tumours using different methods and different observers.

PURPOSEnTo assess errors resulting from manual transfer of contour information for three-dimensional (3-D) target reconstruction, and to determine variations in target volume delineation of brain tumours by different radiation oncologists.nnnMATERIALS AND METHODSnImages of 18 patients with intracranial astrocytomas were used for retrospective treatment planning by five radiation oncologists. In this study, the target outline was delineated on sequential CT slices by an experienced radiation oncologist. Thereafter, the target outline was manually reconstructed by five radiation oncologists onto an A-P or lateral scout film. The same target outline was also reconstructed as a projection using the Beams-eye view capability on a CT simulator unit. The two target outlines were compared by encompassing each shape with the smallest rectangle. The manually-reconstructed radiation field was termed Field manually established on X-ray film (F-X), and the automatically-established field was termed Field established by CT simulator (F-CT). In a second part of this study, four radiation oncologists defined contours from contrast enhanced CT images of nine patients with intracranial astrocytomas. The CT images of these nine cases included five pre-operative cases and four post-operative cases. Both gross tumour volume (GTV) and clinical target volume (CTV) were outlined on sequential CT slices. The target outlines for the four radiation oncologists were compared by identifying the smallest rectangular field surrounding the projection of these contours. The field established by each radiation oncologist was termed Field of target volume (F-TV), and the overlapping portion of the four F-TVs for each case was termed Overlapped field of the target volume (Fo-TV).nnnRESULTSnThe average distance between the isocentres of F-X and F-CT was 0.6 +/- 0.4 cm (mean +/- SD). The average ratio of the area of F-X divided by the area of F-CT was 1.04 +/- 0.12. The area of F-X was wider than the area of F-CT for four of the five oncologists. The ratio of the area of F-TV divided by the area of Fo-TV was calculated. The average ratio was relatively greater for CTV (2.07 in pre-operative cases and 2.11 in post-operative cases) than for GTV (1.12 in pre-operative cases and 1.41 in post-operative cases). Among radiation oncologists, variations in the delineation of GTV were smaller than those of CTV.nnnCONCLUSIONSnWhen using an X-ray simulator in treatment planning, errors resulting from the manual transfer of CT contour information to planar radiographs must be considered. When computer techniques are used to project contours onto radiographs errors resulting from individual variations when performing the contouring must be considered.

Development of an integrated radiotherapy network system

PURPOSEnTo introduce the process of developing an integrated radiotherapy network.nnnMETHODS AND MATERIALSnWe developed a new radiotherapy treatment-planning system in 1987 that we named the Computer Tomography (CT) simulator. CT images were immediately transported to multiimage monitors and to a planning computer, and treatment planning could be performed with the patient lying on the CT couch. The results of planning were used to guide a laser projector, and radiation fields were projected onto the skin of the patient. Since 1991, an integrated radiotherapy network system has been developed, which consists of a picture archiving and communicating system (PACS), a radiotherapy information database, a CT simulator, and a linear accelerator with a multileaf collimator.nnnRESULTSnClinical experience has been accumulated in more than 1,000 patients. Based on our 7 years of experience, we have modified several components of our original CT simulator and have developed a second generation CT simulator. A standard protocol has been developed for communication between the CT scanner, treatment planning computer, and radiotherapy apparatus using the Ethernet network. As a result, treatment planning data can be transported to the linear accelerator within 1 min after completion of treatment planning.nnnCONCLUSIONnThis system enables us to make optimal use of CT information and to devise accurate three-dimensional (3D) treatment-planning programs. Our network also allows for the performance of fully computer-controlled dynamic arc conformal therapy.

Radiotherapy combined with transcatheter arterial infusion chemotherapy for locally advanced cervical cancer

Twenty-four patients with locally advanced cervical cancer were treated with radiation therapy (RT) and transcatheter arterial infusion (TAI) chemotherapy, while 22 patients were treated with RT alone. RT consisted of a combination of external irradiation and high-dose-rate intracavitary brachytherapy. TAI therapy consisted of two sessions using cisplatin and pirarubicin, performed concurrently during the periods of external irradiation. The local-regional control rates at 1 year for the patients treated with RT plus TAI and for those treated with RT alone were 87.5% and 58.3%, respectively (p < 0.05). The 3-year cause-specific survival (CSS) rates for RT plus TAI, and RT alone were 67.1% and 55.9%, respectively (p = n.s.). The 3-year CSS rate for the 14 patients treated with RT and TAI who had well- or moderately differentiated squamous cell carcinoma without pelvic lymph node swelling was 100%, while that for the 19 patients with the same background treated with RT alone was 49% (p < 0.01). Radiation therapy combined with TAI appears to be an effective and safe treatment modality for patients with locally advanced cervical cancer.

Cefepime monotherapy for febrile neutropenia in patients with lung cancer

UNLABELLEDnWe assessed the efficacy and safety of cefepime monotherapy (1 g intravenously every 8 h) for febrile neutropenia in patients with lung cancer in a multi-institutional phase II study. Patients treated with chemotherapy with or without radiotherapy for lung cancer were eligible for this study. Other eligibility criteria included fever (temperature of ≥38.0 °C) and an absolute neutrophil count of <500/mm(3) or <1000/mm(3) with an expected decline to <500/mm(3) within the next 48 h. Risk assessment was performed using the Multinational Association of Supportive Care in Cancer risk-index score. Cefepime 1 g was given intravenously every 8 h. The primary endpoint was the response rate at the end of cefepime therapy. Co-administration of granulocyte-colony-stimulating factor was permitted. Of 54 patients enrolled, 39 were classified in the low-risk group and 15 in the high-risk group. Overall response rate was 78% (95% CI: 64.4-88.0%). The response rates were 85% (95% CI: 69.5-94.1%) in the low-risk group and 60% (95% CI: 32.3-83.7%) in the high-risk group, respectively. One patient died from septic shock due to Enterobacter cloacae bacteremia. There was no significant adverse event. Cefepime 1 g intravenously every 8 h appears to be effective for febrile neutropenia in patients with lung cancer, especially in those with low-risk febrile neutropenia, and is well tolerated.nnnCLINICAL TRIAL REGISTRATIONnUMIN Clinical Trials Registry, UMIN000006157.

A phase II study of carboplatin and prolonged administration of oral etoposide in patients with small-cell lung cancer

Prolonged oral administration of etoposide may have a theoretical advantage over intravenous infusion, and carboplatin has a more favorable toxicity profile than cisplatin. A combination of carboplatin 300 mg/m2 and oral etoposide 40 mg/m2/day for 21 days was assessed in 74 (42 limited, 32 extensive disease) previously untreated patients with small-cell lung cancer. Response rate was 69% (CR 19%, PR 50%,) for limited disease and 72% (CR 9%, PR 63%) for extensive disease. Median response duration and overall survival was 6.6 and 10.1 months for limited disease, and 5.3 and 9.1 months for extensive disease, respectively. One-year and two-year survival was 36 and 10% for limited disease and 31 and 2% for extensive disease, respectively. The major toxicity was hematological with grade 4 or greater neutropenia in 36% and grade 4 thrombocytopenia in 16%, and one patient died of neutropenic fever. Non-hematologic toxicities were mild and grade 3 emesis was observed in 5% of patients. Carboplatin combined with 21-day oral etoposide showed only modest activity against small-cell lung cancer with high toxicity and did not merit further evaluation.