Influence of different air CT numbers for IVDT on the dose distribution in TomoTherapy MVCT.

This study aims to evaluate the effect of different air computed tomography (CT) numbers of the image value density table (IVDT) on the retrospective dose calculation of head-and-neck (HN) radiotherapy using TomoTherapy megavoltage CT (MVCT) images. The CT numbers of the inside and outside air and each tissue-equivalent plug of the "Cheese" phantom were obtained from TomoTherapy MVCT. Two IVDTs with different air CT numbers were created and applied to MVCT images of the HN anthropomorphic phantom and recalculated by Planned Adaptive to verify dose distribution. We defined the recalculation dose with MVCT images using both inside and outside air of the IVDT as IVDT MVCT inair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{inair}}$ and IVDT MVCT outair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{outair}}$ , respectively. Treatment planning doses calculated on kVCT images were compared with those calculated on MVCT images using two different IVDT tables, namely, IVDT MVCT inair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{inair}}$ and IVDT MVCT outair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{outair}}$ . The difference between average MVCT numbers ±1 standard deviation on inside and outside air of the calibration phantom was 65 ± 36 HU. This difference in MVCT number of air exceeded the recommendation lung tolerance for dose calculation error of 2%. The dose differences between the planning target volume (PTV): D98% , D50% , D2% and the organ at risk (OAR): Dmax , Dmean recalculated by IVDT MVCT inair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{inair}}$ and IVDT MVCT outair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{outair}}$ using MVCT images were a maximum of 0.7% and 1.2%, respectively. Recalculated doses to the PTV and OAR with MVCT showed that IVDT MVCT outair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{outair}}$ was 0.5%-0.7% closer to the kVCT treatment planning dose than IVDT MVCT inair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{inair}}$ . This study showed that IVDT MVCT outair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{outair}}$ was more accurate than IVDT MVCT inair ${\mathrm{IVDT}}_{\mathrm{MVCT}}^{\mathrm{inair}}$ in recalculating the dose HN cases of MVCT using TomoTherapy.

Flow-preserved coil embolization using a side-holed indwelling catheter for common hepatic artery pseudoaneurysm: report of three cases.

We report three cases of hepatic artery pseudoaneurysm, which were all treated successfully using a combination of coil embolization and a side-holed 5F indwelling catheter for maintaining minimal hepatic artery blood flow with exclusion of the pseudoaneurysm. The tip of an infusion catheter was placed in the right hepatic artery and a side hole was positioned at the celiac axis. Coil embolization was then performed from the proper to the common hepatic artery using detachable coils. Hemostasis was achieved in all patients, with a final angiogram showing the hepatic arteries through the indwelling catheter. One major hepatic infarction and one focal liver abscess caused by reflux cholangitis manifested on postoperative days (PODs) 11 and 87, respectively. All patients survived and the indwelling catheter was removed on POD 136­382 without complication.

Ocular adnexal mucosa-associated lymphoid tissue lymphoma treated with radiotherapy.

Forty-two patients with stage IE ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma were retrospectively analyzed. Five-year local control and progression-free survival rates were 100 and 77%, respectively. The most common relapsed site was the contralateral orbit. Thirty Gy of local irradiation seemed to be quite effective and safe.

Improvement of three-dimensional treatment planning models of small lung targets using high-speed multi-slice computed tomographic imaging.

PURPOSE: To improve the reliability of the patient model and reduce treatment volume by acquiring multi-slice computed tomographic (CT) data with the patients' single holding of breath at normal inhalation and exhalation. METHODS AND MATERIALS: Seven patients with nine small peripheral lung cancer tumors underwent CT scanning under three respiration conditions using multi-slice CT: free breathing (FB), shallow inspiration (SI), and shallow expiration (SE). To compare the treatment plan created using the two-respiratory-phase images (SI + SE) with the plans created using only SE images or using only FB images, we attempted to calculate the true dosimetric characteristics for three-dimensional treatment planning taking respiratory movement into consideration. Minimum dose to the gross tumor volume (GTV) and ipsilateral lung dose-volume histogram (DVH) were calculated for the inhalation and exhalation positions of shallow breathing. RESULTS: There was no significant difference between minimum doses of the GTV in the three treatment plans when using anteroposterior/posteroanterior parallel-opposed fields. However, there was a significant difference between the minimum doses of the GTV in the two-phase treatment plan and the minimum dose in the other treatment plans when using the four-field technique, consisting of shaped anterior, posterior, right and left lateral fields (p = 0.03, 0.04). Comparison of the percent volume of ipsilateral lung receiving a dose exceeding 20 Gy (V(20)) based on inhalation and exhalation CT data revealed that the V(20) of the two-phase plan was the smallest of the three treatment planning fields (p < 0.001). CONCLUSION: Two-phase planning using multi-slice CT provides an immediate reduction in the amount of normal tissue treated and improved reliability of patient data for DVH modeling.

Radiotherapy for medically inoperable non-small cell lung cancer at clinical stage I and II.

We reviewed the records of 36 patients with medically inoperable stage I-II non-small cell lung carcinoma who were treated with radiotherapy. The median dose to the target was 60 Gy with conventional fractionation. Fifteen patients were treated without elective irradiation fields, while the remaining 21 were treated with extended fields including elective mediastinal regional lymph nodes. The overall survival rates at three and five years were 32.3% and 18.8%, the cause-specific survival rates were 40.9% and 27.3%, and the local control rates were 31.7% and 23.8%, respectively. In multivariate analysis the radiation dose had a marginally significant influence on the cause-specific survival, while tumor size had a significant influence on the local control rate. Only one patient had relapse in the regional mediastinal lymph nodes as the only site of metastasis. We conclude that the dose used in the present study is inadequate and recommend that further efforts be made to improve local control by dose escalation within a small target volume.

[Endovascular stent graft for management of ureteroarterial fistula: a case report].

We report a case of ureteral-iliac artery fistula and its minimally invasive management with endovascular stent grafting. A 76-year-old male was admitted with massive gross hematuria from an ilial conduit. He underwent a radical cystectomy with ileal loop urinary diversion for bladder cancer 7 months ago and had undergone placement of a 7 Fr single-J ureteral catheter for repair of a partial disruption of the left ureteroileal anastomosis. Although the fistula was not confirmed radiographically, a left ureteral-common iliac artery fistula was highly suspected. The patient was treated by percutaneous placement of an autoexpandable covered stent graft across the left common iliac and left external iliac artery. After successful endovascular management of the ureteroarterial fistula, the patient's hematuria resolved and he recovered fully. During 10 months of follow up, he has been free of hemorrhagic episodes. Because open surgical repair may be difficult and associated with significant risk for complications, endovascular intervention may provide a safety treatment alternative.

Anticoagulant-induced pseudothrombocytopenia occurring after transcatheter arterial embolization for hepatocellular carcinoma.

Pseudothrombocytopenia (PTCP) is the in vitro phenomenon of anticoagulant-activated platelet agglutination that results in spuriously low platelet counts. We report the case of a 65-year-old man with EDTA- and sodium citrate-dependent PTCP occurring after transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) due to hepatitis C cirrhosis. Invasion of the portal and hepatic veins by HCC formed severe trans-tumoral arterio-venous shunts that were effectively treated by TAE. Two days after the therapy, PTCP was seen on blood count and continued for 4 months. The patient received unnecessary treatment for disseminated intravascular coagulation (DIC) until the diagnosis of PTCP was established. PTCP is a rare complication but should be considered after TAE for HCC; lack of recognition may lead the physician to misdiagnosis and patient mismanagement.

Efficacy and feasibility of cisplatin-based concurrent chemoradiotherapy for nasopharyngeal carcinoma.

OBJECTIVE: To investigate the efficacy and feasibility of a cisplatin-based concurrent chemoradiotherapy (CRT) protocol based on Intergroup Study 0099 for nasopharyngeal carcinoma (NPC). METHODS: Sixteen patients with stage II-IVB NPC were treated with a protocol of cisplatin-based concurrent CRT and adjuvant chemotherapy from 1998 to 2002. Three courses of cisplatin (80 mg/m2) were scheduled during 70 Gy of radiotherapy (RT), and two agents of adjuvant chemotherapy (FP regimen: cisplatin 80 mg/m2 and 5-fluorouracil 800 mg/m2/day by 4-day continuous infusion) were challenged. Overall survival (OS) and relapse-free survival (RFS) rates were calculated by the Kaplan-Meier method. RESULTS: Median follow-up duration was 45 months. Both 3-year OS and RFS rates were 81%. Proportions of patients who tolerated each scheduled treatment were 94% for RT, 63% for concurrent chemotherapy and 38% for adjuvant chemotherapy. CONCLUSIONS: Our protocol of the cisplatin-based concurrent CRT followed by adjuvant chemotherapy consisting of FP regimen was effective for Japanese patients with NPC. However, the doses and numbers of cycle of chemotherapy need to be modified because of the low compliance rate. Larger numbers of data accumulation and/or multi-institutional trials may be warranted to confirm the efficacy of this protocol.

[Bilateral massive ovarian edema: a case report including MR findings and etiology].

A 42-year-old woman with bilateral massive ovarian edema (MOE) is presented. MOE is usually seen in women 6 to 33 years of age. Therefore, accurate re-operative assessment of MOE is important to avoid unnecessary oophorectomy procedures. MR findings of MOE are characteristic and reflect very well the diffuse stromal edema noted on microscopy. The etiology and MR findings of MOE are discussed.

[Hypothyroidism after radiotherapy to the neck].

PURPOSE: The purpose of this study was to investigate the incidence and possible predictors of hypothyroidism after radiotherapy to the neck, focusing on radiation dose-volume factors. METHODS AND MATERIALS: Thyroid function was measured in 169 patients treated with radiation ports including the thyroid, between 1989 and 2000. Hypothyroidism was determined with an endpoint of elevated serum thyroid stimulating hormone(TSH) levels > 10.0 microU/ml. In 60 patients, radiation dose-volume factors were calculated; e.g., total volume of the thyroid, mean radiation dose to the thyroid, and %-volume of the thyroid which received radiation doses of no less than 10-70 Gy(V10-V70). The evaluated risk factors for hypothyroidism included these dose-volume factors, sex, age, primary disease, combined chemotherapy, and follow-up period. RESULTS: Hypothyroidism was detected in 33 (19.5%) of the 169 patients. None of them had clinical symptoms of hypothyroidism. V10, V20, and V30 seemed to be possible predictors of hypothyroidism and had a significant impact on the peak level of serum TSH. CONCLUSION: Radiation dose-volume factors of the thyroid seemed to correlate with the incidence of hypothyroidism, and V10, V20, and V30 had a significant impact on the peak level of serum TSH.