Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations

OBJECTIVE

Both helical CT and fiberoptic bronchoscopy are used in the staging of pulmonary tumors for therapeutic decision making. The improved resolution offered by helical CT has led to the clinical use of three-dimensional reconstruction techniques such as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ surfaces and compared it with corresponding fiberoptic examinations of the tracheobronchial system.

SUBJECTS AND METHODS

Twenty patients with malignancies of the lung and mediastinum were examined with both virtual bronchoscopy and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and reconstructed from the cross-sectional images on a separate workstation. Stenoses and tumor infiltration were classified from the fiberoptic examination. These results were compared with the virtual bronchoscopy findings.

RESULTS

Virtual bronchoscopy of diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the advantage of being able to visualize areas beyond even high-grade stenoses. However, on virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five patients. In another patient, strong heart pulsation produced motion artifacts that prevented evaluation of the reconstruction.

CONCLUSION

Virtual bronchoscopy represents a new noninvasive method for evaluating helical CT findings. In comparison with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to visualize areas beyond even high-grade stenoses. In addition to the limited view of fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in the cross-sectional images and evaluated together with the virtual representation. However, it was not possible to detect small infiltrations with virtual bronchoscopy. This new representation of helical CT data might be helpful for postoperative follow-up examinations, such as after stent implantation, and can be carried out without additional risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and experience with three-dimensional-reconstructions to differentiate between real stenoses and artificial stenoses that might be caused by pulsation artifacts.

Displaced metallic biliary stents: technique and rationale for interventional radiologic retrieval

OBJECTIVE

We investigated the spontaneous course and the possibility of transhepatic removal of displaced biliary stents.

MATERIALS AND METHODS

Displaced biliary stents were observed in 11 patients (13-75 years old) between October 1988 and August 1996. Stent types included the Palmaz stent (n = 3), Wallstent (n = 3), and the Strecker stent (n = 5). Reasons for stent displacement included primary misplacement (n = 4), dislocation due to transhepatic endoscopy with biopsy (n = 2), dislocation resulting from a recanalization maneuver in stent occlusion (n = 3), and unknown causes (n = 2). In three cases, the stent was displaced into the proximal bile duct system. Seven patients had primary malignancy.

RESULTS

Eight of 11 displaced biliary stents were removed transhepatically. Extraction was performed using either a wire loop (n = 4) or forceps (n = 4). No complications occurred. In the remaining three patients, whose stents were displaced into the intestine, no invasive action was taken. In one of these patients, a Palmaz stent was passed spontaneously after 1 week. In the second of these patients, a 6 cm Wallstent remained innocuously at a position in the right lower abdomen, and the patient died as a result of malignancy. In the third patient, who had a 10-cm Wallstent, an abscess developed in the stent region 4 months after displacement and resulted in formation of an ileocutaneous fistula.

CONCLUSION

Transhepatic extraction of displaced biliary stents is technically possible, even in the case of rigid stents such as the Palmaz stent. Because of the risk of intestinal perforation, displaced stents should be removed.

[Therapy of acute traumatic vascular injuries using covered stents]

PURPOSE

Evaluation of percutaneously implanted covered stents in acute vascular bleeding as therapeutic alternative to conventional surgical treatment.

MATERIALS AND METHODS

8 patients aged 26 to 83 years with acute vascular lesions caused by traumas, and subsequent haemorrhage, were transferred to our department. Because of general inoperability or difficult surgical access, interdisciplinary evaluation favoured an interventional treatment. In 6 patients stents could be placed percutaneously to the aorta, subclavian and iliac arteries. In one case we had to implant three stents into the thoracic aorta.

RESULTS

In 7 interventionally treated patients the stents could be placed exactly on the lesions (88%). The bleeding could be stopped immediately in 6 cases (75%). In one patient we had to implant successfully two more stents in reintervention (12%). In another patient the available prosthesis was too short, so that the patient had to be referred to the OR for surgical treatment (12%). There were no complications during the treatment.

CONCLUSION

First results in the use of covered stents as interventional treatment of acute vascular lesions are encouraging and may represent a possible alternative to surgical therapy in locally limited bleedings, presupposing that all different types and sizes of industrially produced covered stents are available. Further investigations to compare surgical and interventional techniques are warranted.

Palliative and adjuvant regional chemotherapy in pancreatic cancer

To improve the dismal prognosis of patients (pts) with pancreatic cancer we treated 32 patients with non-resectable (UICC III, 17 pts; UICC IV, 15 pts--group 1) and 20 patients with resected (UICC I, 1 pt; UICC II, 3 pts; UICC III, 16 pts--group 2) pancreatic cancer with palliative (group I) and adjuvant post-operative (group II) coeliac axis intra-arterial cyclic infusions (CAI). CAI consisted of mitoxantrone 10 mg/m2 on day 1, folinic acid 170 mg/m2 and 5-FU 600 mg/m2 during days 2-4, and cis-platinum 60 mg/m2 on day 5 for up to 11 (group I) or six (group II) cycles. In a total of 211 cycles toxicities at the level of WHO III occurred in 0-6% and of WHO IV in 0%. The median survival times, compared with institutional historical controls (treated vs controls), were 12 vs 4.8 months in UICC III (P < 0.006) and 4 vs 2.9 months in UICC IV (P < 0.05) group I pts, and 21 vs 9.3 months in group II (P < 0.0003). Hepatic disease progression appeared to be suppressed with CAI, which also appears to be effective for palliative and adjuvant treatment in non-resectable and resected pancreatic cancer.

Sensitivity of computed tomography in detecting local recurrence of prostatic carcinoma following radical prostatectomy

The aim of this study was to evaluate CT imaging in the post-operative follow-up and in the detection of recurrence after radical prostatectomy in cases of prostatic carcinoma. In over 500 patients undergoing radical prostatectomy for prostatic carcinoma, 22 cases with local recurrence were found. CT examinations of the pelvis were retrospectively evaluated in these patients. Local recurrence was detected by PSA uptake and confirmed by transrectal ultrasound (TRUS) in combination with guided biopsy. In 22 cases of confirmed local recurrence, positive results on CT were found in eight patients (36%) and negative results in nine patients (41%). In the remaining five cases (23%), no distinction could be made between scar and local recurrence. All cases definitively classified as recurrent tumour disease showed a soft tissue mass of 2 cm or more. CT sensitivity in local recurrence of prostatic carcinoma after surgery is low. Even in a very careful follow-up, the understaging would be up to 41%. In comparison, PSA, TRUS and needle biopsy are the methods of choice and are superior to CT imaging. Based on these results, there would be no reason for including pelvic CT examinations in the follow-up of prostatic carcinoma after radical prostatectomy.

Percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease using a transluminal endatherectomy catheter (TEC): initial results and angiographic follow-Up

PURPOSE

To evaluate the clinical results of percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease.

METHODS

Rotational atherectomy was performed in 39 patients aged 39-87 years (mean 66.6 years). A total of 71 lesions (43 stenoses and 28 occlusions) were treated in 40 limbs. Additional balloon angioplasty was required in 54% of lesions. Fifteen patients (37.5%) presented in Fontaine stage II, 10 patients (25%) in Fontaine stage III and 15 patients (37.5%) in Fontaine stage IV. Rotational atherectomy at 750 rpm was carried out over a 0.014-inch guidewire with continuous aspiration into a vacuum bottle. Follow-up angiography and color flow Doppler examinations were performed in 22 patients (23 limbs) after a mean period of 6 months (range 2-14 months).

RESULTS

There was one primary technical failure. In 36 of 40 lesions there was a good angiographic result with residual stenoses in less than 30%. In 70 lesions treated by rotational atherectomy, however, 54% showed residual stenoses of 30%-50% and these cases required additional balloon angioplasty. The mean ankle-brachial index improved significantly (p << 0.001) from 0.49 before the procedure to 1.01 after the procedure. A single distal embolus, related to primary recanalization, occurred and there were two large inguinal hematomas. Cumulative clinical patency after 6 months was 83.8% and cumulative angiographic patency after 6 months was 79.1%.

CONCLUSION

Percutaneous rotational atherectomy is a promising approach for the treatment of chronic peripheral vascular disease. Further prospective, randomized studies are necessary to compare percutaneous transluminal angioplasty with this new technical approach.

[A new method in the determination of individual delay time in bolus application in spiral CT]

Helical-CT examinations, particularly CT angiography, require precise timing between the examination procedure and the individual dynamics of contrast medium distribution in the arteriovenous system of the patient. The necessary delay between contrast medium injection and onset of has usually been either estimated or determined by means of an additional helical CT examination. The present paper introduces a new technique which allows bolus analysis without an additional scan. Prior to a CT angiography with 10 patients, two techniques for bolus analysis (BA) were compared. Prior to diagnostic contrast medium enhanced examination, a native (BA I) and a dynamic (BA II) examination were performed. Ten seconds prior to the start of each examination, a 10 ml test bolus was applied with an injection flow rate of 3 ml/s. Both examinations lasted for 30 s. During BA I, increase in attenuation in the aorta was compared at different sites, during BA II consistently at the same site. Comparison of the individual peak times yielded a coefficient of correlation of r = 0.926. The median value for BA I was 18.4 +/- 5.4 s and 19.2 +/- 4.5 s for BA II. The difference between measurement of peak time was 1.2 +/- 1.16 s. This modified technique for bolus analysis during the primary native scan of the upper abdominal organs permits calculation of the required individual delay time between contrast medium application and scan start: no additional examination is required and the method can be performed with any helical CT unit.

[Interventional treatment of hemobilia]

PURPOSE

Aim of the study was to assess the use of embolisation in cases of iatrogenic haemobilia.

METHOD

In 18 patients with severe haemobilia after percutaneous biliary system drainage or stent implantation, an embolisation with minicoils (17 x) or gelfoam particles, was performed. To achieve a sufficient vascular obstruction, Histoacryl (4 x) or Ethibloc (1 x) were additionally used in five cases. A transarterial approach was used in 17 cases. In one patient, an approach through the biliary system was possible.

RESULTS

In all cases, the bleeding source was identified (5 false aneurysms, three biliary leaks, 9 irregularities at the junction of the artery and drainage catheter, 1 multiple collaterals at the proximal end of the stent). In 17 out of 18 cases, haemorrhage ceased definitely. In one case of a patient with pancreas carcinoma and obstruction of the portal vein as well as a simultaneous high grade stenosis of the hepatic artery propria, it was only possible to embolise small collaterals to avoid liver necrosis. This resulted in an incomplete bleeding of control. An infected haematoma was the only complication. It was treated by drainage over 10 days. During an observation period ranging approximately 7.6 months, 10 of the patients died due to their basic illness.

CONCLUSION

Embolisation is an effective procedure in the treatment of haemobilia, with a low complication rate.

Short-term results with use of the Amplatz thrombectomy device in the treatment of acute lower limb occlusions

PURPOSE

To evaluate the clinical efficacy of the Amplatz device for the treatment of acute occlusions of the lower limb arteries.

MATERIALS AND METHODS

Forty patients with acute occlusion of the lower limb arteries (3 hours to 8 days; mean, 2 days) were treated using the Amplatz clot macerator. Acute thrombotic lower limb occlusion was due to an embolic event in 32 patients and to atherosclerotic disease in eight patients.

RESULTS

Complete success, with complete clearing of thrombotic material without an adjunctive procedure, was achieved in 75% (30 of 40) of the patients. Mean thrombectomy time in these patients was 75 seconds. Partial success, with incomplete clearing of the thrombus, requiring additional procedures such as local thrombolysis, angioplasty, or atherectomy, was achieved in 20% (eight of 40) of the patients. The Doppler index increased significantly (P < .001) from .45 before intervention to .96 after intervention. There were two failures (5%). No major complications occurred.

CONCLUSION

Mechanical thrombectomy with use of the Amplatz device is a promising approach for quick recanalization of acute peripheral thromboembolic occlusions. Further studies are needed to prove the long-term patency after mechanical thrombectomy with use of this device.

Celiac artery adjuvant chemotherapy. Results of a prospective trial

CONCLUSION

Celiac artery infusion (CAI) seems to be a qualified and successful method for adjuvant treatment of pancreatic cancer. To improve the dismal prognosis of resected pancreatic cancer patients, we performed postoperative regional chemotherapy via the celiac axis.

BACKGROUND

From 1994-1995, 20 patients with pancreatic cancer (18 ductal adenocarcinoma, 2 cystadenocarcinoma) received adjuvant celiac axis intra-arterial infusions (CAI) after resection of their tumors. Sixteen patients had macroscopically complete tumor removal (R0/R1 resection, 80% of the patients), whereas four patients had gross residual disease remaining after resection (R2 resection, 20% of the patients). Postoperative tumor stages were UICC I in 1 patient, UICC II in 3 patients, and UICC III in 16 patients.

METHODS

CAI was performed for six postoperative cycles via catheters placed into the celiac artery using Seldinger's technique. The chemotherapeutic protocol consisted of mitoxantrone (Novantron), Wyeth-Lederle (Münster, Germany) 10 mg/m2 (d 1), folinic acid (Leucovorin, Wyeth-Lederle, or Rescuvolin, Medac, Hamburg, Germany) 170 mg/m2 for 10 min, followed by 5-FU (Fluoroblastin, Farmitalia, Freiburg, Germany) 600 mg/m2 for 120 min (d 2-4), and Cisplatin (Cisplatin-medac, Medac) 60 mg/m2 (d 5). The cycles were repeated after a rest period of 4 wk. Cisplatin infusions were accompanied by supportive antiemetic (8 mg Tropisetrone i.v. [Navoban, Sandoz, Nürnberg, Germany] and 8 mg Dexametason i.v.) and diuretic measures.

RESULTS

Toxicity WHO III occurred in 8% of 100 cycles, and no toxic side effects WHO IV were encountered. The median survival of 21 mo in the treated group was nearly twice as long as the 9.3 mo of a historical matched control group (p < 0.0003). CAI seems to be a qualified and successful method for adjuvant treatment of pancreatic cancer.

[Infectious spondylitis. A retrospective evaluation of MRI markers]

AIM AND METHODS

The aim of the present study was to evaluate the MRI criteria of infectious spondylitis (spondylodiscitis). The MR images of 23 patients suffering from spondylodisitis (78% unspecific, 22% specific) were retrospectively analyzed.

RESULTS

The height of the intervertebral discs involved was normal in 40%, reduced in 43% and increased in 17% of the cases. The most common findings can be summarized in an MR triad: 1) The vertebral bodies involved are hypointense in T1-weighted images (100%) with a lack of delineation of the intervertebral discs (53%). 2) The injection of Gd-DTPA yields an enhancement of the vertebral bodies involved and intervertebral discs (95% and 74% respectively). 3) The vertebral bodies and intervertebral discs are hyperintense in T2-weighted sequences (76% and 90% respectively). When present, a paravertebral or intraspinal extension of the infection was isointense compared with the adjacent involved vertebral body in the majority of the patients. A differentiation between unspecific and specific etiology based on the MR images was not possible.

CONCLUSIONS

The vertebral bodies affected were usually hypointense in T1-W with enhancement after the administration of Gd-DTPA and hyperintense in T2-W. The discs involved were usually hyperintense in T2-W and demonstrated an inhomogeneous enhancement.

Mechanical thrombectomy of embolic occlusion in both the profunda femoris and superficial femoral arteries in critical limb ischaemia

We report our preliminary experience using the Amplatz device for percutaneous thromboembolectomy in acute occlusion in both the profunda femoris artery (PFA) and superficial femoral artery (SFA) in four patients (mean age 78.5 years). All patients suffered from acute lower limb ischaemia, Fontaine Grade 3, due to cardiac embolization. Estimated occlusion times range from 3 h to 3 days. All four patients were treated successfully. Device activation time for both the PFA and the SFA was 85 s +/- 15 s. Total procedure time was 25 min +/- 10 min. There was no need for adjunctive procedures or intensive care monitoring. We conclude that the Amplatz device is a very effective and safe procedure for the quick restoration of vascular patency in cases of simultaneous embolically occluded PFA and SFA.

Stenting of central venous stenoses in hemodialysis patients: long-term results

From November 1992 through July 1996, 15 Wallstents were implanted for the treatment of symptomatic central arm vein obstructions in 14 hemodialysis patients (10 subclavian, 2 brachiocephalic vein stenoses, 2 subclavian vein occlusions). There were no acute complications. All patients were investigated by clinical examination and color-duplex sonography at regular three month intervals. When recurrent swelling predicted restenosis, phlebography was also performed. During the follow-up, high grade stenoses at the central or peripheral ends of four stents were successfully treated with five overlapping stents, giving a total of 20 Wallstent implantations. Complete occlusion of another subclavian vein distally to the stent at 16 months required ligation of the patient's arteriovenous fistula. Life table analysis including all 20 stents revealed a cumulative primary one year (two year) stent patency of 70% (50%). The cumulative secondary one year (two year) stent patency was 100% (85%). We believe that in hemodialysis patients, PTA plus Wallstent implantation is a safe and effective procedure in the treatment of central venous stenoses and even shorter occlusions. Consequent follow-up allows for timely diagnosis and treatment of restenoses, thus guaranteeing long-term patency rates comparable to those of veno-venous bypass surgery.

[Presentation of a new self-expanding vascular spiral stent]

The technical details as well as first clinical results of a newly developed Nitinol stent are presented. The spiral-shaped Nitinol stent was implanted in two patients with complicated peripheral arterial obstruction after bypass surgery. Stent implantation was very exact and technically simple using a special implantation catheter. While one patient is free of symptoms three months after stent implantation, an early obstruction was observed in the other patient one day after the interventional procedure. The specific spiral design allows a simple percutaneous extraction of the stent. A cross-over use of the stent seems principally possible, but limited due to the length of the implantation catheter of 70 cm. Prospective clinical studies are, however, warranted.

[Virtual cystoscopy based on spiral CT data]

Simulation of three-dimensional cystoscopy based on helical CT scan data in real-time in patients with tumours of the urinary bladder. In three patients with histologically confirmed carcinoma of the urinary bladder, a helical CT scan with double detector technology was carried out preoperatively. A native scan was first performed, followed by an examination in the early contrast medium enhanced phase. After adequate contrasting of the urinary bladder (30 minutes latency), further images were acquired. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and pathohistological findings. All tumours of the urinary bladder identified at fiberoptic cystoscopy were also visualised by virtual cystoscopy. The best reconstruction results were obtained from data acquired after the 30-minute latency period. Virtual cystoscopy represents an interesting option in helical CT scanning, which is able to visualise polypoid tumours of the urinary bladder. Its clinical relevance, however, must be demonstrated in studies with a larger number of patients examined.

[CT osteodensitometry in the area immediate to hip endoprostheses]

The value of metal artifact reduction in quantitative bone density determination in the vicinity of metallic implants was studied.

METHOD

Ten cadaver femora with hip endoprostheses implanted intra vitam were examined in CT with varying slice thicknesses, tube voltage, scan time and magnification factor. The artifact-laden images were then processed using a metal artifact reduction programme (MAR). The metallic implant was removed, allowing the bone slices to be examined again with the same imaging parameters, but without the bothersome metal artifacts. This allowed comparison of bone density values obtained before and after application of MAR with data obtained after implant removal.

RESULTS

A comparison of the bone density measurements between the sample group without implants and the group with indwelling implants prior to MAR showed an unexpected correlation coefficient r = 0.975-0.977. The correlation coefficients after MAR rose to r = 0.987-0.992 in 125 kV and r = 0.989-0.991 in 85 kV modes. The reproducibility of the density measurements for the groups without implants and with implants following MAR showed variation coefficients (VC) of 1.16% and 0.75% respectively. The reproducibility of the manual definition of the region of interest (ROI) in bone showed a VC = 2.19%.

CONCLUSIONS

Bone density in the vicinity of metallic implants can be reliably and reproducibly determined using MAR.

Endovascular stenting in patients with Iliac compression syndrome. Experience in three cases

The authors report their experience in the percutaneous treatment of the iliac compression syndrome in three women (20-53 years old) with acute iliofemoral deep venous thrombosis; in one case, there was an additional thrombus in the inferior caval vein. They were treated by percutaneous implantation of Palmaz stents in the left common iliac vein 1 day after surgical thrombectomy and construction of an arterial venous fistula. All patients showed marked improvement, as determined from venograms obtained immediately after stent implantation. The arteriovenous fistulae were closed 3 months later. At 6 months follow-up, the median clinical and color-coded duplex ultrasound indicates that all stents are patent and all patients are free of symptoms.

[The value of MR-mammography at 1.5 tesla in the differential diagnosis of non-puerperal mastitis and inflammatory breast carcinoma]

PURPOSE

The distinction between mastitis and inflammatory breast carcinoma is an important one. Current methods of evaluation including mammography, ultrasound and clinical examination do not enable this distinction. Dynamic magnetic resonance mammography (MRM) is a study with potential in this regard.

MATERIAL AND METHODS

12 patients, in whom clinical examination, mammography and ultrasound could not distinguish between both diseases, were reviewed retrospectively by means of MRM using a 1.5 T Siemens Magnetom SP and a circular mamma coil. We used dynamic 3-D gradient echo sequences with a duration of one minute.

RESULTS

At present MRM cannot definitely distinguish between mastitis and inflammatory carcinoma, 80% of the inflammatory carcinomas were found to enhance more than 100% in the first minute, compared to 43% for mastitis. No other differences were seen.

CONCLUSION

MRM proved useful in the follow-up of treated mastitis to demonstrate the success of antibiotic treatment of mastitis and to diagnose a histologically unconfirmed inflammatory carcinoma by means of a different follow-up.

[Epidurography: comparison with CT, spiral CT and MR epidurography]

PURPOSE

The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature.

MATERIAL AND METHODS

After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology.

RESULTS

40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space.

CONCLUSION

CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.

[Superselective embolization of tumor nodes in solitary kidney in inoperable patients]

PURPOSE

Evaluation of superselective embolisation of renal tumours in inoperable patients with solitary kidneys.

METHODS AND PATIENTS

Eight inoperable patients with solitary kidneys bearing tumour nodules underwent 1-3 superselective embolisation procedures with ethibloc (5x) or polyvinyl alcohol (1x). Renal function was monitored with creatinine levels. Tumour size was controlled every three months by means of sonography.

RESULTS

Technical success rate was 100%. In 3/3 patients haematuria could be stopped. Post-embolisation renal function was unchanged in 6 patients and deteriorated in two patients; creatinine level rose to a maximum of 2.2 mg%. We observed no other side effects. Seven of eight patients died during a median follow-up period of 9.3 months (4-18 months); in two cases they died due to their underlying malignant disease. One patient had local tumour progress.

CONCLUSIONS

Superselective embolisation of renal tumours in patients with solitary kidneys may be a helpful, well-tolerated therapeutic option in inoperable, symptomatic patients.

CT-guided intraarterial chemotherapy in locally advanced tumors

In a retrospective study, 123 patients with tumors (the majority were recurrent pelvic or breast neoplasms) underwent 376 cycles of intraarterial chemotherapy. Contrast material-enhanced computed tomography was performed to check the position of the catheter during 221 cycles. On the basis of findings, the catheter was repositioned 46 (20.8%) times because of weak contrast enhancement in the tumor region (n=24[10.9%]), involvement of neighboring healthy tissue (n=15[6.8%]), or both (n=7[3.2%]).