Partition model for estimating radiation doses from yttrium-90 microspheres in treating hepatic tumours

A uniform distribution of yttrium-90 (90Y) microspheres throughout the entire liver has always been assumed for dose calculation in treating hepatic tumours. A simple mathematical model was formulated which allows estimation of the activities of a therapeutic dose of 90Y microspheres partitioned between the lungs, the tumour and the normal liver, and hence the radiation doses to them. The doses to the tumour and normal liver were verified by intra-operative direct beta-probing. The percentage of activity shunted to the lung and the tumour-to-normal tissue ratio (T/N) were obtained from gamma scintigraphy using technetium-99m-labelled macroaggregated albumin (MAA) which simulates the 90Y microspheres used in subsequent treatment. The intrahepatic activity was partitioned between the tumour and the normal liver based on the T/N and their masses determined from computerized tomography slices. The corresponding radiation doses were computed using the MIRD formula. The estimated radiation doses were correlated with the doses directly measured using a calibrated beta-probe at laparotomy by linear regression. The radiation doses to the tumour and the normal liver, estimated using the partition model, were close to that measured directly with coefficients of correlation for linear regression: 0.862 for the tumours and 0.804 for the normal liver compartment (P<0.001). The partition model permits a distinction between the radiation doses received by the tumour and the normal liver to be made and the doses thus estimated are close to the actual doses received. The optimal doses to the tumour and normal liver and hence the required quantity of 90Y microspheres to be administered can be easily predetermined.

Optimal position of working ports in laparoscopic surgery: an in vitro study

We investigated the optimal position of the laparoscope in relationship to the working ports. The optical angle (theta), defined as the angle formed by the line of action (determined by the working ports) and the line of vision (determined by the laparoscope), was varied by 30 degrees intervals from 0 degree to 180 degrees to the left and to the right. We also studied the time taken to accomplish a standardized task of tying a square knot with each optical angle in a laparoscopic simulator setting. The optimal position is at the optical angle of 0 degree. The optimal range of the optical angle is 60 degrees to the left and 60 degrees to the right of the optimal position of 0 degree.

Choledocholithiasis: comparison of MR cholangiography and endoscopic retrograde cholangiography

PURPOSE

To prospectively compare magnetic resonance (MR) cholangiography with endoscopic retrograde cholangiography (ERC) in the diagnosis of choledocholithiasis.

MATERIALS AND METHODS

Forty-seven patients with suspected choledocholithiasis underwent non-breath-hold, heavily T2-weighted, respiratory-triggered turbo spin-echo MR cholangiography. They then underwent ERC within 5 hours. The results of the two procedures were compared in 45 patients.

RESULTS

The absence of ductal dilatation was shown in 16 patients at MR cholangiography and at ERC. MR cholangiography showed common duct dilatation in 28 of the 29 patients with dilatation shown at ERC. MR cholangiography helped correctly identify 18 of the 19 patients with choledocholithiasis and 22 of the 26 patients without choledocholithiasis. Sensitivity with MR cholangiography was 95%, specificity was 85%, positive predictive value was 82%, and negative predictive value was 96%. Two of the false-positive findings were due to pneumobilia.

CONCLUSION

Non-breath-hold MR cholangiography is as accurate for the evaluation of choledocholithiasis as ERC.

The use of liver grafts infested with Clonorchis sinensis for orthotopic liver transplantation

In the Orient, millions are known to have Clonorchis sinensis (biliary trematodiasis) infestation. When these infested livers become available as donor organs, there are potentially serious implications that the transplant team would need to consider. We report the use of two such infested livers, one from a cadaveric donor and the other from a live related donor, for orthotopic liver transplantation. The parasite was encountered not only during organ procurement, but also caused early postoperative blockage of the hepatico-jejunostomy splintage tube and cessation of bile flow in the second recipient. Upon follow-up for four and two years, respectively, no other ill effect has been observed in either patient. Repeated examination of stool for ova of C sinensis in both patients during follow-up visits had been negative, indicating that all the parasites probably had been killed by the cold perfusion. In view of the severe shortage of liver grafts and the lack of serious morbidity associated with the use of these infested livers, we have adopted the policy to include these livers for future transplantation. Special considerations and precautions are, however, required during the perioperative period and on long-term follow-up.

Prospective analysis of the distal margin of clearance in anterior resection for rectal carcinoma

The distal resection margin measured in situ at operation, on the fresh specimen and on the fixed specimen was analysed prospectively in 55 consecutive patients undergoing anterior resection for carcinoma of the rectum. There was obvious contraction in length from the operative margin to the specimen margin and to the fixed margin. As measured by contraction coefficients, contraction was greater in more proximal tumours than in distal ones. Eight of 55 patients had microscopic intramural spread in the fixed distal margin and the maximum spread was 12 mm. Taking contraction of the fixed margin into account, the extrapolated microscopic spread in the operative margin ranged from 0 to 47 mm.

Risk of further ulcer complications after an episode of peptic ulcer bleeding

To identify the risk factors for developing recurrent ulcer complications after recovery from an episode of peptic ulcer bleeding 611 patients admitted with peptic ulcer bleeding were studied. Some 557 (91 per cent) were discharged without operation. A total of 22 patients were lost to follow-up and five were excluded as maintenance H2 blockers were required. Of the remaining 530 patients at risk, 169 (32 per cent) developed another complication (166 bleeding, three perforations) over a median follow-up period of 36 months. Patients with duodenal ulcers at the time of bleeding, previous history of peptic ulcer, previous bleeding, history of dyspepsia longer than 3 months, and a short interval between previous ulcer complications and the index bleed were more likely to develop further complications. Sex, age, smoking, coexisting illness, non-steroidal anti-inflammatory drugs intake and time taken to achieve ulcer healing had no predictive value.

Debridement of burn wounds with a surgical ultrasonic aspirator

Ultrasonic ablation of tissue by the surgical ultrasonic aspirator (SUA) is an established technique in neurosurgery and hepatobiliary surgery. We report the first use of SUA in the debridement of burn wound in three patients. Our initial experience suggested that SUA allows meticulous wound debridement and cleansing with minimal bleeding and destruction of normal tissue and, therefore, is an extremely useful surgical instrument to add to the armamentarium of the burn surgeon.

Epinephrine or epinephrine plus alcohol for injection of bleeding ulcers: a prospective randomized trial

BACKGROUND

Rebleeding following epinephrine injection of bleeding peptic ulcers occurs in 10% to 20% of all cases. The addition of a sclerosant has the theoretical advantage of inducing vessel thrombosis and permanent hemostasis.

METHODS

A prospective randomized controlled trial was conducted to compare injections with epinephrine alone or epinephrine plus absolute alcohol in patients with actively bleeding ulcers at endoscopy. Repeat endoscopy was performed 24 hours later; treatment was repeated in the presence of endoscopic signs of rebleeding. Surgery was performed when arterial bleeding could not be controlled endoscopically, clinical rebleeding with hematemesis or shock occurred, or the transfusion total exceeded 8 units.

RESULTS

One hundred sixty patients were enrolled (epinephrine alone, 81; epinephrine and absolute alcohol, 79). They were matched in age, sex, location of ulcers, hemoglobin on admission, shock, and severity of bleeding. Initial hemostasis was comparable: 79 of 81 with epinephrine alone (97.5%) versus 75 of 79 with epinephrine and absolute alcohol (94.9%). No difference was observed between the two with respect to either rebleeding (9 vs 6), need for emergency operation (12 vs 9), transfusion requirement (median, three units vs two units), hospital stay (median, 5 days vs 4 days), mortality (4 vs 7) and ulcer healing at 4 weeks (50 vs 46).

CONCLUSIONS

The additional injection of absolute alcohol after endoscopic epinephrine injection confers no advantage.

Laparoscopic truncal vagotomy and gastroenterostomy for pyloric stenosis

BACKGROUND

Gastric outlet obstruction secondary to chronic duodenal ulceration is an indication for surgery as conservative management with balloon dilatation frequently fails. The standard operation is truncal vagotomy and a drainage procedure. However, development of minimally invasive surgery has revolutionized the surgical approach to this clinical problem.

METHODS

Twelve male patients with pyloric stenosis secondary to duodenal ulceration underwent laparoscopic truncal vagotomy and gastrojejunostomy. The perioperative and long term outcome of this group of patients were analyzed.

RESULTS

The median operating time was 210 (range 180 to 240) minutes. Median postoperative stay was 6 (range 4 to 41) days. Conversion to laparotomy was necessary in one patient. Delayed gastric emptying occurred in two patients but resolved on conservative measures. At a median postoperative followup of 6 (range 1 to 12) months all patients had a good symptomatic outcome (Visick grades I or II).

CONCLUSIONS

Laparoscopic truncal vagotomy and gastrojejunostomy is a feasible technique. Intermediate followup shows good symptomatic results when used for pyloric stenosis.

Urinary 6 beta-hydroxycortisol excretion in Hong Kong Chinese patients with hepatocellular carcinoma and other chronic liver diseases

BACKGROUND

The biotransformation of xenobiotics into toxic metabolites by cytochrome P-450 has been implicated in carcinogenesis. This study investigated CYP3A4 activity, which metabolically activates procarcinogens such as aflatoxin B1, by measuring the urinary 6 beta-hydroxycortisol (6 beta OHF) to free cortisol (F) ratio in patients with hepatocellular carcinoma (HCC) and other chronic liver diseases.

METHODS

One hundred forty-three controls and 150 patients with different liver diseases, including chronic liver disease (due to alcoholism and/or chronic hepatitis B virus infection), cirrhosis (any cause), and resectable and nonresectable HCC, were recruited. Twenty-four hour urine samples were collected for measurement of 6 beta OHF and free cortisol by an enzyme-linked immunosorbent assay (ELISA) and a radioimmunoassay, respectively.

RESULTS

Patients with nonresectable HCC showed a significant increase in 6 beta OHF excretion as well as their 6 beta OHF/F ratio (P < 0.05) when compared with the controls and other liver disease groups including patients with resectable HCC. The nonresectable HCC group showed a bimodal distribution in the 6 beta OHF/F ratio. Using a ratio of 9 or more in all HCC patients, the sensitivity and specificity of using the 6 beta OHF/F ratio to predict nonresectability of HCC was 48.8% and 92.6%, respectively.

CONCLUSIONS

Our results show an increase in mean CYP3A4 enzyme activity, reflected as an increase in the 6 beta OHF/F ratio, in Hong Kong Chinese with nonresectable HCC compared with those with resectable HCC and other liver diseases. Although the role of increased CYP3A4 activity in the aetiology of HCC is not known, our specificity and sensitivity estimates suggest that a high 6 beta OHF/F ratio indicates probable inoperability. However, a normal level is a poor predictor of resectability.

Thoracoscopic resection of oesophageal diverticulum: a case report

The introduction of video-assisted surgery has revolutionized thoracic surgery. The main attraction is the avoidance of a large thoracotomy incision and its associated morbidity. We present the case of a 55-year-old woman with an oesophageal diverticulum presenting with troublesome dysphagia. A thoracoscopic assisted oesophageal diverticulectomy was performed. Post-operative recovery was uneventful, and only two doses of intramuscular opiate analgesic were required. The patient remained asymptomatic at a follow-up of 3 months.

Isoelectric focusing of alphafetoprotein in patients with hepatocellular carcinoma--frequency of specific banding patterns at non-diagnostic serum levels

Serum levels of alphafetoprotein are raised in 60-80% of patients with hepatocellular carcinoma. Although widely used as a serum marker, frequent false-positive results in patients with benign liver disease, result in poor specificity. This occurs particularly when levels of alphafetoprotein fall between 50-500 ng ml-1, the so-called 'grey area'. Recent reports suggest that isoelectric focusing of alphafetoprotein demonstrates certain bands that are more specific for hepatocellular carcinoma. Our aim was to determine whether the apparent specificity of this new approach is gained at the expense of decreased sensitivity. Sera from 110 patients with a 'non-diagnostic' serum alphafetoprotein level (50-500 ng ml-1) were examined by isoelectric focusing and quantified by densitometric scanning. Ten patients with chronic liver disease and a raised serum alphafetoprotein level (50-500 ng ml-1), but with no evidence of hepatocellular carcinoma, were also studied. Isoelectric focusing revealed characteristic hepatocellular carcinoma bands (bands +II and +III) in 96% patients overall, and 100% of those with levels of total alphafetoprotein greater than 100 ng ml-1. No such bands were seen among ten subjects with cirrhosis but without hepatocellular carcinoma. Bands that are characteristic of hepatocellular carcinoma (bands +II or +III) are seen in the great majority of hepatocellular carcinoma patients; their absence makes a diagnosis of hepatocellular carcinoma extremely unlikely.

Malignant anal tumours in the Chinese population in Hong Kong

Malignant anal tumours are rare cancers but are particularly common in Switzerland, Poland and Brazil. Very little is known about this condition in the Chinese population. A retrospective study, covering an 11-year period, was performed. A total of 18 patients were treated at the Prince of Wales Hospital, Hong Kong. There were eight squamous cell carcinomas, seven adenocarcinomas and one each of adenosquamous carcinoma, malignant melanoma and leiomyosarcoma. Bleeding per rectum, with or without perianal pain, was the main presenting symptom. Abdominoperineal resection was the treatment modality used in most cases. Adenocarcinomas, seen mainly in males, accounted for about 39% of cases, a figure much higher than that published elsewhere. Another 44% of patients, predominantly females, had squamous cell carcinoma. None had a positive past history of sexually transmitted disease. The local prevalence of HPV infection is much lower than in the Western world, and the role of HPV in the oncogenesis of anal tumours in the Chinese population awaits elucidation.

Dual therapy versus triple therapy for Helicobacter pylori-associated duodenal ulcers

We compared the ulcer healing effect and eradication of H. pylori by one-week triple therapy of bismuth, metronidazole, and tetracycline with two-week dual therapy of amoxicillin and omeprazole. One hundred twelve patients with confirmed H. pylori infection and duodenal ulcers were recruited in a prospective, randomized, single-blinded trial. Ulcer healing, eradication of H. pylori in the stomach six weeks after randomization and side effect reported by patients during the therapy. Duodenal ulcers were healed in 44 of 49 (89.8%, 95% CI, 81.3-98.3 %) patients receiving triple therapy and in 44 of 53 (83.0%, 95% CI, 72.9-93.1%) patients receiving dual therapy (P=0.32). H. pylori was successfully eradicated in 41 of 49 (83.6%, 95% CI 73.4-94%) patients and in 40 of 53 (75.5%, 95% CI 63.9-87.1%) patients in the triple therapy group and the dual therapy group respectively (P=0.31). Side effects experienced by patients who received triple therapy were significantly more frequent than those who received dual therapy (P=0.0076). In conclusion, a two-week course of omeprazole and amoxicillin achieves a comparable rate of H. pylori and ulcer healing with fewer side effect.

Selective use of preoperative endoscopic retrograde cholangiopancreatography in laparoscopic cholecystectomy

BACKGROUND

The management of possible common bile duct (CBD) stones in patients scheduled for laparoscopic cholecystectomy remains controversial.

METHODS

Prospective evaluation of 609 patients who underwent laparoscopic cholecystectomy was carried out in relation to the use of selective preoperative ERCP for detection of common duct stones. Preoperative ERCP was performed if there is or has been (1) cholangitis, biliary pancreatitis, or jaundice; (2) abnormal serum liver tests or (3) ultrasonogram showing a dilated CBD or ductal stones.

RESULTS

A total of 139 patients underwent preoperative ERCP, and cannulation of CBD was successful in 133 patients (96%). CBD stones were found in 60 patients (45%) and extracted after sphincterotomy. High prevalence of CBD stones was noted in patients with acute cholangitis and CBD stones on ultrasonogram. There were six endoscopic sphincterotomy-related complications (complication rate, 4.5%): bleeding (2), pancreatitis (3), retroduodenal perforation (1). No patient required surgery as the result of a complication. The prediction of the occurrence of ductal stones was further analyzed using stepwise logistic regression. Acute cholangitis and CBD stones on ultrasonogram were shown to be independent significant risk factors with odds ratios of 8.9 and 13.5, respectively.

CONCLUSIONS

With selective preoperative ERCP, suspected CBD stones can be identified and removed prior to laparoscopic cholecystectomy.

Through-the-scope balloon dilation for pyloric stenosis: long-term results

BACKGROUND

Through-the-scope balloon dilation has been used for treatment of benign pyloric stenosis; however, long-term results are lacking in the literature.

METHOD

A retrospective analysis using the Kaplan-Meier method.

RESULTS

Between November 1986 and December 1993, 54 patients underwent through-the-scope balloon dilations for pyloric stenosis. The mean age was 57.5 years. There were 5 (9.3%) initial treatment failures due to tight stenoses and perforations from dilation occurred in 4(7.4%) patients. Forty-five (83.3%) patients underwent successful dilation. Four patients developed rapid restenoses and were found to have malignant obstructions. Forty-one patients entered our study. Time at risk commenced on the date of initial dilation. The end point was defined at the time at which patients presented with recurrent obstruction or other ulcer complications. The median follow-up period was 39 months. The ulcer complication-free probability at 3 months, and at 1, 2, and 3 years was 79.1%, 73.4%, 69.3%, and 54.7%, respectively. In all, 21 (51.2%) patients required subsequent surgery: 18 for recurrent obstructions, 2 for interval perforations, and 1 for bleeding.

CONCLUSION

While through-the-scope balloon dilation may palliate symptoms of obstruction, recurrent obstruction and other ulcer complications are common. It should be reserved only for patients at high risk for operative surgery.

Prospective evaluation of laparoscopic-assisted large bowel excision for cancer

OBJECTIVE

The authors described their experience with laparoscopic-assisted colorectal resection for colorectal carcinoma, both curative and palliative, with emphasis on patient selection. The techniques of the operations were described.

SUMMARY BACKGROUND DATA

Laparoscopic colorectal procedures for treatment of benign lesions have been shown to be less painful and to enhance early postoperative recovery. However, use of laparoscopic procedures for treatment of colorectal cancer are controversial. The authors have used laparoscopic techniques for curative and palliative resections of colorectal carcinoma with satisfactory early results.

METHODS

One hundred patients with colorectal carcinoma were selected over a 30-month period for laparoscopic-assisted colorectal resection. For 17 patients, laparoscopy revealed bulky tumor or locally advanced disease, and open surgery was performed. For 83 patients, laparoscopic-assisted colon and rectal resections were attempted. Procedural data and postoperative results were entered prospectively. The median follow-up period was 15.2 months (range, 2.5-32.7 months).

RESULTS

Fourteen of 83 patients eventually required conversion to open surgery. The median operative time was 180 minutes. The patients could return to a normal diet in a median of 4 days. The median number of doses of analgesics required was two, and the median hospital stay was 6 days. The morbidity rate was 12%, and there was no deaths attributable to the procedure. There were four distant recurrences and one pelvic recurrence.

CONCLUSIONS

Laparoscopic-assisted colorectal resection for selected patients is feasible, and early postoperative results are encouraging. This procedure does not appear to be associated with an excessive recurrence rate, and long-term follow-up is necessary for late survival figures.

Absorbable clips for cystic duct ligation in laparoscopic cholecystectomy

BACKGROUND

The efficacy and applicability of an absorbable polydioxanone (PDS) clip for cystic duct ligation were evaluated in 297 patients undergoing laparoscopic cholecystectomy.

METHODS

The indications for cholecystectomy were symptomatic gallstones (179 patients), acute cholecystitis (67), biliary pancreatitis (23), acute cholangitis (24), and gallbladder polyp (4).

RESULTS

Twenty-five patients required conversion to open surgery (8.4%). The conversion rate was 2.7% for uncomplicated and 17.5% for complicated gallbladder diseases. Of the 272 patients with laparoscopic cholecystectomy, the cystic ducts were successfully ligated with PDS clips in 227 patients (83.5%). The success rate was higher in uncomplicated (163/178) than in complicated (64/94) gallbladder diseases (chi square = 24.6, P < 0.001). There was no clip-related complication on follow-up (range 0.4-39.2, median 17.5 months). In 45 patients, PDS clip failed. They were treated with endoloop (14 patients), Roeder slip knot (13), metallic clips and endoloop (8), metallic clips alone (6), and intracorporeal tie (4).

CONCLUSIONS

The PDS clip is effective and applicable to the majority of patients. It should be attempted first because of the ease of application.

Unexplained septicaemia and pneumoperitoneum in Vietnamese boat people: a self-inflicted condition?

BACKGROUND

Ten Vietnamese boat people with septicaemic shock or pneumoperitoneum were admitted between April and July 1993.

METHODS

In order to investigate the cause of unexplained septicaemic shock and spontaneous pneumoperitoneum in Vietnamese boat people, an audit was carried out. Attention was paid to the mode of presentation, abnormal physical signs, presence of injection marks, radiological signs, subsequent progress outcome.

RESULTS

The clinical and radiological findings were all in favour of self-inflicted conditions. A retrospective review from the hospital record revealed that the emergency admission rate and disappearance rate of the Vietnamese boat people was higher than those of other patients (P<0.001).

CONCLUSION

It is concluded that self-inflicted conditions are a serious problem among the Vietnamese boat people, who may use a hospital admission to avoid the detention centre.

Prospective randomised study of effect of octreotide on rebleeding from oesophageal varices after endoscopic ligation

Up to a third of patients have early rebleeding from oesophageal varices after endoscopic variceal ligation. Octreotide infusion is effective for control of variceal bleeding. We investigated the efficacy of octreotide infusion as an adjunct to endoscopic variceal ligation to prevent early rebleeding from varices. 100 consecutive patients admitted with endoscopically confirmed oesophageal varices and active bleeding or signs of recent haemorrhage were randomly assigned endoscopic variceal ligation alone or octreotide (50 micrograms intravenous bolus injection followed by intravenous infusion at 50 micrograms per h for 5 days) plus endoscopic variceal ligation. Three patients in each group were excluded. Bleeding was controlled in 44 of 47 patients who received variceal ligation alone and in 45 of 47 who received combined treatment (p = 1.0). Recurrent bleeding was documented in 18 (38% [24-52]) patients who received variceal ligation alone and in four (9% [3-21] who received combined treatment (p = 0.0007). The relative risk of rebleeding was lower (0.22 [0.08-0.60]) in the combined therapy group. Ten patients in the variceal ligation group and one in the combined therapy group required balloon tamponade for massive haematesis and haemodynamic instability (p = 0.0039). The in-hospital and 30-day mortality rates were higher in the variceal ligation group than in the combined therapy group (19 vs 9% and 23 vs 11%), but the differences did not reach significance. The relative risks of in-hospital (0.5 [0.04=5.3]) and 30-day (0.45 [0.17-1.2]) mortality were lower in the combined therapy group. Octreotide significantly reduces recurrent bleeding and the need for balloon tamponade in patients with variceal haemorrhage treated by endoscopic variceal ligation.

A prospective study of upper gastrointestinal hemorrhage in patients with hepatocellular carcinoma

Our purpose was to determine, in a prospective study, the causes of gastrointestinal hemorrhage in patients with hepatocellular carcinoma, and the relationship of portal vein invasion with variceal hemorrhage in these patients. During an 11-month period, 55 patients presented with hepatocellular carcinoma presented with signs and/or symptoms of upper gastrointestinal hemorrhage. Forty-seven percent had bleeding from varices, whereas the majority, 53%, had a nonvariceal bleeding source. Among those with nonvariceal bleeding, duodenal ulceration was the commonest cause. Direct tumor invasion into the gastrointestinal tract was found in three patients. Tumor invasion of the portal venous system was detected by ultrasound examination in 76% of the variceal bleeders, compared to only 45% of the nonvariceal bleeders. Despite the very high frequency of cirrhosis among patients with hepatocellular carcinoma, the source of bleeding was variceal in less than half of the patients. Portal vein invasion is a risk factor for subsequent variceal bleed.

Obstructive jaundice secondary to hepatocellular carcinoma

This prospective study aimed to identify different groups of patients with the rare pathology of biliary obstruction caused by hepatocellular carcinoma (HCC). Patients were evaluated with blood tests, chest radiography, ultrasound of the liver and endoscopic retrograde cholangiopancreatography/percutaneous transhepatic cholangiography. Patients who were potentially operable were further assessed with selective hepatic angiography and computed tomography (CT). Of the 38 patients with obstructive jaundice secondary to HCC, the levels of obstruction were extrahepatic in 19 patients and intrahepatic in 19 patients. The clinical presentations and blood biochemistry were similar in these two groups of patients. "Curative' resection was significantly more common in extrahepatic obstruction (8/19) than in intrahepatic obstruction (0/19) (chi 2 with Yates correction P = 0.001). All non-resectable tumours, except in four patients with terminally ill disease, were palliated with stents. Survival in patients who had "curative' liver resection was significantly better than in those who had no resection (median survival 25.3 vs. 2.1 months, log-rank test P = 0.004). Patients with extrahepatic biliary obstruction secondary to HCC had a better chance of being treated by liver resection, which resulted in a significantly improved survival rate compared to patients with intrahepatic obstruction.

Radiation pneumonitis after selective internal radiation treatment with intraarterial 90yttrium-microspheres for inoperable hepatic tumors

PURPOSE

To investigate the clinical, histopathological, and radiological features of radiation pneumonitis arising as a complication of selective internal radiation treatment for liver tumors. To correlate the development of radiation pneumonitis with the degree of lung shunting as assessed by 99mTechnetium-labeled macroaggregated albumin (Tc-MAA) scan.

METHODS AND MATERIALS

Five out of 80 patients who had inoperable hepatic tumors and underwent treatment with intraarterial 90Yttrium- (90Y)-microspheres, developed progressive restrictive ventilatory dysfunction without an infective or cardiovascular cause. Histopathological evidence of a pneumonitis and the presence of microspheres in the lung tissue suggested a diagnosis of radiation pneumonitis. The clinical course, radiological and histopathological findings, percentage tumor shunting to the lungs (lung shunting, as predicted by gamma camera scanning after intraarterial Tc-MAA), and the estimated radiation dose to the lungs were analyzed. In an attempt to reduce pulmonary shunting of the microspheres, three patients received partial hepatic embolization with inert particles before selective internal radiation therapy.

RESULTS

In the five patients who developed radiation pneumonitis, lung shunting percentages (as predicted by Tc-MAA scan) ranged from 13.1 to 45.6% (median 23.7%). The estimated whole lung radiation dose ranged from 10.43 Gy to 36.44 Gy (median 25.04 Gy). Among 75 patients who did not develop radiation pneumonitis, the percentage lung shunting ranged from less than 1% to 15% (median 6%). Nine patients had lung shunting greater than 13% and five of them developed radiation pneumonitis, whereas this developed in none of those in whom shunting was below 13%. The onset of radiation pneumonitis ranged from 1 to 6 months after internal radiation treatment. All five patients exhibited characteristic plain radiographic and computerized tomographic changes comprising extensive consolidation with well-defined lateral margins. Clinical improvement after corticosteroid treatment was seen in two patients. Three patients died from respiratory failure and two from other causes. Partial hepatic arterial embolization reduced the degree of lung shunting to less than 13%, but did not prevent the development of radiation pneumonitis.

CONCLUSION

Radiation pneumonitis may become a complication after intraarterial 90Y-microspheres treatment when lung shunting, as assessed by Tc-MAA scan, is high (above 13%). Prescribed activity of 90Y and lung shunting of Tc-MAA should be considered together before giving selective internal radiation (SIR) therapy for hepatic tumors, and preferably avoided if the lung shunting is above 13%.