- (2006) Volume 7, Issue 1
Subodh Varshney1, Ajit Sewkani1, Sandesh Sharma1, Sorabh Kapoor1, Saleem Naik1, Abhishek Sharma1, Kailash Patel2
Departments of 1Surgical Gastroenterology and 2Radiology. Bhopal Memorial Hospital and Research Centre. Bhopal, MP, India
Received: 12 November 2005 Accepted: 25 November 2005
Context Unresectable pancreatic cancer has a dismal prognosis. Palliative surgery and chemo-radiotherapy have not produced significant improvement in survival. We evaluated the safety and the efficacy of radiofrequency ablation for cytoreduction of unresectable tumors of the pancreas. Case report Radiofrequency ablation was performed in three patients with histologically proven unresectable cancer of the pancreas: two females and one male; 48, 60, and 66 years of age (mean 58 years). The sizes of the pancreatic tumors were 5.0, 6.5, and 8.0 cm (mean 6.5 cm), respectively. Two patients underwent radiofrequency ablation during an open operation while one patient had percutaneous CT guided radiofrequency ablation. All had endobiliary stenting for obstructive jaundice. Partial necrosis (up to 3 cm) of the tumor was ac hieved in all cases. There was no major morbidity or mortality. Self-limiting minor complications occurred in two patients. Conclusion Radiofrequency ablation is a local ablative method used with increasing frequency and may be used safely for cytoreduction in locally advanced inoperable pancreatic malignancies. Further studies are required to ascertain whether this can improve survival/quality of life alone or in combination with other therapies
Catheter Ablation; Pancreas; Pancreatic Neoplasms
RFA: radiofrequency ablation; CECT: contrast enhanced computed tomography
Cancer of the pancreas is the fifth most lethal cancer in the world. Only 10% are confined to the pancreas at the time of presentation, 40% are locally advanced and another 50% have distant metastases [1]. The overall prognosis of unresectable pancreatic cancer is poor [2]. Palliative measures have not produced significant improvement in survival [3, 4]. Chemotherapy and radiation have minimal benefit in these patients [5]. Radiofrequency ablation (RFA) is being successfully used in the treatment of unresectable solid tumors in the liver [6, 7, 8, 9, 10], lung [11, 12], breast [13, 14], kidney [15], adrenal glands [16], spleen [17], prostate [18], bone [19], brain [20], and intrahepatic cholangiocarcinoma [21]. RFA of locally advanced pancreatic cancer as a cytoreductive means is a new treatment option with only a few studies found in the medical literature [22, 23].
We evaluated the feasibility, efficacy, safety and complications of radiofrequency ablation in unresectable pancreatic cancer.
Between May 2001 and July 2003, three patients (two women and one man; 48, 60, and 66 years of age, (mean 58 years) with a large unresectable mass in the head or uncinate process of the pancreas underwent RFA. The sizes of the lesions were 5.0, 6.5, and 8.0 cm (mean 6.5 cm), respectively. All 3 patients presented with surgical obstructive jaundice and abdominal pain. Contrastenhanced computed tomography (CECT) of the abdomen and pelvis according to pancreatic protocol was performed in all 3 patients. The reason for unresectability was encasement and infiltration into the portomesenteric (superior mesenteric and/or portal vein) vessels in all 3 patients. In addition, one patient had a history of stroke and ischemic heart disease, rendering her unfit for any major operative procedure. Endobiliary stenting was carried out in all three patients to relieve jaundice. Histological confirmation of the diagnosis was obtained in all 3 patients before RFA (percutaneous CTguided needle biopsy in two patients and biopsy during side viewing endoscopy in the third).
We used a Berchtold RF generator (Tuttlingen, Germany), generating 40-60 W of power. Radiofrequency needle was placed in the center of the tumor under CT guidance (n=1) or during open operation, under intraoperative ultrasound guidance (n=2). Approximately 4,200 W of energy was delivered using a saline perfused needle with the aim of producing a necrosis 3 cm diameter in the tumor. Intra-operative monitoring of the coagulated tissue was done with intraoperative ultrasound. All patients received antibiotics for seven days (ciprofloxacin 500 mg bid and metronidazole 400 mg tid). Patients were screened for development of pancreatitis by serial serum amylase and lipase at 24 and 48 hours after the procedure. Patients were discharged from the hospital on day five after the percutaneous approach and on day 10 after the open procedure. A followup CECT of the abdomen was performed between two and four weeks after the procedure in order to evaluate the extent of the necrosis of the ablated area. (Figures 1 and 2).
Figure 1. Pre radiofrequency ablation contrast enhanced computed tomography demonstrating large pancreatic head malignancy.
Figure 2. Post radiofrequency ablation contrast enhanced computed tomography demonstrating 3 cm diameter necrosed (non enhancing) area.
Partial necrosis (up to 3 cm) was achieved in all cases of locally advanced cancer of the pancreas. There was no major procedurerelated morbidity or mortality. Two patients had minor complications: self-limiting ascites in one patient (with normal ascitic fluid amylase) and a 2 cm asymptomatic pseudocyst in another patient which was seen on follow-up ultrasonography. Neither patient required any treatment. Two patients had reduced abdominal pain two weeks after the procedure.
One patient died following massive myocardial infarction one month after RFA. This patient had a history of ischemic heart disease and cerebrovascular accident. Another two patients survived for 9 and 11 months, respectively; they died from progression of the disease and widespread metastases.
Pancreatic cancer is the third most common gastrointestinal malignancy. It is a disease with an extremely poor prognosis. Large series of patients with pancreatic cancer suggest that only 5-22% are resectable at the time of presentation [1]. Median survival for unresectable pancreatic cancer is about 4-6 months [3]. Surgical resection is the only potentially curative treatment for pancreatic cancer. Porto-mesenteric involvement is a relative contraindication for resection. Morbidity and mortality after pancreatectomy with vascular reconstruction can be substantial, with no significant survival benefit [2]. Palliative R1 or R2 resectional surgery for locally advanced pancreatic cancer has not shown any survival benefit in larger series with survival ranging from 10.5- 20 months [24]. Chemoradiation generally has minimal symptomatic improvement in these patients [4]. Trials of chemotherapy with or without radiotherapy have shown some improvement in symptoms and quality of life, without significant improvement in survival [25]. Side effects and complications from chemotherapy and radiotherapy should also be considered.
In all our patients, we were able to achieve cytoreduction by producing tumor necrosis 3 cm diameter. RFA has been commonly used for liver [6, 7, 8, 9, 10] and lung [11, 12] tumors where resection is not advisable or refused. RFA has also been used for small breast cancers [13, 14] and renal tumors [15]. The applications of RFA are slowly increasing and have been extended to cancers of the adrenal gland [16], spleen [17], prostate [18], bone [19], and brain [20].
A multi-institutional study published in 1990 shows the efficacy of hyperthermia in advanced or inoperable cancer of deep seated organs including the pancreas [22]. Matsui et al. [23] used RFA in 20 cases of unresectable pancreatic cancer and concluded that the procedure is safe but further trials are required to check the efficacy of the procedure. Falk et al. [26], in 77 patients having unresectable cancer of the pancreas, demonstrated that radiofrequency hyperthermia reduces the dose of chemotherapy, with an improvement in response to treatment. Goldberg et al. [27] studied the safety and efficacy of RFA in experimental models, and concluded that RFA can be used in small neuroendocrine tumors and possibly palliation of unresectable pancreatic cancer. Date et al. [28] demonstrated the safety and efficacy of RFA in the normal pancreas of a porcine model. Elias et al. [29] reported two cases of multiple pancreatic metastases from renal tumors treated with RFA; unfortunately both patients developed severe necrotizing pancreatitis and died. The mortality in their series was probably due to multiple ablations which led to severe pancreatitis. Spillotis et al. [30] recently reported good results using RFA in five patients with inoperable pancreatic cancer.
RFA of pancreatic tumors has the danger of inducing various complications such as acute pancreatitis, a pancreatic fistula, pancreatic ascites, etc. No such complications were seen in our series because we ensured that the normal pancreatic tissue was not ablated, thus avoiding chances of acute pancreatitis and a pancreatic fistula. In our series, one patient died after one month from an unrelated cause and two survived for 9 months and 11 months. It is very difficult to comment on improvement in survival, because of the small numbers involved.
Our study on a small sample of patients demonstrated that RFA of unresectable pancreatic tumors is feasible and safe with minimum morbidity and mortality. The ablated area should be restricted within the tumor to avoid chances of acute pancreatitis or a pancreatic fistula. This method can be used as a cytoreductive measure in an adjuvant setting with the aim of better palliation in locally advanced pancreatic malignancies. Further studies of radiofrequency ablative cytoreduction therapy with or without chemotherapy and chemoradiation are warranted to study the benefit of RFA on survival and quality of life in unresectable pancreatic cancer.
