Stereotactic Body Radiation Therapy for Unresectable Perihilar Cholangiocarcinoma

For patients with perihilar cholangiocarcinoma, surgery is the only treatment modality that can result in cure. Unfortunately, in the majority of these patients the tumors are found to be unresectable at presentation due to local invasive tumor growth or the presence of distant metastases. For these patients palliative chemotherapy is the standard treatment yielding an estimated median overall survival of 12-15.2 months. There is no evidence from randomized trials that supports the routine use of stereotactic body radiation therapy (SBRT) for unresectable cholangiocarcinoma. However, small and most often retrospective studies combining chemotherapy with SBRT showed promising results with overall survival reaching up to 33-35 months.

This pilot study is designed as a first step to confirm and extend these findings. Up to six patients diagnosed with unresectable perihilar cholangiocarcinoma will be treated with standard chemotherapy followed by SBRT in order to assess possible severe side effects of the treatment. As part of this research, patients will be followed with CT- or MRI-scan and blood tests exams until progression. In addition to this clinical evaluation, the investigators will also work towards developing a predictive assay for radiotherapy response of both normal and tumor tissue by establishing normal tissue and tumor organoids and determining several key parameters for their response to ionizing radiation treatment.

Inclusion criteria

In order to be eligible to participate in this study, a subject must be discussed in a multidisciplinary liver tumor board and should meet all of the following criteria:

• Patients diagnosed with perihilar cholangiocarcinoma according to the criteria of the Mayo Clinic, Rochester:

• Positive or strongly suspicious intraluminal brush or biopsy or,
• A radiographic malignant appearing stricture plus either:

• CA 19-9>100 U/ml in the absence of acute bacterial cholangitis, or
• polysomy on FISH, or
• a well-defined mass on cross sectional imaging.
• One tumor mass
• Unresectable tumor
• Finished chemotherapy treatment with Gemcitabine and Cisplatin, preferably 8 cycles. If less cycles are given, patients are still eligible for this study.
• T1-T4 (AJCC staging 7th edition), before chemotherapy
• N0-N1 (AJCC staging 7th edition), radiologically or pathologically suspect, before chemotherapy
• Measurable disease to be selected as a target on CT/MRI-scan, according to RECIST criteria, after chemotherapy within 6 weeks prior to inclusion
• Tumor visibility on CT
• If liver cirrhosis is present, it should be well compensated, with Child-Pugh grade A.
• Age ≥ 18 years
• ECOG performance status 0-1
• Bilirubin ≤1.5 times normal value, AST/ALT ≤5 times ULN, within 6 weeks prior to inclusion
• Platelets ≥ 50x10E9/ l, Leukocytes > 1.5x10E9/l, Hb > 6 mmol/l, within 6 weeks prior to inclusion
• Written informed consent, after chemotherapy
• Willing and able to comply to the follow-up schedule
• Able to start SBRT within 12 weeks after completion of chemotherapy.

Exclusion criteria

• Eligibility for resection
• Prior surgery or transplantation
• Multifocal tumor
• Tumor extension in stomach, colon, duodenum, pancreas or abdominal wall.
• N2, (AJCC staging 7th edition), radiologically or pathologically suspect, before chemotherapy
• Distant metastases
• Progression (local or distant) during or after chemotherapy Ascites
• Previous radiotherapy to the liver
• Current pregnancy