Stereotactic radiotherapy of pancreatic cancer: a systematic review on pain relief

Locally advanced pancreatic carcinoma (LAPC) has a poor prognosis and the purpose of treatment is survival prolongation and symptom palliation. Radiotherapy has been reported to reduce pain in LAPC. Stereotactic RT (SBRT) is considered as an emerging radiotherapy technique able to achieve high local control rates with acceptable toxicity. However, its role in pain palliation is not clear. To review the impact on pain relief with SBRT in LAPC patients, a literature search was performed on PubMed, Scopus, and Embase (January 2000-December 2017) for prospective and retrospective articles published in English. Fourteen studies (479 patients) reporting the effect of SBRT on pain relief were finally included in this analysis. SBRT was delivered with both standard and/or robotic linear accelerators. The median prescribed SBRT doses ranged from 16.5 to 45 Gy (median: 27.8 Gy), and the number of fractions ranged from 1 to 6 (median: 3.5). Twelve of the 14 studies reported the percentage of pain relief (in patients with pain at presentation) with a global overall response rate (complete and partial response) of 84.9% (95% CI, 75.8%-91.5%), with high heterogeneity (Q(2) test: P<0.001; I-2=83.63%). All studies reported toxicity data. Acute and late toxicity (grade >= 3) rates were 3.3%-18.0% and 6.0%-8.2%, respectively. Reported gastrointestinal side effects were duodenal obstruction/ulcer, small bowel obstruction, duodenal bleeding, hemorrhage, and gastric perforation. SBRT achieves pain relief in most patients with pancreatic cancer with an acceptable gastrointestinal toxicity rate. Further prospective studies are needed to define optimal dose/fractionation and the best systemic therapies modality integration to reduce toxicity and improve the palliative outcome. Finally, the quality of life and, particularly, pain control should be considered as an endpoint in all future trials on this emerging treatment technique.