Long-term normal tissue effects of intraoperative electron radiation therapy (IOERT): late sequelae, tumor recurrence, and second malignancies

Value of Intraoperative Radiotherapy in Locally Advanced Rectal Cancer

“…IORT is a boosting technique that has been proven to be feasible to integrate in the multimodality treatment of locally advanced rectal cancer without increased normal tissue toxicity. 28 Previous studies have demonstrated that IORT achieves good local control and high survival rates in primary locally advanced rectal cancer. 7,10,11,21,[29][30][31][32] Most of the results reported regarding IORT in rectal cancer originate from a few centers, and randomized trials are lacking.…”

Intraoperative radiation therapy

“…The analysis of the University of Navarre experience did correlate the estimation of risk of normal tissue damage (calculated by the additive effect from treatment modalities) with the relative incidence of grade 3-4 toxicities [106]. Unexpectedly, 91% of bone sarcoma patients belonged to the high-risk group of the late normal tissue damage, and 60% developed grade 3-4 complications.…”

“…A similar event has never been reported in clinical IOERT experiences. The Azinovic and Calvo analysis identified eight patients with second tumours with a questionable possibility in three cases to be marginal to the external beam radiation volume (two bladder cancers after IOERT prostate cancer and one right renal cancer after IOERT for bile duct carcinoma), but documented exclusion of second tumours mass component in the anatomic boosted region [106]. Although the median follow-up for this series is 94 months, further time might be required to better address the risk of second malignancies.…”

Guidelines for quality assurance in intra-operative radiation therapy

“…Ionisation chambers, as previously reported, are advised against: due to the high density of electric charges produced in the volume of the chamber for each radiation pulse, in fact, the correction factor for the ion recombination 11,15,39,40 can be largely overestimated when the correction methods recommended in the international dosimetry protocols are applied. The recombination factor, moreover, may vary depending on the depth in the phantom of the point of measurement.…”

“…The late toxicity effects of IORT more frequently described in the literature refer to the peripheral nerves and to the ureter. Collapse of the vertebral bodies, bleeding from rupture of big vessels and brain demielinisation 10,11 has been rarely reported. In all these situations the late toxicity has not been associated to IORT as only cause, but also to the surgical manipulation and to the neoplastic infiltration 12 .…”