‘Full Dose’ Reirradiation of Human Cervical Spinal Cord

Abstract

With the progress of modern multimodality cancer treatment, retreatment of late recurrences or second tumors became more commonly encountered in management of patients with cancer. Spinal cord retreatment with radiation is a common problem in this regard. Because radiation myelopathy may result in functional deficits, many oncologists are concerned about radiation-induced myelopathy when retreating tumors located within or immediately adjacent to the previous radiation portal. The treatment decision is complicated because it requires a pertinent assessment of prognostic factors with and without reirradiation, radiobiologic estimation of recovery of occult spinal cord damage from the previous treatment, as well as interactions because of multimodality treatment. Recent studies regarding reirradiation of spinal cord in animals using limb paralysis as an endpoint have shown substantial and almost complete recovery of spinal cord injury after a sufficient time after the initial radiotherapy. We report a case of "full" dose reirradiation of the entire cervical spinal cord in a patient who has not developed clinically detectable radiation-induced myelopathy on long-term follow-up of 17 years after the first radiotherapy and 5 years after the second radiotherapy.

Partial volume tolerance of the spinal cord and complications of single‐dose radiosurgery

“…There are many other host and tumor factors that are important in the prevention and management of radiation-induced spinal cord complication. 19,20 This patient did not have any other comorbidity that may augment the expression of radiation effects. There is a possibility that the use of chemotherapy (carboplatin and taxotere in this case) or newer targeted therapies (herceptin in this case) may have played a part with a radiosensitizing effect.…”

Effektivität und Toxizität einer Re-Bestrahlung (Re-RT) bei metastatisch bedingter Rückenmarkkompression (MBRK)

“…Das Risiko für das Auftreten einer Myelopathie hängt u.a. von der applizierten Äquivalentdosis in 2-Gy-Fraktionen (EQD2) ab [1,2,6,8,18].…”

“…Im Fall einer erneuten RT (Re-Bestrahlung [Re-RT]) kann es zu einer vergleichsweise hohen kumulativen EQD2 (EQD2 der primären RT plus EQD2 der Re-RT) im Rückenmark kommen [11,18]. Aus diesem Grund stehen viele Radioonkologen einer Re-RT im Bereich der Wirbelsäule ablehnend gegenüber.…”

Prognostic factors for functional outcome and survival after reirradiation for in‐field recurrences of metastatic spinal cord compression

“…However, many radiation oncologists have reservations about implementing spinal Re-RT because of concerns that it may result in radiation myelopathy and severe neurological dysfunction. The risk of radiation myelopathy depends on the biologically effective dose (BED) delivered to the spinal cord, [3][4][5] which takes into account both the total radiation dose and the dose per fraction. Re-RT of the previously treated spinal cord results in a comparably high cumulative BED (BED of the first course of RT plus BED of the Re-RT).…”