Interdisciplinary challenges and aims of flap or graft reconstruction surgery of sinonasal cancers: What radiologists and radiation oncologists need to know

Abstract

In sinonasal cancer surgery, a fundamental challenge is to understand the postoperative imaging changes after reconstruction. Misinterpretation of post-operative imaging may lead to a misdiagnosis of tumor recurrence. Because radiotherapy planning is based on imaging, there are many gaps in knowledge to be filled in the interpretation of postoperative imaging to properly define radiotherapy tumor volumes in the presence of flaps. On the other hand, radiotherapy may be responsible for tissue fibrosis or atrophy, the anatomy of the reconstructed region and the functional outcomes may change after radiotherapy compared to surgery alone. This narrative review illustrates the interdisciplinary aims and challenges of sinonasal reconstructive surgery using flaps or grafts. It is particularly relevant to radiologists and radiation oncologists, at a time when intensity modulated radiotherapy and proton therapy have the potential to further contribute to reduction of morbidity.

Keywords: flap; imaging; radiotherapy; reconstructive surgery; sinonasal tumors.

Figure 1

Duraplasty with fascia lata (FaLa) after endoscopic transnasal craniectomy for an intestinal type adenocarcinoma. (A) Endoscopic view of the surgical field after tumor removal: the right and left orbital walls (RO and LO, respectively), the sphenoid sinus (SphS) and the frontal lobe (asterisk) are exposed; the dotted line marks the limits of dural resection. (B) The first layer of fascia lata is placed intradurally to obtain watertight closure.

Figure 2

Pre-operative (A) and early post-operative aspect (postoperative day5) of a skull base reconstruction with fascia-lata and abdominal fat graft (B) for an intestinal type adenocarcinoma on T2-weighted MRI sequences.

Figure 3

Post-operative aspect of a nasoseptal flap (A) and of a left superficial temporoparietal fascia flap (B) on contrast-enhanced T1-weighted MRI sequences. Note the hyperintense aspect of the flaps after contrast enhancement (white arrowheads).

Figure 4

Covering of the lateral nasopharyngeal wall with a superficial temporoparietal fascia flap (sTPFF) after left endoscopic rhinopharyngectomy for recurrent nasopharyngeal carcinoma. (A) the sTPFF is pedicled on the superficial temporal artery; it is transposed in the nasal cavity through a temporal/infratemporal fossa tunnel (arrow). (B) Post-operative endoscopic view after 2 months: the flap (dotted line) has been introduced through an opening in the posterior wall of the left maxillary sinus (PWMS) and covers the lateral wall of the nasopharynx (asterisk), thus protecting the parapharyngeal internal carotid artery.

Figure 5

Covering of the anterior skull base with a pericranial flap (PF) after endoscopic transnasal craniectomy for an olfactory neuroblastoma in a previously irradiated patient. (A) Lining of the pericranial flap (red line) pedicled on the left supraorbital and supratrochlear pedicles. (B) The flap is placed against the whole anterior skull base through an opening in the superior aspect of the anterior wall of the frontal sinus. (C) Final endoscopic view, with the flap covering the whole anterior skull base, from the right to the left orbit (RO and LO, respectively) laterally and from the frontal sinus (white arrow head) to the sellar region posteriorly.

Figure 6

A proposition for reconstruction strategies according to the location and size of the defect after surgical removal of the tumor.

Figure 7

Postoperative radiotherapy planning of a left palatine squamous cell carcinoma following reconstructive surgery with a soft-tissue forearm flap. The flap (yellow line) was not delineated for RT planning and has been delineated a posteriori independently of referring radiation oncologist and blind to CTV delineation. Analysis of radiation dose distribution suggests that the flap was considered as a target volume and received the highest dose prescription level (66 Gy, within red 62.7Gy isodose).