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Tropiano et al. Mini-invasive Surg 2024;8:17 https://dx.doi.org/10.20517/2574-1225.2024.41 Page 3 of 15

In the present work, we evaluate a monoinstitutional series of NV-SCC treated with IRT through anatomic
implantation (“anatomic IRT”) and focus on specific toxicities and strategies to avoid them.

METHODS
Patients
Patients with NV-SCC, treated between March 2022 and October 2023 with IRT within the North Sardinia
Tumor Board, involving the Otolaryngology Division of the University Hospital of Sassari and the
Radiation Oncology Division of Mater Olbia Hospital, have been included. This study adhered to the ethical
principles outlined in the Declaration of Helsinki. Ethical approval was not mandated by Italian law (GU
No. 76, 31 March 2008) due to its observational retrospective design. Informed consent for the procedure
and photographic documentation were obtained.

The minimal required work-up included physical examination, rhinoscopy, rigid nasal endoscopy, neck
ultrasound performed by the head and neck surgeon (FB) and contrast-enhanced computed tomography
(CT) of the face, neck and chest. Whenever the actual spread in soft tissues of the nose/cheek/superior lip
was not clearly defined, magnetic resonance imaging (MRI) completed the diagnostic work-up of the
primary tumor. In case of doubts concerning lymph nodes at imaging, an ultrasound-guided fine needle
aspiration biopsy (FNAB) of the suspicious node(s) was performed.

For staging purposes, we used both the Rome Classification and the UICC/AJCC system for T, and the
[42]
UICC/AJCC system for N classification .

Treatment modalities
A variable number of 6-Fr flexible implant tubes were inserted using metal guide channels [Figure 1] and
fixed by buttons that can be anchored to the skin by stitches and are anyway going to be adherent to
increase the reliability of the treatment plan [Figure 2]. The implants are best applied under general
anesthesia; orotracheal intubation is preferred and a laryngeal mask should be avoided to minimize the
hindrance by the anesthesiology tube which should be stabilized as far away as possible from the operating
field. The implantation was performed by a head and neck surgeon in the presence of experienced IRT
radiation oncologists.

Infiltration of the subperichondral planes with local anesthetics, with or without adrenaline, as in functional
nose surgery, is fundamental to obtain analgesia in case of local anesthesia and is helpful in facilitating the
optimal catheter path along the planes avoiding piercing of the mucoperichondrium. The exact
configuration and number of catheters is tailored to the extent, depth, and shape of the lesion according to
pre-implant MRI or CT scan, clinical experience, work-up data, and intraoperative findings. The dose is
prescribed after implant encompassing the full clinical target volume (CTV) and sparing as much as
possible the surrounding healthy structures. For this reason, interaction between the surgeon and the IRT
radiation oncologist is always recommended at the implantation phase in the surgical theater.

Anatomic implantation
With this technique, a “fully interstitial” implant is preferable. However, when this approach is insufficient
for adequate CTV coverage by overreaching all the limits of the lesion, alternative methods can be used to
obtain complete coverage and stabilize the tubes. A scenario may be the presence of a bulky skin spread,
which can be approached with a “contact” strategy, by placing the tubes on the skin in the area of such
exophytic spread [Figure 3]. A different, very common situation is the extension of the lesion posterior to
the limit of the NV, which is the plane tangential to the piriform opening [4,42] . If this extension is limited and