My sister (26) has been diagonised with lesion in left lateral of the tongue. As per MRI:

MRI Neck/thyroid (Contrast) of 03-OCT-2022:
Results:
An irregular area of altered signal intensity is seen in anterior 2/3rds of left lateral aspect of tongue involving the intrinsic muscles. The lesion
measures ~3.6 x 1.1 x 1.8 cm in AP x T x CC dimensions. The surface of the lesion is flat with depth of invasion similar to tumor thickness ~ 1.1
cm. It appears hypointense on T1WI, hyperintense on T2WI/STIR and shows heterogeneous post-contrast enhancement. It is not crossing the
midline. There is no evidence of extension beyond the intrinsic muscles of tongue/invasion of floor of mouth/mandibular involvement.
No signficnat cervical lymphadenopathy seen.
The nasopharynx, oropharynx, hypopharynx & larynx reveal no obvious discrete mass.
The rest of the soft tissue spaces of the neck are unremarkable.
The parotid, submandibular and sublingual glands are normal in size and signal intensity. Both lobes of thyroid are also normal in size and signal
intensity.
The carotid vessels and jugular veins reveal normal flow voids.
Mandible and maxilla are normal in signal intensity.
Bony cervical spine and the intervertebral discs appear normal.
IMPRESSION:
MR features are suggestive of:
•Mitotic lesion involving anterior 2/3rds of left lateral aspect of tongue with extensions signal characteristics as described.
-Suggested: HPE correlation.

I want to know about the treatment process, surgery is the only way ? or we can have immunotherapy ?