Giant T4 cutaneous squamous cell carcinoma (cSCC) of the scalp with extensive bone infiltration are a treatment challenge. The subgaleal plane offers little resistance to tumors and cSCC can spread for long distances with invasion of the dura mater, vessels, and brain [
1,
2]. In many cases, the size of the T4 cSCC impedes sufficient surgical margins or requires resections with unreasonable cosmetic results [
3,
4]. International guidelines consider definitive radiotherapy (RT) as a curative alternative to surgery for patients with cSCC in sensitive anatomical areas of the head and neck where surgery compromises function or cosmesis, and for patients who cannot undergo an operation (for example due to presence of comorbidities). Furthermore, some patients prefer a noninvasive treatment. Definitive RT plays a major role in these patients, with encouraging results [
3,
4]. Better understanding of tolerance doses, advances in treatment planning, and better nursing management for patients receiving RT contributes to a low risk of severe late complications after RT, which range from 5% to 9% [
5‐
7]. Unfortunately, there is a misbelief that tumors with extensive bone involvement have worse local control by RT [
8]. The literature shows sufficient data to the contrary [
5,
6,
8]. Mapping the RT literature of RT demonstrates that cSCC with bone involvement has a 5-year local control of 40% and a 5-year cause-specific survival of 52% after definitive RT [
5]. It is time to emphasize the sufficient rates of local control and cause-specific survival after definitive RT. This case must be reported to show that patients with large cSCC of the scalp and massive bone destruction can have a sustained complete response after definitive RT and programmed cell death protein-1 (PD-1) inhibiting antibody therapy. We show the largely unknown fact that even large bone defects can heal with the resolution of tumor and inflammation by secondary intention with good cosmetic results. Given the increase in unresectable tumors, we believe this case has clinical impact across more than one clinical specialty.