Selective neck irradiation for supraglottic cancer: focus on Sublevel IIb omission.
OBJECTIVE
To estimate selective neck irradiation omitting surgical Sublevel IIb.


METHODS
Bilateral necks of 47 patients (94 necks) were subjected to definitive radiotherapy for supraglottic cancer. Sixty-nine and 25 necks were clinically node negative (cN-) and clinically node positive (cN+), respectively. We subdivided Sublevel IIb by the international consensus guideline for radiotherapy into Sublevel IIb/a, directly posterior to the internal jugular vein, and Sublevel IIb/b, which was behind Sublevel IIb/a and coincided with surgical Sublevel IIb. Bilateral (Sub)levels IIa, III, IV and IIb/a were routinely irradiated, whereas Sublevel IIb/b was omitted from the elective clinical target volume in 73/94 treated necks (78%).


RESULTS
Two patients presented with ipsilateral Sublevel IIb/a metastases. No Sublevel IIb/b metastasis was observed. Five patients experienced cervical lymph node recurrence; Sublevel IIb/a recurrence developed in two patients, whereas no Sublevel IIb/b recurrence occurred even in the cN- necks of cN+ patients or cN0 patients. The 5-year regional control rates were 91.5% for Sublevel IIb/b-omitted patients and 77.8% for Sublevel IIb/b treated patients.


CONCLUSIONS
Selective neck irradiation omitting Sublevel IIb/b did not compromise regional control and could be indicated for cN- neck of supraglottic cancer.
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka naoyukikana@gmail.com.
Naoyuki
N
Kanayama
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka Department of Radiation Oncology, Yao Municipal Hospital, Osaka.
Kinji
K
Nishiyama
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
Yoshifumi
Y
Kawaguchi
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
Koji
K
Konishi
Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka.
Kazuhiko
K
Ogawa
Department of Otolaryngology, Head and Neck Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Motoyuki
M
Suzuki
Department of Otolaryngology, Head and Neck Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Tadashi
T
Yoshii
Department of Otolaryngology, Head and Neck Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Takashi
T
Fujii
Department of Otolaryngology, Head and Neck Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
Kunitoshi
K
Yoshino
Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka.
Teruki
T
Teshima
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000473:pathology; D037981:Neck Dissection; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy*; D000077195:Squamous Cell Carcinoma of Head and Neck; D016896:Treatment Outcome
Sublevel IIb; radiotherapy; selective neck irradiation; supraglottic cancer