ESTRO 2024 - Abstract Book

S1447

Clinical - Head & neck

ESTRO 2024

Pattern of Failure after Adjuvant Radiation Therapy in Squamous Cell Carcinoma Buccal Mucosa Patient

Mariam Hina 1 , Bilal Mazhar Qureshi 1 , Maria Tariq 1 , Rabia Tahseen 1 , Maham Khan 1 , Nawazish Zehra 1 , Yumna Jamil 2 , Mahak Ghulam Hussain 2 , Sarosh Faham Khan 2 , Sehrish Abrar 1 , Nasir Ali 1 , Ahmed Nadeem Abbasi 1 , Asim Hafiz 1 1 Aga Khan university Hospital, Oncology, Karachi, Pakistan. 2 Dow University of Health Sciences, Medicine, Karachi, Pakistan

Purpose/Objective:

To evaluate the incidence and characteristics of pattern of failure in patients with squamous cell carcinoma buccal mucosa following adjuvant radiation therapy

Material/Methods:

A retrospective analysis of the hospital's database was conducted for the period from January 2020 to December 2021, including all histopathologically confirmed cases of squamous cell carcinoma of the buccal mucosa patients who underwent definitive surgery followed by adjuvant radiation therapy at our center. All patients were staged according to American Joint Committee on Cancer (AJCC) 8th Edition. Demographic details, treatment characteristics and clinical outcomes along with pattern of failure were recorded and analyzed.

Results:

Total 69 patients were analyzed, with median age of 47 years (IQR 31-72). Eighty five percent of the patients (n=59) were male. According to AJCC 8th Edition TNM staging; 1.4% (n=1) patient were present in Stage I, 17% (n=12) in Stage II, 14% (n=10) in Stage III, 53% (n=37) in Stage IVA, and 10% (n=7) in Stage IVB. All patients were treated with Intensity Modulated Radiation Therapy (IMRT) or Volumetric Modulated Arc Therapy (VMAT) except for one patient who was treated with 3D-Conformal radiation Therapy (3DCRT) technique. The average interval from diagnosis to the initiation of radiation therapy was 6.5 weeks. Among the total patients, 49.2% (n=34) received dose of 7000 cGy in 35 fractions, 46.3% (n=32) received 6600 cGy in 33 fractions, and 4.3% (n=3 patients) received 5500 cGy in 20 fractions. Twenty percent patients (n=13) experienced disease recurrence; 54%(n=7) had solitary local recurrence, 7.6% (n=1) had loco-regional recurrence, 15.3% (n=2) had local and distant recurrence both, and 23% (n=3) had distant-only recurrence. Recurrences were most common in stage IV , 53% (n=7), advanced nodal disease N2 & N3 50% (n=7), DOI > 5mm 15%(n=9), close and positive margin 27% (n=10) and peri-neural invasion (PNI) 18.7% (n=3). The interval from radiation therapy completion to recurrence onset was about 7.69 months.

Conclusion:

Our study suggests 20% rate of recurrence in patients during the initial years following adjuvant radiation therapy, encompassing both local and distant recurrences. However, it's crucial to acknowledge that the retrospective nature of our study has inherent limitations, underscoring the need for more comprehensive data to gain a profound understanding of the patterns of failure and it’s influencing factors.