Dosejustert kjemoradioterapi ved HPV-assosiert orofarynx-kreft hos eldre ((DACHOC-E))

Cisplatin: 30-40 mg/m2/week, every week during radiation. Dose should be based on actual body weight. The first cisplatin infusion should be started within 24 hours before or after the first scheduled radiation treatment.

Intensity Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT) are mandatory for this study.

55 Gy radiation in 5 weeks using 5 fractions per week + Cisplatin every week

Instead of standard bilateral or extensive neck fields, the current radiation fields will cover disease with only 3cm expansion. The clinical target volumes doses are biologically equivalent to the standard but given in a shorter hypofractionated approach.

Assuming the primary endpoint (non-inferior 2 year locoregional control) is met and both of these toxicity outcome goals are met, then concurrent short course radiotherapy would be considered an effective and less toxic alternative to concurrent standard arm, in locally advanced HPV-associated carcinoma of the oropharynx.

Frailty index G8 score 14 as major determinant of benefit and tolerance to treatment through:

Per prior study score <14 (1-17) is an indicator of frailty. The frailty as a factor in completing therapy (yes or no) and number of days break from therapy will be used as a variable.

G20 frailty index (G-20 is the actual name and not abbreviation) is as follows:

A Has food intake declined over the past 3 months due to loss of appetite, digestive problems, chewing or swallowing difficulties? B Weight loss during the last 3 months C Mobility D Neuropsychological problems E Body Mass Index (BMI (weight in kg) / (height in m²) F Takes more than 3 medications per day G In comparison with other people of the same age, how does the patient consider his/her health status? H Age

Acute toxicity (Grade 3 or higher)

Late toxicity (Grade 3 or higher)

Pattern failure (local in field, local marginal miss, local regional failure, distant failure, combination of the above).

As some of the patient may have recurrence in the radiation fields, this will be termed local recurrence. Recurrence outside the radiation fields but in the head and neck area will be quantified as regional failure. Failure outside the head and neck area will be classified as distant failure. This outcome will be quantified as global number of failure out of the 20 patients and their distribution will be quantified in a diagram as explain above.