The paper aims to show the multilevel and complex cooperation and the inclusion of the psychotherapist leading the psychotherapy in the medical team at the radiotherapy and clinical oncology clinic. We illustrate these interventions with the case of Stan. This 43‐year‐old firefighter was diagnosed with advanced head and neck cancer and pre‐existing mental health problems meeting the criteria of ICD‐10: obsessive‐compulsive disorder, post‐traumatic stress disorder and psychoactive substance abuse. During the treatment, suicidal thoughts and impulses emerged, triggered at the hospital by electronic noises and the feeling of entrapment without a way out. This situation put the patient at high risk and the whole healthcare team needed an urgent effective response. The patient agreed to stay in the secured room, where he was cared for by doctors, nurses, a dietitian, and a psychotherapist. He actively attended daily sessions with noticeable engagement. Psychotherapy sessions focused on alleviating posttraumatic stress disorder and OCD. Mindfulness and breathwork‐based exercises were implemented to increase non‐judgemental self‐awareness and regulate the over‐aroused nervous system. As a result, the patient's mental health has improved and the completion of the cancer treatment was possible. Psychotherapy, good therapeutic alliance, and attentive teamwork effectively managed his mental health and treatment‐related symptoms.