Page 56 - Flexible Robotics in Medicine

40 Chapter 3

frequent cancer in Singapore. Patients with NPC often suffer from a painless lump in
their neck due to swollen lymph nodes [4]. Other more noticeable symptoms include
nose blockage, bloody nasal discharge, hearing loss, recurring ear infections, facial
pain or numbness, and headaches [6]. NPC is a form of cancer that is most commonly
found in the southern parts of China and accounts for 18% of the total cancer cases in
China [3]. It is known as Cantonese cancer due to the high occurrence rate in Guangdong
[4]. The occurrence rate for other countries that are not in East Asia and Africa, such as
the United States is at a lower rate of 1 in 100,000 people [7].Itisobservedthatthe
earlier stages of NPC have a higher survival rate compared to the later stages. Hence
detecting NPC at the earlier stages is crucial to improving the survival rate of the
average patient.

3.1.1 Diagnostic methods

Nasopharyngeal cancer is often diagnosed when patients visit the doctor after the
symptoms of the disease are observed. Current forms of diagnosis include checking of
family history, followed by a medical examination of the nasopharynx. Imaging tests and
biopsies are then performed to verify further and often confirms the diagnosis. The most
common imaging tests include the examination of the nasopharynx region that employs
two main methods, indirect nasopharyngoscopy and direct nasopharyngoscopy. The
efficacy of the direct nasopharyngoscopy makes it the preferred approach used to
examine the nasopharynx.

By inserting a fiber-optic nasopharyngoscope through the nasal inlet, the doctor will be
able to examine and observe the nasopharynx to diagnose the disease [7]. Alternatively,
indirect nasopharyngoscopy is the observation of the nasopharyngoscopy that makes use
of unique mirrors for viewing. Direct nasopharyngoscopy keeps the optical components
inside a flexible tube (an endoscope), which is inserted through the nose for a direct cone
of vision to the nasopharynx [7]. For indirect nasopharyngoscopy, mirrors are placed
below the soft and hard palate of the patient’s throat for the physician to look around the
pharynx. [8] The indirect method is not as invasive as the direct nasopharyngoscopy, but
the diagnosis will not be conclusive as the mirrors provide a partial view, thus limiting
the range and clarity. After receiving treatment, patients should still be on the alert, as
there is the possibility of recurrence and metastasis of the cancerous tissue at the
nasopharyngeal region [9].

Even though the direct nasopharyngoscopy appears to be superior to the indirect approach,
the direct method is invasive and may cause discomfort to the patient. Given that this
method is more conclusive in surveillance and diagnosis, physicians are increasingly
convinced that the risks are justified.