Nasopharynx Cancer Clinical Outcomes
Cancer of the Nasopharynx (NPC) is sixth most frequent cancer affecting Singaporean men occurring at an incidence of 10.8 per 100000 men per year. It is a cancer that affects younger Singaporeans with the majority affected between 40-65 years of age.
NPC is a highly curable malignancy that is generally managed using high dose radiation therapy (RT) or x-ray therapy, occasionally in combination with chemotherapy injections. The RT doses delivered to the head and neck region are high and the surrounding normal tissues such as salivary glands, temporal lobe and optic nerves are exposed to potential RT long-term side effects.
At NCIS, the radiation therapy techniques that are used in patients are 3D conformal RT (3DCRT) and Intensity Modulated RT (IMRT). Both of these techniques utilise accurately placed multiple beams of radiation to hit the target and protect the surrounding normal tissues. Thus the radiation treatment technique that is required is very sophisticated and must be delivered carefully with close attention to high quality assurance.
Figure 1 : CT scan of patient with Nasopharynx Cancer (arrow); NCIS radiation
therapy unit; and radiation plan for IMRT treatment
Local Control of NPC as a Radiation Oncology Clinical Quality Indicator
The most important immediate outcome of NPC treatment is control of the cancer at the initial primary site of the cancer at the back of the nose. In curative therapy the radiation therapy is principally directed to this site and the surrounding tissues and lymph nodes. For early stage NPC (stage I/II) RT is used as the only treatment, thus the success is dependent upon the accurate, quality delivery of radiation beams.
For this reason the local control of the NPC is used as a clinical quality indicator at NCIS Radiation Oncology and our results are compared with international cancer units delivering sophisticated radiation treatment 1,2. Using these measures, local control of NPC has improved from 93% to 96% at 2 years after therapy over the last 4 years. The results are now also comparable to the major US centers of San Francisco and New York.
Definition
- Stage I/II NPC refers to patients who are diagnosed with a cancer in the nasopharynx that is localised to the postnasal space / extended into immediate surrounding tissues or with lymph node involvement limited to one side of the neck.
- Local control of the cancer refers to no relapse of cancer in the head and neck region and is defined at 2 years after diagnosis
NPC Local Control Results at NCIS Radiation Oncology
Figure 2 : Percentage Local Control of Stage I/II NPC at NCIS compared with major
US Centres 1-4.
Conclusion
The local control for Stage I/II NPC is equivalent to major international centres and confirms quality delivery of radiation therapy at NCIS. Further improvements to RT techniques, especially with increased use of IMRT, have been introduced at NCIS to maximise local control and minimise side effects of RT.
Footnotes:
1. Thiagarajan A, Lin K, Tiong CE, Tan LK, Loh TK, Goh BC, Lu JJ. Sequential external beam radiotherapy and high-dose-rate intracavitary brachytherapy in T1 and T2 nasopharyngeal carcinoma: an evaluation of long-term outcome. Laryngoscope. 2006 Jun;116(6):938-43.
2. Lu JJ, Shakespeare TP, Thiagarajan A, Zhang X, Liang L, Tan S. Prospective phase II trial of concomitant boost radiotherapy for stage II nasopharyngeal carcinoma: an evaluation of response and toxicity. Laryngoscope. 2005 May;115(5):806-10.
3. Lee N, Xia P, Quivey JM et al (UCSF San Francisco USA). Intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma: an update of the UCSF experience. Int J Radiat Oncol Biol Phys. 2002 May 1;53(1):12-22.
4. Wolden SL, Chen WC, Pfister DG et al (MSKCC New York USA). Intensity-modulated radiation therapy (IMRT) for nasopharynx cancer: update of the Memorial Sloan-Kettering experience. Int J Radiat Oncol Biol Phys. 2006 Jan 1;64(1):57-62.
This material does not cover all information and is not intended as a substitute for professional care. Please consult your physician on any matters regarding your health.
