Radiothérapie conformationnelle avec modulation d'intensité des cancers des voies aérodigestives supérieures avec irradiation bilatérale du cou : résultats préliminaires

[Intensity-modulated radiation therapy and stereotactic body radiation therapy for head and neck tumors: evidence-based medicine]

Over the last decade, there have been many technical advances in radiation therapy, such as the spread of intensity-modulated conformal radiotherapy, and the rise of stereotactic body radiation therapy. By allowing better dose-to-target conformation and thus better organs at risk-sparing, these techniques seem very promising, particularly in the field of head and neck tumors. The present work aims at analyzing the level of evidence and recommendation supporting the use of high-technology radiotherapy in head and neck neoplasms, by reviewing the available literature.

Cancers ORL: les grands principes thérapeutiques

Cancers of the upper aerodigestive tract cover the solid tumors of the oral cavity, pharynx and larynx. The principal risk factors identified are smoking and alcohol. Moreover, the combination of alcohol and smoking increases the relative risk by more than simple multiplication. The pretreatment work-up represents the starting point in the natural history of the patient's disease and conditions recovery and time course; it must be both specific and exhaustive. It leads to a TNM classification or staging that is a major prognostic factor and essential to determination of the appropriate therapy. Patients with cancer of the upper aerodigestive tract must receive cooperative multidisciplinary treatment. Conservative treatment strategies must be favored. Treatment is essentially surgical and radiological. Prognosis for survival is poor. For all stages and sites together, 5-year survival remains between 30 and 40%.

Impact of intensity-modulated radiotherapy on health-related quality of life for head and neck cancer patients: matched-pair comparison with conventional radiotherapy

PURPOSE

To assess the benefit of intensity-modulated radiotherapy (IMRT) compared with conventional RT for the quality of life (QOL) of head and neck cancer survivors.

METHODS AND MATERIALS

Cross-sectional QOL measures (European Organization for Research and Treatment of Cancer QOL questionnaire C30 and head and neck cancer module) were used with a French multicenter cohort of patients cured of head and neck cancer (follow-up > or = 1 year) who had received bilateral neck RT (> or = 45 Gy) as a part of their initial treatment. We compared the QOL mean scores regarding RT modality (conventional RT vs. IMRT). The patients of the two groups were matched (one to one) according to the delay between the end of RT and the timing of the QOL evaluation and the T stage. Each QOL item was divided into two relevant levels of severity: "not severe" (responses, "not at all" and "a little") vs. "severe" (responses "quite a bit" and "very much"). The association between the type of RT and the prevalence of severe symptoms was approximated, through multivariate analysis using the prevalence odds ratio.

RESULTS

Two comparable groups (67 pairs) were available. Better scores were observed on the head and neck cancer module QOL questionnaire for the IMRT group, especially for dry mouth and sticky saliva (p < 0.0001). Severe symptoms were more frequent with conventional RT concerning saliva modifications and oral discomfort. The adjusted prevalence odds ratios were 3.17 (p = 0.04) for dry mouth, 3.16 (p = 0.02) for sticky saliva, 3.58 (p = 0.02) for pain in the mouth, 3.35 (p = 0.04) for pain in the jaw, 2.60 (p = 0.02) for difficulties opening the mouth, 2.76 (p = 0.02) for difficulties with swallowing, and 2.68 (p = 0.03) for trouble with eating.

CONCLUSION

The QOL assessment of head and neck cancer survivors demonstrated the benefit of IMRT, particularly in the areas of salivary dysfunction and oral discomfort.

Irradiation adaptation to the tumor activity with the help of intensity-modulated radiation therapy for head and neck cancers

The aim of this study was to set up the appropriate geometry to perform a high-precision irradiation, based on tumor activity (TA). The elaboration of a new treatment protocol based on TA required a specific geometry in order to use this type of irradiation. Using a treatment planning system TPS and two head and neck phantoms specially created, we have performed TPS characterization according to different treatment plans. Two models were created and used: a simplistic and an anatomical model. Our results showed that high-precision radiotherapy in limited zones is possible with intensity modulated radiation therapy (IMRT) when several conditions such as location, number of Organs at risk (OAR's), distance between planning target volume (PTV) and OAR, presence, volume and location of the TA, number of fields are met. In order to use this irradiation method adapted to the TA, a precise geometry will be necessary. However such high total and fractionated doses should be carefully evaluated before being prescribed clinically.

[Hypopharyngeal squamous cell carcinoma: retrospective study of 149 patients]

PURPOSE

Hypopharyngeal squamous cell carcinoma is associated to one of the most unfavorable prognosis among the cancers of the head and neck. The purpose of this study is to analyze its therapeutic modalities in the Salah-Azaïz Institute (Tunis) and to compare their results.

PATIENTS AND METHOD

This retrospective study concerns 271 hypopharyngeal squamous cell carcinomas, compiled in the Carcinologic Surgery Department of Head and Neck of the Salah-Azaïz Institute over a period of 25 years (from 1977 to 2002). The average age of the patients was of 56 years; sex-ratio was on average of 1.2 (man/woman). The indication of a curative treatment was initially retained for 149 (55%) patients, who were the only ones retained for the analysis of results.

RESULTS

We retained the indication of a protocol including surgery and postoperating radiotherapy for 26.2% of the patients. Postoperation mortality rate was 5.1%; the operating rate of morbidity was 46.2%. For 13.5% of the patients, postoperating radiotherapy was permanently interrupted because of a gradual deterioration of the patients' health in the course of treatment. We retained the indication of exclusive radiotherapy for 59.7% of the patients. The average age was of 56 years and the sex-ratio of 1.2. The external radiotherapy was conventional. Radiotherapy had to be permanently interrupted in progress in 32.6% of cases on account of an deterioration of the patients' health; the rate of morbidity of the radiotherapy was 33.3%. We indicated a protocol of conservation of organ with induction chemotherapy for 21 patients (14.1%). The average age was of 53 years (28-65 years) and sex-ratio (man/woman) of 0.5. The global survival was 25.5% at one year, 18.1% at two years, 11.4% at three years and 7.4% at five years. All the patients selected for chemotherapy died in the course of treatment. The rates of survival in two and five years according to protocols surgery-radiotherapy and exclusive radiotherapy were respectively: 21.5 and 12%, and 18.3 and 10%. The difference between the rates of survival of this two protocols is not significant (P =0.08).

CONCLUSION

Although the induction chemotherapy entails a particularly high death rate in our series, the association surgery-radiotherapy and the exclusive radiotherapy seem to be similarly efficient for the treatment of the hypopharyngeal carcinoma.

[Regional failure of hypopharyngeal squamous cell carcinoma]

PURPOSE

Lymph nodes and distant metastases contribute to the poor prognosis of hypopharyngeal squamous cell carcinoma. The purpose of this study is to estimate the frequency, mode and prognosis factors related to regional and distant metastasis.

PATIENTS AND METHOD

The authors' report is based on a retrospective study concerning 271 hypopharyngeal squamous cell carcinoma, compiled in the service of Surgery of Head and Neck Cancers of the Salah-Azaïz Institute (1977-2002). Frequency and histoclinical characters of cervical and distant metastases have been assessed, as well as their prognosis factors among 155 patients treated in a curative purpose.

RESULTS

39.1% of the tumours were classified N0, 24.4% N1, 10.7% N2 and 25.8% N3 (UICC 2002). The cervical nodal invasion was significantly more frequent for the classified tumors T3T4 than for the T1T2 (for pyriform sinus, postcricoid esophagus, posterior wall, and total hypopharynx, respectively : P =0.001, P =0.007, P =0.047 and P =0.0005). A cervical lymphatic evidement was preferred in thirty two patients. Among N0, 46.9% were N+; The frequencies of the capsular effraction were not significantly different for the N0N1 from for the N2N3 (P =0.11). The two and five years survival rates were respectively 32.5 and 20.5% for N0, and 10.9% and zero for N3. The survival differences after two and five years between the N0N1 and the N2N3 were significant (P =0.04). A regional failure was noticed for 18.5% of the patients. The tumoral site did not influence significantly the rate of nodal failure (P =0.98), neither the clinical status N (P =0.34). Capsular effraction was a significant factor for the regional failure (P =0.007). Distant metastasis significantly occurred more frequently among the patients initially classified N2N3 than those classified N0N1 (P =0.03), and in case of capsular effraction (P =0.0009).

CONCLUSION

Hypopharyngeal squamous cell carcinoma has a high rate of lymph nodes metastasis, correlated to the local extension, and a high rate of occult nodal metastasis. Lymph node clinical status does not seem to have influenced the patients survival; however, capsular effraction constitutes a major prognosis factor of regional failure and distant metastasis. Distant metastases are frequent, particularly in case of wide local and regional tumoral extension.