A feasibility study using three-dimensional conformal boost technique in locally advanced carcinoma of the nasopharynx

The treatment outcome and radiation-induced toxicity for patients with head and neck carcinoma in the IMRT era: a systematic review with dosimetric and clinical parameters

A descriptive analysis was made in terms of the related radiation induced acute and late mucositis and xerostomia along with survival and tumor control rates (significance level at 0.016, bonferroni correction), for irradiation in head and neck carcinomas with either 2D Radiation Therapy (2DRT) and 3D conformal (3DCRT) or Intensity Modulated Radiation Therapy (IMRT). The mean score of grade > II xerostomia for IMRT versus 2-3D RT was 0.31 ± 0.23 and 0.56 ± 0.23, respectively (Mann Whitney, P < 0.001). The parotid-dose for IMRT versus 2-3D RT was 29.56 ± 5.45 and 50.73 ± 6.79, respectively (Mann Whitney, P = 0.016). The reported mean parotid-gland doses were significantly correlated with late xerostomia (spearman test, rho = 0.5013, P < 0.001). A trend was noted for the superiority of IMRT concerning the acute oral mucositis. The 3-year overall survival for either IMRT or 2-3DRT was 89.5% and 82.7%, respectively (P = 0.026, Kruskal-Wallis test). The mean 3-year locoregional control rate was 83.6% (range: 70-97%) and 74.4 (range: 61-82%), respectively (P = 0.025, Kruskal-Wallis). In conclusion, no significant differences in terms of locoregional control, overall survival and acute mucositis could be noted, while late xerostomia is definitely higher in 2-3D RT versus IMRT. Patients with head and neck carcinoma should be referred preferably to IMRT techniques.

Dose Escalation of Three-dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomised Study

AIMS

To investigate prospectively the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma (NPC) in a randomised study.

MATERIALS AND METHODS

Thirty-six patients with locally recurrent NPC (>6 months interval from previous radical radiotherapy, no cervical lymph-node involvement and no distant metastasis) were enrolled. Treatment included conventional external-beam radiotherapy to 54 Gy, followed by a 3D-CRT boost to the gross tumour region. Patients were randomised to three boost dose levels: 16 Gy, 20 Gy and 24 Gy for groups I, II and III, respectively, with 12 patients in each group. All boost doses were delivered in 4-Gy fractions and 3 fractions per week. Median follow-up was 27 months (range 14-44 months).

RESULTS

Three-year, local-recurrence-free survival rate was significantly higher (72%) for the high-dose group III than for groups I and II (37% and 28%, respectively, P = 0.047). No significant difference was found in the 3-year overall survival rate among the three groups (72%, 59% and 82% for groups I, II and III, respectively). Three-year distant metastases rates were 17%, 0% and 18%, respectively. Skull-base invasion (P = 0.017) and pathology (P = 0.0006) correlated with overall survival. Treatment was well tolerated and no significant difference was observed among the three groups in acute and late toxicities (grade III toxicity is minimal: 17%, 17%, 0% of oral mucositis and 25%, 17%, 17% of nasopharyngeal mucositis in groups I, II, III, respectively, and 8% leukocytopenia only in group II; no grade IV toxicity occurred in any of the groups except for a fatal bleeding in group III).

CONCLUSIONS

Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent NPC. Dose escalation to the boost volume to 78 Gy (54 Gy + 24 Gy boost) results in improved recurrence-free survival compared with lower doses.

Parotid gland-sparing 3-dimensional conformal radiotherapy results in less severe dry mouth in nasopharyngeal cancer patients: a dosimetric and clinical comparison with conventional radiotherapy

BACKGROUND AND PURPOSE

This study examined the efficacy of parotid gland sparing of three-dimensional conformal radiotherapy (3DCRT) compared with conventional radiotherapy for NPC patients. Both the dose given to the parotids and clinical assessment of dry mouth were conducted.

MATERIALS AND METHODS

Dry mouth was assessed for 108 patients treated with conventional technique and 72 treated with 3DCRT. Dose analysis was performed in 48 patients of the 3DCRT group. A dose of 70 Gy was given to the midplane in conventional radiotherapy and to 90% isodose volume in 3DCRT. Prognostic factors affecting the severity of dry mouth were analyzed using Generalized Estimating Equation (GEE).

RESULTS

In the 3DCRT group about 50% of the patients' parotid glands received less than 25 Gy. Parallel analysis of dry mouth shows a significant decrease in the incidence of severe xerostomia after 3DCRT. The proportion of patients without dry mouth was also significantly higher in the 3DCRT group than the conventional group at 1-3 years after completion of radiotherapy. Although 3DCRT delivered a higher dose to the tumor, it spared the parotid gland significantly better than the conventional treatment. Late toxicities were mostly similar between the 2 groups while local control in T4 patients and survival were improved for 3DCRT.

CONCLUSION

Dosimetrically and clinically 3DCRT is better than conventional technique regarding parotid gland protection.

Treatment results of 59 young patients with nasopharyngeal carcinoma

PURPOSE

To evaluate the outcome of patients </=30 years old with non-metastatic nasopharyngeal carcinoma and discover adverse prognostic factors.

MATERIALS AND METHODS

We performed a database search maintained by the Department of Radiation Oncology of Hacettepe University School of Medicine for patients with nasopharyngeal cancer who were </=30 years old at presentation. This search identified 59 (23.7%) patients among 248 patients treated between 1994 and 2001 that met the inclusion criteria for this retrospective study. Patients were staged according to AJCC 1997 classification. There were 1 (2%) patient with stage I, 7 (12%) with stage IIb, 25 (42%) with stage III, 9 (15%) with stage IVA, and 17 (29%) with stage IVB. Thirteen (22%) patients were stage T1, 16 (27%) were T2, 21 (36%) were T3, and 9 (15%) were T4. Nodal staging at presentation was as follows; 7 (12%) N0, 22 (37%) N1, 13 (22%) N2, 13 (22%) N3a, and 4 (7%) N3b. All patients were treated with fractionated external beam radiotherapy (EBRT) to a median dose of 65Gy. While 12 (20.3%) patients were treated with EBRT alone, 47 (79.7%) received chemotherapy beside EBRT. Twenty-five (42.3%) patients older than 17 years of age received brachytherapy boost in addition to EBRT.

RESULTS

The median follow-up time for all patients was 46 months (range, 1-111 months). While only 3 patients (5%) developed local recurrence (1/21 T3 and 2/9 T4 patients), 13 patients (22%) developed distant metastases (6/35 N1 and 2 and 7/17 N3 patients). None of the patients had regional failure. Four patients (6.7%) died due to the treatment related toxicity. The actuarial 5-year local control (LC), regional control (RC), distant metastasis-free survival (DMFS) and disease-free survival (DFS) rates were 96%, 100%, 76.5%, and 74.5%, respectively. The actuarial 5-year disease-specific survival (DSS) was 70.6%. DFS at 5 years is significantly longer in patients aged <16 years than ones >17 (90.5% versus 64.7%; p=0.02). Patients aged <16 years had longer 5 year DMFS (90.5% versus 67.7%; p=0.05) with a borderline significance. DMFS is significantly shorter in patients initially presented with N3 disease compared to N0-2 disease (58.8% versus 84.4%; p=0.04).

CONCLUSIONS

We suggest that RT combined with multiagent chemotherapy is effective in achieving satisfactory DFS and comparable OS in young patients with NPC. Results of both previous series and ours are evoking the necessity of early administration of efficient chemotherapeutic agents in addition to radiotherapy, but indistinct is the precise regimen and the intensity along the radiotherapy. All efforts towards decreasing late side effects of treatment should be encouraged in this long life expected group.