Very accelerated versus conventional radiotherapy in HNSCC: Results of the GORTEC 94-02 randomized trial

Radiobiological basis and clinical results of the simultaneous integrated boost (SIB) in intensity modulated radiotherapy (IMRT) for head and neck cancer: A review

The simultaneous integrated boost (SIB)-IMRT technique allows the simultaneous delivery of different dose levels to different target volumes within a single treatment fraction. The most significant aspect associated with SIB-IMRT is related to the fractionation strategy, concerning two time-dose parameters: (1) the shortening of the overall treatment time (OTT); (2) the increase of fraction size (FS) to the boost volume. The SIB-IMRT technique represents, therefore, a new way to investigate the accelerated fractionation in definitive treatment of head and neck (H&N) cancers. The aims of this paper are the following: (1) to briefly review the influence of OTT and FS on H&N tumors and on acutely and late responding normal tissues; (2) to review the results of clinical studies of accelerated radiotherapy not employing IMRT in H&N cancer; (3) to review the clinical experiences of the SIB-IMRT technique and to compare the different SIB regimes in terms of radiobiological efficacy.

Early experience with a hybrid accelerated radiotherapy schedule for locally advanced head and neck cancer

BACKGROUND

Our aim was to determine feasibility and efficacy of a hybrid radiotherapy schedule in locally advanced head and neck cancer.

METHODS

Seventy-three patients with locally advanced head and neck cancer were irradiated according to a hybrid accelerated schedule consisting of 20 fractions of 2 Gy (once daily), followed by 20 fractions of 1.6 Gy (twice daily), to a total dose of 72 Gy.

RESULTS

Locoregional control was 55% after 2 years. Overall survival was 59%, disease-specific survival was 63%, and disease-free survival was 46%. Acute toxicity was prospectively scored in all 73 patients: the most frequent toxicities were mucositis (50.7%, grade 3), dysphagia (47.9%, grade 3), and dermatitis (34.5%, grade 3). All patients were treated to full dose, without treatment interruption.

CONCLUSION

With this regimen, acceptable locoregional control and survival rates are achieved. Toxicity was well manageable, suggesting that a combination of this schedule with concomitant chemotherapy is possible and could lead to further improvement in the treatment of locally advanced head and neck cancer.

The influence of epidermal growth factor receptor and tumor differentiation on the response to accelerated radiotherapy of squamous cell carcinomas of the head and neck in the randomized DAHANCA 6 and 7 study

BACKGROUND AND PURPOSE

Reduction of the overall treatment time of radiotherapy has increased locoregional control and disease specific survival in squamous cell carcinomas of the head and neck (HNSCC), but the response is heterogeneous. EGFr is often overexpressed in HNSCC and has been related to the repopulation taking place during radiotherapy. The aim of the current study was to address the influence of EGFr and histopathological differentiation when the overall treatment time of radiotherapy was moderately reduced.

PATIENTS AND METHODS

Eight hundred and three patients with representative pretreatment tissue samples from the randomized DAHANCA 6 and 7 study of 5 vs. 6 fx/wk of radiotherapy. EGFr was visualized using immunohistochemistry and separated into high and low expression before correlation with clinical data.

RESULTS

Tumors with high EGFr (84%) responded better to moderately accelerated radiotherapy, than carcinomas with low EGFr, using locoregional control as endpoint and a similar pattern was seen, stratifying by well/moderate vs. poor tumor differentiation. Therefore, a combined parameter was constructed showing a more prominent separation of response: tumors with high EGFr and well/moderate differentiation did benefit from moderate acceleration of treatment regarding locoregional control, HR 0.54 (0.37-0.78), whereas such an effect was not seen in tumors with low EGFr and/or poor differentiation, HR 0.8 (0.51-1.25). These results reflected the disease specific survival as well and were confirmed in multivariable analyses.

CONCLUSIONS

Moderately accelerated fractionation is superior to conventional treatment in HNSCC but the response is heterogeneous and may be predicted by high expression of EGFr and well/moderate tumor differentiation.

Strategies to overcome accelerated repopulation and hypoxia--what have we learned from clinical trials?

Accelerated repopulation and tumor hypoxia are significant causes of treatment failure following radiotherapy for locally advanced head and neck squamous cell carcinoma (HNSCC). Accelerated fractionation schedules were designed to counter accelerated repopulation. Review of the randomized trials of accelerated fractionation reveals that the best results have been obtained with regimens that deliver the full conventional dose with a modest degree of acceleration by use of either a concomitant boost or 6 days/week treatment. However, the role of accelerated fractionation when chemoradiation is used has not been established. Although tumor hypoxia is an established adverse prognostic factor in head and neck cancer treated with radiotherapy, progress has been hampered by the lack of a widely available and reproducible method of hypoxia detection and by the limitations of previous treatments designed to overcome hypoxia. The advent of noninvasive hypoxic imaging with positron emission tomography (PET), and new treatment approaches, such as accelerated radiotherapy with carbogen and nicotinamide (ARCON) and hypoxic cytotoxins, has led to renewed optimism that hypoxia can be overcome or exploited to improve the outcomes in locally advanced head and neck cancer.

Investigation of relationship between change in locoregional control and change in overall survival in randomized controlled trials of modified radiotherapy in head-and-neck cancer

PURPOSE

To establish whether a relationship exists between improvement in locoregional control (LRC) and improvement in overall survival (OS) in trials of modified radiotherapy for head-and-neck cancer and to attempt to quantify the relationship.

METHODS AND MATERIALS

A systematic review of the literature was performed for randomized controlled trials of radiotherapy for head-and-neck cancer involving the use of altered fractionation or hypoxic sensitizers. The changes in LRC at 2 years and OS at 5 years were recorded for each trial. Regression analysis was used to investigate the relationship between the two variables.

RESULTS

Nineteen relevant trials were identified. Fourteen reported sufficient data for analysis. Linear regression analysis showed a statistically significant correlation between LRC and OS with a slope of 0.67 (95% confidence interval, 0.38-0.96, p = 0.00017).

CONCLUSIONS

We have demonstrated a relationship between a change in LRC and a change in OS in randomized trials of modified radiotherapy for head-and-neck cancer. A 10% improvement in the 2-year LRC is predicted to lead to a 6.7% improvement in the 5-year OS. This type of analysis may have applications in other tumor sites.

Radiotherapy for cancer of the head and neck: altered fractionation regimens

A greater understanding of radiobiology led to the development of two classes of radiation fractionation schedules for the treatment of head and neck cancers. The aim of accelerated fractionation is to reduce tumour proliferation, which is a major cause of relapse, by shortening the total duration of radiotherapy. By contrast, hyperfractionation exploits the differential sensitivity of tumour cells and normal tissues to radiation, to increase the therapeutic gain. The results of clinical trials of various types of altered fractionation schedules in head and neck carcinomas are examined in this review. Acceleration of radiation by 1 week without dose reduction and hyperfractionation are consistently better than standard fractionation for locoregional control of intermediate to advanced carcinomas without an increase in late toxic effects. However, improvement in survival of patients has not been consistent. Clinical investigations show that improvement in locoregional disease control and consistent gain in survival have been achieved with combinations of radiotherapy and concurrent chemotherapy in patients with mostly stage IV carcinomas. However, these benefits have been at the expense of increased late morbidity. Consequently, concurrent radiochemotherapy is now preferred for non-surgical treatment of patients with locally advanced carcinomas, whereas altered fractionation is generally selected for patients with intermediate-stage tumours or who are medically unfit to receive chemotherapy. Further data is needed before the combination of altered fractionation with chemotherapy can be recommended outside of a study setting.

Organ preservation therapy using induction plus concurrent chemoradiation for advanced resectable oropharyngeal carcinoma: a University of Pennsylvania Phase II Trial

PURPOSE

To determine the efficacy, feasibility, and toxicity of a new regimen for locally advanced oropharyngeal carcinoma.

PATIENTS AND METHODS

Patients had technically resectable stage III/IV squamous cell carcinoma of the oropharynx, exclusive of T1-2N1. Induction chemotherapy consisted of carboplatin (area under the curve formula equal to 6) and paclitaxel 200 mg/m(2) for two cycles, followed by re-evaluation. Patients with major response continued to definitive radiotherapy (70 Gy over 7 weeks) plus concurrent once-weekly paclitaxel (30 mg/m(2)/wk). Patients with advanced neck disease also underwent post-radiation therapy neck dissection and two more chemotherapy cycles.

RESULTS

Fifty-three patients were enrolled. Median follow-up was 31 months (minimum follow-up for survivors was 18 months). The major response rate to induction chemotherapy was 89%; 90% of patients had a complete response after concurrent chemoradiation. Actuarial survival at 3 years was 70%, and 3-year event-free survival was 59%. The 3-year actuarial locoregional control was 82% and the 3-year actuarial rate of distant metastases was 19%. Organ preservation was achieved in 77% of all patients. One patient (2%) died during therapy. Late grade 3 toxicity occurred in 24% of patients, consisting mainly of chronic dysphagia/aspiration and/or radiation soft tissue ulceration. The treatment-related mortality rate was 4% (two patients died from respiratory failure).

CONCLUSION

Response to induction chemotherapy as studied in this trial was not useful as a predictive marker for ultimate outcome or organ conservation. Overall, however, this regimen offers good disease control and survival for patients with locally advanced oropharyngeal carcinoma, comparable with other concurrent chemoradiation programs. Further study of similar protocols is indicated.

Pilot trial of concomitant chemotherapy with paclitaxel and split-course radiotherapy for very advanced squamous cell carcinoma of head and neck

PURPOSE

The combination of chemotherapy and irradiation is considered the standard of care for the treatment of advanced squamous cell carcinoma of head and neck (SCCHN). Paclitaxel has shown a single-agent activity in SCCHN. Besides, this drug is a promising radiosensitizer for some human solid tumors. This is a phase II trial to evaluate the feasibility, efficacy, and toxicity of paclitaxel administered concurrently with split-course radiotherapy in advanced unresectable SCCHN. Methods and Materials Thirty-one patients with advanced SCCHN were enrolled in this trial. Radiotherapy consisted of 66 to 70 Gy delivered over 8 to 10 weeks to the primary tumor and lymphatic drainage, with a fractionation scheme of 1.8 to 2 Gy/field/d. After the initial five patients were treated, a 1-week treatment break was introduced. Paclitaxel was administered weekly in a 1-hour intravenous infusion at a projected dosage of 45 mg/m(2)/wk.

RESULTS

The complete and partial response rates, based on a 4-week postradiation evaluation were 43.3% and 40%, respectively, with an overall response rate of 83.3%. Median survival was 49.4 weeks, and 1-year survival was 48%. Freedom from local progression was 65.6% at 1 year. Thirty-six percent and 20% of the patients are alive and disease free at 1 and 2 years, respectively. Grade 3/4 of acute toxicity consisted mostly of mucositis, cutaneous reaction, and weight loss.

CONCLUSIONS

Paclitaxel concurrent with radiotherapy seems to be active in squamous cell carcinoma of the head and neck. In the regimen selected for this trial, toxicity was significant and led to a prolongation of treatment time.

Does histologic grade have a role in the management of head and neck cancers?

PURPOSE

High histologic grade is usually associated with a greater propensity to distant metastases (DM). Its role to predict DM in head and neck cancer is not yet defined. The aim of this study is to evaluate the role of histologic grade as an independent predictor of DM and to determine a subgroup of patients who may benefit from systemic chemotherapy.

PATIENTS AND METHODS

This is a retrospective study of 1,266 consecutive patients treated by definitive or postoperative radiotherapy between 1989 and 1997. All patients received at least 50 Gy. All stages and subsites of head/neck were included. DM rates were evaluated by the Kaplan-Meier method with a subsequent Cox analysis.

RESULTS

There is a strong correlation of grade with N stage (P <.000001). The metastases-free survival (MFS) was 98%, 90%, and 72% for grades 1, 2, and 3, respectively (P <.000001). In patients with N0 stage, MFS is always greater than 90%, whatever the grade. In the 222 N1 patients, MFS was more than 90% in grade 1 and 2 but dropped to 75% for grade 3 (P =.001). In patients with N2 and N3, MFS was 91%, 79%, and 59% for grades 1, 2, and 3, respectively (P =.008). The same conclusion is applicable when only patients with neck control are analyzed. In a Cox model, grade was an independent predictor of DM (P =.000001) as well as T stage (P =.003), N stage (P =.000001), and neck failure (P =.0003). Higher grade was also an independent predictor of survival (P =.02).

CONCLUSION

Patients with histologic grade 1 and grade 2 (except N3) are at low risk of DM. Patients with grade 2 and N3 or patients with grade 3 and N1 to N3 have a higher risk of distant metastases and should be considered for systemic treatment.