Some recent studies:

Intensity-modulated radiotherapy in postoperative treatment of oral cavity cancers.

Gomez DR, Int J Radiat Oncol Biol Phys. 2009 Mar 15;73(4):1096-103. Epub 2008 Aug 15.

Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center

The role of definitive radiation therapy in squamous cell carcinoma of the oral tongue.

Korb LJ, Spaulding CA, Constable WC  Cancer 1991 Jun 1;67(11):2733-7

Division of Radiation Oncology, University of Virginia Health Sciences Center, Charlottesville 22908.

Between 1968 and 1985, 114 patients with squamous cell carcinoma of the tongue were evaluated in the Department of Radiation Oncology at the University of Virginia (Charlottesville, VA); of these, 86 received treatment with curative intent. The majority were treated with radiation therapy alone, whereas the remainder were treated with radiation therapy with preoperative or postoperative surgery. There were 17 T1 primary malignancies, 40 T2, 27 T3, and 2 T4. Clinically positive adenopathy was present in 48% of the patients overall and ranged from 35% in the T1 group to 100% in the T4 group. Twenty-six percent of patients either presented with or later had second malignancies. At 36 months, the patient status was evaluated as dead of disease (37%), dead of intercurrent disease (23%), alive with disease (1%), and alive without evidence of disease (38%). Seventy-five patients received external beam therapy and 32 patients received an implant as either all or part of their treatment. Average doses were in the range of 6000 Gy. Adjusted local control rate at 3 years was not statistically different for different treatment techniques used on either T1 or T2 primary malignancies. The rates were 89% versus 88% for T1 lesions treated with definitive radiation therapy versus postoperative radiation therapy. For T2 primary malignancies, the rates were 67%, 71%, and 83% for the definitive, preoperative, and postoperative radiation therapy groups, respectively. For T3 lesions, there was close to statistical significance with the corresponding rates being 47%, 50%, and 100%, respectively. When the effect of implants was examined for T1 and T2 lesions, no difference in local control rate at 3 years was noticed with or without an implant. Survival was improved for the group presenting with positive neck disease when compared with the N0 group. The external beam severe complication rate was less than 5%, and the implant complication rate was 6%.

Definitive radiotherapy for carcinoma of the oral tongue.

Leung TW, Lee AW, Chan DK      Acta Oncol 1993;32(5):559-64

Institute of Radiology and Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong.

This is a retrospective analysis of 117 patients with carcinoma of the oral tongue treated by definitive radiotherapy during 1979-1990. Sixty-seven per cent of patients presented with T1-2 disease. Their cumulative incidence of local failure was 10% (5/50) for those suitable for treatment with implant alone, 81% (13/16) for those treated with external irradiation alone and 67% (8/12) after combined treatment. These differences could largely be explained by selection factors as smaller and less bulky tumours generally were selected for implant treatment. Among the patients who achieved local control, there was no incidence of regional relapse (0/9) for those with elective neck irradiation, but 33% (15/46) for those without. This incidence correlated with size of primary tumour. Radiotherapy achieved effective local control in 13% (5/39) of T3-4 tumours, and regional control in 43% (12/28) of N1-3 cases. Only 32% (24/76) of patients with local and/or regional recurrence were successfully salvaged.

Primary radiotherapy in the treatment of stage I and II oral tongue cancers: importance of the proportion of therapy delivered with interstitial therapy.

Wendt CD, Int J Radiat Oncol Biol Phys 1990 Jun;18(6):1287-92

Department of Clinical Radiotherapy, M.D. Anderson Cancer Center, Houston, TX 77030.

From January 1963 through December 1979, 103 patients with Stage T1N0 and T2N0 squamous cell carcinomas of the oral tongue were treated with definitive radiotherapy. The primary was Stage T1 in 18 patients and T2 in 85 patients. Therapy to the primary consisted of interstitial therapy only in 18 patients, 16-37 Gy in 2.4-4.0 Gy fractions followed by interstitial therapy to doses of 38-55 Gy in 31 patients, external therapy of 40-50 Gy with interstitial therapy of 20-40 Gy in 46 patients, and external beam only to doses of 45-82 Gy in 8 patients. Follow-up ranged from 2 to 290 months (median 159 months). Five of the 8 patients treated with external therapy alone and 6 of the 18 patients treated with interstitial therapy failed at the primary site. In those patients treated with a combination of external and interstitial therapy the 2-year local control rate was 92% for patients treated with external therapy to doses of less than 40 Gy combined with a moderately high dose of brachytherapy, compared with 65% for patients who received external therapy to doses of greater than or equal to 40 Gy with lower brachytherapy doses (p = .01). Conversely the risk of failure in the neck was directly related to the dose delivered by external beam therapy. In field recurrence occurred in 44% of patients receiving no therapy to the neck. 27% in those receiving less than 40 Gy, and 11% in those patients with neck treatment to greater than or equal to 40 Gy. Eleven of 87 (13%) of patients who were at risk for complications for greater than or equal to 24 months developed severe complications; severe complications were more likely to occur in the group who received most of their therapy with external beam irradiation. These data show that a high dose of interstitial therapy is necessary to secure optimum local control of early primary tongue cancer. Because of the high frequency of moderate to severe late complications in this series we have adopted a policy of initial surgery for most oral tongue cancers with postoperative radiotherapy if indicated by pathological features predictive of a high rate of local-regional failure.

T2 oral tongue carcinoma treated with radiotherapy: analysis of local control and complications.

Mendenhall WM, Parsons JT, Stringer SP, Cassisi NJ, Million RR    Radiother Oncol 1989 Dec;16(4):275-81

Department of Radiation Oncology, University of Florida, Gainesville.

The purpose of this paper is to analyze the time factor and the proportion of the total dose delivered with external-beam irradiation versus interstitial implant in 42 patients with previously untreated T2 squamous cell carcinoma of the oral tongue managed with irradiation alone between 1964 and 1986. Treatment was delivered with interstitial implant alone (4 patients), external-beam radiotherapy and implant (34 patients), or external-beam radiotherapy alone (4 patients). The following are the rates of local control with radiotherapy and ultimate local control, including patients successfully salvaged after a local recurrence: 21/35 (60%) and 26/35 (74%). In the group of patients treated with external-beam radiotherapy and an interstitial implant, local control was 12/16 (75%) for an implant plus less than or equal to 3000 cGy external-beam radiotherapy compared with 6/15 (40%) for an implant plus greater than 3000 cGy external-beam radiotherapy. For the entire group of patients, local control was 16/21 (76%) if the treatment time was less than 40 days and 5/14 (36%) if the overall treatment time was greater than 40 days.

The management of patients with carcinoma of the tongue.

Mitchell R, Crighton LE    Br J Oral Maxillofac Surg 1993 Oct;31(5):304-8

Department of Oral and Maxillofacial Surgery, University of Edinburgh.

Surgery, radiotherapy or the combination of these two modalities remains the accepted treatment for squamous carcinoma of the tongue. In the 10-year period between 1982 and 1992, 121 patients presented to the combined Maxillofacial/Radiation Oncology Clinic, Royal Infirmary, Edinburgh with carcinoma of the tongue. The majority of T1 tumours have been treated by surgical excision, almost equal numbers of T2 tumours were treated by surgery or radiotherapy, T3 and T4 tumours without evidence of nodal disease were treated by radiotherapy. Patients presenting with established nodal disease or involvement of bone were treated primarily by surgery. The patients presenting with T3 and T4 tumours were combined to produce a more realistic figure for statistical analysis. The actual 5-year survival rates for patients presenting from 1982 to 1987 for T1, T2 and T3/4 tumours are 83%, 63% and 0% respectively. Five year actuarial survival rates for patients from 1987 to 1992 are 89%, 69% and 47%. In the absence of nodal disease in the retrospective group, T1, T2 and T3/4 carcinomas of the tongue have actual 5-year survival rates of 93%, 87% and 0% respectively. Patients who present with or later develop nodal disease have a poorer prognosis with survival rates of 33%, 33% and 0% for T1, T2 and T3/4 tumours. The size of the primary tumour did not significantly affect the five year survival rate when nodal disease was present.

Carcinoma of the oral tongue: a comparison of results and complications of treatment with radiotherapy and/or surgery.

Fein DA, Mendenhall WM, Parsons JT, McCarty PJ, Stringer SP, Million RR, Cassisi NJ  Head Neck 1994 Jul-Aug;16(4):358-65

Department of Radiation Oncology, University of Florida College of Medicine, Gainesville.

To evaluate the results of a shift in treatment policy in 1985 in favor of primary surgical treatment for carcinoma of the oral tongue, the results of radiotherapy (with or without neck dissection, 105 patients) were compared with those for surgery (with or without radiotherapy, 65 patients). RESULTS. Local control rates were improved for T3 (p = .03) and T4 (p = .08) patients treated surgically but were similar for T1-T2 patients. Local-regional control and survival rates were not significantly different. The rate of severe complications was significantly higher (p = .01) for T3 patients treated with surgery, particularly in the subset of patients who received postoperative radiotherapy. CONCLUSIONS. We generally recommend surgical treatment for T1-T2 patients with the addition of postoperative twice-a-day radiotherapy in selected cases. For selected T3-T4 patients we are investigating split-course twice-a-day preoperative radiotherapy in the hope that the extent of the surgical procedure, and hence the rate of severe complications, will be reduced.

Surgery as a single modality therapy for squamous cell carcinoma of the oral tongue.

Hicks WL Jr, North JH Jr, Loree TR, Maamoun S, Mullins A, Orner JB, Bakamjian VY, Shedd DP   Am J Otolaryngol 1998 Jan-Feb;19(1):24-8

Department of Head and Neck Surgery, Roswell Park Cancer Institute, Buffalo, NY, USA.

From 1971 to 1993, 79 patients with squamous cell carcinoma of the oral tongue were treated with surgery alone at Roswell Park Cancer Institute. RESULTS: Clinically, 69% of the patients presented with stage I/II disease and 31% presented with stage III/IV. Survival by pathological stage I to IV was 89%, 95%, 76%, and 65%, respectively. Surgical therapy ranged from partial to total glossectomy. There were no patients with positive margins. Local recurrence was observed in 15% of patients with close margins (< 1 cm) and 9% of patients with adequate margins (> or = 1 cm). The incidence of pathological node positive (N+) disease was 6%, 36%, 50%, and 67% for T1, T2, T3, and T4 tumors, respectively. Twenty-five percent of patients undergoing elective neck dissection were pathological N+. All pathological confirmed nodal disease was at level I or II. Of the 43 patients with clinical N0 disease, 16% subsequently developed regional recurrence, all of which were surgically salvaged. CONCLUSION: Locoregional control in patients with squamous cell carcinoma of the oral tongue can be achieved with primary surgical therapy. Adequate margins are crucial to local control. Salvage neck dissection may result in long-term survival for patients with regional relapse. Because of the high rate of occult disease (41%), we currently recommend prophylactic treatment of regional lymphatics for primary clinical disease of T2 or greater.

Interstitial brachytherapy for stage I and II squamous cell carcinoma of the oral tongue: factors influencing local control and soft tissue complications.

Fujita M, Hirokawa Y, Kashiwado K, Akagi Y, Kashimoto K, Kiriu H, Matsuura K, Ito K    Int J Radiat Oncol Biol Phys 1999 Jul 1;44(4):767-75

Department of Oral and Maxillofacial Radiology, Hiroshima University School of Dentistry, Japan. mfujita@ipc.hiroshima-u.ac.jp

PURPOSE: Our aim was to study the treatment parameters that influence local control and soft tissue complications (STC) in a series of 207 Stage I and II squamous cell carcinomas of the oral tongue treated by interstitial brachytherapy (BRT) alone (127 patients), or by a combination using external beam irradiation (EBI) (80 patients) between 1980 and 1993. METHODS AND MATERIALS: The patient distribution was 93 T1, 72 T2a, and 42 T2b. The prescribed BRT dose at the plane 5 mm from the plane of the radioactive sources was 65-70 Gy in BRT alone, and 50-60 Gy in the combined treatment using EBI. Generally, an EBI dose of 30 Gy was used. No prophylactic neck treatment was performed. RESULTS: The 5-year local recurrence-free rate for T1, T2a, and T2b was 92.9%, 81.9%, and 71.8%, respectively (p < 0.05).  To acheive better local control and fewer STC, we recommend the following relationships between dose and dose rate. In BRT alone, dose rate should be maintained at < 0.6 Gy/h with a preferable BRT dose 65-70 Gy. In the combined treatment, total dose, BRT dose and dose rate should be kept between > 85 Gy and < = 100Gy, between > 55 Gy and < = 70 Gy, and < 0.55 Gy/h, respectively. We also recommend longer follow-up periods; more than 5 years might be necessary for late local recurrences and for secondary cancers.