Exclusive radiation therapy: the treatment of early tonsillar tumors

Additional parameters to improve the prognostic value of the 8th edition of the UICC classification for human papillomavirus-related oropharyngeal tumors

Background

The prognostic reliability of the UICC's TNM classification (8th edition) for human papillomavirus (HPV)‐positive tonsillar squamous cell carcinomas (TSCCs) compared to the 7th edition was explored, and its improvement by using additional anatomical and nonanatomical parameters.

Methods

One hundred and ten HPV‐positive and 225 HPV‐negative TSCCs were retrospectively analyzed. Survival was correlated with patient and tumor characteristics (7th and 8th edition UICC TNM classification).

Results

In HPV‐positive TSCCs, the 8th edition UICC's TNM classification correlated better with prognosis than the 7th edition. Also, smoking status was a stronger prognosticator of survival than UICC staging. Non‐ or former smokers had a 5‐year overall survival of 95.1% regardless of tumor stage. Furthermore, age (>65 years), cN3, and M1 classification were significant prognostic factors.

Conclusion

The prognostic value of the 8th edition UICC's TNM classification improved significantly when compared to the 7th edition. Nonetheless, further improvement is possible by adding nonanatomical factors (smoking, age >65 year) and separating N0‐N2 from N3.

Radiotherapy alone or combined with chemotherapy as definitive treatment for squamous cell carcinoma of the tonsil

This study is aimed at updating our institution's experience with definitive radiotherapy (RT) for squamous cell carcinoma of the tonsil. We reviewed 531 patients treated between 1983 and 2012 with definitive RT for squamous cell carcinoma of the tonsil. Of these, 179 patients were treated with either induction (n = 19) or concomitant (n = 160) chemotherapy. Planned neck dissection was performed on 217 patients: unilaterally in 199 and bilaterally in 18 patients. Median follow-up was 5.2 years for all patients (range 0.1-31.6 years) and 8.2 years for living patients (range 1.9-31.6 years). The 5-year local control rates by T stage were as follows: T1, 94 %; T2, 87 %; T3 79 %; T4, 70 %; and overall, 83 %. Multivariate analysis revealed that local control was significantly influenced by T stage and neck dissection. The 5-year cause-specific survival rates by overall stage were as follows: I, 94 %; II, 88 %; III, 87 %; IVA, 75 %; IVB, 52 %; and overall, 78 %. Multivariate analysis revealed that cause-specific survival was significantly influenced by T stage, N stage, overall stage, fractionation, neck dissection, sex, and ethnicity. Of 77 patients treated with ipsilateral fields only, contralateral neck failure occurred in 1 %. The rate of severe complications was 12 %. Definitive RT for patients with tonsillar squamous cell carcinoma provides control rates equivalent to other modalities with a comparatively low incidence of late complications. Patients with anterior tonsillar pillar or tonsillar fossa primaries that are well lateralized with no base of tongue or soft palate extension may be treated with ipsilateral fields.

Role of surgery in the management of head and neck cancer: a contemporary view of the data in the era of organ preservation

OBJECTIVE

Review of the literature on the role of surgery in the management of head and neck cancer in the era of organ preservation.

METHOD

Literature search based on the essential practice guidelines set out by the US National Comprehensive Cancer Network.

RESULTS

Despite the increasing popularity of non-surgical treatment options, the surgeon remains a key figure in the multidisciplinary head and neck cancer team, along with the radiation oncologist, the medical oncologist and the speech and swallowing therapist. Even when organ preservation is successful, early and late toxicity may cause serious complications, including laryngeal dysfunction with a 'frozen larynx'. When organ preservation fails, salvage surgery is often associated with increased complications and reduced survival.

CONCLUSION

There is a definite need to apply more rigorous standards to the use of organ preservation strategies, and to re-evaluate the role of surgery in head and neck cancer treatment.

Course and prognosis of basaloid squamous cell carcinoma of the head and neck: a case-control study of 62 patients

OBJECTIVE

To describe the natural history and evaluate the prognosis of basaloid squamous cell carcinoma (BSCC) of the upper aero-digestive tract as compared to the usual squamous cell carcinoma (SCC).

MATERIALS AND METHODS

Sixty-two patients with BSCC and 62 patients with SCC were matched with regards to TNM classification, localisation and therapeutic modalities. Histological criteria, follow-up and 5-year survival were compared among the two groups.

RESULTS

Survival rates were significantly higher in patients with SCC as compared to patients with BSCC. The rate of distant metastasis was six times higher in cases of BSCC, which was the major cause of mortality.

CONCLUSION

This study reveals that BSCC has distinct histo-pathologic features and an aggressive clinical course, justifying its consideration as a separate entity with poor prognosis. The authors propose to systematically perform a chest CT-scan and FDG-PET to rule out early distant metastasis and to include adjuvant chemotherapy in treatment protocols.

Definitive radiotherapy for tonsillar squamous cell carcinoma

PURPOSE

The purpose of this study is to update our experience with definitive radiotherapy (RT) for carcinoma of the tonsillar area.

PATIENTS AND METHODS

There were 503 patients treated between October 1964 and May 2003 (potential follow-up for at least 2 years). Of these, 198 patients underwent a planned neck dissection and 57 patients received induction (18 patients) or concomitant (39 patients) chemotherapy.

RESULTS

The 5-year local control rates were as follows: T1, 88%; T2, 84%; T3, 78%; and T4, 61%. Multivariate analysis revealed that local control was significantly influenced by T stage, primary site, and fractionation. Local control after RT for early stage cancers was higher for tonsillar fossa/posterior pillar tumors than for those arising from the anterior tonsillar pillar. The 5-year cause-specific survival rates were as follows: I, 100%; II, 86%; III, 84%; IVA, 73%; and IVB, 46%. Multivariate analysis revealed that cause-specific survival was significantly influenced by T stage, overall stage, neck dissection, race, and gender. The incidence of severe late complications was 9%.

CONCLUSION

Based on our data and a review of the literature, definitive RT provides cure rates that are as good as those after surgery, and is associated with a lower rate of severe complications. Patients with lateralized tumors may be safely treated with ipsilateral field arrangements. Our limited experience with intensity modulated radiotherapy suggests that it is as efficacious as conventional RT.

Exclusive brachytherapy for T1 and T2 squamous cell carcinomas of the velotonsillar area: Results in 44 patients

PURPOSE

To evaluate the role of interstitial brachytherapy as an exclusive radiotherapy modality for primary T1-T2 squamous cell carcinomas (SCC) of the velotonsillar area.

METHODS AND MATERIALS

Between 1992 and 2000, 44 patients with T1-T2 SCC of the tonsil (n = 36) and soft palate (n = 8) were treated to the primary with brachytherapy alone (37 patients) or after a limited resection (7 patients). Eight patients had prior external beam radiation therapy (EBRT) for previous head-and-neck carcinoma. Nineteen patients had initial neck dissection. The mean brachytherapy dose was 58.7 Gy, and the mean reference dose rate and Ir-192 linear activity were 58.2 cGy/h and 1.51 mCi/cm respectively.

RESULTS

With a 75-month median follow-up, 1 patient recurred locally. Isolated nodal relapses occurred in 4 patients, none of whom had initial neck dissection, and salvage therapy was successful in 2. Five-year overall and progression-free survival rates were 76% and 68%, respectively. Full-course radiation therapy was possible in 7 of 12 patients who developed a second primary head-and-neck carcinoma. Late toxicity was limited to 6 mild soft-tissue necroses, and was significantly associated with previous surgery to the primary and high linear activity.

CONCLUSIONS

Exclusive brachytherapy for T1-T2 velotonsillar carcinomas is safe and effective, and permits definitive reirradiation for a second head-and-neck cancer. Initial neck dissection should be performed for optimal selection for exclusive brachytherapy.

Evolution et pronostic du carcinome basaloïde squameux des voies aéro-digestives supérieures

INTRODUCTION

The course and prognosis of basaloid squamous cell carcinoma (BSCC) are not well known.

OBJECTIVES

To study the course and prognosis in a population of BSCC patients.

MATERIALS AND METHODS

We analyzed a retrospective cohort of 49 patients with BSCC in comparison with a cross-matched population of 49 patients treated for well- to moderately differentiated squamous cell carcinoma (SCC).

RESULTS

The statistical analysis showed that survival in BSCC group was lower than in the SCC group. Local recurrence in the BSCC group was not higher than in the SCC group, but mortality by distant metastasis was six times higher than in the SCC population.

CONCLUSIONS

We consider BSCC patients as a high-risk population and we complete diagnosis explorations including a FDG-PET before curative treatment. We also recommend post-operative or exclusive radiotherapy which may be associated with concomitant chemotherapy.

Management of Contralateral N0 Neck in Tonsillar Squamous Cell Carcinoma

OBJECTIVES

It is well established that tonsillar squamous cell carcinomas have a high probability of disseminating to the neck. An ipsilateral neck treatment is mandatory during initial treatment of stages II to IV tonsillar carcinomas. However, as of yet, no consensus exists whether to perform elective contralateral neck management.

MATERIALS AND METHODS

A retrospective analysis of 43 N0-3 tonsillar cancer patients with contralateral clinically negative necks from 1992 to 2002 was performed. All patients had a contralateral elective neck dissection. Surgical treatment was followed by postoperative radiotherapy in 33 patients. The follow-up period ranged from 2 to 120 (mean 38) months. The Kaplan-Meier method and log-rank test were used to calculate the disease-specific survival rates and prognostic significance of contralateral occult lymph node metastasis.

RESULTS

Clinically negative, but pathologically positive, contralateral lymph nodes occurred in 16% (7 of 43). Of the 33 cases with an ipsilateral node positive neck, contralateral occult lymph node metastases developed in 21% (7 of 33), in contrast with 0% in ipsilateral N0 necks. On the basis of the clinical staging of the tumor, 5% (1 of 22) of the cases showed lymph node metastases in T2 tumors, 36% (5 of 14) in T3, and 25% (1 of 4) in T4. None of the T1 tumors (3 cases) had pathologically positive lymph nodes (T1 + T2 vs. T3 + T4, P < .05). Patients with no evidence of contralateral nodal cancer had significantly improved disease-specific survival over patients with any pathologically positive nodes (5 year disease-specific survival rate 92% vs. 28%, P = < .05).

CONCLUSION

The risk of contralateral occult neck involvement in above T3 staged tonsillar squamous cell carcinomas with unilateral metastases was high (approximately 21%), and patients who present with a contralateral metastatic neck have a worse prognosis than those who are staged as N0. Therefore, we advocate an elective contralateral neck treatment in tonsillar squamous cell carcinoma patients with ipsilateral node metastases.

Different prognostic indices in 310 patients with tonsillar carcinomas

BACKGROUND

Several modifications of the TNM system have been reported as better prognostic tools than the original classification in head and neck cancer, but none of these modifications has been tested in a large series of tonsillar carcinomas. These studies did not examine host and treatment factors as predictors in addition to TNM.

METHODS

Three hundred and ten consecutively untreated patients with squamous cell carcinoma of the tonsillar region admitted to the Norwegian Radium Hospital and/or the National Hospital between 1960 and 1996 were included.

RESULTS

The five reported TN-based stage modifications were all highly significant predictors of survival. Four clinical variables indicating shorter disease-specific survival were identified: age > 60, male gender, total radiation dose < 70 Gy, and duration of radiotherapy > 50 days.

CONCLUSIONS

Earlier reported TNM-based stage modifications are all very useful predictors of survival in tonsillar carcinomas. In addition, age, gender, total radiation dose, and duration of radiotherapy were important prognostic factors. We propose that both host and treatment factors should be tested carefully when building new prognostic indices in tonsillar carcinomas.

The benefits and pitfalls of ipsilateral radiotherapy in carcinoma of the tonsillar region

PURPOSE

Ipsilateral techniques designed to restrict treatment to the primary tumor and neck on the same side have been used in selected cases of cases of carcinoma of the tonsillar region at our institution for many years. The primary purpose of this study is to evaluate the risk of failure in the opposite neck in cases selected for unilateral radiotherapy over a 21-year period.

METHODS AND MATERIALS

Ipsilateral radiotherapy techniques were used in 228 of 642 patients with carcinoma of the tonsillar region from 1970 to 1991. Local control, regional lymph-node control (including contralateral failure), and survival were calculated for different degrees of tumor extent treated with these techniques.

RESULTS

Mean follow-up was 7 years. Cases tended to be T1 and T2, with N0 disease. The 3-year actuarial local control rate was 77% and cause-specific survival was 76%. Opposite neck failure was seen in 8 patients (crude rate of 3.5%). In the earlier period of the study, primary coverage was problematic in a proportion of cases and resulted in higher rates of local failure.

CONCLUSION

Appropriately selected cases of carcinoma of the tonsil show minimal risk of failure in the opposite neck with ipsilateral techniques. Patients should undergo computed tomography planning to ensure adequate target coverage.

Radiation therapy for squamous cell carcinoma of the tonsillar region: a preferred alternative to surgery?

PURPOSE

There are no definitive randomized studies that compare radiotherapy (RT) with surgery for tonsillar cancer. The purpose of this study was to evaluate the results of RT alone and RT combined with a planned neck dissection for carcinoma of the tonsillar area and to compare these data with the results of treatment with primary surgery.

PATIENTS AND METHODS

Four hundred patients were treated between October 1964 and December 1997 and observed for at least 2 years. One hundred forty-one patients underwent planned neck dissection, and 18 patients received induction (17 patients) or concomitant (one patient) chemotherapy.

RESULTS

Five-year local control rates, by tumor stage, were as follows: T1, 83%; T2, 81%; T3, 74%; and T4, 60%. Multivariate analysis revealed that local control was significantly influenced by tumor stage (P =.0001), fractionation schedule (P =.0038), and external beam dose (P =.0227). Local control after RT for early-stage cancers was higher for tonsillar fossa/posterior pillar cancers than for those arising from the anterior tonsillar pillar. Five-year cause-specific survival rates, by disease stage, were as follows: I, 100%; II, 86%; III, 82%; IVa, 63%; and IVb, 22%. Multivariate analysis revealed that cause-specific survival was significantly influenced by overall stage (P =.0001), planned neck dissection (P =.0074), and histologic differentiation (P =.0307). The incidence of severe late complications after treatment was 5%.

CONCLUSION

RT alone or combined with a planned neck dissection provides cure rates that are as good as those after surgery and is associated with a lower rate of severe complications.

Ipsilateral irradiation for carcinomas of tonsillar region and soft palate based on computed tomographic simulation

PURPOSE

To reduce xerostomia in selected patients with carcinomas of the tonsillar region and soft palate.

METHODS AND MATERIALS

We evaluated the treatment results of 32 patients with tonsillar region and soft palate carcinoma treated by radical radiotherapy between May 1989 and December 1996. They have a unilateral tumor that did not cross midline and have no contralateral neck lymphnode metastasis and treated with an ipsilateral technique (an anterior oblique and a posterior oblique field). All patients were planned with computed tomographic (CT) simulation and given 65 Gy in 26 fractions in 6.5 weeks with or without 5-15 Gy boost irradiation. The median follow-up was 44 months (4-86 months).

RESULTS

Five-year overall, cause-specific survival, local control, and regional control rate was 64, 79, 74 and 81%. No failure at the contralateral neck occurred. Moderate or severe symptomatic xerostomia was seen in 3 (9%) patients and ostero-radionecrosis requiring surgery occurred in one (3.3%) of 32 patients.

CONCLUSION

It is suggested that the ipsilateral technique is indicated in patients who had an unilateral tonsillar region or soft palate carcinoma that did not cross midline and have no contralateral neck lymphnode metastasis.

Cancer of the tonsil: the results of ipsilateral radiation treatment

BACKGROUND AND PURPOSE

The use of ipsilateral irradiation techniques to treat patients with carcinoma of the tonsil reduces the acute radiation reaction in the contralateral pharynx and late damage to the contralateral salivary tissue. However, this may also spare microscopic disease in apparently uninvolved contralateral lymph nodes. The purpose of this study was to analyse the survival and recurrence rates and sites of recurrance in a group of patients with carcinoma of the tonsil treated with ipsilateral techniques.

MATERIALS AND METHODS

Between 1975 and 1993, 271 patients with invasive squamous cell cancer of the tonsil were referred to the Vancouver Cancer Centre (VCC). One hundred and seventy-eight received ipsilateral radiation treatment. Three received surgery only, six post-operative radiation, 12 supportive treatment only and 72 bilateral radiation treatment. In the absence of bilateral neck nodes and extensive lymphodenopathy, field sizes were generally kept small to include the primary tumour and the first echelon of nodes. The most common dose was 60 Gy in 25 daily fractions in 5 weeks (2.4 Gy per day).

RESULTS AND DISCUSSION

The disease specific survival for all patients treated by radical radiation treatment was 61% at 5 years. For the 178 patients who received ipsilateral radiation treatment the overall primary tumour control rate by ipsilateral radiation treatment alone was 75% and for T1 and T2 tumours 84%. Eight (7.5%) of 101 of these patients with N0 nodes at presentation and without prior failure at the primary site, developed nodal recurrence (four within the initially radiated high dose volume). Two developed contralateral nodes, and two developed field edge nodal recurrence, one cured by surgery. In 54 patients with N1 disease, five developed nodal recurrence, two within field, two contralateral, one of whom was cured by surgery, and one at field edge. In 23 patients with N2a, N2b or N3 disease node control was achieved from radiation treatment in 11 and two more were cured by surgery. All nodal failures were within the radiated volume. Overall, 10 of the 25 patients with nodal failure were cured by subsequent surgery.

CONCLUSIONS

Ipsilateral treatment of patients with carcinoma of the tonsil gives survival results that are at least as good as those reported with bilateral treatment with fewer side effects and a very low risk of failure in the contralateral neck.

Surgery versus radiation therapy as single-modality treatment of tonsillar fossa carcinoma: the Roswell Park Cancer Institute experience (1971-1991)

OBJECTIVE

To compare the efficacy and treatment outcomes in patients with tonsillar fossa cancer using surgery or radiation as a single modality therapy.

METHODS

From 1971 to 1991 239 patients with oral pharyngeal cancer were treated at Roswell Park Cancer Institute. Of these patients 90 had tonsillar carcinoma. Seventy-six of these patients received either surgery (SA) (n = 56) or radiation therapy (RA) (n = 20) as single-modality therapy and are the subject of this review. All patients in the radiation arm of this review were surgical candidates who declined primary surgical therapy.

RESULTS

Sixty-three percent of the SA and 80% of the RA treatment groups presented with either stage III or stage IV disease (P < or = .05). Forty-seven percent of the SA group and 52% of the RA patients had clinically positive regional disease at initial presentation. There was a predictable pattern of nodal presentation, with level II the most frequently involved region. The rate of occult metastasis was 27% and was evenly distributed between T1 and T4 disease. The overall local control rate in the SA group was 75%, compared with 60% in the RA group (P value was not significant). The disease-specific survival (all stages) was 61% in the SA group and 37% in the RA group (P < or = .05). The disease-free survival for stage III and stage IV disease in the SA group was 47% and in the RA group 27% (P < or = .05). Survival measured against clinical response to radiation therapy, in complete responders (all stages) was 83%; by contrast there were no survivors past 24 months in the partial response group (P < or = .001).

CONCLUSION

The results from this study suggest that for early disease (stage I/II), surgery or radiation therapy as single-modality treatment is equally effective. For advanced disease radiation therapy is inferior to surgery as a single-modality treatment, as measured by ultimate survival and the local control of disease. There is, however, a subset of patients with advanced disease who respond to radiation therapy and whose survival is equivalent to our surgical cohort of patients.

Target volume definition in radiation therapy

Target volume definition in radiation therapy is a broad field of interdisciplinary research. We give a brief history of clinical research in this field and outline some remarkable steps which led to the well-defined target volume concepts. The challenges in target volume definition for high-precision conformal radiation therapy are discussed, and possibilities of improving target volume definition, such as the integration of modern imaging modalities and the use of computer-based systems to support the radiation oncologist are indicated, as well as novel techniques for increasing the accuracy of patient positioning. All these tools should be evaluated with regard to their potential for increasing the therapeutic ratio and, as appropriate, should be implemented in clinical practice. However, target volume definition is a complex process influenced by many factors, currently under investigation. While questions remain in this field, and the impact of the influencing factors is not defined, the process of target volume definition should remain the subject of clinical research.

Consistency of three-dimensional planning target volumes across physicians and institutions

PURPOSE

Three-dimensional treatment planning depends upon exact and consistent delineation of target volumes. This study tested whether different physicians from different institutions vary significantly in their creation of planning target volumes (PTVs).

METHODS AND MATERIALS

Eight physicians from three different institutions created partial planning target volumes for nine clinical test cases. Their target volumes were evaluated qualitatively and quantitatively. Quantitative results were tested for significant differences.

RESULTS

Qualitative analysis showed the physicians to vary in (a) the margin placed around the clinical target volume, (b) the margin used near critical structures, and (c) handling of concavities in the clinical target volume. Quantitative analysis showed these variations to result in statistically significant differences in the measured volume of the physicians' planning target volumes.

CONCLUSIONS

Individual physicians and institutions differ significantly in their creation of planning target volumes, suggesting individual and institutional differences in the working definition for the PTV. Implications of this fact are discussed, along with areas where standardization can be improved.

Oropharyngeal carcinoma treated with radiotherapy: a 30-year experience

PURPOSE

This study was done to determine the outcome in patients with oropharyngeal carcinoma treated at the University of Florida with radiotherapy alone to the primary site, for comparison with reported results of other types of treatment.

METHODS AND MATERIALS

Of a consecutive cohort of 785 patients with biopsy-proven, previously untreated, invasive squamous cell carcinoma of the oropharynx, this report is based on the 490 patients who had continuous-course irradiation with curative intent at the University of Florida between October 1964 and January 1991. All patients had a minimum 2-year follow-up. Forty-eight percent had Stage T3 or T4 disease, and 64% had clinically apparent neck node metastases. The median radiation dose was 68 Gy for once-a-day treatment and 76.8 Gy for twice-a-day treatment. Patients with advanced neck node disease had planned neck dissection(s) after radiotherapy.

RESULTS

The overall local control rate after radiotherapy alone was 73%. The ultimate local control rate (including surgical salvage) was 78%. At 5 years, the probability of control of neck disease was 85%; control above the clavicles, 67%; absolute survival, 44%; cause-specific survival, 77%; distant metastasis (as the first or only site of failure), 11%. Thirteen patients (2.6%) experienced severe treatment complications.

CONCLUSION

Radiotherapy results in tumor control and survival rates comparable with rates achieved with combined irradiation and surgery, with less morbidity.

Head and neck cancer

This synthesis of the literature on radiotherapy for head and neck cancer is based on 424 scientific articles, including 3 meta-analyses, 38 randomized studies, 45 prospective studies, and 246 retrospective studies. These studies involve 79174 patients. The literature review shows that radiotherapy, either alone or in combination with surgery, plays an essential role in treating head and neck cancers. When tumors are localized, many tumor patients can be cured by radiotherapy alone and thereby maintain full organ function (1, 2). Current technical advancements in radiotherapy offer the potential for better local tumor control with lower morbidity (3). This, however, will require more sophisticated dose planning resources. To further improve treatment results for advanced tumors, other fractionation schedules, mainly hyperfractionation, should be introduced (5). This mainly increases the demands on staff resources for radiotherapy. The combination of radiotherapy and chemotherapy should be subjected to further controlled studies involving a sufficiently large number of patients (4, 5). Interstitial treatment (in the hands of experienced radiotherapists) yields good results for selected cancers. The method should be more generally accessible in Sweden. Intraoperative radiotherapy should be targeted for further study and development.

Definitive radiotherapy for T1 and T2 squamous cell carcinoma of the tonsil

BACKGROUND

To assess whether survival or local control of early squamous cell carcinoma of the tonsil has been compromised by a moderate-dose approach.

METHODS

Between 1970 and 1989, 185 patients with SCCa of the tonsil were seen at our institution. Fifty-three patients with T1 (30) and T2 (23) lesions treated with definitive radiotherapy were reviewed. Median follow-up was 60 months. The effects of total dose and site of the primary on survival and local regional control were analyzed.

RESULTS

Three-year determinate survival was 77%. Mean total dose was 63.1 Gy. Site of the primary significantly affected survival (86% for fossa, 54% for pillars, p < 0.025). Local control at 2 years was 81% and was independent of dose > or = 63 Gy or site of the primary. Grade 4 complications defined by the RTOG/EORTC Acute Morbidity criteria occurred in three patients.

CONCLUSIONS

Tumor doses on the order of 63 Gy or less result in excellent local control and survival rates for T1 and T2 carcinomas of the tonsil. Local control rates are better for fossa lesions than for pillar lesions.

Salvage irradiation by brachytherapy of velotonsillar squamous cell carcinoma in a previously irradiated field: results in 73 cases

PURPOSE

The salvage brachytherapy performed in patients presenting velotonsillar carcinoma in a previously irradiated field is evaluated in terms of local control, complications and survival.

METHODS AND MATERIALS

Between 1976 and 1990, 73 patients presenting with velotonsillar squamous cell carcinoma in a previously irradiated area were treated at Center Alexis Vautrin with brachytherapy along using an 192Ir implant (afterloading technique) with curative intent. According to the UICC 1987 TNM classification, there were 45 T1 N0, 20 T2 N0, one T3 NO, one T3 N2 and six Tx Nx.

RESULTS

The 5-year actuarial local control for T1 N0 and T2 N0 are 80% and 67% respectively. The regional relapse rate was 10% in both groups. Grade 2 complications occurred in 13% of patients and these were neither related to the volume treated nor the dose rate. There were no Grade 3 or 4 complications. The 5-year specific survival is 64%, with a plateau after the 5th year, but the 5-year overall survival is only 30%. Fourty-two percent of the patients in this series died from another carcinoma. All but two of these were related to continued alcohol and tobacco intoxication.

CONCLUSION

We conclude that brachytherapy alone (60 Gy) is optimal treatment for patients presenting with velontonsillar carcinoma in a previously irradiated field. The greatest challenge is the screening of these patients and the prevention of subsequent head and neck cancers. Recognizing the fact that these patients are at high risk for subsequent malignancies of upper aerodigestive tract, lung and esophagus, close surveillance is necessary for: (a) early diagnosis and prompt treatment; and (b) development of prevention strategies of field cancerization.

Radioresponsiveness of human glioma, sarcoma, and breast cancer spheroids depends on tumor differentiation

PURPOSE

Differences in the intrinsic radiosensitivity within and between different tumor classes have been noticed for human tumor cell lines using the clonogenic assay. By far, most of the cell lines studied up to now were derived from poorly differentiated tumors. In this study, the influence of tumor differentiation on the radiation doses necessary to control 50% of small oxic spheroids (SCD50) was determined. Evidence of a distinct dependence of radioresponsiveness on tumor progression provides a background for an investigation of the underlying mechanisms.

METHODS AND MATERIALS

Spheroids were aggregated from 1000-1500 cells in agarose coated 24 multi-well plates. Their diameters ranged from 156 to 405 microns, depending on the cell line. Spheroids were irradiated with graded 60Co single doses using spheroid control as end point and a minimum follow-up period of 3 months.

RESULTS

Cell lines from three low grade gliomas and 10 malignant gliomas were studied in the spheroid control assay. The group mean SCD50 values were 6.1 +/- 1.6 Gy and 13.1 +/- 3.3 Gy, respectively. Four cell lines from grade 2 soft tissue sarcomas had a mean SCD50 value of 6.2 +/- 0.5 Gy and one undifferentiated sarcoma line of 11.0 Gy. Three well-differentiated breast cancer lines expressed the cell adhesion molecule E-cadherin, had an epithelioid morphology in monolayer culture, were estrogen receptor positive or contact inhibited in multicellular spheroids. Two undifferentiated breast cancer lines had a fibroblastoid morphology and were marker negative. The mean SCD50 value of the former was 10.5 +/- 1.0 Gy while that of the undifferentiated lines was 14.8 +/- 2.8 Gy. Analysis of variance revealed a significant effect of the tumor type as well as the grade of dedifferentiation on the SCD50 after irradiation with one fraction or 2Gy/fraction. The surviving fractions at 2 Gy (SF2), obtained from the spheroid control rates after different fractionation schedules by approximation of the linear quadratic model assuming Poisson statistics were significantly dependent on tumor type (p = 0.001, ANOVA F-test) but not on tumor differentiation (p = 0.27). The alpha/beta ratios did not depend on tumor type (p = 0.08, ANOVA F-Test) but significantly increased with the grade of tumor cell dedifferentiation (p = 0.03).

CONCLUSION

The spheroid model is suitable for measuring the radioresponsiveness of differentiated cell lines with very low colony forming efficiencies. Tumor cell differentiation is an important factor for the radioresponsiveness and recovery capacity of human tumor cells.

Place of Iridium 192 implantation in definitive irradiation of faucial arch squamous cell carcinomas

PURPOSE

We have reviewed the results of 165 T1 and T2 squamous cell carcinomas of the faucial arch treated by definitive irradiation including or not Iridium 192 brachytherapy to ascertain whether a significant relationship existed between Iridium implantation, local control, complications, and survival.

METHODS AND MATERIALS

From March 1971 to November 1990, 58 T1 and 107 T2 (NO: 107/165; N1: 30/165; N2: 9/165; N3: 19/165) biopsy proven squamous cell carcinomas of the tonsillar region (104/165) and the soft palate and uvula (61/165) were treated in Henri Mondor Hospital by definitive irradiation with curative intent. From 1971 to 1981 (period 1), only guide gutter technique was available, so that implants were reserved for small tumors: patients were either managed by definitive telecobaltherapy to tumor site and neck node areas (Group 1; n = 48; mean dose: 70 Gy; confidence interval: +/- 5.5; 5 fractions of 1.8 Gy per week) or by exclusive Iridium implant (Group 2; n = 11; all T1NO; 64 Gy +/- 4.8) or by a combination of external beam radiation therapy to tumor site and neck nodes areas and Iridium implant (Group 3; n = 40). In 1981 (Period 2), a new plastic tube technique, which enables implantation of larger areas, was introduced in the department and all patients (Group 4; n = 66) were then managed by external radiation therapy (Group 3 + 4: 47 Gy +/- 4.3) followed by an Iridium implant (31 Gy +/- 10.5). Clinically positive neck nodes either received additional external dose with electrons or were excised.

RESULTS

Overall 5-year survival (Kaplan Meier) was 21%, 50.5%, and 60% in groups 1, 2, and 3 + 4, respectively (p < 0.001, log rank). Five-year local control was 58%, 100%, and 91%, respectively (p < 0.001). Five-year necrosis rate was 4.5%, 20.5% and 18%, respectively (N.S.). Comparison of results between the two periods of the study (Group 1 + 2 + 3 vs. group 4) show that these two groups are statistically comparable according to site and size of tumor and N status and that both local control (77% vs. 94% at 5 years; p < 0.01) and disease-free survival (56% vs. 71%; p = 0.03) were improved after 1980, while there was a trend to an increase in overall survival (42% vs. 53% at 5 years; p = 0.08); nodal control (86% vs. 95% at 5 years), and necrosis rate (11% vs. 20% at 5 years) were not modified. Multivariate analysis showed that both local control (p < 0.0001) and overall survival (p < 0.0001) were improved when tumor was implanted.

CONCLUSION

We recommend then to treat T1 and T2 squamous cell carcinomas of the faucial arch by external radiation therapy to tumor site and neck areas (45 Gy/25 fractions/5 weeks) followed by a 30 Gy Iridium implant and, for patients with clinically positive nodes, either a further 25-30 Gy electron beam irradiation to the nodes or neck node dissection.

Carcinoma of the tonsillar region: a multivariate analysis of 243 patients treated with radical radiotherapy

Between October 1964 and June 1990, 243 patients with squamous cell carcinoma of the tonsillar region were treated with continuous-course radical radiotherapy at the University of Florida. All patients had a minimum 2-year follow-up. Patients were staged according to the AJCC system; stage IV was stratified into two subsets: favorable, IVA (T1-T3 or N2A-N3A); and unfavorable, IVB (T4 or N3B). The initial and ultimate local control rates (including surgical salvage) according to T stage were as follows: T1, 87% and 100%, T2, 79% and 92%; T3, 71% and 76%; and T4, 44% and 48%. Multivariate analysis demonstrated that anterior extension of the primary tumor (p = .0001) and T stage (p = .014) were the most significant parameters affecting local control after radiotherapy. For T4 lesions, twice-daily irradiation significantly improved local control (p = .04). The 5-year absolute and cause-specific survival rates as a function of modified AJCC stage were as follows: I, 37% and 100%; II, 55% and 90%; III, 55% and 85%; IVA, 35% and 60%; and IVB, 23% and 38%. The probability of a severe complication was 3% for the entire group of patients.

Velotonsillar squamous cell carcinoma: 277 cases treated by combined external irradiation and brachytherapy--results according to extension, localization, and dose rate

From 1977 to 1987, 277 patients with velotonsillar cancer (oropharyngeal cancer excluding base of tongue and valleculae) were treated by brachytherapy either alone (14 patients) or combined with external beam irradiation (263 patients) using a new afterloading Iridium-192 technique. The distribution of patients according to the localisation was as follows: 106 tonsillar region, 98 soft palate, 45 anterior pillar, 8 posterior pillar and 20 pharyngoglossal sulcus. According to the UICC TNM classification of 1979, the patients were staged as follows: 65 T1, 103 T2, 101 T3, 8 TX. 172 patients were NO, 74 N1, 3 N2, 20 N3 et 8 NX. According to the tumor extension, the 5 year actuarial local control, locoregional control, specific survival and overall survival by T stage (T1 [65 pts], T2 [103 pts.], T3 [101 pts]) were respectively: local control: 89%, 86%, 69%; locoregional control: 84%, 80%, 67%; specific survival (excluding patients dead with intercurrent disease or second cancer): 78%, 62%, 46%; overall survival: 62%, 53%, 43%. No local recurrence was detected after 3 years. According to the localization, the tumors arising from the tonsillar region, the soft palate and the posterior pillars (A Group) had a better prognosis than the tumors arising from the anterior pillars and glossotonsillar sulcus (B Group). The complications were classified into four grades according to their extension and duration: Grade 1 (minor) with very small tissue ulcer which healed within 2 months with medical treatment (20%). Grade 2 (moderate) (5%), grade 3 (severe) (1.4%), grade 4 (fatal) (0.4%). The dose rate seemed to be relatively higher in patients with grade 2 and 3 complications (70 cGy per hour on average) versus the dose rate of patients without complications (50 cGy per hour) but the difference was not significant. In conclusion, the brachytherapy boost after external irradiation can be performed under favourable conditions with an acceptable rate of complications. It was set out in order to attempt to improve the local control of the tumor while preserving the salivary function and lessening the muscular fibrosis. It shows how experienced the team is, however only a randomized study would allow to state whether this technique brings about a real improvement especially as for tumors T2 or T3.