Glottic carcinoma limited to the vocal cords

Prospective Observational Comparative Study of Response and Toxicities in Early Glottic Cancer Using Telecobalt Versus 3D-CRT

The study was performed with 50 patients, 24 patients in Arm A and 26 patients in Arm B. Arm A-Conventional Telecobalt RT 66 Gy/33 fraction in stage T1N0M0 and stage T2N0M0 and Arm B-3D-CRT 66 Gy/33 fraction in T1N0M0 and T2N0M0 used. At the end of RT, 6 weeks, 3 months acute and late toxicities were noted by RTOG/EORTC morbidity scoring criteria for skin reaction, dysphagia and laryngeal toxicity. Fiber optic Laryngoscopy clinical assessment criteria were used to assess response after 6 weeks, 3 months of treatment completion. At 6 weeks of follow-up-Both Arm A and B complete response rate were 83.3% and 88.5% respectively and at 3 months rate were 85.0% and 95.7% respectively. There was no superiority of results with 3D-CRT over 2DRT. At the end of RT dysphagia grade 3 toxicity seen 1 patient (4.2%) but in Arm B (total 26 patients) no grade 3 toxicity found. At the end of 6 week and 3 month, one patient (4.3%) had grade 3 toxicity on Arm B only at 3 month. All these results are comparable. At the end of RT, one patient (3.8%) had incidentally dermatitis grade 3 toxicity in Arm B only. But all the results are comparable. On follow up, 6 week and 3 months, no grade 3 toxicity noted. At the end of RT, grade 3 laryngeal toxicity noted in 3 (12.5%) in Arm A and 2 (7.7%) in Arm B, not statistically significant. At 6 week, grade 3 toxicity found in 3/24 (12.5%) in Arm A and 2/26 (7.7%) in Arm B, at 3 months, 1/26 (4.3%) patient had incidental grade 3 toxicity only in Arm B. As conformal radiotherapy is more time consuming, less available in India and more costly than 2DRT, we can consider Conventional 2D planning for patients in India where most of people belong to low economic profile. Due to limitation in sample size and long-term follow-up further randomized studies are needed to validate the results.

Radiotherapy for T1 Carcinoma of the Glottis

Aims and background

The management of patients with T1 carcinoma of the glottic larynx is controversial, because surgery and radiation therapy are reported to be effective treatments. Several studies have shown radiotherapy to be safe and effective, with a high percentage of voice preservation and minimal complications, but most Italian physicians prefer to surgically treat such patients.

Methods

From 1980 to 1990, 36 patients with stage I squamous cell glottic carcinoma were treated with radiotherapy alone at the Institute of Radiology of University of Rome “La Sapienza”. In all patients the irradiation fields were limited to the larynx, with field size ranging from 4 × 4 cm to 7 × 7 cm. Total tumor doses ranged between 51 and 70 Gy (median 60 Gy) with a mean number of 30 fractions of 2 to 3 Gy per fraction (3 or 5 fractions per week).

Results

After a median follow-up of 98 months, we observed an overall survival rate at 5 years of 91.4% and actuarial 10-year survival of 85.7%. Local control was achieved in 97.1% of cases, with an event-free survival of 94.2% at 5 and 10 years. No major complications like necrosis or persistent edema of the larynx were observed. Minor complications like dysphonia (8%) and dysphagia (5.5%) were temporary; laryngeal function was completely preserved at the end of therapy. Final voice quality ranged from good to excellent.

Conclusions

Our series confirms that radiation therapy has a major role in the management of early glottic cancer, with results comparable to surgical approaches and with better voice preservation.

[Treatment of T1N0 glottis carcinoma with radiotherapy. Results at our center and review of the literature]

OBJECTIVE

To evaluate the results of radiotherapy in the treatment of patients with T1N0 glottic squamous cell carcinoma.

MATERIAL AND METHODS

Retrospective study of a cohort of 338 patients with T1N0 glottic carcinoma treated with radiotherapy at our institution between 1985-1997. A review of the literature published during the last ten years was carried out.

RESULTS

Local control with radiotherapy in our patients was 82%, reaching 97% when salvage surgery was included. The local control with radiotherapy in most of the published series ranges between 81.90%.

CONCLUSIONS

Treatment with radiotherapy achieves local control in early glottic carcinomas (T1N0) in 80-90% of cases. In our centre such treatment achieved local control in 82% of cases.

Laser cordotomy versus radiotherapy: an objective cost analysis

This study presents a cost analysis of and comparison between laser cordotomy and external beam irradiation for the treatment of early glottic carcinoma. It compares the curative results of the two modalities from data of a retrospective study at my institution and a literature review of published cure rates. It also reviews the results of objective voice assessments in cases representing both treatments. The findings of this study indicate that the cure rates are equivalent and that voice quality obtained after laser cordotomy is comparable to that obtained after irradiation, yet the total cost of external beam radiotherapy is significantly higher than that of laser surgery. Hence, the findings of this study provide strong support for initially treating early glottic tumors with laser surgery.

Influence of fraction size, total dose, and overall time on local control of T1-T2 glottic carcinoma

PURPOSE

To evaluate the influence of fraction size, overall time, total dose, and other prognostic factors on local control of T1 and T2 glottic carcinomas.

METHODS AND MATERIALS

Between 1956 and 1995, 398 consecutive patients with early glottic carcinoma (315 T1 and 83 T2) were treated with once-a-day definitive radiotherapy at the University of California, San Francisco, and associated institutions. Treatment was delivered 5 days per week. Minimum tumor dose ranged from 46.6 to 77.6 Gy (median: 63 Gy). The fraction size was < 1.8 Gy in 146; 1.8-1.99 Gy in 128; 2.0-2.24 Gy in 62, and > or = 2.25 Gy in 62 patients. Overall time ranged from 34 to 75 days (median: 50 days). The majority of patients treated with a fraction size of 2.25 Gy completed therapy within 43 days. Median follow-up of all alive patients was 116 months (range 3-436 months).

RESULTS

Five-year local control was 85% for T1 and 70% for T2 glottic carcinomas (p = 0.0004). For T1 lesions, within the dose and time range evaluated, there was no apparent relationship between fraction size, overall time, total dose, and local control on multivariate analysis. Treatment era was the only significant prognostic factor (p = 0.02), and anterior commissure (AC) involvement was of borderline significance (p = 0.056). Five-year local control was 77% for patients treated between 1956-1970, 89% for between 1971-1980, and 91% for between 1981-1995; 80% for patients with AC involvement and 88% for those without. For T2 lesions, prognostic factors for local control on multivariate analysis were: overall time (p = 0.003), fraction size (p = 0.003), total dose (p = 0.01), impaired vocal cord mobility (p = 0.02), and subglottic extension (p = 0.04). Five-year local control was 100% for T2 lesions treated with overall time < or = 43 days vs. 84% for overall time > 43 days; 100% for fraction size > or = 2.25 Gy vs. 44% for fraction size < 1.8 Gy; 78% for total dose > 65 Gy vs. 60% for total dose < or = 65 Gy; 79% for normal cord mobility vs. 45% for impaired cord mobility, and 58% for lesions with subglottic extension vs. 77% for those without. The severe complication rate for the entire group was low: 1.8%.

CONCLUSIONS

Total dose, fraction size, and overall time were significant factors for local control of T2 but not T1 glottic carcinomas. Anterior commissure involvement was associated with decreased local control for T1 but not T2 lesions. For T1 lesions, local control improved over the treatment era. For T2 lesions, local control decreased with impaired cord mobility and subglottic extension.

Does tumor control decrease by prolonging overall treatment time or interrupting treatment in laryngeal cancer?

PURPOSE

To evaluate treatment results of radiotherapy in laryngeal cancer and to retrospectively investigate the influence of treatment interruptions on local control rates. A multivariate analysis was performed to investigate the role of overall treatment time on local control rates.

MATERIAL AND METHODS

From 1962 to end 1986, 864 patients with cancer of the larynx were treated with primary radiotherapy, with a variation of doses and treatment times. In 352 patients a systematic interruption of 2 weeks was done after 50 Gy (split-course). Local control rates were calculated by the actuarial method. A multivariate analysis was subsequently performed in order to identify independent variables influencing local control rates.

RESULTS

The univariate analysis showed that in patients treated with a split-course schedule, local control rates were significantly lower in glottic cancer (p < 0.001), with differences of 7% in T1 (p = 0.05) and 11% in T2 (p = 0.11). In node-negative supraglottic cancer a difference of 10% (p = 0.16) was observed. The multivariate analysis showed the following factors to significantly influence local control: site, total dose, total treatment time, T and N stage. Split-course treatment was not an independently significant factor, probably caused by time being a stronger factor. In subgroup analysis, the effect of total treatment time remained statistically significant in T2 glottic cancer.

CONCLUSION

A significant negative influence of treatment interruption was seen in glottic cancer, and a trend toward significance in node-negative supraglottic cancer in univariate analysis. A multivariate analysis showed a negative influence of prolonging treatment time in the total patient group. The effect remained significant in T2 glottic cancer in subsequent subgroup analysis, possibly due to the fact that there is little variation in tumour volume in this group. In larger tumours, where there is substantial variation in tumour volume and a higher probability of heterogeneity in radiosensitivity, the effect of dose-time variations could be more difficult to discern.

Laser cordectomy or radiotherapy: cure rates, communication, and cost

Health care costs have risen dramatically in recent years. Cost-containment strategies have become necessary to ensure that adequate medical care is accessible to all who need it. These strategies include choosing the least costly of several treatment modalities with equal efficacy. Radiotherapy has been considered by some as the treatment of choice for early glottic tumors. Rationale for this is based on two major assumptions: that cure rates are equal for radiotherapy and surgery, and that voice preservation and quality is superior with radiotherapy. Implicit in these assumptions is the idea that cost of therapy should not be a factor in selecting an alternative. This study presents a literature review of cure rates for laser cordectomy and radiotherapy for T1 glottic cancers. An objective voice analysis was performed on 14 patients with T1 glottic cancers treated with laser cordectomy and the results were compared to a group of 20 patients treated with radiotherapy for similar early tumors. Finally, the average total cost of each modality was calculated and compared. Our findings indicate that: (1) cure rates are equivalent; (2) voice quality after laser cordectomy is as good as that noted after radiotherapy; and (3) total cost of therapy is much less for laser cordectomy than for radiotherapy. We advocate laser cordectomy rather than radiotherapy for most early glottic tumors.

Prognostic factor of telecobalt therapy for early glottic carcinoma

BACKGROUND

Local control rates of T1 and T2 glottic carcinoma treated with radiation alone were reported as 80-91% and 63-76%, respectively. The authors investigated the factors that affect the local control rate for early glottic carcinoma.

METHODS

From 1967 through 1982, 330 patients with early glottic carcinoma (T1: 274 patients; T2: 56) were treated with telecobalt therapy at the Department of Radiology, Osaka University Hospital, Osaka, Japan.

RESULTS

Five-year actuarial survival rates of patients with T1 and T2 were 79% and 80%, respectively. Five-year local disease control rates of patients with T1 and T2 disease were 81% and 67%, respectively. In 243 of 254 patients treated with 2 Gy a day, tumor response could be evaluated at the dose level of 40 Gy. For tumors treated with a daily dose of 2 Gy, local control rates of 153 tumors that disappeared at 40 Gy and 90 tumors that persisted at 40 Gy were 83% and 62%, respectively (P < 0.001). Field size and daily fraction size did not affect the local control rate.

CONCLUSION

Evaluation of tumor response at 40 Gy was an important indicator of local disease control for early glottic cancers treated with 2 Gy a day.

Radiation therapy of glottic carcinoma: Peter MacCallum Cancer Institute experience

The medical records of patients with T1N0, T2N0 and T3N0 squamous cell carcinomas of the glottis treated at the Peter MacCallum Cancer Institute between January 1983 and October 1988 were retrospectively reviewed. One hundred and twenty-seven patients were identified. There were 93 T1, 26 T2 and eight T3 tumours. These patients were treated with curative radiotherapy (60-70 Gy). The survival from glottic cancer of patients with T1, T2 and T3 tumours at 5 years was estimated to be 97, 62 and 100% respectively. The local disease free survival for T1 and T2 disease at 5 years was estimated to be 82 and 65% respectively. The local disease free survival for T3 tumours at 2 years was estimated to be 63% with 5 year survival not yet reached. The surgical salvage rates for 24 radiotherapy failures were 77, 25 and 66% for T1, T2 and T3 tumours respectively. Radiotherapy remains the treatment of choice for T1 tumours and a viable alternative to primary laryngectomy in more advanced glottic tumours, with salvage surgery in reserve.

Radiotherapy in T1 laryngeal cancer: prognostic factors for locoregional control and survival, uni- and multivariate analysis

From 1975 through 1985, 194 patients with T1 glottic, 37 patients with T1 supraglottic, and 3 patients with T1 subglottic cancer were treated with radiotherapy. Local control and ultimate locoregional control (after salvage surgery) was 91% and 97% for T1 glottic, 84% and 81% for T1 supraglottic, and 2/3 and 3/3, respectively for subglottic tumors. In uni- and multivariate analysis local control for glottic tumors was associated with extension of the tumor on the vocal cord (entire length of vocal cord vs others, p = 0.01) and continuation of smoking after therapy (yes/no, p = 0.03). No prognostic factor for local control was found in supraglottic tumors. However, regional control and survival were impaired by N stage (N0 vs N+, p less than 0.0005), local recurrence (yes/no, p less than 0.0005), and extension of the tumor (one supraglottic subsite vs more than one, p less than 0.05). Mild late complications were seen in 13% of patients without salvage therapy. Following univariate analysis, field size, fraction size (greater than 2 Gy), maximum tumor dose (greater than 70 Gy), age, post-treatment biopsy, and tumor site were associated with complication rate. Following multivariate analysis, site, fraction size, maximum tumor dose, and continuation of smoking after therapy were independent prognostic factors for mild late complications (mostly arytenoid edema).

Primary irradiation, surgery or combined therapy in squamous cell carcinoma of the larynx. A comparison of treatment results from two centers

We compared two groups of patients with squamous cell carcinoma of the larynx. Group 1 consisted of 483 patients treated from 1958 through 1978. Primary surgery was selected in 41% pre- or postoperative radiation therapy in 16% and primary radiation therapy in 43%. Group 2 consisted of 247 patients treated from 1978 through 1983. Primary surgery was selected in only 1.6%, pre- or postoperative radiation therapy in 23%, and primary radiation therapy, with surgery in reserve for residual or recurrent carcinoma, in 76%. Although the results were comparable for patients with early stage tumors in the two groups, significantly higher local-regional tumor control rates and corrected survival rates were recorded for patients with advanced tumors in group 2. More patients survived with a cancer-free functional larynx, the surgical salvage rates were higher, the complication rates and the death rates lower in group 2 compared to group 1.

Radiation therapy in early glottic cancer. Analysis of 177 consecutive cases

Early vocal cord carcinomas (TiS or T1) in a consecutive series of 177 patients treated by primary radiotherapy over a 10-year period 1970-79 at the Department of General Oncology, Radiumhemmet, Karolinska Sjukhuset, were analysed regarding treatment results. In 137 cases the tumours were invasive (T1N0M0) and in 40 cases carcinoma of in situ type (TiS). Patient were treated with cobalt 60 gamma irradiation in fractions of 2 Gy up to a total dose of 64 Gy delivered as split course (CRE=17.8). Minimum follow-up time was 5 years. Tumour recurred in 21 cases (12%). All but 4 patients were rescued by subsequent surgery, giving 98% total survival. Treatment failures after primary radiotherapy were analysed in detail. Failures could not be attributed to treatment irregularities. No difference in pretreatment tumour size was detected when cured patients were compared with patients who relapsed. Biological factors that cause a relative radioresistance are considered to be the main reason for radiotherapy failures in early glottic cancer.

Radiation therapy in early carcinoma of the true vocal cords (stage I and II)

Seventy-four patients with Stage I and twenty patients with Stage II carcinoma of the true vocal cords received radiation therapy from 1971 to 1983. Sixteen patients had second primary cancers with the most common site being the lung. The patients were treated with 4 MeV linear accelerator X ray or 60Co machine with the average total dose of 6600 rads in 33 fractions, 5 days a week by parallel opposing ports. Local control rate by radiation therapy was 86% in Stage I and 70% in Stage II. Eight of twelve (8 of 12) failures were salvaged by surgery. The actuarial 5-year survival was 92 and 80%. Seventy-six (76%) of patients had good quality of voice after treatment.

Radiation treatment of laryngeal carcinoma with special reference to CRE values

In a retrospective analysis of 203 cases of laryngeal carcinoma treated with radiation therapy, conventional absorbed dose levels and CRE calculations were compared as regards the prediction of treatment failure, tumor recurrences and major complications. The recurrence rate for T1 and T2 tumors was 14 per cent and for T3-4 tumors 26 per cent. Poorly differentiated (grade 3) tumors had a significantly higher recurrence rate than well and moderately well differentiated (grades 1 and 2) ones. Corrected 10-year survival rates were 89, 82 and 52 per cent, respectively for T1, T2 and T3-4 tumors. There was a significant relationship between the recurrence rate and the CRE level while the total absorbed dose in Gy or the size of the treatment field could not be correlated to treatment failure. Major complications occurred in 8 (3.9%) patients and they had all received treatment giving CRE values of 1920 reu or more.