Quality of life and salivary output in patients with head-and-neck cancer five years after radiotherapy

BACKGROUND

To describe long-term changes in time of quality of life (QOL) and the relation with parotid salivary output in patients with head-and-neck cancer treated with radiotherapy.

METHODS

Forty-four patients completed the EORTC-QLQ-C30(+3) and the EORTC-QLQ-H&N35 questionnaires before treatment, 6 weeks, 6 months, 12 months, and at least 3.5 years after treatment. At the same time points, stimulated bilateral parotid flow rates were measured.

RESULTS

There was a deterioration of most QOL items after radiotherapy compared with baseline, with gradual improvement during 5 years follow-up. The specific xerostomia-related items showed improvement in time, but did not return to baseline. Global QOL did not alter significantly in time, although 41% of patients complained of moderate or severe xerostomia at 5 years follow-up. Five years after radiotherapy the mean cumulated parotid flow ratio returned to baseline but 20% of patients had a flow ratio <25%. The change in time of xerostomia was significantly related with the change in flow ratio (p = 0.01).

CONCLUSION

Most of the xerostomia-related QOL scores improved in time after radiotherapy without altering the global QOL, which remained high. The recovery of the dry mouth feeling was significantly correlated with the recovery in parotid flow ratio.

[Tumor growth during the waiting period for radiotherapy in patients with oropharyngeal carcinoma]

OBJECTIVE

To quantify the potential increase in tumour volume during the waiting time for radiotherapy in patients with oropharyngeal squamous cell carcinoma.

DESIGN

Retrospective study.

METHOD

The tumour volumes as assessed on the diagnostic CT scan and the planning CT scan were compared. Thirteen patients with oropharyngeal carcinoma were included in this study. Both their diagnostic CT scan (CT-1) and their planning CT scan (CT-2) were performed in the Utrecht university medical centre. Tumour volume was calculated by delineating the tumour on CT slices and multiplying the surface area by the inter-slice distance. Tumour volumes were delineated by three independent observers. Tumour growth during the waiting time was defined as the difference in tumour volume on CT-2 and CT-1, calculated as the average of three observations.

RESULTS

The mean time between CT-1 and CT-2 was 33 days. The mean waiting period between the histopathological diagnosis and the start of radiotherapy was 56 days. Three groups could be distinguished: in one group the growth was less than 25% (n = 4), in one group the growth varied between 25 and 100% (n = 5), and in a third group there was growth of more than 100% (n = 4). Apart from this, in three cases the TNM stage had to be adjusted as a result of tumour progression.

CONCLUSION

This study showed that the tumour volume increased by more than 50% during the waiting time for radiotherapy in 8 out of 13 patients with squamous cell carcinoma of the oropharynx.

Quantitative dose-volume response analysis of changes in parotid gland function after radiotherapy in the head-and-neck region

PURPOSE

To study the radiation tolerance of the parotid glands as a function of dose and volume irradiated.

METHODS AND MATERIALS

One hundred eight patients treated with primary or postoperative radiotherapy for various malignancies in the head-and-neck region were prospectively evaluated. Stimulated parotid flow rate was measured before radiotherapy and 6 weeks, 6 months, and 1 year after radiotherapy. Parotid gland dose-volume histograms were derived from CT-based treatment planning. The normal tissue complication probability model proposed by Lyman was fit to the data. A complication was defined as stimulated parotid flow rate <25% of the preradiotherapy flow rate.

RESULTS

The mean stimulated preradiotherapy flow rate of 174 parotid glands was 0.34 mL/min. The mean flow rate reduced to 0.12 mL/min 6 weeks postradiotherapy, but recovered to a mean flow rate of 0.20 mL/min at 1 year after radiotherapy. Reduction in postradiotherapy flow rate correlated significantly with mean parotid dose. No threshold dose was found. Increasing the irradiated volume of parotid glands from 0%-40% to 90-100% in patients with a mean parotid dose of 35-45 Gy resulted in a decrease in flow ratio from, respectively, approximately 100% to less than 10% 6 weeks after radiation. The flow ratio of the 90%-100% group partially recovered to 15% at 6 months and to 30% at 1 year after radiotherapy. The normal tissue complication probability model parameter TD(50) (the dose to the whole organ leading to a complication probability of 50%) was found to be 31, 35, and 39 Gy at 6 weeks, 6 months, and 1 year postradiotherapy, respectively. The volume dependency parameter n was around 1, which means that the mean parotid dose correlates best with the observed complications. There was no steep dose-response curve (m = 0.45 at 1 year postradiotherapy).

CONCLUSIONS

This study on dose/volume/parotid gland function relationships revealed a linear correlation between postradiotherapy flow ratio and parotid gland dose and a strong volume dependency. No threshold dose was found. Recovery of parotid gland function was shown at 6 months and 1 year after radiotherapy. In radiation planning, attempts should be made to achieve a mean parotid gland dose at least below 39 Gy (leading to a complication probability of 50%).

F-18-fluoro-deoxy-glucose positron-emission tomography scanning in detection of local recurrence after radiotherapy for laryngeal/ pharyngeal cancer

BACKGROUND

The objective of this investigation was to determine whether F18-fluoro-deoxy-glucose (FDG) positron-emission tomography (PET) could differentiate between local recurrence and late radiation effects after radiotherapy for laryngeal/pharyngeal cancer.

METHODS

In a prospective study of 75 patients (67 larynx, eight oro/hypopharynx), 160 laryngoscopies and 109 FDG PET scans were performed on the head and neck region. The mean follow-up time after the first FDG PET scan was 23 months (minimum 1 year).

RESULTS

Local recurrence was diagnosed in 37 patients: 19 after the first biopsy and 18 after follow-up biopsies. For all of the negative initial FDG scans (27), the biopsies that were taken at the same time were negative and no recurrence was seen for at least 1 year. The first FDG scan was a true positive in 34 of 48 patients. In 12 of the 14 patients with false-positive results, FDG scans were repeated; a decreased FDG uptake was found in 9 of the 12. The sensitivity and specificity of the first scan were respectively 92% and 63%; including subsequent FDG scans, the rates were 97% and 82%, respectively.

CONCLUSIONS

When a local recurrence is suspected after radiotherapy for cancer of the larynx/pharynx, an FDG PET scan should be the first diagnostic step. No biopsy is needed if the scan is negative. If the scan is positive and the biopsy negative, a decreased FDG uptake measured in a follow-up scan indicates that a local recurrence is unlikely.

White matter lesions and encephalopathy in patients treated for primary central nervous system lymphoma

A retrospective analysis of the clinical presentations and neuroimaging characteristics of 33 patients with a primary central nervous system lymphoma (PCNL) who received cranial radiotherapy was performed to assess incidence of and risk factors for radiation-induced encephalopathy. CT and MRI scans were revised by a neurologist and a radiologist in conference. White matter abnormalities before and after radiotherapy on the last scan before recurrence were quantified according to a semi-quantitative scale. All available medical records were retrieved and reviewed with respect to demographic and tumor-related variables, treatment modalities, disease-free and overall survival and clinical symptoms and signs of encephalopathy. CT and MRI scans showed severe white matter lesions in 75% of 20 patients and in 86% of patients aged more than 60 years. Forty percent of patients presented with new clinical signs of cognitive impairment a median of 14.5 months after initial diagnosis (8.5 months after radiotherapy). The risk of white matter lesions appeared greater in patients aged >60 (RR 1.2, 95% CI = 0.8-2.0), in patients with prior white matter lesions (RR 1.3, 95% CI = 0.8-2.1) and in patients with multifocal cerebral lymphoma (RR 1.5, 95% CI = 1.0-2.1). In conclusion, the risk of white matter lesions and clinical symptoms and signs of encephalopathy is high in patients treated by radiotherapy for PCNL. The risk appears to be greatest in older patients, patients with multifocal tumor and in those with prior white matter lesions on CT or MRI.

Does waiting time for radiotherapy affect local control of T1N0M0 glottic laryngeal carcinoma?

This is a retrospective study of 362 patients with a T1N0M0 glottic laryngeal carcinoma treated by radiotherapy. Waiting time was defined as time from the day of histopathological diagnosis to the first day of radiotherapy. The Cox regression model was used to analyse the influence of waiting time for radiotherapy on the incidence of recurrence. The median follow-up time was 4.4 years. The median waiting time for radiotherapy was 43 days. Local recurrences were found in 58 patients. There was no significant correlation (P= 0.88) between waiting time and the outcome of early glottic cancer as analysed by Cox regression. This retrospective study did not demonstrate an effect of waiting time for radiotherapy on the outcome of early glottic laryngeal cancer.

CT-based parotid gland location: implications for preservation of parotid function

PURPOSE

The position of the parotid gland in relation to surrounding structures was investigated.

MATERIALS AND METHODS

Sixty-five patients with head and neck tumours were prospectively evaluated. Parotid position was determined using beam's eye views of CT images projected on simulator films. Distances between the different borders of the parotid gland and surrounding bony marks were quantitatively assessed.

RESULTS

The parotid gland volume ranged from 12.9 to 46.4 cm(3). The distance between the cranial border of the parotid gland and the tuberculum anterior of the atlas ranged between 0.7 and 4.8 cm. The position of the parotid gland was unaffected by the angle of the mandible.

CONCLUSIONS

The size and position of the parotid gland varies largely among patients. As the extent of radiation-induced salivary dysfunction depends on the volume of the gland tissue exposed, CT-based simulation of radiation fields is necessary.

Preservation of the rat parotid gland function after radiation by prophylactic pilocarpine treatment: radiation dose dependency and compensatory mechanisms

PURPOSE

To study the ability of a prophylactic pilocarpine administration to preserve the rat parotid gland function after unilateral irradiation with graded doses of X-rays.

METHODS

The right parotid gland of male albino Wistar rats was irradiated with single doses of X-rays (10-30 Gy, at 1.5 Gy min(-1)). Pilocarpine (4 mg/kg) was administered intraperitoneally, 1 hour prior to irradiation. Saliva samples of both left and right parotid gland were collected by means of miniaturized Lashley cups 4 days before and 3, 7, 10, and 30 days after irradiation. The parotid salivary flow rate (microl/min) was used as a parameter for the assessment of parotid gland function.

RESULTS

Our data confirm that a single prophylactic treatment of pilocarpine can attenuate radiation-induced loss of gland function. Surprisingly, the effect of pilocarpine was not restricted to the irradiated gland only. Pilocarpine also enhanced the flow rate in the contralateral, nonirradiated gland. The latter effect was found for all doses above 10 Gy and became apparent around 7 days after the radiation treatment. The effectiveness of pilocarpine to attenuate function loss in the irradiated gland decreased with increasing dose and was lost after single doses of 30 Gy.

CONCLUSIONS

Our data provide direct evidence that increasing the compensatory potential of the nondamaged gland, at least in part, underlies the "radioprotective effect" of pilocarpine in case of unilateral radiation. The ability of pilocarpine to ameliorate the early radiation-induced impairment of the parotid gland function in the irradiated gland may therefore be dependent on the remaining number of functional cells, and thus on the volume of the gland that lies within the radiation portal.

The detection of unknown primary tumors in patients with cervical metastases by dual-head positron emission tomography

A dilemma may occur in relation to patients with cervical metastases appearing as the first sign of malignancy in the head and neck region. In these patients, the location of the involved lymph nodes may indicate the location of the primary tumor. However, in two or three per cent of the patients, the primary tumor cannot be identified in the diagnostic workup. The aim of the present study was to investigate the possibility of identification of primary tumors in patients with cervical metastases of unknown origin, by the use of 2-(fluorine-18)fluoro-deoxy-D-glucose (FDG) dual-head positron emission tomography (PET). Ten consecutive patients with a cervical metastases of unknown origin were studied with FDG, using a dual-head PET camera. After the injection of 185 MBq (5 mCi) of FDG, images were performed of the head, neck and chest. In addition, endoscopy and biopsies were carried out with knowledge of the PET study. In patients in whom a primary tumor could not be identified, a follow-up of at least 6 months was used as a control. In five out of 10 patients a primary tumor was identified by FDG-PET. In one patient multiple sites of uptake were seen, and this was found to be consistent with non-Hodgkin lymphoma. In five patients, additional sites of increased uptake were found, these being consistent with unknown metastatic disease. Finally, in six patients, the initial treatment plan was changed due to the PET result in five of them. In one patient, the primary tumor was resected revealing a lesion with a diameter of 6 mm. The detection of FDG in patients with cervical metastases of unknown origin by the use of a dual-head PET camera is a valuable diagnostic tool in the identification of primary lesions.

The detection of local recurrent head and neck cancer with fluorine-18 fluorodeoxyglucose dual-head positron emission tomography

Primary tumors of the larynx and hypopharynx are preferably treated with high-dose radiation therapy. In these patients, it may be difficult to distinguish recurrent disease from post-treatment reactions. The aim of the present study was to assess the value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in the detection of local relapses of laryngeal or hypopharyngeal carcinoma after radiotherapy using a dual-head PET camera. Forty-eight patients (43 male, 5 female; mean age +/-SD, 61+/-9.5 years) with suspected recurrent laryngeal or hypopharyngeal cancer were prospectively studied. The mean interval between initial treatment and suspicion of recurrent disease was 14.6 months (range: 3-100 months). FDG dual-head PET was followed by endoscopy with or without biopsy under general anaesthesia within a period of 2 months in all patients. The mean period of follow-up after FDG dual-head PET was 13.7 months. In 19 out of 31 patients with focally increased uptake, tumour recurrence (mean diameter: 2.4 cm; range 0.4-6.5 cm) was found at initial endoscopy. In five patients recurrence was found during follow-up with a mean interval of 6.6 months. Seven patients had a false-positive study due to benign lesions or swallowing artefacts. In none of the patients with a normal PET study was tumour recurrence found during follow-up. The sensitivity and specificity of FDG dual-head PET were 100% and 71%, respectively. It is concluded that FDG dual-head PET is highly sensitive for the detection of local recurrence of laryngeal and hypopharyngeal carcinoma after radiotherapy. Some lesions were detected with a mean interval of 6.6 months before histological confirmation. In patients suspected of having recurrent laryngeal or hypopharyngeal cancer in whom FDG-PET is negative, endoscopy may be omitted for at least 6 months and possibly for up to 1 year.

Bilateral temporal lobe necrosis after radiotherapy: confounding SPECT results

A patient with seizures and a contrast-enhancing temporal lesion after radiation therapy for a chondrosarcoma of the nasal septum is described. To differentiate between radiation necrosis and recurrent tumor, thallium-201 (201Tl) SPECT was used. 201Tl SPECT revealed high local accumulation suggesting tumor growth; however, pathologic examination demonstrated focal necrosis with reactive changes but without tumor. The 201Tl SPECT findings in this patient demonstrate a possible diagnostic pitfall in differentiating recurrent tumor from radiation necrosis.

Ki-67 and p53 in T2 laryngeal cancer

OBJECTIVE

To study the relationship between the proliferative capacity, represented by the immunohistochemical labeling index (LI) of proliferation marker Ki-67, and the p53 status, as in theory an intact p53 cell cycle checkpoint system should result in a lower proliferative capacity.

STUDY DESIGN

From a group of 128 patients with a T2 laryngeal carcinoma, presented from 1989 to 1993 at the University Hospital Utrecht, 20 patients with recurrent disease and 16 patients without recurrent disease were randomly selected. All patients received primary irradiation.

METHODS

Denaturing gradient gel electrophoresis and immunohistochemistry determined the p53 status. MIB-1 staining was used to determine the Ki-67 LI.

RESULTS

In 36% of specimens we found a p53 mutation with overexpression (LI, 31%). In 8% a p53 mutation without p53 overexpression was found (LI, 18%). Forty-two percent showed no mutation but, nevertheless, overexpression (LI, 35%). Neither mutation nor overexpression was found in 14% (LI, 38%). No correlation exists between p53 status and proliferative capacity of tumors (analysis of variance [ANOVA]; P = .104). The proliferation rate as established with Ki-67 LI positively correlates with response to radiotherapy (P = .006).

CONCLUSIONS

1. Overexpression of wild-type p53 protein does not result in cell cycle arrest measurable by a lower Ki-67 LI in comparison with cases overexpressing mutant type p53 protein. 2. A high Ki-67 LI correlates with a favorable response to radiotherapy.

Fluorine-18-FDG detection of laryngeal cancer postradiotherapy using dual-head coincidence imaging

The aim of this study was to investigate whether, in patients treated for laryngeal carcinoma, a differentiation was possible between local recurrence or local control using a dual-head SPECT camera with PET capability.

METHODS

Eleven male patients (age range 51-71 yr; mean age 62 yr) who had previously undergone radiotherapy for laryngeal carcinoma were studied using 5 mCi (185 MBq) 18F-fluorodeoxyglucose (FDG). The mean interval between initial treatment and 18F-FDG PET was 21.9 mo (range 6-65 mo). Six patients had histologically proven local recurrence and five patients showed local control clinically. The mean follow-up in the local control group was 5.2 mo.

RESULTS

Fluorine-18-FDG PET scans were positive in all six local relapses. Histopathological examination of the laryngectomy specimen revealed a mean tumor size of 2.6 cm (range 1.4-5.0 cm). In one patient, false-positive uptake was seen in an inflammatory lymph node. Fluorine-18-FDG PET scans were negative in all five patients with local control.

CONCLUSION

It is possible to differentiate between local recurrence and local control in patients previously treated for laryngeal carcinoma with a dual-head SPECT scanner with PET capability.

T3 squamous cell carcinoma of the larynx treated by a split-course radiation protocol. A multiinstitutional study

A retrospective multiinstitutional study was initiated analyzing patients with T3 squamous cell carcinoma of the larynx, treated between 1975 and 1984 in eight Dutch head and neck cancer centers. In two institutions the treatment modalities used depended on the assessment of the response of the primary tumor to a first series of radiation. According to this split-course regime protocol, poor responders were offered surgery, that is, subsequent to a first series of radiation, a laryngectomy was performed (RT + S). For good responders (RT-I) or poor responders but medically unfit for and/or refusing surgery (RT-II), the radiation was continued after variable rest periods had elapsed (split-course radiation therapy). This paper analyzes 131 patients treated in the two institutions by this split-course regime protocol. Mean follow-up was 84 months; 89% were male, 11% female. At 10 years a corrected survival of 55% and an overall survival of 20% was observed. For the RT-I the actuarial local relapse rate was 56% versus a relapse rate of only 13% for the RT + S group. The corrected survival rates of the RT-I and RT + S were 54% and 70%, respectively. In contrast: 10 of 12 RT-II patients relapsed locally, and a corrected survival of only 21% was observed. The influence of overall treatment time (OTT) was studied by using the equation of the biological effective dose (BED), being defined as D(1 + d/alpha/beta) - (ln 2/alpha*Tp)*OTT). However, no clear relationship between BED and the risk for local and/or regional relapse could be established.

T3 laryngeal cancer, primary surgery vs planned combined radiotherapy and surgery

The Dutch Co-operative Head and Neck Oncology Group performed a retrospective, nationwide study of laryngeal cancer between 1975 and 1984. The results for T3 laryngeal cancer treated with primary laryngectomy (n = 137) with post-operative radiotherapy when indicated or planned combined (pre-operative) radiotherapy with laryngectomy (n = 113) are analysed. The disease-free survival independent prognostic factors were treatment modality (planned combined treatment fared better, P = 0.001), incomplete resection of disease (P = 0.006), positive lymph nodes in the neck dissection specimen (P = 0.03) and poor differentiation (P = 0.04). Local control (95% vs. 85%, P = 0.01) as well as regional control (96% vs. 79%, P = 0.0001) was improved in the combined group compared with the primary laryngectomy group. Regional control was 69% for N0 patients if the neck nodes were not treated electively, compared with 98% for the planned combined treatment group. It is concluded that elective treatment of the neck nodes in T3 laryngeal cancer is mandatory. Radiotherapy is preferred, since as well as regional control, local control will also improve.

[Uni- and multivariate analysis of prognostic factors in T3 laryngeal cancers]

In 511 patients with T3N0-3M0 laryngeal carcinoma, 24 possible prognostic factors were analysed retrospectively. The factors were age, sex, mode of treatment, duration of several clinical symptoms, the presence of sore throat, otalgia, dyspnoea, and dysphagia, previous tracheotomy, tumour extension, lymph node status (five items), histologic grading, smoking habits, and alcohol intake. For 300 patients in whom surgery was part of the primary treatment, pathologic staging of the primary tumour and of lymph nodes in neck dissection specimens, cartilage invasion, radicality of the operation, differentiation grade, and subglottic extension were also evaluated. Univariate analysis revealed prognostic significance on survival for tumour extension (limited to the glottic region), lymph node status (clinically palpable lymph nodes, cytologically confirmed positive lymph nodes), level of lymph node metastasis (high and midjugular site), histologic grading (poor differentiation grade), and treatment modality (planned combined therapy). In the group that underwent surgery, all factors derived from specimens of the larynx and neck dissections had prognostic significance. Multivariate analysis revealed that the glottic site of the tumour, the presence of cyto- and histopathologically proven metastatic lymph nodes, pretreatment tracheotomy, positive resection margins, and planned combined treatment had a significant influence on corrected actuarial survival.

Prognostic factors for survival in patients with T3 laryngeal carcinoma

In a total of 511 patients with T3,N0-3,M0 laryngeal carcinoma, 24 possible prognostic factors were analyzed retrospectively. The factors were age, sex, mode of treatment, duration of several clinical symptoms, the presence of sore throat, otalgia, dyspnea, and dysphagia, previous tracheotomy, tumor extension, lymph node status (five items), histologic grading, smoking habits, and alcohol intake. For 300 patients in whom surgery was part of the primary treatment, pathologic staging of the primary tumor and of lymph nodes in neck dissection specimens, cartilage invasion, radicality of the operation, differentiation grade, and subglottic extension ware also evaluated. In a univariate analysis for the whole group, tumor extension (limited to the glottic region), lymph node status (clinically palpable lymph nodes, cytologically confirmed positive lymph nodes), level of lymph node metastasis (high and midjugular site), histologic grading (poor differentiation grade), and treatment modality (planned combined therapy) were considered to be prognostic factors of corrected actuarial survival. In the group that underwent surgery, all factors derived from specimens of the larynx and neck dissections had prognostic significance. Multivariate analysis revealed that the glottic site of the tumor, the presence of cyto- and histopathologically proven metastatic lymph nodes, pretreatment tracheotomy, positive resection margins, and planned combined treatment had a significant influence on corrected actuarial survival.

T3 laryngeal cancer: a retrospective study of the Dutch Head and Neck Oncology Cooperative Group: study design and general results

511 Patients with T3 N0-3 M0 squamous cell carcinoma of the larynx, treated in the Netherlands from 1975 until 1984, were retrospectively analysed. Four different treatment policies were followed: primary surgery, planned combination of radiotherapy and surgery, primary radical radiotherapy, and selective radiotherapy. General results are presented. Local control rate was 72%. Regional control rate was 90% for clinically N0 patients and 78% for clinically N+ patients. Salvage therapy was overall successful in 38%. Surgical salvage for local radiation failures (with regional relapse) was successful in 69%, and for regional failures (without local relapse) in 46%. Ultimate locoregional control was 78% and, due to 8% distant metastases, 5-year actuarial corrected survival was 70%. Prognosis did not improve over the years. Corrected survival was independently correlated with tumour extension, involvement of neck nodes and treatment strategy. Corrected survival was similar for primary radiotherapy and primary surgery, but significantly better for planned combined therapy. Multiple primary tumours occurred significantly more often in male (19.5%) than in female patients (7.3%) (P = 0.05), the bronchus being most commonly affected. Cumulative actuarial risk for metachronous tumour was 15% after 5 years and 30% after 10 years so prevention and early detection of these second tumours may play the most important role in improving overall survival rates in the future.

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).

Local control in T3 laryngeal cancer treated with radical radiotherapy, time dose relationship: the concept of nominal standard dose and linear quadratic model

In a retrospective study of the Dutch cooperative head and neck group 104 evaluable patients with T3NxMO squamous cell carcinoma of the larynx were treated primarily with a full course of radiotherapy. The results of treatment are presented in terms of locoregional control. The actuarial 3-year local control rate was 53%. Regional control was 77% for node positive patients and 96% for N0 patients (p = 0.01). Surgical salvage was successful in 53% of cases with a local recurrence and in 3/8 regional recurrences, resulting in an ultimate locoregional control rate of 83% for N0 patients and 68% for N+ patients. A uni- and multivariate analysis of local control rate versus total dose, nominal standard dose, and extrapolated response dose has been done. To calculate extrapolated response dose the linear quadratic equation was used, assuming an a/b of 10 and a potential doubling time of clonogenic cells of 3, 5, and 7 days. In multivariate analysis the extrapolated response dose with a potential doubling time of 5 days was the only independent prognostic factor for local control (p = 0.069) and ultimate locoregional control (p = 0.0015). Nominal standard dose showed no dose-response relationship. Based on the S-shaped dose response curve, using the LQ model, several therapeutical options are discussed.

The importance of vocal cord mobility in T2 laryngeal cancer

In a retrospective study 75 patients with T2 laryngeal cancer treated from 1981 through 1985 were analysed. Of this group 71 patients had a full course of radiotherapy as primary therapy. All 71 patients were given 70 Gy/7 weeks on the primary and 50 Gy/5 weeks on the neck, 2 Gy per fraction. Various prognostic factors for local control and survival were studied. In our patient group we found vocal cord mobility to be an important prognostic factor for ultimate local control and survival. Patients with impaired cord mobility had a significantly worse ultimate local control (76%) than patients with normal cord mobility (98%) and a significantly worse corrected actuarial survival. It is concluded that impaired cord mobility means more advanced disease. Future studies will have to answer the question how to improve the local control rate in patients with impaired cord mobility, for example, by incorporating laryngectomy earlier in the treatment program of those patients who can not be cured by radiotherapy alone or by using innovative radiotherapy protocols.

Radiotherapy in epithelial tumors of the parotid gland: case presentation and literature review

A group of 113 patients irradiated for parotid tumor was studied retrospectively. Sixty-two patients were irradiated after superficial parotidectomy or enucleation of a pleomorphic adenoma. None of them had a recurrence after 5-15 years. Sixteen patients were irradiated postoperatively after surgery for a recurrence of pleomorphic adenoma. Only one of them had developed a recurrent tumor. Thirty-five patients with a malignant parotid tumor were treated by irradiation, 22 after surgery and 13 after biopsy only. Patients with a low malignancy tumor (10/11) and adenoid cystic carcinoma (6/12) responded better than patients with a high malignancy carcinoma (2/12). A tumor larger than 4 cm, facial nerve palsy, lymph node metastasis, and inoperability indicate a poor prognosis. With high dose radiotherapy it is possible to treat inoperable tumors successfully. Adenoid cystic carcinomas can respond well to irradiation alone.

[Is there a role for radiotherapy in the treatment of patients with pleomorphic adenoma of the parotid gland?]

A group of 79 patients primarily operated (n = 63) or operated for local recurrence after previous surgery (n = 16) and irradiated post-operatively was studied retrospectively. Indications for radiation treatment were: enucleation and spill after pseudo-penetration of the capsule or remnants of tumour after partial or total parotidectomy respectively. During follow-up (4-16 years) only one of the patients, irradiated because of recurrence, had a second recurrence. No major complications or malignant degenerations took place. Partial or total parotidectomy with saving of the facial nerve is the treatment of choice rather than a combination of enucleation with radiotherapy. However, in case of remnants after radical surgery or re-excision for recurrent tumour postoperative irradiation appears to be indicated and effective.

Regression after 50 Gy as a selection for therapy in advanced laryngeal cancer

Radiation alone for advanced laryngeal cancer will result in an initial local control rate of 50%. When a local recurrence is diagnosed, only 50% will be successfully salvaged by surgery. To identify patients with a high chance of local control with radiation alone in advanced laryngeal cancer, the clinical response following radiotherapy was assessed a few days after 50 Gy/5 weeks. In patients with T-stage reduction or greater than 50% tumor regression radiotherapy was continued, if not, laryngectomy was performed after 4-6 weeks. According to this protocol 30 patients (out of 50) with T3/T4 laryngeal cancer were treated. Initial local control was assessed 6 weeks after radiotherapy, the ultimate local control included successful salvage surgery. Initial local control in patients, treated with a full course of radiotherapy after T-stage reduction or greater than 50% tumor regression, was 69% for T3 and 43% for T4 while the ultimate local control rate was 85% and 71% respectively. Although the percentage of voice preservation in our study was slightly lower (40%) than data from literature with radiation alone, the ultimate local control was high and comparable with those of combined therapy (in which laryngectomy is a part). The corrected actuarial 5-year survival in all T3 and T4 patients treated with radiation alone and salvage surgery was 73% and 31% respectively and was not different compared to surgery with pre- or post-operative radiotherapy, 74% and 53% respectively. We believe that this protocol may select a favorable group of patients for high dose radiation alone in T3 and probably in T4 laryngeal cancer.