Short-term outpatient follow-up of COVID-19 patients: A multidisciplinary approach

BACKGROUND

Short-term follow-up of COVID-19 patients reveals pulmonary dysfunction, myocardial damage and severe psychological distress. Little is known of the burden of these sequelae, and there are no clear recommendations for follow-up of COVID-19 patients.In this multi-disciplinary evaluation, cardiopulmonary function and psychological impairment after hospitalization for COVID-19 are mapped.

METHODS

We evaluated patients at our outpatient clinic 6 weeks after discharge. Cardiopulmonary function was measured by echocardiography, 24-hours ECG monitoring and pulmonary function testing. Psychological adjustment was measured using questionnaires and semi-structured clinical interviews. A comparison was made between patients admitted to the general ward and Intensive care unit (ICU), and between patients with a high versus low functional status.

FINDINGS

Eighty-one patients were included of whom 34 (41%) had been admitted to the ICU. New York Heart Association class II-III was present in 62% of the patients. Left ventricular function was normal in 78% of patients. ICU patients had a lower diffusion capacity (mean difference 12,5% P = 0.01), lower forced expiratory volume in one second and forced vital capacity (mean difference 14.9%; P<0.001; 15.4%; P<0.001; respectively). Risk of depression, anxiety and PTSD were 17%, 5% and 10% respectively and similar for both ICU and non-ICU patients.

INTERPRETATION

Overall, most patients suffered from functional limitations. Dyspnea on exertion was most frequently reported, possibly related to decreased DLCOc. This could be caused by pulmonary fibrosis, which should be investigated in long-term follow-up. In addition, mechanical ventilation, deconditioning, or pulmonary embolism may play an important role.

Carotid body tumors are not associated with an increased risk for sleep-disordered breathing

PURPOSE

Tumors in the carotid bodies may interfere with their function as peripheral chemoreceptors. An altered control of ventilation may predispose to sleep-disordered breathing. This study aimed to assess whether patients with unilateral or bilateral carotid body tumors (uCBT or bCBT, respectively) or bilateral CBT resection (bCBR) display sleep-disordered breathing and to evaluate the global contribution of the peripheral chemoreceptor to the hypercapnic ventilatory response.

METHODS

Eight uCBT, eight bCBT, and nine bCBR patients and matched controls underwent polysomnography. The peripheral chemoreflex drive was assessed using euoxic and hyperoxic CO2 rebreathing tests. Daytime sleepiness and fatigue were assessed with the Epworth Sleepiness Scale and the Multidimensional Fatigue Index.

RESULTS

All patient groups reported significant fatigue-related complaints, but no differences in excessive daytime sleepiness (EDS) were found. The apnea/hypopnea index (AHI) did not differ significantly between patient groups and controls. Only in bCBT patients, a trend towards a higher AHI was observed, but this did not reach significance (p=0.06). No differences in the peripheral chemoreflex drive were found between patients and controls.

CONCLUSIONS

Patients with (resection of) CBTs have more complaints of fatigue but are not at risk for EDS. The presence or resection of CBTs is neither associated with an altered peripheral chemoreflex drive nor with sleep-disordered breathing.

The music perception abilities of prelingually deaf children with cochlear implants

OBJECTIVE

To investigate the music perception abilities of prelingually deaf children with cochlear implants, in comparison to a group of normal-hearing children, and to consider the factors that contribute to music perception.

METHODS

The music perception abilities of 39 prelingually deaf children with unilateral cochlear implants were compared to the abilities of 39 normal hearing children. To assess the music listening abilities, the MuSIC perception test was adopted. The influence of the child's age, age at implantation, device experience and type of sound-processing strategy on the music perception were evaluated. The effects of auditory performance, nonverbal intellectual abilities, as well as the child's additional musical education on music perception were also considered.

RESULTS

Children with cochlear implants and normal hearing children performed significantly differently with respect to rhythm discrimination (55% vs. 82%, p<0.001), instrument identification (57% vs. 88%, p<0.001) and emotion rating (p=0.022). However we found no significant difference in terms of melody discrimination and dissonance rating between the two groups. There was a positive correlation between auditory performance and melody discrimination (r=0.27; p=0.031), between auditory performance and instrument identification (r=0.20; p=0.059) and between the child's grade (mark) in school music classes and melody discrimination (r=0.34; p=0.030). In children with cochlear implant only, the music perception ability assessed by the emotion rating test was negatively correlated to the child's age (r(S)=-0.38; p=0.001), age at implantation (r(S)=-0.34; p=0.032), and device experience (r(S)=-0.38; p=0.019). The child's grade in school music classes showed a positive correlation to music perception abilities assessed by rhythm discrimination test (r(S)=0.46; p<0.001), melody discrimination test (r(S)=0.28; p=0.018), and instrument identification test (r(S)=0.23; p=0.05).

CONCLUSIONS

As expected, there was a marked difference in the music perception abilities of prelingually deaf children with cochlear implants in comparison to the group of normal hearing children, but not for all the tests of music perception. Additional multi-centre studies, including a larger number of participants and a broader spectrum of music subtests, considering as many as possible of the factors that may contribute to music perception, seem reasonable.

concomitant chemoradiotherapy with mitomycin C and cisplatin in advanced unresectable carcinoma of the head and neck: phase I-II clinical study

PURPOSE

To evaluate the toxicity and efficacy of concomitant chemoradiotherapy with mitomycin C and cisplatin in the treatment of advanced unresectable squamous cell carcinoma of the head and neck.

PATIENTS AND METHODS

Treatment consisted of conventional radiotherapy (70 Gy in 35 fractions), mitomycin C 15 mg/m(2) IV, applied after the delivery of 10 Gy, and cisplatin at an initial dose of 10 mg/m(2)/d IV, applied during the last 10 fractions of irradiation ("chemoboost"). The cisplatin dose was escalated with respect to the toxic side effects by 2 mg/m(2)/d up to the maximum tolerated dose (MTD) or at the most 14 mg/m(2)/d (Phase I study), which was tested in the subsequent Phase II study.

RESULTS

All 36 patients had Stage T4 and/or N3 disease, and the majority had oropharyngeal (50%) or hypopharyngeal (39%) primary tumors. Six patients were treated at each of the three cisplatin dose levels tested (Phase I study). Dose-limiting toxicity was not reached even at 14 mg/m(2)/d of cisplatin, which was determined as the MTD and tested in an additional 18 patients (Phase II study). After a median follow-up time of 48 months, 4-year locoregional control, failure-free, and overall survival rates were 30%, 14%, and 20%, respectively. In 24 patients treated at the cisplatin dose level of 14 mg/m(2)/d, the corresponding rates were 40%, 20%, and 22%, respectively.

CONCLUSION

Concomitant chemoradiotherapy with mitomycin C and cisplatin "chemoboost" at 14 mg/m(2)/d is feasible, with encouraging survival results if the extremely poor disease profile of the treated patients is considered.

Stefin A and Stefin B: Markers for Prognosis in Operable Squamous Cell Carcinoma of the Head and Neck

PURPOSE

The aim of this study was to test the hypothesis about the protective role of high stefin A and stefin B concentrations in operable carcinoma of the head and neck.

METHODS AND MATERIALS

Stefins A and B concentrations were measured in tissue cytosols of nontumorous mucosa and primary tumors from 92 patients. For quantitative analysis of stefins in tumor cytosols, commercially available enzyme-linked immunosorbent assays were used.

RESULTS

Stefin A was upregulated in 53 patients (higher concentrations were measured in tumor samples than in nontumorous mucosa) and was downregulated in 39 patients. The corresponding numbers for stefin B were 49 and 43, respectively. A significantly higher proportion of downregulated cases were found among patients with disease re-appearance. In the Cox model, high stefin A concentrations appeared as independent predictors for favorable disease-free survival. Assuming a "broken stick" model, a significant increase in the recurrence rate after the threshold of 1063 ng/mgp (the 64th percentile in the group) was found, the hazard ratio reaching 3% of the reference value with doubling of the level of stefin A. These results were reconfirmed after pooling the data with two historical data sets into a uniform series involving 182 patients.

CONCLUSIONS

A group of patients at high risk for disease progression was identified, characterized by the downregulated stefin A protein in the tumor compared with the nontumorous mucosa. Stefin A was recognized as a promising candidate marker for prognosis in patients with operable carcinoma of the head and neck.

Endoscopic surgery with curative intent for malignant tumors of the nose and paranasal sinuses

AIM

To assess the efficacy of endoscopic surgical treatment in patients with nasal and paranasal sinus malignancies.

PATIENTS AND METHODS

During the period 1991-2006, 16 patients with nasal and paranasal sinus malignancies underwent endoscopic surgery with curative intent. The lesions included 11 carcinomas, two malignant melanomas, one olfactory neuroblastoma, one hondrosarcoma and one leiomyosarcoma. Tumors originated from the ethmoids in eight, and from the nasal cavity in another eight patients. Oncologic radicality of resection was verified by intraoperative frozen-section examination of biopsy specimens from the margins of the defect site.

RESULTS

Radical resection was accomplished in 15 out of 16 operated patients. There were no major intra- or postoperative complications. Ten patients were postoperatively irradiated. Follow up of the treated patients ranged from 15 to 178 months (median 67 months). One patient with malignant melanoma died of generalized disease nine months after treatment, another with malignant melanoma recurred locally 30 months and again 49 months after first operation and is at the time of evaluation disease free and one died 21 months after operation without evidence of disease.

CONCLUSIONS

It seems that in selected cases, endoscopic surgery with curative intent for removal of malignant tumors of the nasal and paranasal cavities in the hands of highly experienced surgeon is justified.

Patterns of failure in patients with locally advanced head and neck cancer treated postoperatively with irradiation or concomitant irradiation with Mitomycin C and Bleomycin

PURPOSE

The long term results and patterns of failure in patients with squamous cell head and neck carcinoma (SCHNC) treated in a prospective randomized trial in which concomitant postoperative radiochemotherapy with Mitomycin C and Bleomycin (CRT) was compared with radiotherapy only (RT), were analyzed.

PATIENTS AND METHODS

Between March 1997 and December 2001, 114 eligible patients with Stage III or IV SCHNC were randomized. Primary surgical treatment was performed with curative intent in all patients. Patients in both groups were postoperatively irradiated to the total dose of 56-70 Gy. Chemotherapy included Mitomycin C 15 mg/m2 after 10 Gy and 5 mg of Bleomycin twice weekly during irradiation. Median follow-up was 76 months (48-103 months).

RESULTS

At 5 years in the RT and CRT arms, the locoregional control was 65% and 88% (p = 0.026), disease-free survival 33% and 53% (p = 0.035), and overall survival 37% and 55% (p = 0.091) respectively. Patients who benefited from chemotherapy were those with high-risk factors. The probability of distant metastases was 22% in RT and 20% in CRT arm (p = 0.913), of grade III or higher late toxicity 19% in RT and 26% in CRT arm (p = 0.52) and of thyroid dysfunction 36% in RT and 56% in CRT arm (p = 0.24). The probability to develop a second primary malignancy (SPM) was 34% in the RT and 8% in the CRT arm (p = 0.023). One third of deaths were due to infection, but there was no difference between the 2 groups.

CONCLUSION

With concomitant radiochemotherapy, locoregional control and disease free survival were significantly improved. Second primary malignancies in the CRT arm compared to RT arm were significantly less frequent. The high probability of post treatment hypothyroidism in both arms warrants regular laboratory evaluation.

Use of polarised equine endothelial cell cultures and an in vitro thrombosis model for potential characterisation of EHV-1 strain variation

Equine herpesvirus-1 (EHV-1) is responsible for respiratory disease and abortion in pregnant mares. Some high virulence isolates of EHV-1 also cause neurological disease. The pathogenesis of both abortion and neurological disease relates in part, to thrombus formation occurring in the pregnant uterus and central nervous system. The differences in disease outcome may relate to differing abilities of high and low virulence EHV-1 isolates to cause cell-associated viraemia, infect endothelial cells and cause thrombosis at sites distant from the respiratory tract. This study attempted to identify in vitro assays, which could be used to characterise the interaction between these isolates, equine endothelial cells and clotting factors. No significant difference was found between the growth kinetics of high and low virulence isolates of EHV-1 in polarised endothelial cells. For both isolates, virus was released preferentially from the apical surface of the polarised cells. The functional effects of viral infection on endothelial cells, with reference to virally-induced thrombosis were then investigated. Endothelial cells were grown on microcarrier beads, infected with EHV-1 and assayed for procoagulant activity. No significant difference in clotting time was observed between mock and EHV-1 infected endothelial cells in microcarrier cultures. Thus the degree of thrombosis may reflect a more complex interaction between endothelial cells, circulating leucocytes and other factors in the microenvironment.

Serum cystatin C in patients with head and neck carcinoma

BACKGROUND

The balance between proteinases of various classes and their inhibitors was found to be of critical importance for local invasion and metastasizing of tumor cells. The aim of the present study was to determine the changes in the serum cystatin C concentration in patients with squamous cell carcinoma of the head and neck.

METHODS

In the sera of 34 patients with squamous cell carcinoma of the head and neck, the concentration of cysteine proteinase inhibitor cystatin C was determined using ELISA. The serum samples were collected at diagnosis (group A) and 7 to 407 days (median, 59 days) after the therapy (group B). The sera of 30 healthy blood donors served as controls (group C).

RESULTS

A significant increase in the median concentration of cystatin C was found in the patients' sera (group A: 573 ng/ml, P<0.0001; group B: 551 ng/ml, P<0.0001) compared to control group C (320 ng/ml), whereas no difference was observed between groups A and B (P>0.05). Cystatin C concentrations in the sera of group A correlated with the site of primary tumor (P=0.035), being higher in the patients with non-laryngeal tumors (658 ng/ml) than in those with larynx primaries (529 ng/ml). There was a significant trend (RS=-0.535, P=0.049) towards lower cystatin C concentrations with an increasing time delay in post-treatment serum sampling (group B), which was observed in the patients with no relapse of the disease and a sampling later than 45 days after the completion of therapy.

CONCLUSIONS

These results add to the knowledge of the role of cystatin C in invasive behavior of squamous cell carcinoma of the head and neck, and suggest its potential role as a tumor marker in this particular type of cancer.

Inoperable oropharyngeal carcinoma treated with concomitant irradiation, mitomycin C and bleomycin - long term results

Patients with inoperable head and neck tumors were treated concomitantly with radiochemotherapy with mitomycin C and bleomycin in our prospective randomized clinical trial (1991- 1993). For the subgroup of patients with oropharyngeal carcinoma the results with radiochemotherapy were significantly superior to irradiation alone. Such scheme of treatment was then adopted as standard method. Here we present the long-term results and dose- response relationships in patients with inoperable oropharyngeal carcinoma treated by the same radiochemotherapy scheme till 1997. Ninety-five patients with stage III and IV inoperable oropharyngeal squamous cell carcinoma were treated with curative intent, concomitantly with supra-voltage irradiation 2 Gy/day 5 times weekly to 60-73 Gy, bleomycin 5 mg 2 times weekly and. one application of mitomycin C 15 mg/m(2) after 10 Gy. Logistic dose- response curve was calculated. Median follow-up was 85 months. The loco-regional control, disease- free survival and overall survival at 5 years were 55%, 51% and 32% (95% CI: 44-67%, 41-62%, 22-42%), respectively. The probability of new primary malignancy at 5 years was 23%. In multivariate analysis performance status, biological equivalent dose, dose of bleomycin, and stage were identified as independent prognostic factors for loco-regional control, disease-free, and overall survival. Th gamma-value of dose response curve was 2.86. The outcome of the disease was directly proportional to intensity of irradiation and chemotherapy. It appears that in our concomitant radiochemotherapy MiC increased radioresponsiveness of the tumor by its effect on hypoxic fraction.

Cysteine proteinase inhibitor cystatin C in squamous cell carcinoma of the head and neck: relation to prognosis

To determine the role of the cysteine proteinase inhibitor cystatin C in the invasive behavior of squamous cell carcinoma of the head and neck (SCCHN), Cystatin C protein level was measured in 82 pairs of primary tumour tissue and adjacent noncancerous mucosa, using the enzyme-linked immunosorbent assay. The median level of cystatin C in tumour tissue was 1.18 times lower than that in corresponding mucosa (P=0.031). In normal mucosa samples, the cystatin C level was influenced by the site of sampling: it was lower in nonlaryngeal tissue samples (oral cavity, oro- or hypopharynx) than in laryngeal samples (P=0.004). The tumour cystatin C level correlated inversely with pN-stage (P=0.047), whereas a trend of lower cystatin C levels was observed in the group with extranodal tumour extension compared to those with no extranodal spread (P=0.069). In univariate analysis, the patients with low tumour cystatin C levels exhibited poor disease-free survival (DFS, P=0.013) and disease-specific survival (DSS, P=0.013). In multivariate analysis, the most powerful predictor of survival was pN-stage (DFS: P=0.040, HR 2.78; DSS: P=0.011, HR 4.36,), followed by the cystatin C level (DFS: P=0.043, HR 0.22; DSS: P=0.067, HR 0.25). When comparing the prognostic strength of cystatin C to that of stefin A, another cysteine proteinase inhibitor, which emerged as the most significant prognosticator for survival in our previous study analysing the same cohort of patients, stefin A proved to be significantly more reliable predictor for both DFS and DSS than cystatin C. Our results indicate that cystatin C is implicated in the invasive behavior of SCCHN, and that there are variations in regulation of proteolytic pathways under nonmalignant conditions, inherent to individual subsites inside the upper aerodigestive tract. The correlation between high cystatin C levels and improved survival concurs with the concept of the protective role of high levels of cysteine proteinase inhibitors in tissue homogenates that has been previously suggested by the survival results in breast and lung carcinoma as well as SCCHN.

Postoperative concomitant irradiation and chemotherapy with mitomycin C and bleomycin for advanced head-and-neck carcinoma

PURPOSE

In a prospective randomized clinical study, simultaneous postoperative application of irradiation (RT), mitomycin C, and bleomycin was tested in a group of patients with operable advanced head-and-neck carcinoma. It was expected that the planned combined postoperative therapy would reduce the number of locoregional recurrences and prolong survival.

METHODS AND MATERIALS

A total of 114 eligible patients with Stage III or IV squamous cell head-and-neck carcinoma were randomized to receive postoperative RT alone (Group 1) or RT combined with simultaneous mitomycin C and bleomycin (Group 2). Patients were stratified according to the stage and site of the primary tumor and the presence or absence of high-risk prognostic factors. Primary surgical treatment was performed with curative intent in all patients. Patients in both groups were postoperatively irradiated to the total dose of 56-70 Gy. Chemotherapy included mitomycin C 15 mg/m(2) after 10 Gy and 5 mg of bleomycin twice a week during RT to the planned total dose of 70 mg.

RESULTS

At 2 years, patients in the radiochemotherapy group had better locoregional control (86%) than those in the RT alone group (69%; p = 0.037). Disease-free survival and overall survival was also better in the radiochemotherapy group compared with the RT-alone group (76% vs. 60%, p = 0.099; and 74% vs. 64%, p = 0.036, respectively). Patients who benefited from chemotherapy were those with high-risk factors.

CONCLUSION

The results of the present study indicate that concomitant postoperative radiochemotherapy with mitomycin C and bleomycin improves locoregional control and survival in patients with advanced head-and-neck carcinoma. The patients who benefited from chemotherapy were those with high-risk factors.

Hemoglobin as a factor influencing the outcome in inoperable oropharyngeal carcinoma treated by concomitant radiochemotherapy

The aim of the study was to analyze the prognostic significance of hemoglobin (Hb) concentration for loco-regional control and survival of patients with inoperable carcinoma of the oropharynx. Seventy patients with inoperable squamous cell carcinoma of the oropharynx were prospectively treated by concomitant regimen of conventional radiotherapy and chemotherapy with Mitomycin C and Bleomycin. The prognostic value of Hb concentration before the therapy (Hb-S) and at the end of the therapy (Hb-E), the difference between both (DHb), and the average Hb concentration (Hb-Av) were analyzed. Hb concentration was falling significantly (median values, from 139 g/L to p<0.0001) during the first three weeks of the therapy; after that, it reached a plateau. In the last week of therapy, a slight increase (p=0.08) in Hb concentration was recorded. Significant correlation (p<0.0001) was found between Hb-S and other Hb-related parameters. The median follow-up of the patients alive on close-out date was 5.7 years (range 4-10.5 years). Longer disease-free survival (DFS) and disease-specific survival (DSS) correlated with higher values of Hb-S (p=0.0005, p=0.008) and Hb-E (p=0.02, p=0.02), while the Hb-Av was predictive for DFS only (p=0.004). The most significant difference between low- and high-Hb groups was calculated at cut-off concentrations of 122 (Hb-S), 116 (Hb-E), and 120 (Hb-Av) g/L. Only Hb-S was tested in multi- variate model where its independent value for predicting both, DFS (p=0.002; RR 3.6) and DSS (p=0.01; RR 2.9), was confirmed. In our patients, Hb-Swas proved to bean independent prognostic factor in predicting DFS and DSS. We believe that the concentration of Hb > or =120 g/L should be maintained during radiotherapy course.

Impairments of vestibular system in infants at risk of early brain damage

Children with early brain damage often present with balance disorders. We evaluated the vestibular apparatus function in 110 infants at risk of brain lesions. Our study confirmed a statistically significant correlation between vestibular apparatus dysfunction and the degree of neurological risk. Early recognition of vestibular disorders preconditions adequate rehabilatation and supports the acquisition of motor skills.

Cathepsin B and L and stefin A and B levels as serum tumor markers in squamous cell carcinoma of the head and neck

Cysteine proteinases cathepsin (Cath) B and L and their endogenous inhibitors stefin (Stef) A and B concentrations were measured using a quantitative immunosorbent assay (ELISA; KRKA d.d., Novo mesto, Slovenia) in serum samples from 35 patients with primary and 7 patients with recurrent squamous cell carcinoma of the head and neck (SCCHN), obtained at diagnosis (Serum no.1) and after therapy (Serum no. 2), and compared to sera from 30 (Stef B, 90) healthy volunteers. A significantly higher Stef A (P = 0.005) and lower Stef B (P < 0.001) concentrations were measured in patients' Serum no.1 than in controls, and the levels of Caths B and L and Stef A were found to be significantly elevated in Serum no.1 as compared to Serum no. 2 (P = 0.045, P = 0.041 and P = 0.024, respectively). The time of Serum no.2 collection did not influence the concentration of either Caths or Stefs in these samples, and no correlation was observed with the established prognostic factors for any of the parameters studied. Patients with subsequently diagnosed recurrent disease had a significantly lower Cath L concentration than those without evidence of relapse during follow up (P = 0.05). The risk of disease recurrence and SCCHN-related death correlated significantly with low Cath L serum levels (P = 0.012, P = 0.006). The serum levels of Cath B, Stef A and Stef B did not influence significantly the probability of survival.

Otoacoustic emissions and auditory assessment in infants at risk for early brain damage

The importance of early hearing screening has long been recognized, as the prognosis for the hearing impaired child is improved when the diagnosis is made as early as possible, and the intervention is begun immediately. For clinical screening of hearing impairment, the recording of otoacoustic emissions was recommended. As some risk factors for early brain damage are at the same time also risk factors for dysfunction of auditory system, we presumed that infants at risk for brain damage have hearing impairment more frequently than the rest of the population of the same age. We were interested in the role of otoacoustic emission testing during the assessment of auditory function in these infants. There were 110 infants at risk for brain damage included in the study. After thorough otorhinolaryngological examination, auditory function was estimated by recording of otoacoustic emissions, tympanometry, pure tone audiometry and, when necessary, auditory brainstem responses. Otoacoustic emissions were recorded by Madsen-Electronics Celesta 503 in an acoustically treated sound room. We registered spontaneous as well as transient and distortion product otoacoustic emissions. The neurologist formed two groups with different degrees of neurological risk. The collected results of auditory function were compared with the degree of neurological risk. For the statistical analysis, the procedure chi(2) and Fischer test were used. Spontaneous otoacoustic emission was detected in 38.2% of examinees. Evoked otoacoustic emissions were registered in 87.3% of infants. The testing had to be repeated in 32.7% of infants. We observed evoked otoacoustic emissions to be present also in a child with sensorineural hearing impairment and no auditory brainstem responses. Up to 32.7% of infants at risk for brain damage were hard of hearing. Conductive hearing loss was discovered with 25.4% of infants, and eight (7.3%) had sensorineural hearing impairment. In the group of examinees with only risk factors 3.6% had sensorineural impairment and in a group with abnormal motor development, there were 18.5% with that kind of hearing loss. Fischer test confirmed a statistically significant difference between the groups. Infants at risk for brain damage have more frequently impaired auditory function than their peers. For this reason, it is especially important to focus attention on the hearing condition when dealing with this population. Recording of evoked otoacoustic emissions is very helpful in pediatric audiometry, but any interpretation of the results should consider the possibility of auditory neuropathy.

Urokinase-type plasminogen activator, plasminogen activator inhibitor type 1 and cathepsin D: analysis of their prognostic significance in squamous cell carcinoma of the head and neck

BACKGROUND

The aim of the study was to evaluate the prognostic significance of tumour and serum concentrations of urokinase-type plasminogen activator (uPA), its type 1 inhibitor (PAI-1) and cathepsin D (Cath D) in patients with squamous cell carcinoma of the head and neck (SCCHN).

PATIENTS AND METHODS

Determinations of uPA and PAI-1 were made using enzyme-linked immunosorbent assays in tumour and serum samples of 47 and 32/47 patients, respectively. For the determination of tumour (94 patients) and serum (34/94 patients) Cath D concentrations, an immunoradiometric assay was used.

RESULTS

In an univariate survival analysis, the risk of disease recurrence and SCCHN-related death was significantly higher in the patients with high uPA (P = 0.046, P = 0.010) tumours, compared to those with low uPA tumours. In addition, the high serum levels of uPA correlated positively with the rate of relapse (P = 0.007), but not with the mortality rate (P = 0.200). There was no statistically significant difference between low and high PAI-1 groups, regarding either tumour or serum concentration of the inhibitor, and between low and high Cath D tumours. Low Cath D serum levels appeared to be related to longer disease-free interval (P = 0.055), but not to disease-specific survival (P = 0.120).

CONCLUSIONS

The tumour levels of uPA, as well as serum levels of uPA and Cath D could potentially predict the survival probability of patients with SCCHN. However, the strength of this association remains to be investigated on a larger and more homogeneous group of patients.

Autofluorescence imaging in the diagnosis of laryngeal cancer

Differences in autofluorescence (fluorescence without photodynamic drugs) between normal and malignant tissues offer new possibilities in detecting and localizing early laryngeal carcinoma. Autofluorescence imaging was performed using a modified fluorescence endoscopy system from Xillix Technologies (Richmond, Canada). Fluorescence was induced by blue light at 442 nm and captured by an image-intensified camera through a laryngeal telescope. The images were then processed by the system and displayed on a video monitor. Normal tissue appeared green while malignant sites appeared reddish-brown. The autofluorescence imaging technique was compared to standard microlaryngoscopy in 108 patients with laryngeal pathologies (in 74 of whom malignancy was suspected). The acquired reflectance and fluorescence images of each lesion were assessed independently as malignant or not malignant by three ENT specialists who were familiar with the procedure but were not provided with clinical data or histopathological information concerning the lesion. The assessments of pathology were determined from the two imaging modalities and were compared to histopathological findings of the biopsy specimens taken from the lesion. The present study showed that autofluorescence imaging can be a useful complementary method to microlaryngoscopy for detecting and delineating laryngeal malignancies. If in the future, the device can be developed for use in an outpatient office, a significant improvement can be made for the early detection of laryngeal malignancies.

Prognostic significance of cysteine proteinases cathepsins B and L and their endogenous inhibitors stefins A and B in patients with squamous cell carcinoma of the head and neck

Cysteine proteinases cathepsins (Cats) B and L and their endogenous inhibitors stefins (Stefs) A and B are implicated in the processes of local and metastatic tumor spread. They were identified as potential prognosticators in various malignant diseases, particularly in breast cancer. The aim of the present study was to determine the concentrations of Cats B and L and Stefs A and B in the tumor and adjacent normal tissue samples collected from 49 patients (the present group) with squamous cell carcinoma of the head and neck (SCCHN), using quantitative immunosorbent assays (ELISA; KRKA d.d., Novo mesto, Slovenia). Their clinical significance was compared with that from a previous study (the reference group, 45 patients; Budihna et al., Biol. Chem. Hoppe-Seyler, 377: 385-390, 1996). The follow-up of patients from the latter report was updated for this purpose. In the present group, significantly higher concentrations of Cat B (P < 0.0001), Cat L (P < 0.0001) and Stef A (P = 0.006) were found in tumors compared with concentrations in their normal tissue counterparts. Cat concentrations in normal laryngeal tissue were significantly/marginally elevated compared with nonlaryngeal tissue (Cat B, P = 0.02; Cat L, P = 0.06). The tumor concentration of Cat L was found to correlate with pT classification (P = 0.005) and tumor-node-metastasis stage (P = 0.05), whereas the concentrations of Stefs A and B correlated with pN classification (P = 0.007 and P = 0.03, respectively) and tumor-node-metastasis stage of the disease (P = 0.02 and P = 0.03, respectively). There was no statistically significant difference between low and high Cat B or Cat L groups, regarding either disease-free survival or disease-specific survival, using a minimum P approach to determine cutoff concentrations. The risk of disease recurrence and SCCHN-related death was significantly higher in patients with low Stef A (P = 0.0006 and P = 0.0005, respectively) and Stef B (P = 0.0009 and P = 0.0007, respectively) tumors, compared with those with high-Stef A and Stef B tumors. These results remained significant even after Ps were adjusted for a possible bias in the estimated effect on survival. The survival analysis in the reference group also confirmed these findings (Stef A: P = 0.0009 and P = 0.002, respectively; Stef B: P = 0.03 and P = 0.009, respectively). To avoid any possible bias arising from the differences between the laboratories that performed the biochemical analysis, the concentrations of both Stefs in the present group and in the reference group were standardized and coupled together to form a uniform group. In univariate survival analysis, standardized values of Stef A and Stef B correlated inversely with the rate of relapse (P = 0.0000) and mortality rate (P = 0.0000). Multivariate regression analysis showed that the standardized value of Stef A is the strongest independent prognostic factor for both disease-free survival and disease-specific survival. These findings show the specific role of Cats B and L and Stefs A and B in the invasive behavior of SCCHN. Furthermore, Stef A proved to be a reliable prognosticator of the risk of relapse and death in patients with this type of cancer.

The effect of pilocarpine and biperiden on salivary secretion during and after radiotherapy in head and neck cancer patients

PURPOSE

The influence of parasympathicomimetic pilocarpine and anticholinergic biperiden on salivation in patients irradiated for malignant tumors of the head and neck region was assessed in a prospectively designed clinical study.

METHODS AND MATERIALS

Sixty-nine patients, irradiated for head and neck cancer with salivary glands included in the irradiation fields, were randomly assigned into three groups (A, B, and C). Group A consisted of patients receiving pilocarpine, group B of those who were receiving biperiden during radiotherapy and pilocarpine for 6 weeks after its completion, while group C comprised patients not receiving any xerostomy prevention therapy during or after radiotherapy. The quantity of secreted unstimulated saliva was measured before the beginning of radiotherapy, after 30 Gy of irradiation, on completed irradiation, and 3, 6, and 12 months after completion of radiotherapy.

RESULTS

Saliva secretion has been found to be the least affected by irradiation treatment in the group of patients receiving biperiden throughout the course of radiotherapy. Six months after completed irradiation, the differences in the quantity of secreted saliva between groups C and B as well as between groups A and B were statistically significant (P = 0.002 and 0.05 respectively). In patients receiving pilocarpine during radiotherapy, and those in the control group, further decrease in saliva secretion was observed. One year after completed therapy, the quantity of secreted saliva could only be measured in the patients receiving biperiden during radiotherapy: it amounted to 16% of the average quantity of saliva secreted before the beginning of irradiation.

CONCLUSION

It seems that the inhibition of saliva production during irradiation treatment and the stimulation after completed radiotherapy may contribute to the preservation of salivary gland function after therapy.

Cathepsin D in tissue and serum of patients with squamous cell carcinoma of the head and neck

Aspartic proteinase cathepsin D (CD) is believed to be associated with proteolytic processes leading to local invasion and seeding of tumour cells. To estimate a potential prognostic value of cathepsin D in squamous cell carcinoma of the head and neck, its total concentration was measured immunoradiometrically (ELSA-CATH-D kit, CIS bio international) in cytosols of tumour and adjacent normal tissue samples from 111 patients; in 42/111 patients, the CD concentration was determined in serum samples obtained at diagnosis (serum no. 1) and after the therapy (serum no. 2) from each of these patients. Sera of 15 healthy volunteers served as controls. A significantly elevated concentration of CD was measured in tumour cytosols as compared to normal tissue cytosols (31.1 versus 12.6 pmol/mgp, P < 0.0001) and in cytosols of normal laryngeal tissue than of the oral cavity or pharynx (13.3 versus 11.2 pmol/mgp, P = 0.03). The higher CD tumour concentration correlated with the age of the patients (< or =60 versus >60 years, 28.8 versus 32.8 pmol/mgp, P = 0.045) and histopathological tumour grade (G1+2 versus G3, 32.6 versus 24.4 pmol/mgp, P = 0.02). In serum samples, a lower concentration of CD was measured in the control group than in the patients (3.6 versus 4.1 pmol/mls, P = 0.045) and in serum no. 1 than in serum no. 2 (4.1 versus 5.1 pmol/ mls. P = 0.05). The CD concentration in sera obtained at diagnosis was stage-dependent (S(I-III) versus S(IV), 3.9 versus 4.7 pmol/ mls. P = 0.09); there was a trend towards lower CD concentrations with an increasing time delay in serum no. 2 sampling (Rs = -0.20, P = 0.21). No correlation was observed between cytosolic and serum concentrations of CD. We conclude that our results confirm a specific role of CD in the process of invasion and metastasis of squamous cell carcinoma of the head and neck, which might also be of prognostic value in this particular cancer type.

Concomitant radiotherapy with mitomycin C and bleomycin compared with radiotherapy alone in inoperable head and neck cancer: final report

PURPOSE

To compare the efficacy of concomitant irradiation with mitomycin C and bleomycin in patients with inoperable head and neck carcinoma with radiotherapy alone.

METHODS AND MATERIALS

Between March 1991 and December 1993, 64 patients with inoperable head and neck carcinoma (41 with oropharyngeal site) were randomized to radiotherapy alone (group A) or radiotherapy combined with simultaneous application of mitomycin C and bleomycin (group B). In both groups patients were irradiated five times weekly with 2 Gy to a total dose of 66-70 Gy. The planned concomitant treatment in group B was: bleomycin 5 units twice a week i.m., total dose 70 units, mitomycin C 15 mg/m2 i.v. after delivery of 10 Gy, and 10 mg/m2 i.v. on the last day of radiotherapy. To enhance the effect of these two drugs, patients received also nicotinamide, chlorpromazine, and dicoumarol. Because significantly better results were achieved in arm B for patients with inoperable oropharyngeal carcinoma, the study was closed and such patients were after December 1993 routinely treated with the combined therapy (as in arm B). Until October 1996, we treated and followed up 48 such consecutive patients.

RESULTS

Median follow-up of our study patients is 42 months. Complete remission (CR) rate in group A was 31% and in group B 59% (p = 0.04); disease-free survival (DFS) in group A was 8% and in group B 37% (P = 0.01); and overall survival (OS) was 7% in group A and 26% in group B (p = 0.08). CR rate for patients with oropharyngeal carcinoma was 29% in group A (N = 21) and 75% in group B (N = 20) (p = 0.007); DFS in group A was 10% and in group B 48% (p = 0.001); and the OS was 10% in group A and 38% in group B (p = 0.019). In patients with inoperable oropharyngeal carcinoma treated after December 1993, complete remission was achieved in 32/48 (67%, 95% CI: 52%-80%). DFS at the median follow-up of 14 months was 60% (95% CI 43-77%) and OS 58% (95% CI 42-74%).

CONCLUSION

From the results of our study it seems that the concomitant treatment significantly improves CR rate, DFS, and OS in patients with inoperable oropharyngeal carcinoma in comparison with radiotherapy alone.

Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) in tissue and serum of head and neck squamous cell carcinoma patients

The aim of this study was to determine urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) concentrations in tumour and adjacent normal tissue samples from 58 patients, and in serum samples from 40 of 58 patients with squamous cell carcinoma of the head and neck obtained at diagnosis and after completion of therapy. uPA and PAI-1 serum concentrations were also measured in 28 healthy volunteers who served as controls. Measurements were made using enzyme-linked immunosorbent assay (ELISA) techniques. For both uPA and PAI-1, significantly elevated concentrations were measured in tumour tissue as compared with normal tissue (uPA: 8.89 versus 0.41 ng/mg total protein (mgp), P < 0.0001; PAI-1: 23.9 versus 1.47 ng/mgp, P < 0.0001). A statistically significant difference in uPA concentrations was found between normal laryngeal and nonlaryngeal tissue (0.52 versus 0.3 ng/mgp, P = 0.008), and in PAI-1 concentrations between T1 + 2 and T3 + 4 stage of disease (17.32 versus 35.63 ng/mgp, P = 0.04). The uPA concentrations positively correlated with those of PAI-1 measured in both tumour (Rs = 0.62, P < 0.0001) and normal tissue (Rs = 0.30, P = 0.02). In serum samples, lower concentrations of PAI-1 were measured in the control group than in patients with cancer (412.0 versus 680.5 ng/ml serum (mls), P = 0.0006). The time of collection of the serum sample did not influence uPA and PAI-1 concentrations, and no association was observed between their concentrations and any clinical and histopathological prognostic factors tested. Our results indicate that both uPA and PAI-1 may play a specific role in the process of invasion and metastasis, and might also be of prognostic value in squamous cell carcinoma of the head and neck.

Prognostic value of cathepsins B, D and steffins A and B in laryngeal carcinoma

Concentrations of cathepsins A, D and stefins A and B were measured in primary tumor and adjacent normal tissue of 25 patients with laryngeal carcinoma. Median concentrations of both cathepsins and that of stefin B were significantly higher in tumor tissue than in their normal counterparts (cathepsins B and D, P < 0.0001; stefin B, P = 0.01), indicating their possible involvement in the process of tumor spread. Early (T1 and T2) tumors had lower concentrations of stefins A and B than locally advanced (T3 and T4) tumors (P = 0.04). Disease-free and disease-specific survival rates at 45 months were significantly better in patients with tumor concentrations of stefins above or equal to the cut-off values (stefin A, P = 0.001 and P = 0.004; stefin B, P = 0.048 and P = 0.008), indicating that these might be of prognostic value. The concentrations of cathepsins B and D did not correlate with survival.

Laser induced fluorescence in diagnostics of laryngeal cancer

Differences in autofluorescence between normal and malignant tissues offer new possibilities for detecting and localizing early laryngeal carcinomas. In the present study imaging was performed using a specially designed device that exploits differences in fluorescent properties of normal and cancerous tissues without photodynamic drugs. Fluorescence was induced by helium-cadmium laser, captured by an image-intensified camera and displayed on a video monitor after previous computerization. 40 patients were evaluated, of whom 20 had suspect malignancies. Laryngoscopic appearances during standard microlaryngoscopy, fluorescence images and computerized fluorescence intensities were compared to histopathological findings. The experience from this study shows that autofluorescence laryngoscopy may be a useful complementary method for detecting laryngeal malignancies.

Detection and localization of early laryngeal cancer with laser-induced fluorescence: preliminary report

Differences in autofluorescence between normal and malignant tissues offer new possibilities for detecting and localizing early laryngeal carcinomas. In the present study imaging was performed using a specially designed device that exploits differences in fluorescent properties of normal and cancerous tissues without photodynamic drugs. Fluorescence was induced by a helium-cadmium laser, captured by an image-intensified camera and displayed on a video monitor after previous computerization. Thirty patients were evaluated, of whom 18 had suspect malignancies. Laryngoscopic appearances during standard microlaryngoscopy were compared to fluorescence images, computerized fluorescence intensities and histopathological findings. The experience from this study shows that autofluorescence laryngoscopy may be a useful complementary method for detecting laryngeal malignancies.

Early glottic cancer: the influence of primary treatment on voice preservation

PURPOSE

Retrospective analysis was performed to assess the influence of primary surgical or irradiation treatment on local control, survival, and final preservation of larynx in comparable groups of patients with T1N0 and T2N0 glottic cancer.

METHODS AND MATERIALS

Two hundred sixty-three previously untreated patients with invasive squamous cell carcinoma of the glottis (187T1 and 76T2) were treated with primary radiotherapy (159T1 and 60T2) or primary surgery (28T1 and 16T2) between January 1976 and December 1990, at the University of Ljubljana, Slovenia. Conventional one daily fraction of 2 Gy to doses of 60-74 Gy (median: 65 Gy) were used in 98% of primarily irradiated patients through out the observed period. To enable better comparison between the two treatment groups, primarily irradiated patients were retrospectively stratified by the criteria of suitability for primary voice-sparing operation. Several host, tumor, and treatment parameters were analyzed.

RESULTS

Only the stage of the disease significantly influenced both 10-year recurrence-free and disease-specific survival regardless primary treatment modality (p = 0.0002). In all primary irradiated patients local control was significantly better for those with overall treatment time of less than 48 days (p = 0.007). In patients suitable for voice-sparing operation, local control of primarily operated patients was similar to that of patients primarily irradiated with shorter overall treatment time, which was 93 and 88% for T1 and 67 and 64% for T2 tumors, respectively. Ultimate local control in primary surgery and radiotherapy group was 96 and 96% for T1 and 89 and 88% for T2 tumors, respectively. Equal larynx preservation of 100% in T1 and 90% in T2 patients was achieved in finally cured primarily operated patients and those patients primarily irradiated with a shorter overall treatment time. If treatment time was longer than 48 days, significantly worse final larynx preservation of 84% in T1 and 75% in T2 patients was observed (p = 0.003). In patients unsuitable for voice sparing operation, 87% of T1 and 50% of T2 patients in primary radiotherapy group finally had their larynx preserved.

CONCLUSION

Stratification based on criteria of possibility for initial voice-sparing operation is important when comparing primary surgery with primary radiotherapy treatment in early glottic cancer. The detrimental effect of prolonged treatment time of irradiation resulted not only in inferior local control rate but also in worse final larynx preservation.

Prognostic value of cathepsins B, H, L, D and their endogenous inhibitors stefins A and B in head and neck carcinoma

To estimate the prognostic value of cathepsins B, H, L, D and stefins A and B in head and neck carcinoma, their concentrations in cytosols of primary tumours and adjacent normal tissue were measured (cathepsins B, D stefins A, B in 45, cathepsin L in 24 and cathepsin H in 21 patients). Median concentrations of cathepsins B, L, and D were significantly higher in tumour than in the adjacent normal tissue (B and D: p < 0.0001; L: p = 0.004); cathepsin H concentration was higher in normal tissue (p = 0.001). Concentrations of either stefin did not differ significantly between normal and tumour tissue. Concentrations of cathepsins B, H, L, and D were higher in laryngeal than in non-laryngeal normal and tumour tissues. The difference was statistically significant for cathepsin B in tumour tissue (p = 0.045), and marginally significant in normal tissue (p = 0.07). Early tumours had lower concentrations of stefins A and B than locally advanced tumours (stefin A: p = 0.04; stefin B: p = 0.07). Disease-free and disease-specific survival rates were better in patients with concentrations of cathepsin L in tumour tissue below or equal to the cut-off values (p = 0.035; p = 0.05), whereas for cathepsin B the difference was established only for disease-free survival (p = 0.07). The opposite was true for stefin A (p = 0.0002; p = 0.002) and stefin B (p = 0.009; p = 0.003), and in disease-free survival also for cathepsin H (p = 0.055). The concentration of cathepsin D did not correlate with survival. Our data indicate that cathepsins B, H, L and stefins A and B might have prognostic value in head and neck carcinoma.

Radiotherapy, combined with simultaneous chemotherapy with mitomycin C and bleomycin for inoperable head and neck cancer--preliminary report

PURPOSE

Prospectively designed randomized clinical study was undertaken to assess the efficacy of simultaneous application of irradiation, Mitomycin C, and Bleomycin in treatment of patients with inoperable head and neck carcinoma.

METHODS AND MATERIALS

Between March 1991 and October 1993, 49 patients with inoperable head and neck carcinoma were randomly assigned to receive either radiation therapy alone (group A) or radiotherapy combined with simultaneous application of Mitomycin C and Bleomycin (group B). Patients in both groups were irradiated five times weekly with 2 Gy to the total dose of 66-70 Gy. Chemotherapy regimen included intramuscular application of Bleomycin 5 units twice a week, with the planned dose being 70 units and Mitomycin C 15 mg/m2 applied intravenously after delivery of 9-10 Gy of irradiation. The application of Mitomycin C was planned to be repeated on last day of radiotherapy in the dose of 10 mg/m2. In attempt to enhance the effect of chemotherapeutic drugs, patients in group B received also Nicotinamide, Chlorpromazine, and Dicoumarol.

RESULTS

The difference in complete response rate between both treatment groups (24% in group A and 63% in group B) was statistically significant (p = 0.015). The difference in response rate was much more pronounced in patients with oropharyngeal carcinoma only (18% in group A compared to 81% in group B; p = 0.0003), while for all other subgroups added together, there was observed no benefit of multidrug therapy. Median follow-up was 18 months. Disease-free survival of patients in group A (9%) was significantly lower then in group B (48%) (p = 0.001). The difference between both treatment groups was even greater in patients with oropharyngeal carcinoma only: disease-free survival of these patients in group B was 66%, while in group A, all recurred (p = 0.00001).

CONCLUSION

From results of our prospective randomized study it seems that the group of patients that received multidrug treatment with Mytomycin C, Bleomycin, Nicotinamide, Chlorpromazine, and Dicoumarol as enhancers of radiotherapy fared better than patients treated by radiotherapy alone.

Cowden's disease--its importance for otolaryngologists

Cowden's disease is a rare predominantly inherited disease, characterized by mucocutaneous lesions, gastrointestinal polyposis and benign or malignant thyroid and breast tumours. The report deals with a typical case of this disease with emphasis on its importance for otolaryngologists.

Laryngo-tracheo-bronchopathia chondro-osteoplastica

Two cases of laryngo-tracheo-bronchopathia chondro-osteoplastica (LTBCOP) are discussed regarding the pathogenesis of the disease. Our observations support the belief that chronic irritation of the perichondrium in the region of subglottis, trachea and bronchi plays an important role in the aetiology of this disease.

Carcinoma of the paranasal sinuses: results of treatment and some prognostic factors

Between 1979 and 1984, 46 patients, 23 males and 23 females, with carcinoma of the paranasal sinuses were treated at the Institute of Oncology in Ljubljana. A great majority of tumours were in an advanced stage of disease. 21 patients were operated on and all except one were postoperatively irradiated. Radiotherapy was the main treatment in the remaining 25 patients. 14 patients (30%) survived more than five years with no evidence of disease. Patients treated by a combination of surgery and postoperative radiotherapy survived significantly better (12/20-60%) than those treated by irradiation alone (2/25-8%), p less than 0.001. Patient's age and radicality of surgery also influenced the treatment results.

Carcinoma of the nasopharynx: results of radiation treatment and some prognostic factors

Seventy-four patients treated for squamous cell carcinoma (SCC) of the nasopharynx were evaluated for the 5-year survival rate. The influence of stage, age, histological differentiation, total tumour dose and irradiation treatment technique (continuous vs. split-course) upon the survival was evaluated in 64 patients (palliations and histologically unclassified SCC were excluded). The 5-year survival rate in the whole group was 28/74 (38%), and in the group without palliations and unclassified SCC 26/64 (41%). The 5-year survival of patients with T1 carcinoma was better (8/9 = 89%) than of patients with T2 (4/14 = 29%), T3 (7/17 = 41%) and T4 (7/24 = 29%) carcinoma. In the group of 55 patients with T2, T3 and T4 carcinoma, those up to 50 years old had better survival (11/21 = 52%) than patients older than 50 years (7/34 = 21%) (p less than 0.01), patients treated with the tumour dose greater than 65 Gy had better survival (16/38 = 42%) than those treated with 50-65 Gy (2/17 = 12%) (p less than 0.05), and patients older than 50 years, with poorly differentiated carcinoma had better survival (7/20 = 35%) than those of the same age, with well-differentiated carcinoma (0/14 = 0%) (p less than 0.005). The split-course irradiation technique did not improved the 5-year survival rate, although on average the total tumour dose in this type of treatment was for 7.9 Gy higher than in the continuous irradiation.

A new, less toxic polymerization system for the embedding of soft tissues in glycol methacrylate and subsequent preparing of serial sections

The paper describes a new polymerization system for embedding soft tissues in glycol methacrylate (GMA). The polymerization of GMA is initiated by means of a barbituric acid derivative in combination with chloride ions and dibenzoyl peroxide. The catalyst system contains no aromatic amines which constitutes a toxicological advantage over the commonly employed system of peroxide/aromatic amine. Clear blocks are obtained from which 1-2 micrometers sections are easy to cut. In combination with an appropriate softener, polyethylene glycol 400, serial sectioning may be practiced.

N.m.r. relaxation and images of human breast tumours in vitro

It is found that fat and non-fatty tissue in dissected samples of the mamma differ in their T1/T2 ratios. This opens the possibility of locating tumours by n.m.r. imaging, because they have a lower fat content than their surroundings. By means of a sensitive point method, samples were scanned with a resolution of about 0.4 mm X 0.4 mm. The similarity between the shape of a tumour in an n.m.r. and in an X-ray image of a thin section of mamma tissue is quite convincing.

Tumor cell repopulation in the rest interval of split-course radiation treatment

Fifty-two patients who were treated for laryngeal carcinoma stage I and II by either continuous or split-course irradiation were analysed. The 5-year cure by irradiation was the same in both groups. An isoeffect line was drawn for cured tumours and used to estimate the dose necessary to kill the regrowth of tumour cells which survived the first part of the split-course treatment. The estimated dose was 40 +/- 4 cGy per day of the rest interval. The doubling time was then calculated by means of schematic survival curves for fractionated irradiation. It was found that the tumor cells which survive the first part of the split-course treatment have the doubling times 3.5 +/- 0.5 days.