Prognosis of human chorionic gonadotropin-producing seminoma treated by postoperative radiotherapy

PURPOSE

To clarify the controversy about the management and prognosis of human chorionic gonadotropin-producing seminoma, the records of 132 patients with abnormal human chorionic gonadotropin values treated with radiotherapy were analyzed.

METHODS AND MATERIALS

The records of 1169 patients with pure seminoma treated in 10 institutions were screened for serum or urinary human chorionic gonadotropin. One hundred and thirty two patients with elevated human chorionic gonadotropin were found: 96 Stage I, 20 IIA, 7 IIB, 8 III and 1 IV. Median age was 34 y., mean follow-up was 5.0 years [range 1-12 y]. All received infradiaphragmatic radiotherapy (median dose 30 Gy), 25 (2 Stage I, 11 IIA, 5 IIB and 7 III) supradiaphragmatic radiotherapy (median dose: 28.5 Gy) and 10 had also initial chemotherapy (3 Stage IIB 6 III and 1 IV). Patients were allocated to three groups according to human chorionic gonadotropin values: (a) moderate elevation: up to 10 times (104 pts), (b) high elevation: 10 to 100 times (20 pts), (c) very high elevation: over 100 times the upper limit of normal value (8 pts).

RESULTS

The proportion of Stage I, II and III was 76%, 19%, 5% in the ME group versus 50%, 35%, 15% in the high elevation group (p < 0.05). In the very high elevation group there were 7 Stage I and 1 Stage IV. Of 132 patients, six died (three dead of disease, two suicides, one acquired immunodeficiency syndrome). The 5 years overall survival probability was 94%. There were seven recurrences (initial stage: 1 Stage I, 2 IIB, 3 III and 1 IV). Of these, there were one in-field recurrence, 3 out of field and 3 in both sites. In 5 of 7, the human chorionic gonadotrophin level was again elevated at recurrence. The 5 years recurrence-free-survival probability was 94% (98% for Stage I, 100% for Stage IIA and 65% for Stage IIB and III [p < 0.001 between I and IIB + III, p < 0.05 between IIA and IIB + III]). Four of the 7 recurrences were salvaged by chimiotherapy +/- radiotherapy. In the high elevation and very high elevation groups, the 5 years recurrence-free-survival was 88%, vs. 96% for the moderate elevation group (p = 0.10).

CONCLUSION

Based on this series of patients, human chorionic gonadotropin production is not an unfavorable prognostic factor in pure seminoma. Even in the subgroups with high or very high human chorionic gonadotropin levels (who had a higher proportion of advanced stages), the prognosis remained excellent. In Stage I and IIA seminoma with abnormal human chorionic gonadotropin levels, recurrence rate after post-operative radiotherapy alone is extremely low.

[Palliative treatment of malignant stenoses of the esophagus and cardia: laser therapy versus laser + high-dose-rate Iridium 192 afterloading therapy. A prospective randomized study]

In order to compare the local efficiency of two different therapy modalities, 37 patients with advanced inoperable tumors of esophagus and cardia were evaluated hitherto in a prospective randomized study. Twenty patients received an exclusive laser treatment, 17 were additionally submitted to three high-dose-rate iridium-192 afterloading irradiations (single dose at the reference point 1 cm radially to the source: 7 Gy). In both groups, 15 patients died whose survival times were not different (125 versus 130 days), however, a beneficial influence was exerted by the afterloading therapy with respect to the duration of the palliative effect (67 versus 28 days) and the hospitalization time (25 versus 48 days).

Biological effectiveness of neutrons and pi-mesons in gut, bone, and transplantable tumours

At the Munich RENT-facility a screening project was performed to define the biological characteristics of a fission neutron beam envisaged for radiotherapy. The quantitative endpoints used were jejunal crypt survival, late rectal stenosis in rats, osseous healing in traumatized rat femur and regrowth delay of murine transplantable tumours. The results obtained in normal tissues (with the possible exception of bone) demonstrate a high RBE, in accordance with the well documented dependence of RBE on neutron energy. The RBE-values measured in tumours after single dose treatment endorsed the high effectiveness, although--as has been the case with other beams--they gave no conclusive evidence of a therapeutic advantage. Nevertheless, the specific beam characteristics, i.e. a high RBE at the surface and a fast decline of the biologically effective depth dose suggest possible advantages of the RENT beam when applied in the treatment of selected superficial tumours.

First experiences with fission neutrons in the radiation therapy of cancer patients

16 patients have been treated until October 1987 at the mixed reactor beam of the RENT-facility in Munich-Garching. All of them received a single dose of 200 to 250 cGy after complete conventional radiotherapy and in same cases also surgery because of the lack of complete tumor resection or local tumor control after radiation control. The ages ranged from 40 to 84 years. The follow-up amounted between two and 28 months, 8.5 months on the average. The tumors selected appeared to be particularly suitable because of their growth in poorly perfused tissues, after the previous surgery and/or radiotherapy. All cases are briefly reported. The general experience from the very limited study is promising. The local effects to the tumor tissue so far are impressive. No severe side effects which could be related to the RENT-session were observed until now.

[Perioperative chemotherapy in squamous cell carcinomas of the esophagus]

In the majority of patients with esophageal cancer local tumor infiltration and/or distant metastases are responsible for the poor prognosis. Therefore to improve life expectancy additional modalities - chemotherapy alone or in combination with simultaneous radiation - have been introduced perioperatively. In spite of a possible increase of resectability convincing data are lacking which could argue for an uncontrolled introduction of the neoadjuvant approach outside investigational studies.

Laser and endoluminal 192-iridium radiation

The combination of laser and endoluminal 192-iridium irradiation for the palliation of malignancies of the esophagus and the cardia was introduced to overcome the short-term effect of laser treatment alone. On the basis of early experience, this method would seem to prolong the effect of laser treatment alone, and is associated with a low risk of complications. However, the initial optimistic results, claiming permanent relief of dysphagia in 80% of the patients, cannot be reproduced under prospective conditions. The combination of laser and 192-iridium irradiation with other palliative methods, such as external radiation treatment and/or chemotherapy is feasible, and remains to be studied in a comparative way.

Palliation of obstructive oesophageal and cardial carcinomas with laser and endoluminal iridium radiation

The combination of laser with endoluminal 192-iridium radiation for the palliation of malignancies of the oesophagus and the cardia has been introduced to overcome the short-lived effect of laser treatment alone. Concluding from early experience, this method seems to prolong the effect of laser treatment alone, with a low risk of complications. However the initial optimistic results, claiming a permanent relief of dysphagia in 80% of the patients, cannot be reproduced under prospective conditions. The combination of laser and 192-iridium radiation with other palliative methods, such as external radiation and/or chemotherapy is feasible and remains to be studied in a comparative way.

[Percutaneous radiotherapy of cervical cancer]

Whereas the local effect of radiotherapy in the postoperative treatment of uterine cervix cancer developing lymphogenic metastases may be regarded as clearly demonstrated, there is no evidence of its effect on the survival of patients. A definite answer to this question is only possible on the basis of prospective studies. In primary radiotherapy, more importance than in former days is given to percutaneous irradiation which allows a more homogeneous dose to the small pelvis. According to the present state of knowledge it is not justified to do without contact therapy except in cases of a very advanced disease.

[First results of high-dose-rate 192-Iridium afterloading method applied alone or associated with laser therapy in tumors of the respiratory and digestive tracts]

High-dose-rate short-term brachytherapy with 192iridium, preceded by laser therapy if practicable, has been applied in an interdisciplinary collaboration for more than one year at our hospital. Until April, 1985, 127 applications have been made in 49 patients suffering from tumors of the respiratory and upper digestive tract. The palliative effects obtained (74% and 86%, respectively) correspond with those achievable by percutaneous radiotherapy. The local control rates can possibly be improved by an 192iridium boost in the course of a curative radiotherapy.

[Initial experiences with interstitial brachycurietherapy (low dose rate I-125 seeds in carrier/vicryl and high dose rate Ir-192 afterloading system) in the palliative treatment of head and neck tumors]

The local control rates for previously irradiated recurrent tumours of the head and neck is dose dependent. High dose percutaneous irradiation alone is associated with a high complication rate. On the other hand it is possible to apply high local doses by interstitial irradiation, whilst sparing the surrounding tissue. In the last 2 years we have used Iodine 125-seeds in carrier (Vicryl) and a high dose rate Iridium 192-source for the afterloading technique. Our first experiences with 12 patients show reasonable palliation, but not effect on survival.

[Radiologic diagnosis of recurrences and sequelae to therapy of cervical cancer]

A collaboration between gynecologist, radiologist, and gynecologic radiotherapist is necessary in order to diagnose relapses and therapy effects in uterine cervix carcinoma. New imaging methods such as computed tomography, ultrasonography including endo-sonographic procedures and multiple spin echo imaging have to be applied for clinical check-up which is based on the fundamental investigation performed after primary therapy. These methods allow a very precise demonstration of lymph node relapses greater than 2 cm in the wall of the small pelvis as well as of remote metastases. The problem remains to reveal lymph node metastases below 2 cm and beginning recurrences in the cervical and parametrial region after irradiation.

Palliative treatment of malignant stenoses of the upper gastrointestinal tract using a combination of laser and afterloading therapy

Forty-eight patients with malignant stenoses of the esophagus and cardio-esophageal junction were submitted to endocavitary afterloading treatment after prior endoscopic recanalization with the laser. An intraluminal reduction in tumor mass, and rapid elimination of dysphagia proved possible. This technique represents an alternative to the endoscopic implantation of an endoprosthesis. The afterloading tube is placed endoscopically under direct vision. Using a 192Iridium radiation source, 7 Gy were applied at a distance from the tube of 1 cm. Dysphagia was permanently relieved in 77%, while re-stenosis occurred in 23%. The mean survival time was 5.9 months. This procedure is associated with a low incidence of complications, and can be employed on an outpatient basis, and in combination with percutaneous radiotherapy given as boost radiation.

[Intraluminal irradiation with iridium 192--a new method for the treatment of inoperable esophageal cancers?]

In inoperable esophageal carcinoma the intraluminal high dose afterloading therapy with Iridium 192 was employed as an alternative to the palliative resection. Prerequisite for this treatment, which was used in 19 patients during the last year, is the preceding passage restoration of the tumor stenosis by endoscopic laser therapy. Every two weeks the patients are endocavitarily irradiated up to 3 times with a dose of 7 Gy. Observing the patients by endoscopic means the implantation of a tubus is avoidable achieving better quality of life and comparable survival times.

The RENT-project: radiobiological results and planned clinical application

Various preclinical tests have been performed to determine the properties of fast neutrons of a mean energy of 2 MeV produced by an U-235 converter plate in the research reactor of the Technical University of Munich. Experiments have been carried out using two specific beams denoted as RENT I and RENT II (RENT stands for Reaktor Neutron Therapy). RENT II is the unmodified beam with a dose rate of 65 rd/min and a gamma-contamination of nearly 50% in 2 cm depth of a perspex phantom. In RENT I the gamma-component is reduced to 25% after filtration of the beam with 2.5 cm lead, whereas the total dose rate is reduced to 22 rd/min.