Endocrine profiles after radiotherapy in stage I seminoma: impact of two different radiation treatment modalities

Testicular seminoma: Scattered radiation dose to the contralateral testis in the modern era

PURPOSE

Limited data exist on testicular dose measurements using modern radiation treatment techniques and volumes for testicular seminoma. The aim of this study was to report the testicular dose using in vivo measurements in men with testicular seminoma receiving abdominopelvic radiation therapy (APRT) and a modified dog-leg field with and without gonadal shielding.

METHODS AND MATERIALS

Men with histologically confirmed testicular seminoma, either newly diagnosed stage II disease or isolated retroperitoneal relapse on surveillance for stage I disease, treated with APRT had testicular dose measurements recorded using MOSFET dosimeters. Those patients wishing to preserve fertility underwent radiation treatment with daily gonadal shielding. Factors that may influence testicular dose including field size, distance of the remaining testis from the radiation field, and patient separation, were also measured.

RESULTS

Measurements were performed for 16 men; 10 with gonadal shielding and 6 without. The mean measured dose to the testis in the patients with gonadal shielding was 2.6 cGy (standard error, 0.75; range, 0-13) compared with 28.6 cGy (standard error, 12.6; range, 0-86) in the unshielded group for a 20-fraction treatment.

CONCLUSIONS

The use of gonadal shielding during APRT with a modified dog-leg technique results in a low testicular dose that is below the likely threshold for impaired spermatogenesis. In those men wishing to preserve fertility, we recommend the use of gonadal shielding, even with the use of modern radiation therapy techniques.

Acute histopathological responses of testicular tissues after different fractionated abdominal irradiation in rats

PURPOSE

To compare the effects of different fractionated doses of abdominal radiation therapy on acute histopathological responses of testicular tissues in rats.

METHODS

Thirty-three 3-week-old Wistar albino rats were randomized into 6 groups: group 1 (n = 5), control; group 2 (n = 4), hypofractionated total abdominal irradiation (TAI) of 6 Gy/1 fraction/day for 2 days; group 3 (n = 6), hypofractionated TAI of 4 Gy/1 fraction/day for 3 days; group 4 (n = 6), hypofractionated TAI of 3 Gy/1 fraction/day for 4 days; group 5 (n = 6), conventionally fractionated TAI of 2 Gy/1 fraction/day for 6 days; group 6 (n = 6), conventionally fractionated TAI of 1.7 Gy/1 fraction/day for 7 days. Mean epithelial length and diameter of seminiferous tubules of testicular tissues were determined after euthanasia.

RESULTS

Initially, a highly significant decrease in both the mean tubular diameter and epithelial height of the seminiferous tubules was demonstrated in all irradiated rats compared with the control group. No significant differences regarding both damage parameters were found between different hypofractionated radiation therapies. Both conventional radiation therapies reduced the epithelial height and mean diameter of the seminiferous tubules to a lesser extent when compared with 6 Gy/1 fraction/day hypofractionated therapy. It was further shown that parameter values were comparable between rats that received 3 Gy/day hypofractionated therapy and rats that received either of the two conventional therapies. Furthermore, although 4 Gy/day hypofractionation decreased tubular diameter and epithelial length to a greater degree compared with the conventional therapy of 1.7 Gy/1 fraction/day, no statistically significant difference was found when compared with conventional therapy of 2 Gy/1 fraction/day. Additionally, no statistically significant difference was demonstrated between the two types of conventional radiotherapy application.

CONCLUSION

The present study demonstrated that hypofractionated abdominal irradiation leads to more prominent tissue damage in the testes than conventional irradiation.

Sperm banking and the cancer patient

The current concepts, recommendations, and principles of sperm banking as it pertains to the comprehensive care of young men of reproductive age with cancer are reviewed. Obstacles to sperm banking are addressed as well as future directions for fertility-preserving technologies. All cancer therapies-chemotherapy, radiation, and surgery-are potential threats to a man's reproductive potential. In addition, cancer itself can impair spermatogenesis. Thus, sperm cryopreservation prior to initiating life-saving cancer treatment offers men and their families the best chance to father biologically related children and should be offered to all men with cancer before treatment. Better patient and provider education, as well as deliberate, coordinated strategies at comprehensive cancer care centers are necessary to make fertility preservation for male cancer patients a priority during pretreatment planning.

Bone marrow-sparing intensity-modulated radiation therapy for Stage I seminoma

BACKGROUND

A direct association between radiotherapy dose, side-effects and secondary cancers has been described in patients with seminoma. A treatment planning study was performed in order to compare computed tomography-based traditional radiotherapy (CT-tRT) versus bone marrow-sparing intensity-modulated radiation therapy (BMS-IMRT) in patients with Stage I seminoma.

MATERIAL AND METHODS

We optimized in 10 patients a CT-tRT and a BMS-IMRT treatment plan to deliver 20 Gy to the para-aortic nodes. CT-tRT and IMRT consisted of anteroposterior-posterioranterior parallel-opposed and seven non-opposed coplanar fields using 16 and 6-MV photon energies, respectively. Dose-Volume Histograms for clinical target volume (CTV), planning target volume (PTV) and organs at risk (OARs) were compared for both techniques using Wilcoxon matched-pair signed rank-test.

RESULTS

D(mean) to CTV and PTV were similar for both techniques, even if CT-tRT showed a slightly improved target coverage in terms of PTV-D(95%) (19.7 vs. 19.5 Gy, p = 0.005) and PTV-V(95%) (100 vs. 99.7%, p = 0.011) compared to BMS-IMRT. BMS-IMRT resulted in a significant reduction (5.2 Gy, p = 0.005) in the D(mean) to the active bone marrow (ABM). The V(100%) and V(75%) of the OARs were reduced with BMS-IMRT by: ABM-V(100%) = 51.7% and ABM-V(75%) = 42.3%; bowel-V(100%) = 15.7% and bowel-V(75%) = 16.8%; stomach-V(100%) = 22% and stomach-V(75%) = 27.7%; pancreas-V(100%) = 37.1% and pancreas-V(75%) = 35.9% (p = 0.005 for all variables).

CONCLUSIONS

BMS-IMRT reduces markedly the dose to the OARs compared to CT-tRT. This should translate into a reduction in acute and long-term toxicity, as well as into the risk of secondary solid and hematological cancers.

Low incidence of new biochemical and clinical hypogonadism following hypofractionated stereotactic body radiation therapy (SBRT) monotherapy for low- to intermediate-risk prostate cancer

Background

The CyberKnife is an appealing delivery system for hypofractionated stereotactic body radiation therapy (SBRT) because of its ability to deliver highly conformal radiation therapy to moving targets. This conformity is achieved via 100s of non-coplanar radiation beams, which could potentially increase transitory testicular irradiation and result in post-therapy hypogonadism. We report on our early experience with CyberKnife SBRT for low- to intermediate-risk prostate cancer patients and assess the rate of inducing biochemical and clinical hypogonadism.

Methods

Twenty-six patients were treated with hypofractionated SBRT to a dose of 36.25 Gy in 5 fractions. All patients had histologically confirmed low- to intermediate-risk prostate adenocarcinoma (clinical stage ≤ T2b, Gleason score ≤ 7, PSA ≤ 20 ng/ml). PSA and total testosterone levels were obtained pre-treatment, 1 month post-treatment and every 3 months thereafter, for 1 year. Biochemical hypogonadism was defined as a total serum testosterone level below 8 nmol/L. Urinary and gastrointestinal toxicity was assessed using Common Toxicity Criteria v3; quality of life was assessed using the American Urological Association Symptom Score, Sexual Health Inventory for Men and Expanded Prostate Cancer Index Composite questionnaires.

Results

All 26 patients completed the treatment with a median 15 months (range, 13-19 months) follow-up. Median pre-treatment PSA was 5.75 ng/ml (range, 2.3-10.3 ng/ml), and a decrease to a median of 0.7 ng/ml (range, 0.2-1.8 ng/ml) was observed by one year post-treatment. The median pre-treatment total serum testosterone level was 13.81 nmol/L (range, 5.55 - 39.87 nmol/L). Post-treatment testosterone levels slowly decreased with the median value at one year follow-up of 10.53 nmol/L, significantly lower than the pre-treatment value (p < 0.013). The median absolute fall was 3.28 nmol/L and the median percent fall was 23.75%. There was no increase in biochemical hypogonadism at one year post-treatment. Average EPIC sexual and hormonal scores were not significantly changed by one year post-treatment.

Conclusions

Hypofractionated SBRT offers the radiobiological benefit of a large fraction size and is well-tolerated by men with low- to intermediate-risk prostate cancer. Early results are encouraging with an excellent biochemical response. The rate of new biochemical and clinical hypogonadism was low one year after treatment.

Gonadal dysfunction and fertility problems in cancer survivors

Gonadal dysfunction and fertility problems are adverse effects of cancer treatment or may be associated with specific malignancies. This review focuses on these problems in the young cancer survivors, where methods of protecting or restoring endocrine function and fertility need to be considered. In females, treatment adverse effects can result in infertility, but premature ovarian failure (POF) is probably relevant for more female cancer survivors, affecting also those who do not wish post-treatment parenthood. POF affects present and future health, especially through oestrogen deficiency symptoms and an increased risk of developing osteoporosis. A lower risk of developing POF has been considered in young females than in older due to a larger pool of oocytes. However, a recent long-term follow-up study reported a prevalence of POF in young females with Hodgkin's lymphoma of 37% showing that young age at time of treatment only delays the development of POF. In male gonads, germ cells are much more sensitive to irradiation and chemotherapy than Leydig cells. Thus, infertility is a more common adverse effect than hypogonadism. Some malignancies are particular relevant. Persistent azoospermia was formerly common after treatment for Hodgkin's lymphoma, but currently, most patients recover spermatogenesis. Modern treatment of childhood acute lymphoblastic leukemia is also unlikely to cause infertility. Norwegian testicular cancer survivors diagnosed in 1980-1994 who attempted conception had an overall 15-year actuarial post-treatment paternity rate of 71% (range 48-92% depending on the treatment). However, the rate was significantly higher among men diagnosed in1989-1994 (over 80%) than in 1980-1988 (about 63%). Patients at risk for hypogonadism and infertility should be defined prior to treatment, and available methods for gonadal preservation should maximally be utilised. During follow-up, oncologists should routinely address these issues.

A comprehensive systematic review of testicular germ cell tumor surveillance

BACKGROUND

Testicular cancer is the most common malignancy in men aged 15-34, and its incidence has been increasing over the past half-century. Survival for stage I testis cancer approaches 100% regardless of management strategy which is often dictated by other factors such as perceived morbidity. Advances in treatment have attempted to decrease morbidity and surveillance is thought to achieve this goal.

METHODS

An English language literature search of MEDLINE from 1966 to December 2005 and CINAHL from 1982 to December 2005 was conducted using a broad search strategy. Comparative and descriptive original articles on outcomes of seminoma or NSGCT surveillance would be deemed eligible and review articles containing no original data were omitted. One hundred and thirty-eight articles were selected for formal review, during which a database was compiled that documented the first author, publication year, tumor histologic type, study purpose or topic(s), methodology, sample size, median follow-up, and relevant results.

RESULTS

Most evidence for the efficacy of surveillance is from descriptive series or non-experimental comparative studies. Relapse occurs in approximately 28% and 17% of surveillance patients in NSGCT and seminoma, respectively, and cause-specific survival is approximately 98% and 100%, respectively. Compliance with surveillance ranges from poor to adequate, however there is no evidence that compliance impacts clinical outcome. Cost analyses have yielded inconsistent results when comparing treatment modalities. There is scant literature on quality of life and psychosocial issues and results are inconsistent. Active surveillance appears to be appropriate and perhaps optimal first line management of clinical stage I seminoma and non-seminomatous germ cell tumors. Further quantitative and qualitative research is warranted to deepen understanding of these issues that may impact treatment decision-making.

Semen Quality in Men with Malignant Diseases before and after Therapy and the Role of Cryopreservation

OBJECTIVE

To review the literature and answer questions about semen quality in young cancer patients before and after therapy and the importance of sperm cryopreservation.

METHODS

All aspects of sperm cryopreservation and effects of therapies on semen quality were examined on the basis of MedLine database searches.

RESULTS

Chemotherapy, radiation, or their combination results in a significant reduction of sperm quality and as a consequence an indefinite time of infertility follows. The type of cancer and the pretreatment sperm concentrations were the most significant factors governing posttreatment semen quality and recovery of spermatogenesis. Due to their age, fertility and sexual functioning are key issues for these patients. Yet there is no medical protection of the germinal epithelium available. Male germ cell transplantation is in its infancy and still there are no therapeutical options to improve spermatogenesis after damage has occurred. Consequently, cryopreservation represents the only preemptive measure for conserving fertility.

CONCLUSION

This manuscript updates the current knowledge of diverse chemotherapeutic treatment regimens and their gonadotoxic effects as well as the development of posttreatment fertility in cancer patients. The importance and rationale of sperm cryopreservation are discussed and possible future options are highlighted.

Data required for testicular dose calculation during radiotherapy of seminoma

The purpose of this study was to provide the required data for the direct calculation of testicular dose resulting from radiotherapy in patients with seminoma. Paraortic (PA) treatment fields and dog-leg (DL) portals including paraortic and ipsilateral pelvic nodes were simulated on a male anthropomorphic phantom equipped with an artificial testicle. Anterior and posterior irradiations were performed for five different PA and DL field dimensions. Dose measurements were carried out using a calibrated ionization chamber. The dependence of testicular dose upon the distance separating the testicle from the treatment volume and upon the tissue thickness at the entrance point of the beam was investigated. A clamshell lead shield was used to reduce testicular dose. The scattered dose to testicle was measured in nine patients using thermoluminescent dosimeters. Phantom and patient exposures were generated with a 6 MV x-ray beam. Linear and nonlinear regression analysis was employed to obtain formulas describing the relation between the radiation dose to an unshielded and/or shielded testicle with the field size and the distance from the inferior field edge. Correction factors showing the variation of testicular dose with the patient thickness along beam axis were found. Bland-Altman statistical analysis showed that testicular dose obtained by the proposed calculation method may differ from the measured dose value by less than 25%. The current study presents a method providing reasonable estimations of testicular dose for individual patients undergoing PA or DL radiotherapy.

Radiotherapy in the management of common genitourinary malignancies

A continued role for radiation therapy in the multidisciplinary management of genitourinary malignancies seems certain. Treatment outcomes continue to improve, accompanied by diminishing rates of toxicity. With continued technologic advances in the delivery of radiation, including the use of adaptive radiotherapy, the discovery and application of novel treatment agents, and the combined efforts of urologists, medical oncologists, and radiation oncologists, patients who have genitourinary malignancies have an excellent chance of cure.

New Guidelines for Clinical Stage I Testicular Seminoma?

Clinical stage I (CS I) seminoma has been the subject of various studies aimed at finding the ideal treatment. Due to its high radiosensitivity, radiotherapy has been the standard approach for decades. However, the fact that CS I seminoma has a recurrence rate of only 15-20% has prompted many suggestions for better treatment stratification offering surveillance therapy for a subgroup of patients. Moreover, carboplatinum-based monochemotherapy has been the topic of various retrospective studies demonstrating equal effectiveness for adjuvant chemotherapy with one cycle of carboplatin. Since seminoma affects men in their mid-30s, only few reports have been published on long-term survival with reference to radiotoxicity and secondary malignancies. Long-term side effects and secondary malignancies pose an increasing problem for long-term survivors of primary malignancies treated by chemo- or radiotherapy. This becomes evident after a follow-up of 15 years. Since recent studies have disclosed unexpectedly high long-term morbidity and mortality after irradiation, this article critically reviews the value of radiotherapy and carboplatinum-based chemotherapy as equally effective treatment options for CS I seminoma.

Paternity following treatment for testicular cancer

BACKGROUND

Studies of fertility in men treated for testicular cancer have mainly addressed serum follicle-stimulating hormone levels and sperm parameters. We assessed post-treatment paternity among long-term survivors of testicular cancer.

METHODS

Men (n = 1814) who had been treated for unilateral testicular cancer in Norway during 1980 through 1994 were invited to participate in a national multi-center follow-up survey in 1998 through 2002. The participants were allocated to five groups according to the treatment received after orchiectomy, including treatment at relapse (surveillance, retroperitoneal lymph node dissection, radiotherapy, low-dose chemotherapy [i.e., < or = 850 mg cisplatin], and high-dose chemotherapy [i.e., > 850 mg cisplatin]). Cox proportional hazards analysis was used to assess predictive factors for post-treatment paternity. Statistical tests were two-sided.

RESULTS

A total of 1433 men were assessable, of whom 827 were fathers at diagnosis. Post-treatment conception was attempted by 554 men, among whom the overall 15-year actuarial post-treatment paternity rate was 71% (95% confidence interval [CI] = 66% to 75%) without the use of cryopreserved semen. This rate ranged from 48% (95% CI = 30% to 69%) in the high-dose chemotherapy group to 92% (95% CI = 78% to 98%) in the surveillance group (P < .001). The median actuarial time from diagnosis to the birth of the first child after treatment was 6.6 years overall but varied according to treatment. Assisted reproductive technologies were used by 22% of the couples who attempted conception after treatment. Dry ejaculation, treatment group, pretreatment fatherhood, and marital status were statistically significant independent predictors for post-treatment fatherhood, with dry ejaculation as the most important negative factor.

CONCLUSIONS

Although the overall paternity rate after treatment for testicular cancer was high, the ability to conceive and the time to conception reflected the intensity of treatment. These data may help inform patients about their future ability to father biological children.

European consensus on diagnosis and treatment of germ cell cancer: a report of the European Germ Cell Cancer Consensus Group (EGCCCG)

Germ cell tumour is the most frequent malignant tumour type in young men with a 100% rise in the incidence every 20 years. Despite this, the high sensitivity of germ cell tumours to platinum-based chemotherapy, together with radiation and surgical measures, leads to the high cure rate of > or = 99% in early stages and 90%, 75-80% and 50% in advanced disease with 'good', 'intermediate' and 'poor' prognostic criteria (IGCCCG classification), respectively. The high cure rate in patients with limited metastatic disease allows the reduction of overall treatment load, and therefore less acute and long-term toxicity, e.g. organ sparing surgery for specific cases, reduced dose and treatment volume of irradiation or substitution of node dissection by surveillance or adjuvant chemotherapy according to the presence or absence of vascular invasion. Thus, different treatment options according to prognostic factors including histology, stage and patient factors and possibilities of the treating centre as well may be used to define the treatment strategy which is definitively chosen for an individual patient. However, this strategy of reduction of treatment load as well as the treatment itself require very high expertise of the treating physician with careful management and follow-up and thorough cooperation by the patient as well to maintain the high rate for cure. Treatment decisions must be based on the available evidence which has been the basis for this consensus guideline delivering a clear proposal for diagnostic and treatment measures in each stage of gonadal and extragonadal germ cell tumour and individual clinical situations. Since this guideline is based on the highest evidence level available today, a deviation from these proposals should be a rare and justified exception.

Radiotherapy for early stages testicular seminoma: patterns of care study in Germany

BACKGROUND AND PURPOSE

To evaluate compliance of radiotherapeutic departments with 1997 German consensus guidelines for staging and treatment of testicular cancer patients.

MATERIAL AND METHODS

A questionnaire was mailed to all departments of radiotherapy in Germany as identified by the data-base of the German Society for Radiation Oncology (DEGRO). The questionnaire was analysed with particular respect to institutional characteristics, frequency of seminoma patients treated per year, treatment techniques, and institutional compliance with consensus guidelines.

RESULTS

Fifty-six institutions (39%) returned the questionnaire, 46% of which fully complied with consensus guidelines concerning staging requirements. A minimum workup with computed tomography (CT) of abdomen and pelvis, X-ray or CT of the chest and tumour markers was mandatory in 87.5% of the departments. Compliance with the recommended treatment schedule was high in stage I with less than 5% major violations of recommended dose prescription or target volume definition. In stage IIA/B, however, 22.6 and 10.2% of the departments showed major deviations from either standardised treatment target volumes or total doses of irradiation, respectively.

CONCLUSIONS

Compliance with consensus recommendations in German departments for radiotherapy is satisfactory in many institutions. However, major deviations from treatment guidelines were observed in stage II disease indicating the need for continuous improvement in the quality of testicular cancer patient management.

Radiotherapy of testicular intraepithelial neoplasia (TIN): a novel treatment regimen for a rare disease

PURPOSE

Testicular intraepithelial neoplasia (TIN) is a consistent precursor of most invasive germ cell tumors, currently treated by radiotherapy with 20 Gy, which destroys TIN but preserves Leydig cells. Nevertheless, analysis has shown dose-dependent dysfunction even with low therapeutic doses of 20 Gy in some cases. Therefore, we tested a dose reduction regimen by delivering smaller fractional doses to enhance the tolerance of Leydig cells.

METHODS AND MATERIALS

Between 1993 and 1999, 9 patients were treated for TIN in a prospective multicenter trial. A total dose of 13 Gy was administered in 10 fractions of 1.3 Gy. Hormonal levels of follicle-stimulating hormone, luteinizing hormone, and testosterone were assayed serially.

RESULTS

During a median follow-up time of 36 months, no patient showed evidence of local disease. A first postradiation biopsy was obtained 3-12 months after radiotherapy; 5 patients underwent a second biopsy 2-3 years after treatment. All biopsies showed a Sertoli cell-only pattern. Follicle-stimulating hormone levels continued to increase 1 year after radiotherapy, signaling eradicated spermiogenesis. Luteinizing hormone and testosterone remained within the normal range 2 years after radiotherapy.

CONCLUSIONS

In the treatment of TIN, there seems to be a dose reduction potential to 13 Gy by lowering single fractional doses, which enhances the therapeutic ratio in favor of the Leydig cells.

Impact of cytotoxic treatment on long-term fertility in patients with germ-cell cancer

More than half of the patients with testicular germ-cell cancer show impaired spermatogenesis before undergoing cytotoxic treatment. The known pre-treatment infertility and the reversibility of the fertility problems observed in some after successful anti-cancer treatment have so far prevented an assessment of the true role of cytotoxic therapy in long-term fertility. The introduction of wait-and-see strategies (surveillance) for testicular cancer patients and recent prospective trials comparing patients with and without cytotoxic treatment have provided the means for estimating the extent to which treatment itself affects long-term fertility. Whether or not spermatogenesis is irreversibly impaired by chemotherapy is determined by the cumulative dose of cisplatin: at doses below 400 mg/m2, long-term effects on sperm production as well as on endocrine function are unlikely to occur. Higher doses should be expected to cause long-term losses of exocrine and endocrine gonadal function. In contrast, for adjuvant retroperitoneal radiotherapy in stage I seminoma patients, no data are available comparing long-term gonadal function with patients on surveillance. However, using modern radiation techniques, radiation doses to the para-aortic field (< 30 Gy) and testis shielding providing testis scatter radiation (< 30 cG), radiation-induced impairment of fertility is very unlikely.

Management of testicular seminoma

Testicular seminoma is highly curable with currently available treatments. Today, there is good evidence that patients with Stage I disease can be treated equally well with either immediate adjuvant para-aortic and ipsilateral pelvic radiotherapy or close surveillance with treatment at the time of relapse. The decision as to which of these management strategies is adopted in an individual case is a complex function of physician preference, and the emotional, social, and economic circumstances of the patient. Ongoing research in Stage I seminoma is focused at reducing the side-effects of treatment either by modifying the radiation treatment plan or by using adjuvant chemotherapy in lieu of radiation. Stage II patients with small bulk retroperitoneal lymphadenopathy have a high probability of long-term disease control with radiotherapy. Patients with bulky Stage II disease or Stage III disease should be treated with cisplatin-based chemotherapy.

[The gonadal loading during the irradiation of lymph outflow in operated seminomas. In-vivo dosimetry]

BACKGROUND

This article should demonstrate the problems concerning gonadal dose in seminoma patients, the impact of shielding and possible consequences for therapy and advising of patients with desire to have children.

PATIENTS AND METHOD

Since November 1993 gonadal doses of 43 patients (Stage I/II, Royal Marsden) have been determined in 80 measurements with 2 ionization chambers on the ipsi- and contralateral side of the remaining testicle. The patients were all treated with ap/pa "hockey-stick"-shaped fields on a 6 MV linear accelerator. With single doses of 1.8 Gy in midplane, total doses of 34.2 Gy were applied in 13, and 30.6 Gy in 30 men. Protection was used in 33 patients, 6 times with conventional shielding, later plus an additional clam-shell from ap. The results of 22 measurements on 6 men with and without protection are of special interest. In 25 patients a sperm analysis before radiotherapy was conducted.

RESULTS

Before the beginning of radiotherapy (RT) 56% of available patients have shown an impaired spermatogenesis. The mean gonadal doses were 2.4% of midplane dose-MD (4.8 cGy), 1.8% MD (3.2 cGy) and 1% MD (1.8 cGy) per fraction for patients without (n-patients = 10, m-measurements = 15), with conventional (n = 6, m = 7), and additional clam-shell shielding (n = 33, m = 58). The corresponding median values were 2.1% (SD 1.07), 1.7% (SD 0.28) and 1% (SD 0.41) of midplane dose (Table 1, Figure 1). According to direct comparisons, a dose reduction of about half can be expected in most cases (Figure 2). Mean dose fluctuations of 11.6% (median 10%) have to be taken into account.

CONCLUSION

Effective shielding can diminish gonadal dose in seminoma patients to about 1% of midplane and gives a good possibility of taking the maintenance of fertility and the desire to have children into account (Table 2). The application should be considered especially for patients with impaired spermatogenesis before RT. Eventual fluctuations induced us to determine the gonadal dose 3 times per patient in direct measurements (Table 3).

Seminoma of the testis: is scrotal shielding necessary when radiotherapy is limited to the para-aortic nodes?

PURPOSE

To evaluate the influence of different shielding conditions and field geometry on the scatter dose to the remaining testicle during postoperative radiotherapy (RT) in seminoma.

MATERIALS AND METHODS

Testicular dose measurements were made with LiF thermoluminescent dosimeters (TLD) in 29 patients with stage I and IIA seminoma. The target volume consisted of para-aortic (PA) and para-aortic and homolateral iliac (PAI) lymph nodes in 14 and 15 patients, respectively. All patients had a scrotal shield as well as an additional block extending 7 cm inferiorly from the caudal field edge to shield the testicle from external scatter and collimator leakage. Doses with and without testicular blocks were measured for all patients. In seven patients treated exclusively to the PA region the gonadal dose was assessed according to four different shielding conditions: without any protection, with a gonadal shield alone, with the addition of an inferior field border block to the gonadal shield, and with the field border block alone.

RESULTS

For patients treated with PAI fields the mean testicular doses per fraction were 3.89 cGy (S.D. +/- 1.44) and 1.48 cGy (S.D. +/- 0.51) without and with gonadal shielding, respectively (P-value < 0.001); the corresponding values for PA fields were 1.86 cGy (S.D. +/- 0.86) and 0.65 cGy (S.D. +/- 0.35). For the patients treated to the PA region and assessed according to the four different shielding conditions, the additional external block to the testicular shield did not reduce significantly the measured dose on the testis.

CONCLUSIONS

These results suggest a benefit of gonadal shielding even in seminoma patients undergoing radiotherapy limited to the para-aortic region.

Long-term side effects of treatment for testis cancer

Patients newly diagnosed with testis cancer can now expect excellent results with respect to long-term, disease-free survival after treatment. Given the young age of presentation for many of these patients, the long-term consequences of curing testis cancer have become a major concern. Surgery, radiation, and chemotherapy for testis cancer have all been associated with potential long-term side-effects. Consequently, new treatment regimens have been directed toward minimizing these possible side-effects while at the same time maintaining high cure rates (i.e., limiting the size of radiation fields, decreasing the number of chemotherapy cycles, eliminating bleomycin). Patients and physicians must be made aware of the potential adverse side effects of treatment for testis cancer. At the present time, however, it appears that the beneficial effects of such treatment, with respect to overall and disease-free survival, far outweigh the limited probability of persistent treatment-related side effects in patients newly diagnosed with testis cancer.