Radiotherapy Treatment Planning for Testicular Seminoma

Lymph Node Dissection in Testicular Cancer: The State of the Art and Future Perspectives

PURPOSE OF REVIEW

This narrative review provides a comprehensive overview of the evolving role of retroperitoneal lymph node dissection (RPLND) in the management of testicular cancer (TC). It explores the significance of RPLND as both a diagnostic and therapeutic tool, highlighting its contribution to accurate staging, its impact on oncological outcomes, and its influence on subsequent treatment decisions.

RECENT FINDINGS

RPLND serves as an essential diagnostic procedure, aiding in the precise assessment of lymph node involvement and guiding personalized treatment strategies. It has demonstrated therapeutic value, particularly in patients with specific risk factors and disease stages, contributing to improved oncological outcomes and survival rates. Recent studies have emphasized the importance of meticulous patient selection and nerve-sparing techniques to mitigate complications while optimizing outcomes. Additionally, modern imaging and surgical approaches have expanded the potential applications of RPLND. In the context of TC management, RPLND remains a valuable and evolving tool. Its dual role in staging and therapy underscores its relevance in contemporary urological practice. This review highlights the critical role of RPLND in enhancing patient care and shaping treatment strategies, emphasizing the need for further research to refine patient selection and surgical techniques.

Clinical Outcomes of De Novo Versus Relapsed Early Metastatic Testicular Seminoma Treated With Contemporary Radiation Therapy

PURPOSE

Chemotherapy (CHT) or radiation therapy (RT) are first-line treatments for clinical stage II (CS-II) testicular seminoma. Historically, clinical stage I (CS-I) seminoma was also treated with CHT or RT, but in the past 2 decades practice has shifted toward active surveillance for CS-I with RT or CHT reserved for patients with progression to CS-II. Limited data exist on contemporary RT techniques and patient stratification (ie, de novo [CS-II at orchiectomy] vs relapsed [CS-II diagnosed during surveillance after orchiectomy for CS-I]). We investigated outcomes in CS-II patients treated with RT in the modern era across 2 institutions.

METHODS AND MATERIALS

A retrospective review identified 73 patients treated with RT for CS-II A or B seminoma between 2001 and 2022. Recurrence-free survival (RFS) was calculated by the Kaplan-Meier method and univariate analyses were performed with log-rank or Cox proportional hazard regression. Recurrence was defined as biopsy-proven metastatic seminoma after RT completion. Second malignancies were defined as a biopsy-proven malignancy originating in the prior RT field.

RESULTS

Thirty-eight (52%) patients presented with de novo CS-II and 35 (48%) patients had relapsed CS-II. Median follow-up was 4.8 years (IQR: 2.3-8.1). Five-year RFS was 82% overall (92% in relapsed patients and 73% in de novo patients). Relapsed CS-II disease had lower recurrence rates after RT compared with de novo CS-II disease. All recurrences occurred outside the prior RT field and were salvaged. Disease-specific survival was 100%. Two second malignancies occurred (prostate, colorectal cancer at 67 months and 119 months post-RT, respectively).

CONCLUSIONS

In patients with CS-II seminoma treated with modern RT, there were no in-field recurrences. Presentation with de novo CS-II is associated with out-of-field recurrence. Subject to further larger-scale validation, our results suggest that compared with CS-II at time of relapse, de novo CS-II may portend more aggressive or micrometastatic disease beyond the retroperitoneum, raising the possibility of benefit from CHT after radiation.

Radiation Therapy for Stage IIA/B Seminoma: Modeling Secondary Cancer Risk for Protons and VMAT versus 3D Photons

Radiation therapy (RT) is an effective treatment for stage IIA and select stage IIB seminomas. However, given the long life expectancy of seminoma patients, there are concerns about the risk of secondary cancers from RT. This study assessed differences in secondary cancer risk for stage II seminoma patients following proton pencil-beam scanning (PBS) and photon VMAT, compared to 3D conformal photon RT. Ten seminoma patients, five with a IIA staging who received 30 GyRBE and five with a IIB staging who received 36 GyRBE, had three RT plans generated. Doses to organs at risk (OAR) were evaluated, and secondary cancer risks were calculated as the Excess Absolute Risk (EAR) and Lifetime Attributable Risk (LAR). PBS reduced the mean OAR dose by 60% on average compared to 3D, and reduced the EAR and LAR for all OAR, with the greatest reductions seen for the bowel, liver, and stomach. VMAT reduced high doses but increased the low-dose bath, leading to an increased EAR and LAR for some OAR. PBS provided superior dosimetric sparing of OAR compared to 3D and VMAT in stage II seminoma cases, with models demonstrating that this may reduce secondary cancer risk. Therefore, proton therapy shows the potential to reduce acute and late side effects of RT for this population.

Vaginal Dose Reduction by Changing the Ovoid Loading Pattern in Image Guided Intracavitary Brachytherapy of Cervix

Aim

Locally advanced cervical cancer is frequently treated using a combination of external beam radiotherapy and brachytherapy. Radiotherapy often leads to vaginal morbidity, which poses a significant problem. This study aims to analyze the impact of reducing ovoid loading on dosimetry.

Materials and methods

We analyzed forty-five CT-based intracavitary brachytherapy plans from fifteen patients. Three plan sets were created for the 45 applications: a standard loading plan (A), a plan with reduced ovoid loading (B), and a tandem-only loading plan (C). We generated Dose-Volume Histograms and recorded dose volume parameters for the three plan sets.

Results

The D90 for the Clinical Target Volume (CTV) did not show significant differences among the three plan sets (p = 0.20). The average D90 values for plans A, B, and C were 8.15 Gy, 8.16 Gy, and 7.4 Gy, respectively. No statistically significant differences were observed in D2cc bladder (p = 0.09) (average values: 6.8 Gy, 6.5 Gy, and 5.9 Gy for plans A, B, and C, respectively) and D2cc sigmoid (p = 0.43) (average values: 2.8 Gy, 2.6 Gy, and 2.4 Gy, respectively) among the three plan sets. However, there was a statistically significant difference in D2cc rectum (p < 0.001) (average values: 4 Gy, 3.3 Gy, and 1.8 Gy, respectively), as well as in vaginal dose points (p < 0.001).

Conclusion

Reducing ovoid loading significantly decreased the doses to vaginal dose points and the rectum without compromising the dose to the Clinical Target Volume (CTV). Therefore, in carefully selected cases, the adoption of tandem-only loading or reduced ovoid loading could be considered to minimize vaginal morbidity following high dose rate intracavitary brachytherapy.

Advances in radiation therapy for testicular seminoma

PURPOSE

Novel techniques and advances in radiation therapy (RT) have been explored to treat testicular seminoma, a highly radiosensitive and curable histology. We evaluated the historical and current indications for radiation therapy (RT) in testicular seminoma.

METHODS

A narrative literature review was performed. Studies of RT for testicular seminoma were included. Additionally, recent trials testing the use of combination or surgical therapies for clinical stage (CS) II were included. Search parameters included radiation therapy, testicular seminoma, surgery, and chemoradiation. Parameters and outcomes assessed were progression-free survival (PFS), overall survival (OS), acute toxicities, long-term sequelae, and rates of secondary malignancies.

RESULTS

Practice defining and changing studies in the use or omission of radiation therapy for testicular seminoma were identified along with resultant changes in National Comprehensive Cancer Network (NCCN) and European guidelines. Recent trials in combined chemoradiation and upfront surgical approaches to CS II disease were reviewed.

CONCLUSION

RT has historically been used as adjuvant treatment for CS I disease and is highly effective at treating CS II (A/B) testicular seminoma. The drive to maintain therapeutic efficacy and reduce acute and long-term side effects, namely secondary malignancies, is being tested using new radiation technologies, combined modality therapy in the form of chemoradiation and with upfront surgical approaches. Also, as guidelines now "strongly prefer" surveillance instead of adjuvant RT for CS I disease, the current CS II population comprises patients presenting with CS II disease ("de novo") and those who present with CSII after relapsing post orchiectomy for CS I ("relapsed"). Emerging evidence suggests that these two groups have different outcomes with respect to RT and chemoradiation. Consequently, future trials may need to sub-stratify according to these groups.

Dose comparison of robustly optimized intensity modulated proton therapy (IMPT) vs IMRT and VMAT photon plans for testicular seminoma

BACKGROUND

Patients with stage II seminoma have traditionally been treated with photons to the retroperitoneal and iliac space, which leads to a substantial dose bath to abdominal and pelvic organs at risk (OAR). As these patients are young and with excellent prognosis, reducing dose to OAR and thereby the risk of secondary cancer is of utmost importance. We compared IMPT to opposing IMRT fields and VMAT, assessing dose to OAR and both overall and organ-specific secondary cancer risk.

MATERIAL AND METHODS

A comparative treatment planning study was conducted on planning CT-scans from ten patients with stage II seminoma, treated with photons to a 'dog-leg' field with doses ranging from 20 to 25 Gy and a 10 Gy sequential boost to the metastatic lymph node(s). Photon plans were either 3-4 field IMRT (Eclipse) or 1-2 arc VMAT (Pinnacle). Proton plans used robust (5 mm; 3.5%) IMPT (Eclipse), multi field optimization with 3 posterior fields supplemented by 2 anterior fields at the level of the iliac vessels. Thirty plans were generated. Mean doses to OARs were compared for IMRT vs IMPT and VMAT vs IMPT. The risk of secondary cancer was calculated according to the model described by Schneider, using excess absolute risk (EAR, per 10,000 persons per year) for body outline, stomach, duodenum, pancreas, bowel, bladder and spinal cord.

RESULTS

Mean doses to all OARs were significantly lower with IMPT except similar kidney (IMRT) and spinal cord (VMAT) doses. The relative EAR for body outline was 0.59 for IMPT/IMRT (p < .05) and 0.33 for IMPT/VMAT (p < .05). Organ specific secondary cancer risk was also lower for IMPT except for pancreas and duodenum.

CONCLUSION

Proton therapy reduced radiation dose to OAR compared to both IMRT and VMAT plans, and potentially reduce the risk of secondary cancer both overall and for most OAR.

Magnetic resonance versus computed tomography for the detection of retroperitoneal lymph node metastasis due to testicular cancer: A systematic literature review

INTRODUCTION

It is essential to see if MRI can be used as an alternative to CT for the detection of retroperitoneal lymphadenopathy in patients with testicular neoplasms. By doing so, the amount of radiation received by these young patients might be reduced.

MATERIAL AND METHODS

A systematic literature review was carried out in 5 databases between January 1984 until December 2020. The articles included were randomized and non-randomized clinical trials, cross-sectional studies, cohort, case and control, and retrospective studies that compare the accuracy of MRI against CT to detect retroperitoneal lymph nodes in patients with testicular neoplasms.

RESULTS

The search string initially retrieved 222 non duplicated papers from which a total of 3 studies of diagnostic accuracy were included for analysis. These articles evaluated a total of 127 patients with testicular neoplasm; the sample size per study ranged from 25 to 52 patients, with a mean age between 29-34 years. MRI presented a sensitivity ranging from 98-80% and specificity of 100 % when read by an experienced radiologist. However, when it was read by a radiologist with 1 year of experience, the sensitivity dropped to 78 % and specificity to 91%.

CONCLUSION

This systematic literature review shows a knowledge gap since not much has been published regarding this topic; therefore, randomized clinical trials are mandatory. Research on when to use MRI over CT is necessary to reduce radiation exposure. The authors strongly suggest that readers start researching on this subject.

Para-aortic lymph node metastasis in lower Thoracic Esophageal Squamous Cell Carcinoma after Radical Esophagectomy: a CT-based atlas and its clinical implications for Adjuvant Radiotherapy

Background: Our previous work showed that para-aortic lymph node (PALN) metastasis was the major failure pattern in lower thoracic esophageal squamous cell carcinoma (LTESCC) patients who presented abdominal LN failure after curative surgery. We thereby aim to generate a computerized tomography (CT)-based documentation of PALNs and to propose a clinical target volume (CTV) for this region. Methods: Sixty-five patients were enrolled. The epicentre of each PALN was drawn onto an axial CT image of a standard patient with reference to the surrounding anatomical landmarks. A CTV for PALN was generated based on the final result of node distribution, and was evaluated for dosimetric performance in three simulated patients. Results: All the studied 248 LNs were below the level of 1.0 cm above the celiac artery (CA), and 94.76% were above the bottom of vertebra L3. Horizontally, 93.33% of the LNs in the celiac level were located within an expansion of 1.5 cm on the CA, and 94.12% of the LNs in the superior mesenteric artery (SMA) level were within 1.5 cm on the left side of the SMA. Below the SMA, all the LNs were behind the left renal vein, left to the right border of the inferior vena cava, and 98.51% of the LNs were medial to the lateral surface of the left psoas major. The proposed CTV could cover 92.74% of the LNs and was dosimetrically feasible. Conclusions: The proposed CTV is the first one to focus on the high-risk area of abdominal failure in LTESCC patients after surgery and can serve as a reference in the adjuvant radiotherapy for LTESCC patients.

Outcomes and Toxicities of Proton and Photon Radiation Therapy for Testicular Seminoma

Purpose

To determine the clinical outcomes and toxicities of proton beam therapy (PBT) versus 3D-conformal photon radiation therapy (XRT) in patients with testicular seminoma.

Materials and Methods

This observational study evaluated consecutive patients with testicular seminoma who were treated with inguinal orchiectomy and radiation therapy at a single, tertiary, high-volume center in 2008-19. Acute toxicity was scored with the Common Terminology Criteria for Adverse Events V 4.0. Organs at risk were contoured retrospectively by 2 investigators. Recurrences and secondary malignancies were based on routine follow-up imaging, either computed tomography or magnetic resonance imaging.

Results

Fifty-five patients were treated with radiation therapy, 11 in the PBT-arm and 44 in the XRT-arm, with a median follow-up interval of 61 months (interquartile range [IQR]: 32-79 months). Acute treatment-related diarrhea, grade 1 to 2, was more common among XRT-treated patients (0% vs 29.5%, P = .039), and dermatitis, grade 1, was more likely among PBT-treated patients (27.3% vs 2.3%, P = .004). Dosimetrically, PBT-treated patients, relative to XRT-treated patients, had lower dose to organs at risk including the kidney, bladder, femoral head, spinal cord, bowel, pancreas, and stomach. The 5-year overall survival rate was 100% and disease-free survival rate was 96.4% for all patients. Two patients, all in the XRT-arm, had disease recurrence: 1 in the pelvis and 1 in the lung. Three patients, all in the XRT-arm, were diagnosed with a secondary malignancy: 1 in-field pancreaticoblastoma, 1 in-field colon adenocarcinoma, and a stage IV T-cell lymphoma.

Conclusion

Proton beam therapy for testicular seminoma resulted in excellent clinical outcomes and was associated with lower rates of acute diarrhea but higher rates of acute dermatitis. Proton beam therapy resulted in no in-field secondary malignancies and a more favorable dosimetric profile for organs at risk relative to XRT. Reduced dose to organs at risk, such as the kidneys, may result in long-term improvement in function.

ESMO Consensus Conference on testicular germ cell cancer: diagnosis, treatment and follow-up

The European Society for Medical Oncology (ESMO) consensus conference on testicular cancer was held on 3-5 November 2016 in Paris, France. The conference included a multidisciplinary panel of 36 leading experts in the diagnosis and treatment of testicular cancer (34 panel members attended the conference; an additional two panel members [CB and K-PD] participated in all preparatory work and subsequent manuscript development). The aim of the conference was to develop detailed recommendations on topics relating to testicular cancer that are not covered in detail in the current ESMO Clinical Practice Guidelines (CPGs) and where the available level of evidence is insufficient. The main topics identified for discussion related to: (1) diagnostic work-up and patient assessment; (2) stage I disease; (3) stage II-III disease; (4) post-chemotherapy surgery, salvage chemotherapy, salvage and desperation surgery and special topics; and (5) survivorship and follow-up schemes. The experts addressed questions relating to one of the five topics within five working groups. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel. A consensus vote was obtained following whole-panel discussions, and the consensus recommendations were then further developed in post-meeting discussions in written form. This manuscript presents the results of the expert panel discussions, including the consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

On thin ice: barriers to adoption of surveillance for patients with stage I testicular seminoma. Survey of US radiation oncologists

Purpose:

Most men with stage I testicular seminoma are cured with surgery alone, which is a preferred strategy per national guidelines. The current pattern of practice among US radiation oncologists (ROs) is unknown.

Materials and Methods:

We surveyed practicing US ROs via an online questionnaire. Respondent's characteristics, self-rated knowledge, perceived patient compliance rates with observation were analyzed for association with treatment recommendations.

Results:

We received 353 responses from ROs, of whom 23% considered themselves experts. A vast majority (84%) recommend observation as a default strategy, however this rate drops to 3% if the patient is believed to be noncompliant. 33% of respondents believe that survival is jeopardized in case of disease recurrence, and among these respondents only 5% support observation. 22% of respondents over-estimate the likelihood of noncompliance with observation to be in the 50-80% range. Responders with a higher perceived noncompliance rate are more likely to recommend adjuvant therapy (Fisher's exact p<0.01). Only 7% of respondents recommend observation for stage IS seminoma and 45% administer adjuvant RT in patients with elevated pre-orchiectomy alpha-fetal protein levels.

Conclusions:

Many US ROs over-estimate the likelihood that stage I testicular seminoma patients will be noncompliant with surveillance and incorrectly believe that overall survival is jeopardized if disease recurs on surveillance. Observation is quickly dismissed for patients who are not deemed to be compliant with observation, and is generally not accepted for patients with stage IS disease. There is clearly an opportunity for improved physician education on evidence-based management of stage I testicular seminoma.

Stage IIA and IIB testicular seminoma treated postorchiectomy with radiation therapy versus other approaches: a population-based analysis of 241 patients

Objectives

To evaluate post-orchiectomy utilization of radiation therapy (RT) versus other management approaches in stage IIA and IIB testicular seminoma patients.

Materials and Methods

Two hundred and forty-one patients with stage IIA and IIB testicular seminoma were identified between 1988 and 2003 using the Surveillance, Epidemiology, and End Results (SEER) database.

Results

Median follow-up was 10 years. Patients with stage IIA disease underwent RT more frequently than those with stage IIB disease (72% vs. 46%, respectively; P<0.001). There was no significant change in RT utilization for stage IIA or IIB disease between 1988 and 2003 (P = 0.89).

Conclusions

Between 1988 and 2003, stage IIA patients underwent RT more often than stage IIB patients in the United States. There was no significant change in RT utilization for stage IIA or IIB disease during this time period. Based on reports describing excellent progression-free survival with cisplatin-based chemotherapy, this approach has increased in popularity since 2003 and may eventually become the most popular treatment approach for both stage IIA and IIB testicular seminoma.

Radiotherapy for Stage IIA seminoma: The Northern Israel Oncology Center Experience, 1971-2010

AIM

To evaluate treatment details, outcome, relapse rate and side-effects in Stage IIA seminoma irradiated and followed for a period of 39 years.

BACKGROUND

Seminoma is a very radiosensitive disease and radiation therapy alone is able to achieve long-term disease-free survival, even in advanced Stage disease. Due to the lack of long-term prospective studies, it is of value to follow patients and try to determine the appropriate volume to be irradiated and the dose which can achieve total cure with minimal acute and chronic side-effects.

PATIENTS AND METHODS

A retrospective review of 24 Stage IIA seminoma patients irradiated between 1971 and 2010 was performed. All patients underwent orchiectomy and meticulous clinical, biochemical and radiological staging.

RESULTS

Median age at diagnosis was 36 years and median follow-up was 84 months. A majority of patients received the "hockey-stick" irradiation schedule (para-aortic lymph nodes and hemi-pelvis) to a total dose of 2250-2500 cGy and a boost to radiologically involved nodes of 500-1000 cGy. Treatment was well-tolerated. Twenty-one (88%) patients are alive with no evidence of disease. Two patients died due to unknown causes, while one patient died due to head of the pancreas carcinoma, most probably radiation-induced.

CONCLUSIONS

In Stage II seminoma, radiotherapy can provide excellent results with low rates of toxicity. Reduction of total dose and size of fields without affecting the good results should be considered. Due to prolonged survival, awareness of second primary tumor is indicated.

Anaplastic variant of classical seminoma of the testis: northern Israel oncology center experience and brief review of literature

OBJECTIVES

There are only sporadic reports on the clinical behavior and appropriate treatment of anaplastic seminoma. This retrospective study summarizes our experience with the anaplastic variant of classical (typical) seminoma.

METHODS

Between 1986 and 2006, seven anaplastic seminoma patients were staged and treated at the Northern Israel Oncology Center. Staging procedures included meticulous physical and neurological examinations, complete blood count, full biochemistry profile, specific tumor markers, testicular ultrasound, and other radiological measures. All patients underwent inguinal orchiectomy and were staged properly. Six patients had stage I disease, and one patient had stage IIA disease. Patients were irradiated with doses ranging from 2,500 to 3,000 cGy, and the stage IIA patient received an additional 1,000 cGy boost to radiographically involved lymph nodes.

RESULTS

After a mean follow-up of 11 years, six patients are alive with no evidence of disease. One patient died due to an unknown, non-oncological, cause, unrelated to his previous testicular tumor, while in complete remission.

CONCLUSIONS

Despite the low patient numbers and the retrospective nature of our study, it can be concluded that radiotherapy treatment for early-stage anaplastic seminoma patients might achieve the same excellent survival as for classical seminoma. However, the general consensus achieved through large-scale studies suggests that active surveillance should be offered to all stage I seminoma patients, regardless of the pathologic variant.

Mapping patterns of nodal metastases in seminoma: rethinking radiotherapy fields

BACKGROUND AND PURPOSE

To analyze the location of metastatic lymph nodes in seminoma patients relative to vascular and bony anatomy and conventional radiation fields.

MATERIALS AND METHODS

Cross-sectional scans of 90 seminoma patients with infradiaphragmatic adenopathy were analyzed. The position of each node respective to vascular anatomy was transferred to a standardized template. Conventional radiation fields were overlaid on the template and locations of metastatic nodes were assessed.

RESULTS

One hundred and forty-five nodes were radiographically positive. Eighty-four percent, 9%, and 7% of nodes were located in the para-aortic, common iliac, and pelvic regions, respectively. Ninety-nine percent of nodes were within a 2.5 cm lateral and 2.1cm anterior expansion of the aorta inferior to T12/L1. No radiographically positive nodes were identified within the renal hilum or superior to L1 in left-sided seminomas. For right-sided seminomas, no radiographically positive nodes were superior to L2. Three percent of all radiographically positive nodes would have been located outside of conventional and modified fields.

CONCLUSIONS

Infradiaphragmatic nodal metastases from a contemporary cohort of seminoma patients localized to a smaller area than is targeted by conventional radiation fields. Modified treatment fields based on vascular, rather than bony, anatomy are smaller and may allow for a significant decrease in normal tissue irradiation and toxicity.