The role of radiotherapy in the management of squamous cell cancer of the penis

PURPOSE

To review the evidence for radiotherapy in the management of primary penile cancer, either as brachytherapy or external beam radiation, and the role of external beam radiotherapy in node positive penile cancer.

METHODS

English language literature was reviewed for the past 3 decades. As penile cancer is uncommon in developed nations, high quality evidence to guide management is limited. Single institution reports often span decades during which time staging systems and treatments have evolved, reducing their relevance to current practice. Successful clinical trials require collaboration not only among disciplines but also among multiple institutions and nations.

RESULTS

Radiotherapy is a definitive organ-preserving option for T1-T2 penile cancers. Interstitial brachytherapy is associated with penile preservation in 85% of men at 5 years, maintained in 70% by 10 years. Results of external radiotherapy are not quite as promising but nonetheless 60% of men will have an intact penis at 5 years. Inguino-pelvic external radiotherapy has been reported to increase overall survival when delivered as adjuvant treatment for men with pN3 groin but pN0 pelvic nodes, and improve disease specific survival for those with involved pelvic nodes. InPACT (ECOG-ACRIN_8134) is investigating the role of inguino-pelvic chemo-radiotherapy for men with pN3 inguinal nodes but imaging negative pelvic nodes.

CONCLUSIONS

Radiotherapy has a well-defined role to play in treatment of squamous cell cancers of other sites, such as vulva, anal canal, uterine cervix and head and neck malignancies. Emerging data support the incorporation of radiotherapy into treatment paradigms for penile cancer.

Novel portable apparatus for outpatient high-dose-rate (HDR) brachytherapy in penile cancer

BACKGROUND

Penile squamous cell carcinoma (PSC) is traditionally treated with surgical resection with significant morbidity. Penile sparing approaches, such as brachytherapy, require expertise, prolonged inpatient stays, poor patient convenience, and heterogenous plans with variable long-term toxicity. In this study, we describe the protocol for novel portable apparatus created for PSC, allowing outpatient hybrid interstitial/surface brachytherapy, improving homogeneity and patient convenience.

METHODS

A portable brachytherapy apparatus was developed utilizing a foley catheter, prostate template, 6F interstitial catheters, 5 mm bolus, and a jock strap. The apparatus allowed for internal and external catheter placement housed in a jock strap to allow mobility and defecation without affecting the implant. High-dose-rate brachytherapy was performed as an outpatient.

RESULTS

The apparatus was then used on a 62-year-old male with cT2pN0M0 (stage IIA) PSC with bilateral glans and urethral meatus involvement, who elected for definitive brachytherapy (4000cGy in 10 fractions over 5-days). Given external dwell positions, heterogeneity correction of the template was calculated (AAPM TG186) with <2% variation. Patient had minimal impact on his active lifestyle during treatment and had complete clinical response at 3-months. Grade 2 skin desquamation resolved at 2-months, with no necrosis. At 6-months, he was able to resume sexual intercourse, and at 12-months, he remained disease-free with sexual and urinary function intact.

CONCLUSIONS

Novel portable implant allows for improved patient convenience, reduced inpatient stay, capable of optimizing dosimetry with hybrid brachytherapy. This outpatient treatment allows the opportunity to increase fractionation, offering high local-control and lower toxicity. Future studies utilizing this apparatus for more fractionated regimens with further lower dose-per-fraction (∼3 Gy/fraction) is recommended.

Updates in the use of radiotherapy in the management of primary and locally-advanced penile cancer

Objective

Penile cancer is a rare malignancy in most developed countries, but may represent a significant oncologic challenge in certain African, Asian, and South American regions. Various treatment approaches have been described in penile cancer, including radiotherapy. This review aimed to provide a synopsis of radiotherapy use in penile cancer management and the associated toxicities. In addition, we aimed to discuss palliative radiation for metastases to the penis and provide a brief overview of how tumor biology may assist with treatment decision-making.

Methods

Peer-reviewed manuscripts related to the treatment of penile cancer with radiotherapy were evaluated by a PubMed search (1960–2021) in order to assess its role in the definitive and adjuvant settings. Selected manuscripts were also evaluated for descriptions of radiation-related toxicity.

Results

Though surgical resection of the primary is an excellent option for tumor control, select patients may be treated with organ-sparing radiotherapy by either external beam radiation or brachytherapy. Data from randomized controlled trials comparing radiotherapy and surgery are lacking, and thus management is frequently determined by institutional practice patterns and available expertise. Similarly, this lack of clinical trial data leads to divergence in opinion regarding lymph node management. This is further complicated in that many cited studies evaluating lymph node radiotherapy used non-modern radiotherapy delivery techniques. Groin toxicity from either surgery or radiotherapy remains a challenging problem and further risk assessment is needed to guide intensification with multi-modal therapy. Intrinsic differences in tumor biology, based on human papillomavirus infection, may help aid future prognostic and predictive models in patient risk stratification or treatment approach.

Conclusion

Penile cancer is a rare disease with limited clinical trial data driving the majority of treatment decisions. As a result, the goal of management is to effectively treat the disease while balancing the importance of quality of life through integrated multidisciplinary discussions. More international collaborations and interrogations of penile cancer biology are needed to better understand this disease and improve patient outcomes.

High-dose rate brachytherapy in localized penile cancer: 5-Year clinical outcome analysis

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Penile cancer is a rare tumor.

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The organ preservation perspective makes the treatment challenging.

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For early stage, conservative brachytherapy achieved excellent oncological outcome.

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Conservative brachytherapy reported encouraging functional results.

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HDR brachytherapy represents an attractive therapeutic option.

Purpose

To analyze the oncological outcome and toxicity profile after conservative treatment based on multicatheter interstitial high-dose rate brachytherapy (MHB) for patients presenting a localized penile cancer.

Materials and methods

Patients with histologically proven, non-metastatic (T1-T2 N0-N2 M0) localized penile cancer were treated with MHB. Needles were placed under general anesthesia into the target volume using a dedicated template. Treatment planning was performed using a post-implant CT-scan to deliver 35 Gy or 39 Gy (9f, 5d) for adjuvant or definitive treatment respectively. Five-year oncological outcome was evaluated with local relapse-free (LRFS), regional relapse-free (RRFS), and metastasis-free survival (MFS), specific (SS) and overall survival (OS). In pre-treatment and follow-up consultations, skin, urinary and sexual toxicities were investigated using CTCAEv4.0 classification, International Prostate Symptom Score (IPSS) and International Index of Erectile Function 5-items (IIEF-5). Dosimetry data were also analyzed.

Results

From 03/2006 to 05/2020, with a median follow-up of 72.4 months [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], 29 pts, mainly T1 (75.9%) and N0 (89.7%), underwent MHB. Eleven (38%) and 18 pts (62%) received MHB as adjuvant or definitive treatment respectively. Five-year LRFS, RRFS, MFS, SS and OS were 82%, 82%, 89%, 88% and 73% respectively. Six patients (20.7%) experienced local relapse and underwent salvage penectomy leading to a penile preservation rate of 79.3%. Acute skin toxicity was reported 1 month after MHB, with 28% G1, 66% G2 and 6% G3. Late skin complications were telangiectasia for 5 pts (17%) and necrosis for 3 pts (10.3% requiring hyperbaric oxygen therapy). Comparing pre- and post-treatment status, no significant change was observed for skin appearance, IPSS and IIEF-5.

Conclusion

MHB represents an efficient first line conservative treatment option for early penile cancers. Oncological outcome and late toxicity profile appear encouraging. However, larger-scale cohorts with longer follow-up are needed to more accurately precise the features of the best candidate to MHB.

High-dose-rate brachytherapy for localized penile cancer: Evolution of a technique

PURPOSE

High-dose-rate (HDR) brachytherapy is a convenient treatment option for selected patients with T1-T2 penile squamous cell carcinoma (SCC), providing high rates of penile preservation and tumor control. We present the results of penile SCC treated with HDR brachytherapy either interstitially or via a surface mold.

METHODS AND MATERIALS

Between November 2009 and April 2019, seven patients (2 T1a and 5 T2) were treated with interstitial HDR and 8 (1 Tis, six T1a, and one T1b) with surface mold. Prescribed dose for interstitial patients ranged from 38.4 Gy in 6 days (3.2 Gy × 12) to 53 Gy in 9 days (3.12 × 17), BID. All patients treated with mold brachytherapy received 40 Gy in 10 fractions BID. Toxicity and oncological results were assessed for both groups, and their relation with dosimetry is described.

RESULTS

Median follow up was 90 months for interstitial and 27 months for those treated with surface mold. Fourteen of 15 patients are alive and disease-free; one surface mold patient died of non-small-cell lung cancer. There was one relapse in each group, each treated with salvage penectomy. The potency was preserved in 82%. For interstitial, G2 necrosis occurred in 43%, G2 meatal stenosis in 29% and G3 stenosis in 14%.

CONCLUSIONS

Both techniques have excellent rates of tumor control and organ preservation. Implant geometry and homogeneity constraints must be carefully designed to minimize toxicity in interstitial brachytherapy. Urethral contouring and reporting of dosimetric parameters should be defined.