The course of DD comprises three disease phases which reveal different radiation sensitivities:

Unlike in aggressive fibromatoses, for DD and LD no invasion of voluntary muscles occurs. DD and LD may slowly progress and stabilize for years, but rarely regress spontaneously. Without therapy the average progression rate is about 50 % within a period of 5 years (Millesi 1981). In LD, the slowly growing nodules and cords are rarely detected in the early phase, until dysfunction (walking difficulties, pain, tension, or pressure sensation) leads the patient to medical attention. In addition, the occurrence of concomitant knuckle pads and Peyronie disease in males supports the diagnosis (Donato and Morrison 1996).

The clinical course of DD and LD is dependent on the individual patient’s disposition (Strickland et al. 1990). Spontaneous regression of DD is quite rare; moreover, slow progression may be interrupted by phases of stagnation; other cases rapidly progress within a very short time causing contracture-induced dislocation of digital joints in DD and walking difficulties in LD. Special subtypes are differentiated according to their characteristic clinical course, e.g., depending on comorbidities, like diabetes mellitus, or depending on the age at the disease onset or depending on the time course or uni- or bilateral affliction (McFarlane et al. 1990).

Radiotherapy provides a primary approach to the afflicted areas in the early stage of the disease, when other preventive or prophylactic methods are still unavailable.

Over the past decades, the use of radiotherapy (RT) has been more and more limited to the early and still proliferative phases of the disease where surgery plays no role and radiosensitive targets are still available. This excludes patients with “dormant disease” (which may last for years) and those with more advanced disease starting from a finger extension deficit of more than 30°; thus, only patients with “early progressive disease” who are usually characterized by multiple progressive nodules, fresh formation of a few cords, and/or presence of only a minor functional deficit (10–30°) may qualify for the implementation of radiotherapy to prevent further disease progression. Patients with “late progressive disease” with major functional deficits (>30°) do not anymore qualify for the use of RT. Typical clinical examples are shown in Figs. 46.2 and 46.3.

The indication for RT strictly follows the clinical staging, which is based on the amount of extension deficit of finger movement for DD (Tubiana et al. 1966) and the functional impairment due to involvement of the skin or the deep structures of the foot in LD (Sammarco 2001) (Tables 46.2 and 46.3).

Despite decades of clinical and experimental research up to now, no cure is available for both DD and LD. All noninvasive and invasive treatments, including options like local injections with collagenase, application of systemic medication, performance of minimally invasive surgery including percutaneous needle fasciotomy, or open, radical open surgery, aim to prevent progression or to improve the impaired functional status. Moreover, in the very early DD and LD stages, a “wait and see” policy is always advised, as no conservative treatment has been proven effective. About two thirds of detected DD and LD cases will never progress to a stage where surgery is a final treatment option. Glucocorticoid injections may lead to regression but can also induce severe complications like atrophy at the injection site or rupture of tendons and have no long-term impact on disease progression (Ketchum and Donahue 2000). Without any therapy the clinical progression of DD is observed in about 50 % of patients after 6 years (Millesi 1981). This development is to be stopped by the early intervention using ionizing radiation. The gold standard for advanced DD and LD remains surgery, with the major goal of improving the finger function by reducing the contractures and thus restoring a disabled hand or foot function.

While hand or foot surgery is usually justified to improve a severe functional deficit (usually at stages I–II), RT always aims to prevent the progressive symptoms (formation of new nodules and cords; reduction of symptoms like pressure, itching, and sometimes pain) and to avoid future finger deviation and functional impairment (e.g., grip and spreading or holding functions of the fingers). However the implementation of radiotherapy implies the presence of radiosensitive target cells or biological mechanisms within the disease process for a successful interaction. Radiotherapy is effective for prevention of disease progression in early stages of DD (Keilholz et al. 1996; Adamietz et al 2001; Seegenschmiedt et al. 2001; Seegenschmiedt et al. 2012a) and LD (Seegenschmiedt and Attassi 2003; Grenfell and Borg 2014; Heyd et al. 2010; Seegenschmiedt et al. 2012b) with mild acute or late side effects.

There is a good radiobiological rationale for the long-term efficacy of the use of ionizing radiation on proliferating fibroblasts and myofibroblasts because they are radiosensitive cells; ionizing radiation effectively impairs their proliferative activity by induction of free radicals which leads to a reduced cell density (Murrell et al. 1990; Murrell and Francis 1994); this can stabilize the disease as long as the proliferation dominates in early DD/LD stages N and I. However, in the later stages, the disease is already characterized by repair and contraction of fibrous tissue: ionizing radiation is ineffective in these tissues. The major rationale is to use RT in early sensitive stages to avoid disease progression with later dysfunction that might require hand surgery.

A careful physical examination of both hands and feet is needed and if possible with frequent follow-up to demonstrate any changes within a period of 3–6 months to establish whether the disease is progressing.

Figure 46.4 shows a 52-year-old male with progressive development of nodules and cords within one year follow-up and decision to provide radiotherapy for early stage N Dupuytren Disease.

Table 46.4 summarizes the different treatment indications depending on the disease stage and reveals the specific indication for radiotherapy in contrast to other therapies. There is much less choice of treatment for the early stages than in later stages of DD. Radiotherapy should be only indicated in progressive disease, when nodules and cords start to grow toward the situation where an initial angulation deficit occurs. Generally there are alternative conservative and surgical options available (Mafi et al. 2012). Actually we lack clinical studies, to answer whether radiotherapy may prevent early relapses after surgery for DD, while for LD some clinical studies suggest a possibly successful treatment option.

Prior to the onset of RT, it is important to document the exact disease record including the family history, the professional activities, the additional disorders (like diabetes, etc.), and the course of disease in the specific situation. All details are documented in a questionnaire and special data format. All findings from the physical examination are documented together with a photograph of all involved extremities.